Irs Rule PDF
Irs Rule PDF
Irs Rule PDF
for the
Construction and Classification
of Steel Ships
Part 1
Regulations
January 2014
Publications of Indian Register of Shipping
2. Rule Books
2.1 Rules and Regulations for the Construction and Classification of Steel Ships,
July 2013 comprising of following six parts, which are further divided in chapters
Part 1 : Regulations
Part 2 : Inspection and Testing of Materials
Part 3 : General Hull Requirements
Part 4 : Main and Auxiliary Machinery
Part 5 : Special Ship Types
(This part is published in two Volumes I & II)
Part 6 : Fire Safety Requirements
2.2 Rules and Regulations for the Construction and Classification of Inland
Waterways Ships, January 1997, comprising of following five* parts which are
further divided in chapters.
Part 1 : Regulations
Part 2 : Inspection and Testing of Materials
(* This part is same as the Part 2 in 2.1 above)
Part 3 : General Hull Requirements
Part 4 : Main and Auxiliary Machinery
Part 5 : Special Ship Types (To be published)
2.3 Rules and Regulations for the Construction and Classification of Mobile
Offshore Drilling Units, January 2013 (This supersedes, March 2006 edition).
2.4 Rules and Regulations for the Construction and Classification of High Speed
Crafts and Light Crafts, July 2011. (Also available on CD)
2.5 Rules and Regulations for the Construction and Classification of Naval Ships,
January 2010, comprising of following six parts, which are further divided in
chapters.
(Only available on CD)
3. Classification Notes
− Marine Gears - Calculation of load capacity of involute parallel axis spur and helical
gears, January 1997.
− Cable trays/protective casing made of plastics materials, July 2003.
− Type approval of mechanical joints used in piping, January 2014.
− Type approval, installation and testing of water level detectors on bulk carriers and
single hold cargo ships other than bulk carriers, January 2013.
− Guidelines for non-destructive examination of steel castings for marine application,
January 2005.
− Guidelines for non-destructive examination of hull and machinery steel forgings,
January 2005.
− Guidelines for approval / acceptance of alternative means of access to spaces in oil
tankers, bulk carriers, ore carriers and combination carriers, August 2006.
− Approval scheme for the manufacturing process of normal and higher strength hull
structural steels, January, 2009.
− Calculation of crankshafts for internal combustion engines, January, 2012.
− Type testing procedure for crankcase explosion relief valves, February, 2008.
− Type testing procedure for crankcase oil mist detection and alarm equipment,
February, 2008.
− Type approval of electrical equipment used in control, protection, safety and internal
communication in marine environment, February, 2008.
− Application of IRS Rules to Indian River Sea Vessels, August, 2013.
General Information
This consolidated version of the ‘Rules and Regulations for the Construction and
Classification of Steel Ships’ (January, 2014) supersedes the July, 2013 edition
of the Rules and includes the amendments published in Rules Change Notice
No.1 of January, 2014.
Section / Subject/amendment
Clause
2 / 2.21 & New sub-section “Transparency of classification and statutory information” added and
Table 2.21.1 new table “Transparency of information” added which gives details.
2 / Table It is clarified that for special survey-II, requirement of examining transverse bulkhead
2.4.9.1b topside, hopper side and double side ballast tanks applies to one side only ( port or
starboard)
7 / 7.3 Requirement for machinery verification runs at the time of docking surveys is deleted
and shifted section 8.
8 / 8.1.6 New clause added giving requirement for machinery verification runs during special
surveys.
3 / Table 3.4.2 Condition of supply, grade and mechanical properties for EH 47 steel plates are
specified
Section / Subject/amendment
Clause
7 / Table 7.2.3 & The required mechanical properties of deposited metal tests and butt weld test
Table 7.3.2 specimens are specified for welding consumables for use with high strength
extremely thick steel plates of EH47 grade and thickness > 50 mm and upto 100 mm
2 / 2.3 Distances for calculation of accelerations are elaborated with help of supporting
diagrams
Section / Subject/amendment
Clause
1 / 1.3.4 Clarification added for maximum allowable percentage of aluminium content in paints
in cargo spaces.
The amendment is to be applied from 1 Jan 2014 to new tankers and new application
of coating and piping on existing tankers
2 / 2.4 Consideration for acceptance of smaller access openings is deleted
5 / IR 5.3.2.1.1 Testing requirements of safety valves and valves other than safety valves are
clarified.
5 / IR 5.3.2.1.2 It is clarified that for safety valves, set pressure is to be tested at ambient temperature
Section / Subject/amendment
Clause
4 / 4.5.6 MSC Circular reference for Guidance for approval of local application fire fighting
systems is updated.
8 / 8.2.1.1 Clause allowing use of dry pipe system for control station under specific condition is
added
Part 1
Regulations
Contents
Chapter 1 General
Contents
Chapter 1 : General
1.8 Access of Surveyor to ships, shipyards or 2.18 Suspension, withdrawal and deletion
works of class
2.1 General
Section 3 : Classification of Ships not Built
2.2 Application of Rules under the Survey of Indian Register of
Shipping
2.3 Scope of classification
3.1 General procedure for classification of ships
2.4 Interpretations of the Rules not built under survey of IRS
Section 2 : Surveys - Bulk Carriers and Ore 6.4 Special Surveys - Hull
Carriers
6.5 Special Surveys - Machinery
2.1 Scope
8.19 Survey requirements : Electrical equipment 13.5 Requirements of first special survey
survey
13.6 Subsequent special surveys
8.20 Survey requirements : Electrical propelling
machinery 13.7 Loading port surveys
11.3 Modified survey 15.2 For tankers and combination carriers with
notation VCS2
11.4 Partial survey
11.5 Tailshaft Condition Monitoring (TCM) Section 16 : Surveys of Thermal Oil Heating
Systems
12.1 General 16.2 Oil fired thermal oil heater and economiser
16.10 Repairs
16.5 Piping arrangement
Section 17 : Surveys of external Fire Fighting
16.6 Expansion tank Systems
End of Chapter
Chapter 1
General
Contents
Section
1 General Information
2 Classification Regulations
3 Classification of Ships not built under the Survey of Indian Register of Shipping
Section 1
General Information
b) Important alterations to Rules once framed 1.3.4 In addition to the foregoing, the Technical
as may be required from time to time. Committee may co-opt to the main body other
members of high managerial positions in Ship
1.3.2 All decisions of the Technical Committee Building and Engineering, Naval Architecture,
including amendments and/or additions to the Marine Insurance, Steel Making, etc.
Rules for classification surveys and building of
ships' hull, their machinery and equipment to be 1.3.5 Nomination of all members to the
reported to the Board of Directors. Technical Committee to be subject to
confirmation by the Board.
1.3.3 The Technical Committee to be constituted
as follows: 1.3.6 The Technical Committee can appoint
panels from amongst its body to which
representatives of any organisation or industry
or individuals specialised in relevant disciplines
could be co-opted for the purpose of considering
any particular Technical problem or area of
Rules.
1.3.7 The Board of Directors to appoint reference including the dissolution of the
biennially, the Chairman of the Technical Technical Committee.
Committee and the Technical Committee to
appoint from their own body biennially a Vice- 1.4 Survey reports
Chairman. The same members are not to be
eligible to hold office of Chairman or Vice- 1.4.1 All reports of survey are to be made by the
Chairman, as the case may be, for more than Surveyors according to the form prescribed and
two terms in succession unless on the occasion submitted for consideration of the Board or the
of the third term, the appointing body approves Sub-Committee of Classification, but the
of their continuation by a majority of at least character assigned by the latter is to be reported
three-fourths of the members present. The to the Board. The Board may, in specified
appointment of Vice-Chairman to be confirmed instances, vest in the Managing Director
by the Board of Directors. discretionary powers to act on its behalf, and all
such actions being reported to the Board at its
1.3.8 The terms of office of all members to be subsequent meeting.
not more than four years, one-fourth of all
members (including those co-opted) to retire at 1.4.2 The reports of the Surveyors shall, subject
the end of each calender year. The members so to the approval of the Managing Director, be
retiring being those who have been longest in open to inspection of the Owner and any other
office since their last nomination and such person authorised in writing by the Owner.
members to be eligible for re-nomination for a Copies of the reports will, subject to the
second term. Unless specially so authorised by approval of the Managing Director, be supplied
the Board of Directors, no member other than to Owners or their representatives.
Chairman and/or Vice- Chairman, who has
served for two periods of nomination, to be 1.5 Register of Ships
eligible for re-nomination for a third term until
after the expiration of at least one year. In the 1.5.1 A Register Of Ships to be printed annually
event of any vacancy occurring before the for the use of subscribers contains the names of
expiration of the normal term of office, a ships, character of class notations assigned
representative to be nominated to fill the together with other relevant useful information
vacancy from the same group/body/institution for ships classed with IRS or registered in India.
and for such nominee the date of his nomination
by the respective body to be considered as date 1.6 Liability
of his joining the Technical Committee for
purposes of his retirement by rotation. 1.6.1 Whilst Indian Register of Shipping
(hereinafter referred to as IRS) and its
1.3.9 The meeting of the Technical Committee Board/Committees use their best endeavours to
to be convened as often and at such time and ensure that the functions of IRS are properly
place as may appear necessary, but there shall carried out, in providing services, information or
be at least two meetings in each year. advice, neither IRS nor any of its servants or
agents warrants the accuracy of any information
1.3.10 The members desiring to propose or advice supplied. Except as set out herein,
alterations in, or additions to the Rules for the neither IRS nor any of its servants or agents (on
classification, survey or building of ship (hull and behalf of each of whom IRS has agreed this
machinery) shall give notice of such proposals clause) shall be liable for any loss damage or
to the Secretary. Every meeting to be convened expense whatever sustained by any person due
by notice from the Secretary, if possible one to any act or omission or error of whatsoever
month before the date of the meeting and the nature and howsoever caused of IRS, its
Secretary to send to each member an Agenda servants or agents or due to any inaccuracy of
paper as soon as possible thereafter. whatsoever nature and howsoever caused in
any information or advice given in any way
Proposals for changes to rules may also be whatsoever by or on behalf of IRS, even if held
given by Flag Administrations, shipowners, to amount to a breach of warranty.
shipbuilders and other interested parties who Nevertheless, if any person uses services of
may not be represented in the Technical IRS, or relies on any information or advice given
Committee. by or on behalf of IRS and suffers loss, damage
or expenses thereby which is proved to have
1.3.11 The Board of Directors reserves to been due to any negligent act omission or error
themselves the right of altering, adding to or of IRS its servants or agents or any negligent
rescinding any/or all of the above terms of inaccuracy in information or advice given by or
1.6.2 Any notice of claim for loss, damage or - Firms engaged in tightness testing of
expense as referred to in 1.6.1 shall be made in hatches with ultrasonic equipment
writing to IRS Head Office within six months of
the date when the service, information or advice - Firms carrying out in-water survey of
was first provided, failing which all the rights to ships and mobile offshore units.
any such claim shall be forfeited and IRS shall
be relieved and discharged from all liabilities. - Firms engaged in the examination of
bow, stern, side and inner doors.
1.7 Audits and assessments by external
organizations b) Statutory services
1.7.1 The surveys required by the regulations, - Firms engaged in surveys and
and conducted by IRS may be subject to Audit maintenance of fire extinguishing
by an independent Accredited Certification Body equipment and systems
(ACB) as per the requirements of ISO
9001:2008 standard and Quality Management - Firms engaged in service on inflatable
System Certification Scheme (QSCS) of IACS. liferafts, inflatable lifejackets, hydrostatic
For this purpose, ACB auditors are to be given release units, etc.
the necessary access to the ship, shipyard or
works when requested by IRS - Firms engaged in the servicing and
testing of radio communication
Access is also to be given to auditors or equipment
inspectors accompanying the Surveyors as
required by other external organizations. - Firms engaged in inspection and testing
of centralised gas welding and cutting
1.8 Access of Surveyor to ships, shipyards equipment
or works
- Firms engaged in surveys and
1.8.1 The Surveyors are to be given free access maintenance of self contained breathing
to ships classed with IRS as well as to apparatus
shipyards, works, etc. so as to perform their
duties, and are to receive adequate assistance - Firms engaged in the annual
for this purpose. performance testing of voyage data
recorder
1.9 Requirements for service suppliers
- Firms engaged in the surveys of low
1.9.1 Firms providing following services on location lighting systems using photo
behalf of the Owner, the results of which are luminescent materials
used by Surveyors in making decision affecting
classification and/or affecting statutory - Firms engaged in sound pressure level
certifications, are to be approved by IRS in measurements of public address and
advance in accordance with the laid down general alarm systems
procedures.
- Firms engaged in testing of coating
IRS may also accept the services of firms systems in accordance with the
approved by other IACS member classification requirements of IMO performance
societies. standards for protective coatings.
1.9.2 For statutory services, approvals done by Surveyors would attend onboard a ship in order
the flag Administration itself or duly authorised to assist in the rectification of reported
organisations acting on behalf of the flag deficiencies or other discrepancies that affect or
Administration or by other organisations that are may affect classification or the statutory
acceptable to the flag Administration (e.g. other certificates issued by IRS. The owner and the
governments, etc.) may be accepted. vessel's flag state will be notified of such
attendance and survey. IRS Surveyors will also
1.10 Responding to Port State Control cooperate with Port States by providing
inspectors with background information.
1.10.1 When requested by Port State and upon
concurrence by the vessel's owner/master IRS
Section 2
Classification Regulations
required to understand such information/ 2.5.5 Type notation : A notation indicating that
instructions in the performance of their duties. the ship has been designed and constructed
with applicable Rules to that type of ship, e.g.
2.2 Application of Rules "Bulk Carrier", "Oil Tanker", etc.
2.2.1 Unless directed otherwise by IRS, no new 2.5.6 Cargo notation : A notation indicating that
Regulations or amendments to the Rules the ship has been designed, modified or
relating to the character of classification or class arranged to carry one or more particular
notation is to be applied to the existing vessels. cargoes, e.g. "Phosphoric Acid". Ships with one
or more particular cargo notations are not
2.2.2 Unless directed otherwise by IRS, no new thereby prevented from carrying other cargoes
Rules and Regulations or amendments to the for which they are suitable.
existing Rules & Regulations become applicable
within 6 months after the date of issue. 2.5.7 Special feature notation : A notation
indicating that the ship incorporates special
2.3 Scope of classification features which significantly affect the design,
e.g. "movable decks".
2.3.1 Classification covers ship's hull,
appendages and machinery including electrical 2.5.8 Service restriction notation : A notation
systems to the extent as specified in these indicating that a ship has been classed on the
Rules & Regulations. Classification does not understanding that it will be operated only in
guarantee the design or performance of a vessel suitable areas or conditions which have been
except for those aspects covered by the rule agreed to by IRS e.g. "Sheltered Water
requirements and subject to the conditions of Service".
operation of the vessel mentioned in 2.1.2.
2.6 Character of classification
2.3.2 On application by Builder or Owner, 2.6.1 The following Characters and symbols are
certain installation, e.g. refrigerating machinery assigned by IRS to indicate classification of
may be classed by IRS. Steel Ships. (For explanation of abbreviations,
see Appendix I).
2.4 Interpretations of the Rules
2.6.2 Character SUL assigned to sea-going
2.4.1 The correct interpretation of the vessels indicates that the hull and its
requirements contained in the Rules and other appendages and equipment (i.e. anchors, chain
Regulations is the sole responsibility and at the cable and hawsers) meet the Rule requirements
sole discretion of IRS. for assignment of this Character of Class.
2.5.2 Fetch : The extent of clear water across 2.6.3 Character SU- assigned to sea-going
which a wind has blown before reaching the vessels indicates that the hull and its
ship. appendages meet the Rule requirements but
equipment (i.e. anchors, chain cable and
2.5.3 Sheltered water : Water where the fetch hawsers) is not supplied or maintained as per
is six nautical miles or less. the relevant Rules but is considered by IRS to
be acceptable for particular service.
2.5.4 Reasonable weather : Reasonable
weather is assumed to exclude winds exceeding 2.6.4 Character SU assigned to sea-going
Beaufort force six associated with sea states vessels indicates that the hull and its
resulting in green water being frequently taken appendages meet the Rule requirements but
on board the ship's deck. However it is realised where special consideration has been given for
that this is largely a matter of judgment and reason of particular purpose of service and
good seamanship and can vary for particular normal equipment may be unnecessary. In such
ships. cases letter 'L' is omitted from the Character
SUL.
2.6.6 The distinguishing mark inserted e) Specified Operating Area Service : Service
before a Character of Class (SUL, SU-, SU, IY within one or more geographical area(s)
as appropriate) is assigned to new ships where which will form part of the Class Notation.
the hull and its appendages, equipment and the
machinery, as appropriate, are constructed 2.8 Class notations - Machinery
under special survey of IRS in compliance with
the Rules to the satisfaction of IRS. 2.8.1 The class notations that may be assigned
by IRS are given in Appendix 1. IRS may
2.7 Class notations - Hull prescribe additional notations as found
necessary/ expedient from time to time.
2.7.1 When requested by an Owner and agreed
to by IRS or when considered necessary by IRS, 2.9 Materials, components, equipment and
a class notation will be appended to the machinery
character of classification. This class notation
will consist of one of, or a combination of - a
type notation, a cargo notation, a special duties 2.9.1 The materials used in the construction of
notation, a special features notation and/or a hull and machinery intended for classification, or
service restriction notation, e.g. SUL in the repair of ships already classed, are to be
CHEMICAL TANKER, "Sulphuric Acid", ESP, of good quality and free from defects and are to
"Indian Coastal Service". be tested in accordance with the relevant Rules.
The steel is to be manufactured by an approved
2.7.2 Details of the ship types and additional process at works recognized by IRS.
class notations are given in Appendix 1 and Alternatively, tests to the satisfaction of IRS will
applicable Chapters in Pt.5 of the Rules. be required to demonstrate the suitability of the
steel.
2.7.3 Service restriction notation will generally
be assigned in one of the forms given below, but Consideration may be given by IRS to accept
this does not preclude the Owners or the works approved by IACS Member Societies
Shipbuilders from requesting special with whom IRS currently has Cooperation
consideration for other forms of restrictions. Agreements for this purpose.
construction, and maintenance of class for ships 2.13 Classification of new constructions
in service are carried out.
2.13.1 The request for classification of new
2.11 Repairs constructions is to be submitted to IRS by the
shipyard or shipowner in the form provided by
2.11.1 Any repairs to the hull, machinery and IRS. The request is to include complete details
equipment either as a result of damage or wear regarding class notation and statutory
and tear which are required for the maintenance certificates required, where applicable.
of ship's class are to be carried out under the
inspection of and to the satisfaction of the The IRS Rules in force on the date of contract
Surveyors. for construction of the vessel (See 2.14) will be
applicable for classification, in general.
2.11.2 Where a vessel is damaged to an extent However, statutory requirements coming into
resulting in towage outside port limits, it shall be force after the date of contract for construction
the Owners' responsibility to notify IRS at the may have to be complied with if they become
first practicable opportunity. applicable based on any other criteria such as
the date on which vessel is constructed (keel
2.11.3 Where such repairs are effected at a port laid).
where there is no Surveyor of IRS, the ship is to
be surveyed by one of its Surveyors at the 2.13.2 Where orders for major machinery and
earliest opportunity. equipment are placed on manufacturer or
suppliers, IRS will have to be informed.
2.11.4 Where repairs to hull, machinery or Responsibility for compliance with IRS Rules
equipment, which affect or may affect and Regulations shall be with the
classification, are to be carried out by a riding manufacturers/suppliers.
crew, they are to be planned in advance. A
complete repair procedure including the extent Where relevant, the date of application for
of proposed repairs and the need for Surveyor's certification of specific major machinery will also
attendance during the voyage is to be submitted be considered in addition to the date of contract
to and agreed upon by the Surveyor reasonably for construction of the vessel, for determining
in advance. Failure to notify IRS, in advance of the applicable rules for such machinery.
the repairs, may result in suspension of the
vessel's class. 2.13.3 Plans and particulars as specified in the
Rules will have to be submitted to IRS in
Where in any emergency circumstance, triplicate sufficiently in advance of
emergency repairs are to be effected commencement of construction. One copy with
immediately, the repairs should be documented stamp of approval will be returned. Any
in the ship’s log and submitted thereafter to IRS deviation from approved drawings will require to
for use in determining further survey be approved by IRS prior to execution of work.
requirements.
IRS reserves the right to request for additional
2.12 Alterations plans, information or particulars to be submitted.
2.12.1 Any alterations proposed to be carried Where it is proposed to use existing previously
out to approved scantlings and arrangements of approved plans for a new contract, written
the hull, machinery or equipment are to meet application is to be made to IRS.
with the approval of IRS and for this purpose
plans and technical particulars are to be Approval of plans and calculations by IRS does
submitted for approval in advance. Such not relieve the Builders of their responsibility for
approved alterations are to be carried out under the design, construction and installation of the
the inspection of, and to the satisfaction of, the various parts, nor does it absolve the Builders
Surveyors. If such alterations are carried out on from their duty of carrying out any alterations or
items which may affect the classification of the additions to the various parts on board deemed
ship without informing IRS, the class of the necessary by IRS during construction or
vessel will be liable to be suspended except in installation on board or trials.
the case of emergency repairs mentioned in
2.11.4. 2.13.4 IRS will assess the production facilities
and procedures of the shipyard and other
manufacturers as to whether they meet the
requirements of the construction Rules.
2.13.5 During construction of a vessel, IRS will b) If the alterations are subject to classification
ensure by surveys that parts of hull and requirements, these alterations are to
machinery requiring approval have been comply with the classification requirements
constructed in compliance with approved in effect on the date on which the alterations
drawings, all required tests and trials are are contracted between the prospective
performed satisfactorily, workmanship is in owner and the shipbuilder or, in the absence
compliance with current engineering practices of the alteration contract, comply with the
and welded parts are produced by qualified classification requirements in effect on the
welders. date on which the alterations are submitted
to IRS for approval.
2.13.6 All hull, machinery and electrical
installations will be subjected to operational The optional vessels will be considered part of
trials in the presence of IRS Surveyor. the same series of vessels if the option is
exercised not later than 1 year after the contract
2.13.7 On completion of the ship copies of as to build the series was signed.
fitted plans showing the ship as built, essential
certificates and records, loading manual etc. are 2.14.3 If a contract for construction is later
to be submitted by the Builder generally prior to amended to include additional vessels or
issuance of the Interim Certificate of Class. additional options, the date of “contract for
construction” for such vessels is the date on
2.13.8 For each new construction the which the amendment to the contract, is signed
shipbuilder is required to prepare and deliver a between the prospective owner and the
ship construction file containing documents / shipbuilder. The amendment to the contract is to
plans / manuals etc. for facilitating the future be considered as a “new contract” to which
inspection of survey, repair and maintenance as 2.14.1 and 2.14.2 above apply.
detailed in Pt.3, Ch.1, Sec.3. Some of these
documents may be directly supplied by other 2.14.4 If a contract for construction is amended
parties e.g. shipowner, for inclusion in the ship to change the ship type, the date of “contract for
construction file. The ship construction file is to construction” of this modified vessel, or vessels,
be maintained onboard each ship. is the date on which revised contract or new
contract is signed between the Owner, or
2.14 Date of contract for construction Owners, and the shipbuilder.
commencing service, the date of commissioning 2.18 Suspension, withdrawal and deletion of
may be specified on the classification certificate. class
2.18.1.9 The class of a vessel will be liable to be the ship is in condition to sail to the nearest
suspended if the Owner fails to notify IRS of any port of call).
damage to the ship‘s hull, machinery or
equipment, which may adversely affect If class has already been automatically
classification of the vessel or subsequently fails suspended in such cases, it may be reinstated
to arrange for the survey as may be advised by subject to the conditions prescribed above.
IRS.
2.18.1.14 When a vessel is intended for a single
2.18.1.10 The class of a vessel will be voyage from laid-up position to repair yard with
suspended after a major casualty to the ship, any periodical survey overdue, the vessel’s
such as grounding, sinking or breaking up, if the class suspension may be held in abeyance and
Owner is unable to arrange for the ship’s survey consideration may be given to allow the vessel
by IRS and commence repairs within a to proceed on a single direct ballast voyage from
reasonable period of the occurrence of the the site of lay up to the repair yard, upon
casualty, unless otherwise agreed to with IRS. agreement with the Flag Administration,
provided IRS finds the vessel in satisfactory
2.18.1.11 Vessels laid up in accordance with the condition after surveys, the extent of which are
Rules prior to surveys becoming overdue will not to be based on surveys overdue and duration of
be suspended when surveys addressed above lay-up. A short-term Class Certificate with
become overdue. conditions for the intended voyage may be
issued. This is not applicable to vessels whose
However, ships which are laid up after being class was already suspended prior to being laid-
suspended as a result of surveys becoming up.
overdue, will remain suspended until the
overdue surveys are completed. 2.18.1.15 Classification will be reinstated upon
satisfactory completion of overdue survey. Such
2.18.1.12 When a vessel is intended for a surveys will be credited from the date originally
demolition voyage with any periodical survey due. However, the vessel will remain disclassed
overdue, the vessel’s class will not be from the date of suspension until the date class
suspended till completion of a single direct is reinstated.
ballast voyage from the lay up or final discharge
port to the demolition yard. 2.18.1.16 The Owners and the Flag State,
where applicable, would be informed in writing,
2.18.1.13 Force Majeure : If, due to of the suspension and reinstatement of
circumstances defined in Chapter 2, 1.11.3, the Classification.
vessel is in a port where the overdue surveys
cannot be completed at the expiry of the periods 2.18.2 Withdrawal
allowed above, IRS may allow the vessel to sail,
in class, directly to an agreed discharge port, 2.18.2.1 Ship’s class will be withdrawn, at the
and if necessary, thereafter in ballast, to an end of six months of suspension, if the Owner
agreed port at which the survey will be has not commenced any action to reinstate the
completed, provided: ship’s class. A longer suspension period may be
granted when the vessel is not trading or in
a) Re-examination of the ship’s record is cases of lay-up awaiting attendance for
carried out by IRS, reinstatement or disposition, in the event of a
casualty.
b) IRS carries out the due and/or overdue
surveys and examination of 2.18.2.2 When the class of a ship holding IRS
Recommendations / Conditions of Class at class, is withdrawn by IRS in consequence of a
the first port of call when there is an request from the Owners, the notation "Class
unforeseen inability of IRS to attend the withdrawn at Owners' request" (with date) will be
vessel in the present port, and made in the subsequent reprints of the Register
Of Ships. This entry will continue till the ship’s
c) IRS is satisfied that the vessel is in condition class is reinstated or deleted.
to sail for one trip to a discharge port and
subsequent ballast voyage to a repair facility 2.18.2.3 When the Regulations as regards
if necessary (where there is unforeseen surveys on the hull or equipment or machinery
inability of IRS to attend the vessel in the have not been complied with and the ship
present port, the master is to confirm that thereby is not entitled to retain her class, the
class will be withdrawn and the notation "Class
withdrawn" (with date) will be made in the 2.19.3 The date of reclassification will appear in
subsequent reprints of the Register Of Ships. the supplement to the Register Of Ships and the
This entry will continue till the ship’s class is subsequent issue of Register Of Ships.
reinstated or deleted.
2.20 Condition improvement program
2.18.2.4 The withdrawal of a vessel will be
confirmed in writing to the Owner and the Flag 2.20.1 The Condition Improvement Program
State, where applicable. (CIP) of IRS classed ships is aimed at improving
fleet quality and safety and reducing the risk of
2.18.3 Deletion of Class Port State Control detentions.
2.18.3.1 A ship will be considered to “cease to Under this program vessels requiring special
exist” when it is destroyed by scrapping or by attention are identified based on multiple risk
sinking to unsalvageable depths or abandoned criteria and study of the recent history of the
by the owner. vessel such as survey status, conditions of
class, recommendations, detentions etc. and the
2.18.3.2 A ship can also be considered to shipowner so informed.
“cease to exist” when it is broken up either by
grounding or due to structural failure or due to 2.20.2 Vessels identified for condition
actions of war or sabotage. improvement would be subject to additional
surveys over and above the normal
2.18.3.3 Ship’s class will be deleted when it classification surveys. For this purpose,
ceases to exist. surveyors are to be given necessary access to
the ship for identification of deficiencies and
2.19 Reclassification of ships recommendation of repairs. Deficiencies
requiring immediate attention as indicated by the
2.19.1 When Owners request for reclassification Surveyor are to be repaired promptly and
of a ship for which the class previously assigned thoroughly.
has been withdrawn, IRS will require a Special
Survey for Reclassification to be held by the 2.21 Transparency of classification and
Surveyors. The extent of the survey will depend statutory information
upon the age of the ship and the circumstances
of each case. 2.21.1 The classification and statutory
information which may be released to
2.19.2 If the ship is found or placed in good and Shipowners, Flag State, Port state, Insurance
efficient condition in accordance with the company and Shipyards as relevant and the
requirements of the Rules and Regulations at conditions for their release are indicated in
the Special Survey for Reclassification, IRS may Table 2.21.1.
decide to reinstate her original class or assign
such other class as considered appropriate.
B. Ships in Operation:
Certificates/Reports 7 1 6 5
Overdue Surveys 7 7 1 1
Text of Conditions of 7 1 1 5
Class/Recommendations
Text of Overdue Conditions of 7 1 1 1
Class/Recommendations
Executive Hull Summary 7 3 3 3
Statutory Services
Due Dates of Statutory Surveys 7 7 1 1
3. Other Information:
Correspondence File with Yard 6 6 5&6
and/or Owner
Audit of Class Societies QA System 4 4 4 4
Section 3
3.1 General procedure for classification of 3.1.3 For vessels not built under survey of IRS
ships not built under survey of IRS but subsequently taken in class with the above
procedure, the mark signifying the survey during
3.1.1 Plans of hull and machinery in duplicate, construction will be omitted.
together with torsional vibration calculations,
where applicable, as specified in 3.2.5 are to be 3.1.4 Once a vessel has been taken into IRS
submitted for approval. It is preferable to have class, periodical surveys are subsequently to be
the plans approved before the classification held as per these rules.
survey is commenced.
3.2 Plans and data to be furnished as
3.1.2 Full special classification surveys would required in 3.1.1
require to be carried out by IRS Surveyors in
order to satisfy themselves regarding the 3.2.1 Plans of hull and equipment showing the
workmanship and condition of the ship and to main scantlings and arrangements of the actual
verify the approved scantlings and ship and any proposed alterations are to be
arrangements. The scope of these surveys may, submitted for approval. These should normally
however, be modified in the case of vessels built comprise of the following plans:
under the Special Survey and holding valid
certificates of class of established classification For information
societies or equivalent, if prior to commence-
ment of survey by IRS, documentary evidence - General arrangement
of all hull and machinery classification surveys
held by the other society subsequent to last - Capacity plan
special survey carried out by them could be
produced. In such cases, a special survey - Hydrostatic Curves
notation will not be assigned in conjunction with
the classification survey. The next special - Loading Manual
survey therefore would become due five years
from the special survey held by the other society - Loading Instrument Details
and not five years from classification with IRS.
- Lightweight Distribution
In cases of transfer of class from another society
to single class of IRS, the interim certificate of For approval
class or any other documents enabling the ship
to trade, can be issued : - Midship section
a) In case of vessels less than 15 years of age - Longitudinal section and decks
Appendix 1
Table of characters of class and type notations of IRS, their expanded form and significance
Abbreviation Expanded Form Significance
Characters of Class
Denotes vessels which are classed with Indian
Register of Shipping where the hull and its
SUL SARVOUTAM LANGER
appendages and equipment (i.e. anchors, chain
cables, hawsers) meet the Rule requirements.
Denotes vessels which are classed with IRS where
the hull and its appendages meet the rule
requirements but when the equipment of ship is not
SU- SARVOUTAM
supplied or maintained as per the relevant Rules but is
considered by IRS to be acceptable for particular
service
Denotes vessels which are classed with IRS where
the hull and its appendages meet the rule
SU SARVOUTAM requirements but where for reason of their particular
purpose or service normal equipment may be
unnecessary
Denotes that for self propelled seagoing vessels, the
IY INDIAN YANTRA machinery installation complies with the applicable
requirements of Indian Register of Shipping
This distinguishing mark inserted before a Character
of Class is assigned to new ships where the hull and
its appendages, equipment and the machinery as
SWASTIKA
appropriate, are constructed under special survey of
IRS in compliance with the Rules to the satisfaction of
IRS
When a Class Notation is enclosed within brackets, it
[ ] indicates that applicable arrangements exist on board
but the notation has been temporarily suspended
Class Notations - Hull
Service in sheltered water adjacent to sand banks,
Sheltered Water Service reefs, breakwaters or other coastal features, and in
sheltered water between islands
Service in sheltered waters and also for short
Restricted Water Service distances (generally less than 15 nautical miles)
beyond sheltered waters in 'reasonable weather'
Service along a coast, during the course of which the
vessel does not go more than 20 nautical miles from
the nearest land and may cross gulfs or similar
Specified Coastal Service features recognised by the local Administration as a
part of the coastal service. The geographical limits will
form part of the Class Notation, e.g. "Indian Coastal
Service"
Service between two or more points or other
Specified Route Service geographical features which will form part of the Class
Notation
Service within one or more geographical area(s) which
Specified Operating Area Service
will form part of the Class Notation
End of Chapter
Chapter 2
Periodical Surveys
Contents
Section
1 General Requirements
2 Surveys - Bulk Carriers and Ore Carriers
3 Surveys - Oil Tankers, Ore or Oil Carriers, Oil or Bulk Carriers
4 Surveys - Chemical Tankers
5 Surveys - Liquefied Gas Carriers
6 Surveys - Other Ship Types
7 Docking Surveys
8 Machinery - Special Surveys
9 Boiler Surveys
10 Steam Pipes Surveys
11 Surveys of Propeller Shafts, Tube Shafts and Propellers
12 Surveys of Inert Gas Systems
13 Surveys of Vessels with Refrigerated Cargo Installations
14 Planned Maintenance System
15 Surveys – Vapour Control Systems
16 Surveys of Thermal Oil Heating Systems
17 Surveys of External Fire Fighting Systems
Section 1
General Requirements
(Any specific requirements of the flag Administration are also to be complied with)
Class survey Survey interval in
Survey
notation years
Hull : Special Survey SSH 5
5
Hull : Continuous Survey CSH 5
Machinery : Special Survey SSM 5
Machinery : Continuous Survey CSM 5
4
Intermediate Survey IS 2 or 3
1
Annual Survey AS 1
2
Docking Survey DS 2.5
Tailshaft Survey
3,8
with approved oil gland TS(OG) 5
3,8
with continuous liner TS(CL) 5
3,8
with shaft of corrosion resistant material TS(NC) 5
with condition monitoring TS(TCM) See Note 7
3
other than above TS 2.5
Notes:
1 Survey may be carried out within 3 months on either side of the anniversary date.
2 At least 2 Surveys are to be carried out within any 5 year special survey cycle, but the interval between
two consecutive surveys is not to exceed 3 years and one of these two docking surveys should coincide
with the Special Survey. Proposals for alternative means for providing underwater inspection equivalent to
drydocking survey would be considered by IRS as detailed in Sec.7. However, for vessels operating solely
in fresh-water only one docking survey coinciding with the special survey need be carried out till special
survey no. IV provided the interval between consecutive docking surveys does not exceed 5 years.
3 Upon request, IRS may extend the survey period to harmonise with docking survey.
4 Survey may be carried out either at or between the second or third Annual Survey.
5 At the request of the Owner, IRS may agree that the special survey of the hull, for ships other than bulk
carriers, oil tankers, combination carriers, chemical tankers, liquefied gas carriers and general dry cargo
ships, be carried out on the continuous basis.
6 At least 2 surveys are to be carried out within any 5 year special survey cycle. The interval between two
consecutive surveys is not to exceed 3 years.
7 Condition monitoring records are to be verified at the time of annual surveys and during docking survey.
No specific time interval is required between complete tailshaft surveys (See section 11.5).
8 See 11.1.2 for requirements for applicability of 5 years survey interval.
1
Annual Survey AS(JUS) 1
Special Survey SS(JUS) 5
Cargo refrigerating plant HY
1
Annual Survey AS(HY) 1
Special Survey SS(HY) 5
Continuous Survey CS(HY) 5
Dynamic positioning system DP(1), (2) and (3)
1
Annual Survey AS(DP) 1
Special Survey SS(DP) 5
1
Annual Survey AS(NV) 1
Special Survey SS(NV) 5
Un-attended Machinery SYJ
Spaces
2 Survey may be carried out either at or between the second or third annual
survey.
and compressor rooms, cofferdams, ballast side skin (regardless of the width of the wing
tanks and void spaces adjacent to the cargo space).
containment spaces and also deck areas
throughout the entire length and breadth of the 1.2.17 ‘General dry cargo ship’ means ships
part of the ship over the above mentioned carrying solid cargoes other than:
spaces.
- bulk carriers and ore carriers which are
In the case of bulk carriers and general dry subject to the requirements of Sec.2;
cargo ships, cargo area is that part of the ship - dedicated Container carriers;
which contains all cargo holds and adjacent - dedicated forest product carriers (not timber
areas including fuel tanks, cofferdams, ballast or log carriers);
tanks and void spaces etc. within the - ro-ro cargo ships;
longitudinal extent from the aft bulkhead of the - refrigerated cargo ships;
aft-most cargo hold to the fwd bulkhead of the - dedicated wood chip carriers;
foremost cargo hold. - dedicated Cement carriers;
- livestock carriers;
Note: The definitions for cargo area given above - ships carrying exclusively deck cargo;
are applicable only for the purpose of identifying - General dry cargo ships of double skin
spaces for examination during hull surveys as construction, with double skin extending for
required by this chapter of the Rules. For the the entire length of the cargo area and for
purpose of design and construction the entire height of the cargo hold to the
requirements, the definitions given in respective upper deck.
chapters of Part 5 of the rules would apply.
1.2.18 Special consideration or specially
1.2.12 Spaces are separate compartments considered (in connection with close-up
including holds, tanks, cofferdams and void surveys and thickness measurements) means
spaces bounding cargo holds, decks and the that sufficient close-up inspection and thickness
outer hull. measurements are to be taken to confirm the
actual average condition of the structure under
1.2.13 A prompt and thorough repair is a the coating.
permanent repair completed at the time of
survey to the satisfaction of the Surveyor, 1.2.19 Air pipe heads installed on the exposed
therein removing the need for the imposition of decks are those extending above the freeboard
any associated condition of classification, or deck or superstructure decks.
recommendation.
1.2.20 A ro-ro Ship is a ship which utilizes a
1.2.14 Anniversary date means the day and loading ramp to enable wheeled vehicles to be
month of each year corresponding to the expiry rolled-on and rolled-off the ship,
date of the classification certificate.
1.2.21 Pitting corrosion is defined as scattered
1.2.15 A Double Hull Oil Tanker is a ship corrosion spots/areas with local material
which is constructed primarily for the carriage of reductions which are greater than the general
oil (See Pt.5, Ch.2, for list of oils) in bulk, which corrosion in the surrounding area.
has the cargo tanks protected by a double hull
which extends for the entire length of the cargo 1.2.22 Edge corrosion is defined as local
area, consisting of double sides and double corrosion at the free edges of plates, stiffeners,
bottom spaces for the carriage of water ballast primary support members and around openings.
or as void spaces. An example of edge corrosion is shown in
Fig.1.2.22.
1.2.16 For the purpose of application of these
requirements, a ‘double skin bulk carrier’ is a 1.2.23 Grooving corrosion is typically local
ship which is constructed generally with single material loss adjacent to weld joints along
deck, top side tanks, hopper side tanks & double abutting stiffeners and at stiffener or plate butts
bottom in cargo spaces and is intended primarily or seams. An example of groove corrosion is
to carry dry cargo in bulk, including such types shown in Fig.1.2.23.
as ore carriers and combination carriers, in
which all cargo holds are bounded by double-
1.3.1.2 During lay-up, vessels are to be Details of the means of access are to be
subjected to a general examination every year. provided in the survey planning questionnaire.
- hydraulic arm vehicles such as guidance on their use are to be made available
conventional cherry pickers for during the survey. A safety check-list should be
surveys of lower and middle part of provided.
shell frames as alternative to
staging: 1.7.16 Adequate and safe lighting is to be
- lifts and moveable platforms; provided for the safe and efficient conduct of the
- boats or rafts provided the structural survey.
capacity of the hold is sufficient to
withstand static loads at all levels of 1.7.17 Adequate protective clothing is to be
water; made available and used (e.g. safety helmet,
- other equivalent means. gloves, safety shoes, etc.) during the survey.
account is the level of the water to be structure. For this purpose, the ullage
rising while the boat or raft is in use; corresponding to the maximum water
level is to be assumed not more than 3
e) The tank, hold or space must contain [m] from the deck plate measured at the
clean ballast water only. Even a thin midspan of deck tranverses and in the
sheen of oil on the water is not middle length of the tank.
acceptable; and
If neither of the above conditions are met, then
f) At no time is the water level to be staging or an “other equivalent means” is to be
allowed to be within 1 m of the deepest provided for the survey of the under deck areas.
under deck web face flat so that the
survey team is not isolated from a direct See also IRS Classification Notes “Guidelines
escape route to the tank hatch. Filling to for approval / acceptance of alternative means
levels above the deck transverses is of access to spaces in oil tankers, bulk carriers,
only to be contemplated if a deck ore carriers and combination carriers”.
access manhole is fitted and open in the
bay being examined, so that an escape 1.8.6 The requirements regarding the usage of
route for the survey party is available at boats or rafts in 1.8.5 does not preclude their
all times. Other effective means of use for moving about within a tank during a
escape to the deck may be considered. survey.
1.8.5 For the under deck areas in tanks, survey - side structure and side plating;
by means of boats or rafts will be allowed if the - deck structure and deck plating;
depth of the webs is 1.5 [m] or less. - bottom structure and bottom plating;
- inner bottom structure and inner bottom
If the depth of the webs is more than 1.5 [m], plating;
boats or rafts may be allowed only when: - inner side structure and inner side plating;
- longitudinal bulkhead(s) plating and
i) the coating of the under deck structure structure;
is in GOOD condition and there is no - transverse watertight or oiltight bulkheads,
evidence of wastage; or plating and structure; and
- hatch covers and hatch coamings.
ii) a permanent means of access is - weld connection between air pipes and deck
provided in each bay to allow safe entry plating;
and exit, which means the following: - air pipe heads;
- ventilators including closing devices;
a) access direct from the deck via a - bunker and vent piping systems in bulk
vertical ladder and a small platform carriers, ore carriers and combination
fitted approximately 2 [m] below the carriers.
deck in each bay; or
Where adequate repair facilities are not
b) access to deck from a longitudinal available, consideration may be given to allow
permanent platform having ladders to the vessel to proceed directly to a repair facility.
deck in each end of the tank. The This may require discharging the cargo and/or
platform shall, for the full length of the temporary repairs for the intended voyage.
tank, be arranged in level with, or
above, the maximum water level 1.9.2 Additionally, when a survey results in the
needed for rafting of under deck identification of corrosion or structural defects,
either of which, in the opinion of the Surveyor, company may be dispensed with in the case
will impair the vessel's fitness for continued of extension of dry-docking survey not
service, remedial measures are to be exceeding 36 months interval provided the
implemented before the ship continues in ship is without outstanding
service. Recommendation / Condition of Class
regarding underwater parts.
1.9.3 Where the damage found on structure
mentioned in 1.9.1 is isolated and of a localized “Exceptional circumstances” means
nature which does not affect the ship’s structural unavailability of dry-docking facilities;
integrity, consideration may be given by the unavailability of repair facilities; unavailability of
surveyor to allow an appropriate temporary essential materials, equipment or spare parts; or
repair to restore watertight or weather tight delays incurred by action taken to avoid severe
integrity and impose a Recommendation / weather conditions.
Condition of Class with a specific time limit.
1.11.2 In the case that the Class Certificate will
1.9.4 Extended thickness measurements when expire when the vessel is expected to be at sea,
required by the rules are to be carried out and an extension to allow for completion of the
necessary repairs completed before the survey Special Survey may be granted provided there
is credited as complete. is documented agreement to such an extension
prior to the expiry date of the certificate and
1.10 Thickness measurements and close-up provided that positive arrangements have been
surveys made for attendance of the Surveyor at the first
port of call and provided that IRS is satisfied that
1.10.1 In any kind of survey, i.e. special, there is technical justification for such an
intermediate, annual or any other surveys extension. Such an extension is to be granted
having the scope similar to annual, intermediate only until arrival at the first port of call after the
or special surveys, thickness measurements of expiry date of the certificate. However, if owing
structures in areas where close-up surveys are to “exceptional circumstances” the special
required are to be carried out simultaneously survey cannot be completed at the first port of
with close-up surveys. call, 1.11.1 may be followed, but the total period
of extension shall in no case be longer than
1.11 Extension of special surveys three months after the original due date of the
special survey.
1.11.1 Under “exceptional circumstances”, IRS
may grant an extension not exceeding three (3) 1.11.3 In case of force majeure as defined
months to allow for completion of the special below, the completion of survey may be
survey provided that the vessel is attended and specially considered.
the attending surveyor(s) so recommend(s) after
the following has been carried out: “Force Majeure” means damage to the ship;
unforeseen inability of IRS to attend the vessel
a) Annual Survey; due to the governmental restrictions on right of
b) Re-examination of Recommendations / access or movement of personnel;
Conditions of Class; unforeseeable delays in port or inability to
c) In the case where dry docking is due prior to discharge cargo due to unusually lengthy
the end of the class extension, an periods of severe weather, strikes or civil strife;
underwater examination is to be carried out acts of war; or other similar circumstances.
by an approved diving company. An
underwater examination by an approved
Section 2
2.2.2.3 If there are indications of difficulty in 2.2.2.7 Cargo hatch covers of the portable type
operating and securing hatch covers, sets in (i.e. wood or steel pontoons) are to be examined
addition to those required by 2.2.2.2, at the to confirm the satisfactory condition of:
discretion of the surveyor, are to be tested in
operation. - wooden covers and portable beams,
carriers or sockets for the portable
Where the cargo hatch securing system does beams and their securing devices;
not function properly, repairs are to be carried
out under the supervision of the Surveyors. - steel pontoons;
c) Clamping devices, retaining bars, cleating 2.2.2.8 All watertight doors in watertight
(for wastage, adjustment and condition of bulkheads, to be examined and tested (locally
rubber components); and remotely) as far as practicable.
d) Closed cover locating devices (for distortion 2.2.2.9 Suspect areas identified at previous
and attachments); special or intermediate surveys are to be close-
up surveyed. Thickness measurements are to
e) Chain or rope pulleys; be taken of the area of substantial corrosion
identified at previous surveys.
f) Guides;
For vessels built under the IACS Common
g) Guide rails and track wheels; Structural Rules, the annual thickness gauging
may be omitted where a protective coating has
h) Stoppers; been applied in accordance with the coating
manufacturer’s requirements and is maintained
i) Wires, chains, tensioners and gypsies; in good condition. In this case, it is
recommended that the necessary
j) Hydraulic system, electrical safety devices documentation of coating is available on board.
and interlocks; and
Where annual gauging is required as per
k) End and interpanel hinges, pins and stools 2.4.12.3, thickness measurement of aft bulk-
where fitted. head of the forward cargo hold is to be carried
out.
2.2.2.5 At each hatchway the coamings, with
panel stiffeners and brackets are to be 2.2.2.10 Examination of ballast tanks is to be
subjected to a close-up survey and checked for carried out when required as a consequence of
corrosion, cracks and deformation, especially of the results of the special and intermediate
the coaming tops. surveys. (See 2.4.5.1, 2.4.5.2 and 2.3.2.1).
When considered necessary by the Surveyor or extent of close-up surveys may be specially
where extensive corrosion exists, thickness considered.
measurement is to be carried out. If the results
of these thickness measurements indicate e) All piping and penetrations in cargo holds,
substantial corrosion additional thickness including overboard piping are to be
measurements are to be carried out to the examined.
extent given in Table 2.4.10.2(a) or Table
2.4.10.2(b). 2.2.2.15 On bulk carriers of over 15 years of age
the following are to be carried out in addition to
2.2.2.11 Anchoring and mooring equipment is to the requirements given in 2.2.2.1 to 2.2.2.14:
be examined as far as is practicable.
a) Overall survey of all cargo holds.
2.2.2.12 Where applicable Surveyor should
satisfy himself regarding the freeboard marks on b) Close-up examination of a selected cargo
the ship's side. hold in addition to the forward cargo hold as
required in 2.2.2.14b) and c).
2.2.2.13 The Surveyor is to confirm that, where
required, an approved loading instrument c) Examination of all piping and penetrations in
together with its operation manual is available cargo holds, including overboard piping.
on board, See Pt.3, Ch.5. It is to be verified by
the Surveyor that the loading instrument is d) Where a hard protective coating in cargo
checked for accuracy at regular intervals by the holds is found to be in GOOD condition, the
ship's staff by applying test loading conditions. extent of close-up surveys may be specially
considered.
2.2.2.14 On bulk carriers of over 10 years of age
the following are to be carried out in addition to 2.2.2.16 Accommodation ladders are to be
the requirements in 2.2.2.1 to 2.2.2.13: examined at annual surveys. Satisfactory
condition of the following items is to be checked,
a) Overall survey of two selected cargo holds in particular :
in double skin bulk carriers and all cargo
holds in the case of other bulk carriers. a) steps;
b) platforms;
b) For single side skin bulk carriers, close-up c) all support points such as pivots, rollers,
survey of sufficient extent, minimum 25 per etc.;
cent of frames, to establish the condition of d) all suspension points such as lugs,
the lower region of the shell frames brackets, etc.;
including approximately lower one third e) stanchions, rigid handrails, hand ropes and
length of side frame at side shell and side turntables;
frame end attachment and the adjacent f) davit structure, wire and sheaves, etc.
shell plating in a forward cargo hold. Where
this level of survey reveals the need for 2.2.2.17 Gangways are to be examined at
remedial measures, the survey is to be annual surveys. Satisfactory condition of the
extended to include a close-up survey of all following items is to be checked, in particular :
of the shell frames and adjacent shell
plating of that cargo hold as well as a close- a) treads;
up survey of sufficient extent of all b) side stringers, cross-members, decking,
remaining holds. deck plates, etc.;
c) all support points such as wheel, roller, etc.;
c) When considered necessary by the d) stanchions, rigid handrails, hand ropes.
Surveyor, thickness measurement is to be
carried out. If the results of these thickness 2.2.2.18 Winches of accommodation ladders
measurements indicate substantial and gangways are to be examined to verify the
corrosion additional thickness measure- satisfactory condition of the following items:
ments are to be carried out to the extent
given in Table 2.4.10.2(a) or Table a) brake mechanism including condition of
2.4.10.2(b). brake pads and band brake, if fitted;
b) remote control system, and
d) Where a hard protective coating in cargo c) power supply system for electric motor.
holds is found to be in GOOD condition, the
2.2.2.19 Davits and fittings on the ship’s deck - Shell frames including their upper and
associated with accommodation ladders and lower end attachments, adjacent shell
gangways are to be examined for satisfactory plating, and transverse bulkheads.
condition at annual surveys. Fittings or
structures for means of access to deck such as - Suspect areas found at the previous
handholds in a gateway or bulwark ladder and special survey.
stanchions are also to be examined.
b) Where considered necessary by the
2.2.2.20 The maintenance and inspection surveyor as a result of the overall and close-
records of accommodation ladders and up survey as described in a) above, the
gangways are to be verified. It is to be confirmed survey is to be extended to include a close-
that supporting wires are being renewed at up survey of all of the shell frames and
intervals not exceeding 5 years. adjacent shell plating of the cargo hold.
2.2.2.21 When examining internal spaces as far 2.2.3.4 For bulk carriers exceeding 15 years of
as practicable, the permanent means of access age:
where appropriate, are to be verified that they
remain in good condition. a) An overall survey of the foremost cargo
hold, including close-up survey is to be
2.2.2.22 For vessels subject to IMO PSPC (See carried out to establish the condition of:
Pt.3, Ch.2, 3.6), it is to be confirmed that the
maintenance, repair and partial recoating of - All shell frames including their upper
dedicated ballast tanks and double side skin and lower end attachments, adjacent
spaces, as appropriate, are recorded in the shell plating and transverse bulkheads.
coating technical file.
- Suspect areas found at the previous
2.2.3 Additional annual survey requirements special survey.
for ships subject to SOLAS XII/9:
2.2.3.5 Extent of thickness measurement:
2.2.3.1 For ships subject to SOLAS XII/9 i.e.:
a) Thickness measurement is to be carried out
- Bulk Carriers of 150 [m] in length and to an extent sufficient to determine both
upwards of single side skin construction as general and local corrosion levels at areas
defined in Pt.5, Ch.1, 1.1.4; and subject to close-up survey, as described in
2.2.3.3a) and 2.2.3.4a) above. The
- Carrying solid bulk cargoes having a density minimum requirement for thickness
of 1780 [kg/m3] and above; and measurements are areas found to be
suspect areas at the previous special
- Contracted for construction before 1 July, survey.
1999 and
Where substantial corrosion is found, the
- Constructed with an insufficient number of extent of thickness measurements is to be
transverse watertight bulkheads to enable increased with the requirements of Table
them to withstand flooding of the foremost 2.4.10.2(a) or Table 2.4.10.2(b).
cargo hold in all loading conditions and
remain afloat in a satisfactory condition of b) The thickness measurement may be
equilibrium as specified in SOLAS XII/4.3. dispensed with provided the surveyor is
satisfied by the close-up survey, that there
2.2.3.2 In accordance with SOLAS XII/9.1 for is no structural diminution and the protective
the foremost cargo hold of such ships, the coating where provided remains effective.
additional survey requirements listed in 2.2.3.3
to 2.2.3.6 shall apply. 2.2.3.6 Where the protective coating in the
foremost cargo hold is found to be in GOOD
2.2.3.3 For bulk carriers of 5 - 15 years of age: condition, the extent of close-up surveys and
thickness measurements may be specially
a) An overall survey of the foremost cargo considered.
hold, including close-up survey of sufficient
extent, minimum 25% of frames, is to be For existing bulk carriers, where owners may
carried out to establish the condition of: elect to coat or recoat cargo holds as noted
above, consideration may be given to the extent
of the close-up and thickness measurement position of the rudder are operating
surveys. Prior to the coating of cargo holds of satisfactorily.
existing ships, scantlings should be ascertained
in the presence of a surveyor. 2.2.4.9 Confirmation that with ships having
emergency steering positions there are means
2.2.3.7 Bilge well alarms to all cargo holds and of relaying heading information and, when
conveyor tunnels are to be verified to confirm appropriate, supplying visual compass readings
their functionality. to the emergency steering positions.
2.2.4.17 Confirmation as far as practicable, the separately so that the two required powerful
operation of the emergency source(s) of jets of water can be produced
electrical power, including their starting simultaneously from different hydrants;
arrangement, the systems supplied, and when
appropriate, their automatic operation. d) verification that fire hoses, nozzles,
applicators and spanners are in good
2.2.4.18 Examining in general, that the working condition and situated at their
precautions provided against shock, fire and respective locations;
other hazards of electrical origin are being
maintained. e) examination of fixed fire fighting system
controls, piping, instructions and marking,
2.2.4.19 A General Examination of automation checking for evidence of proper
equipment is to be carried out. Satisfactory maintenance and servicing including date of
operation of safety devices, bilge level detection last systems tests;
and alarm systems and control systems is to be
verified. f) verification that all semi-portable and
portable fire extinguishers are in their
2.2.4.20 Examination of bunker and vent piping stowed positions, checking for evidence of
systems. proper maintenance and servicing,
conducting random check for evidence of
2.2.4.21 For ships complying with the discharged containers;
requirements of SOLAS XII/12 for hold, ballast
and dry space water level detectors (See g) verification, as far as practicable, that the
2.4.14), the annual survey is to include an remote controls for stopping fans and
examination and a test, at random, of the water machinery and shutting off fuel supplies in
ingress detection systems and of their alarms. machinery spaces are in working order;
2.2.4.22 For ships complying with the h) examination of the closing arrangements of
requirements of SOLAS XII/13 for the availability ventilators, funnel annular spaces, skylights,
of pumping systems (See 2.4.15), the annual doorways and tunnel, where applicable;
survey is to include an examination and a test,
of the means for draining and pumping ballast i) confirmation that the fire fighters’ outfits and
tanks forward of the collision bulkhead and emergency escape breathing devices
bilges of dry spaces any part of which extends (EEBDs) are complete and in good
forward of the foremost cargo hold and of their condition and that the cylinders, including
controls. the spare cylinders, of any required self-
contained breathing apparatus are suitably
2.2.4.23 Confirmation that machinery space charged.
ventilation systems are in good working
condition. j) examination of any manual and automatic
fire doors and proving their operations.
2.2.5 Fire protection, detection and
extinction k) examination of the fire-extinguishing
systems for spaces containing paint and/or
2.2.5.1 The arrangements for fire protection, flammable liquids and deep fat cooking
detection and extinction are to be examined and equipment in accommodation and service
are to include confirmation that no changes spaces;
have been made in the structural fire protection.
Following are to be examined / verified: l) examination of the fire safety requirements
of any helicopter facilities;
a) verification that fire control plans are
properly posted; m) examination of the fire protection
arrangements in cargo spaces, as far as
b) examination as far as possible and testing practicable;
as feasible of the fire and/or smoke
detection system(s); n) examination, when appropriate of the
special arrangements for carrying
c) examination of the fire main system and dangerous goods, including checking the
verification that each fire pump including the electrical equipment and wiring, ventilation,
emergency fire pump can be operated provision of protective clothing and portable
appliances and testing of the water supply, representative appointed by the master or
bilge pumping and any water spray system. Company for the purpose to ascertain that all
the arrangements envisaged in the survey
Surveys carried out by the National Authority of programme are in place, so as to ensure the
the country in which the ship is registered would safe and efficient conduct of the survey work to
normally be accepted as meeting these be carried out.
requirements, at the discretion of the Surveyor.
2.3.2 Vessels of between 5 and 10 years of
2.2.5.2 Confirmation that the means of escape age
from accommodation, machinery spaces and
other spaces are satisfactory. 2.3.2.1 Ballast tanks
2.3.1.2 The following requirements are c) For ballast tanks other than double bottom
applicable for vessels over five years of age. For tanks, where a hard protective coating is
vessels below 5 years of age additional found to be in POOR condition and is not
examination over and above the requirements of renewed or where a soft or semi-hard
Annual survey may be required at the discretion coating has been applied or where a hard
of the Surveyors. protective coating was not applied from the
time of construction, the tank(s) in question
2.3.1.3 For vessels over 10 years of age a are to be examined and thickness
specific survey program is to be worked out by measurements carried out as necessary at
the owner in cooperation with the Surveyors subsequent annual surveys.
considering the requirements of the previous
special survey, executive hull summary of that When such breakdown of hard coating is
survey, later relevant survey records and taking found in double bottom ballast tanks, or
account of any amendments to the survey where a soft or semi-hard coating has been
requirements after the last special survey. The applied or where a hard protective coating
survey program is to be submitted in written has not been applied, the tanks in question
format for approval and kept on board until the may be examined at annual intervals.
intermediate survey has been completed. (See When considered necessary by the
2.4.2 for guidance on preparation of the survey Surveyor, or where extensive corrosion
program). exists, thickness measurements are to be
carried out.
2.3.1.4 Prior to the commencement of any part
of the intermediate survey, a survey planning d) Suspect areas identified at previous
meeting is to be held between the attending surveys are to be overall and close-up
Surveyor(s), the owner’s representative in surveyed.
attendance and where involved, the thickness
measurement company representative and the
master of ship or an appropriately qualified
2.3.4 Vessels of over 15 years of age completed more than 3 months before the expiry
date of the Special Survey, the period of class
2.3.4.1 The requirements of the intermediate will start from the survey completion date.
survey are to be to the same extent as the
previous special survey as required in 2.4 for 2.4.1.4 The Special Survey may be commenced
hull structure and piping systems in way of the at the 4th Annual Survey and be progressed
cargo holds cofferdams, pipe tunnels, void with a view to completion by the 5th anniversary
spaces and fuel oil tanks in the cargo area and date. When the special survey is commenced
all ballast tanks. However, tank testing specified prior to the fourth annual survey, the entire
in 2.4.8, survey of automatic air pipe heads survey is to be completed within 15 months if
specified in 2.4.6.9 and internal examination of such work is to be credited to the special survey
fuel oil, lub.oil and fresh water tanks specified in and in this case the next period of class will start
Table 2.4.6.1 need not be carried out unless from the survey completion date.
deemed necessary by the attending Surveyor.
Thickness measurement is to be carried out for Concurrent crediting to both Intermediate survey
items 1) to 6) of Table 2.4.10.1. and Special survey for surveys and thickness
measurements of spaces is not acceptable.
A survey programme as per 2.4.2 is to be
worked out prior to commencement of survey. 2.4.1.5 As part of the preparation for Special
Survey, the proposed Survey Programme (See
2.3.4.2 The intermediate survey may be 2.4.2) including the schedule for thickness
commenced at the second annual survey and measurements (See 2.4.10) are to be submitted
be progressed during the succeeding year with at least 3 months in advance of the intended
a view to completion by the third annual survey commencement of the Special Survey.
in lieu of the application of 2.4.1.4.
2.4.1.6 Record of Special Survey will not be
2.3.4.3 A survey in dry dock is to be part of the assigned until the Machinery Survey has been
intermediate survey. Any remaining work in completed or postponed in agreement with IRS.
respect of the overall and close-up surveys and
thickness measurements and repairs applicable 2.4.1.7 Ships which have satisfactorily passed a
to the lower portions of cargo holds and ballast Special Survey will have a record entered in the
tanks (i.e. parts below light ballast water line), Supplement to the Register Book indicating the
are to be completed in the dry-dock. assigned date of Special Survey. In addition a
notation "ESP" will be entered for bulk carriers,
2.4 Special Surveys - Hull ore carriers and combination carriers.
2.4.2.2 In developing the Survey Programme, - Nomination of holds and tanks and areas for
the following documentation is to be collected close-up survey (As per Table 2.4.9.1)
and consulted with a view to selecting tanks,
areas and structural areas for examination :
- Nomination of sections for thickness
- Survey status and basic ship information measurement (As per Table 2.4.10.1)
- Main structural plans (scantling drawings), - Damage experience related to the ship in
including information regarding use of high operation.
strength steels, clad steel and stainless
steel 2.4.2.4 IRS will advise the Owner of the
maximum acceptable structural corrosion
- Relevant previous survey and inspection diminution levels applicable to the vessel.
reports of IRS and the Owners
2.4.2.5 The ship is to be prepared for overall
- Information regarding the use of the ship's survey in accordance with the requirements of
holds and tanks, typical cargoes and other Table 2.4.2.5. The preparation is to be of
relevant data sufficient extent to facilitate an examination to
ascertain any excessive corrosion, deformation,
- Information regarding corrosion prevention fractures, damages and other structural
level at the time of construction deterioration.
- Information regarding the relevant 2.4.2.6 Proper preparation and the close co-
maintenance level during operation. operation between the attending surveyor(s) and
the owner’s representatives onboard prior to and
2.4.2.3 The Survey Programme submitted for during the survey are an essential part in the
approval is to account for and comply, as a safe and efficient conduct of the survey. During
minimum, with the requirements of close-up the survey on board safety meetings are to be
survey, thickness measurement and tank testing held regularly.
respectively, and to include relevant information
including at least :
Special Survey No. I Special Survey No. II Special Survey No. III Special Survey No. IV
Age ≤ 5 5 < Age ≤ 10 10 < Age ≤ 15 and subsequently
Age ≥ 15
1) The holds, deep tanks, 1) Requirements of 1) Requirements of 1) Requirements of
peaks, bilges and drain Special Survey I to be Special Survey II to be Special survey III to be
wells, engine and boiler complied with complied with complied with
spaces and other spaces are
to be cleared out and 2) The chain locker is to 2) Portions of wood
cleaned as necessary for be cleaned internally. sheathing, or other
examination. Floor plates in The chain cables are to covering, on steel decks
engine and boiler spaces are be ranged for inspection. are to be removed, as
to be lifted as may be The anchors are to be considered necessary by
necessary for examination of cleaned and placed in an the Surveyor, in order to
the structure underneath. accessible position for ascertain the condition of
Where necessary ceiling, inspection. the plating.
lining, casings and loose
insulation are to be removed
as required by the Surveyor
for examination of the
structure. Compositions on
the plating are to be
examined and sounded, but
need not be disturbed if
found satisfactorily adhering
to the plating.
2) The steelwork is to be
exposed and cleaned as
may be required for its
proper examination by the
Surveyor and close attention
is to be paid to the parts of
the structure which are
particularly liable to
excessive corrosion or to
deterioration due to other
causes.
scaling, illumination, ventilation, personal allowable hull girder sectional properties for hold
safety); transverse section in all cargo holds)
Areas in tanks where a hard protective coating 2.4.6.2 All tanks other than water ballast tanks
is provided and found in GOOD condition, the are to be examined internally in accordance with
extent of thickness measurements may be the requirements of Table 2.4.6.1.
specially considered.
Notes:
2.4.6.3 An overall survey of all cargo holds, 2.4.6.4 Where ballast tanks have been
ballast tanks including double bottom tanks, pipe converted to void spaces, the survey extent is to
tunnels, cofferdams and void spaces bounding be based upon ballast tank requirements.
cargo holds, decks and outer hull is to be carried
out. This examination is to be supplemented by 2.4.6.5 All watertight bulkheads and watertight
thickness measurement and testing as required doors are to be examined. All decks, casings
by 2.4.10 and 2.4.8 to ensure that the structural and superstructures are to be examined.
integrity remains effective. The aim of the Attention is to be given to the corners of
examination is to discover Substantial openings and other discontinuities in way of the
Corrosion, significant deformation, fractures, strength decks and top sides.
damages or other structural deterioration and if
deemed necessary by the Surveyor, a suitable 2.4.6.6 The masts, standing rigging and anchors
non-destructive examination may be required. are to be examined.
All piping systems within the above spaces are The Surveyor should satisfy himself that there
to be examined and operationally tested to are sufficient mooring ropes on board and also
working pressure to attending Surveyors that a tow line is provided when this is a Rule
satisfaction to ensure that the tightness and requirement.
condition remains satisfactory.
Table 2.4.6.8 : Requirements for internal examination of automatic air pipe heads
2.4.6.9 The Surveyor should satisfy himself per cent of its original rule diameter is to be
regarding the efficient condition of the following : renewed.
2.4.6.16 For ships complying with the - proper fit and efficiency of sealing in closed
requirements of SOLAS XII/13 for the availability condition;
of pumping systems, the special survey is to
include an examination and a test of the means - operational testing of hydraulic and power
for draining and pumping ballast tanks forward components, wires, chains and link drives.
of the collision bulkhead and bilges of dry
spaces any part of which extends forward of the 2.4.7.3 Checking the effectiveness of sealing
foremost cargo hold and of their controls. arrangements of all hatch covers by hose testing
or equivalent.
2.4.6.17 Examination of accommodation
ladders, gangways and their winches are to be 2.4.8 Tank testing
carried out as required for annual surveys. In
addition, the accommodation ladders and 2.4.8.1 Boundaries of double bottom, deep,
gangways are to be operationally, tested with ballast, peak and other tanks including holds
the specified maximum operation load. adapted for the carriage of water ballast, are to
be tested with a head of liquid to the top of air
The tests are to be carried out with the load pipes or nearabout to the top of hatches for
applied as uniformly as possible along the ballast/cargo holds. Boundaries of fuel oil, lub.oil
length of the accommodation ladder or and fresh water tanks are to be tested with a
gangway, at an angle of inclination head of liquid to the highest point that liquid will
corresponding to the maximum bending moment rise under service conditions. Tank testing of
on the accommodation ladder or gangway. fuel oil, lub.oil and fresh water tanks may be
specially considered based on a satisfactory
Accommodation ladder winch is to be external examination of the tank boundaries and
operationally tested at special surveys. The a confirmation from the Master stating that the
brake system of the winch is to be tested for pressure testing has been carried out according
holding the maximum operational load on the to the requirement with satisfactory results.
ladder.
2.4.8.2 The testing of double bottom tanks and
For existing installations on board ships other spaces not designed for the carriage of
constructed prior to 01 Jan 2010 where the liquid may be omitted, provided a satisfactory
maximum operational load is not known, load internal examination together with an
nominated by the shipowner or operator may be examination of the tank top is carried out.
considered as the test load.
2.4.9 Close-up surveys
2.4.7 Hatch covers and coamings
2.4.9.1 The minimum requirements for Close-up
The hatch covers and coamings are to be survey are given in Table 2.4.9.1(a) or Table
surveyed as follows: 2.4.9.1(b) or Table 2.4.9.1(c).
Level (b) Immediately above and below the lower stool shelf plate (for those ships fitted with lower stools)
and immediately above the line of the shedder plates.
Level (d) Immediately below the upper deck plating and immediately adjacent to the upper wing tank and
immediately below the upper stool shelf plate for those ships fitted with upper stools, or immediately
below the topside tanks.
Table 2.4.9.1b : Minimum requirements for close-up survey at special hull survey of
double skin bulk carriers other than ore carriers
(A) : Transverse web frame or watertight transverse bulkhead in topside, hopper side and double
side ballast tanks. In fore and aft peak tanks transverse web frame means a complete
transverse web frame ring including adjacent structural members.
(B) : Ordinary transverse frame in double side tanks.
(C) : Cargo hold transverse bulkheads plating, stiffeners and girders.
(D) : Cargo hold hatch covers and coamings.
(E) : Deck plating inside line of hatch openings between cargo hold hatches.
Level (a) : Immediately above the inner bottom and immediately above the line of gussets (if fitted) and
shedders for ships without lower stool.
Level (b) : Immediately above and below the lower stool shelf plate (for those ships fitted with lower
stools) and immediately above the line of the shedder plates.
Level (d) : Immediately below the upper deck plating and immediately adjacent to the upper wing tank
and immediately below the upper stool shelf plate for those ships fitted with upper stools, or immediately
below the topside tanks.
Table 2.4.9.1c : Minimum requirements for close-up survey at special hull survey of ore carriers
2.4.9.2 The Surveyor may extend the close-up the coating in way is still in good
survey as deemed necessary taking into condition, or alternatively
account the maintenance of the spaces under
survey, the condition of the corrosion prevention b) Required to be gauged at annual
system and where spaces have structural intervals.
arrangements or details which have suffered
defects in similar spaces or on similar ships In this case of a) above, it is
according to available information. recommended that the necessary
documentation of coating is available on
2.4.9.3 For areas in tanks and cargo holds board.
where hard protective coatings are found in
GOOD condition, the extent of Close-up survey The Surveyor may further extend the thickness
may be specially considered. measurements as deemed necessary.
Table 2.4.10.1 : Thickness measurement at special hull survey of dry bulk cargo ships
(including double skin bulk carriers)
2) Within the cargo area: 2) Within the cargo area: 2) Within the cargo area:
5) Selected wind and water 5) Selected wind and water 5) All wind and water
strakes outside the cargo strakes outside the cargo strakes outside the cargo
area area area
6) For vessels subject to 6) Same as for Special
compliance of IMO stan- Survey III
dards as mentioned in
2.4.12 thickness measure-
ment applicable to the
vertically corrugated aft
transverse bulkhead of the
foremost cargo hold is to be
carried out as per Table
2.4.12 and Fig.2.4.12
9) Representative exposed
superstructure deck plating
(poop, bridge, forecastle
deck)
10) All keel plates,
additional bottom plates in
way of machinery space, aft
end of tanks and
cofferdams outside cargo
area
Deck structure including cross strips, main cargo hatchways, hatch covers, coamings and
topside tanks
Structural member Extent of measurement Pattern of measurement
Cross deck strip plating Suspect cross deck strip plating 5 point pattern between
underdeck stiffeners over 1
metre length
Underdeck stiffeners Transverse members 5 point pattern at each end and
mid span
Longitudinal members 5 point pattern on both web and
flange
Hatch covers Side and end skirts, each 3 5 point pattern at each location
locations
3 longitudinal bands, 2 outboard 5 point measurement each band
strakes and centerline strake
Hatch coamings Each side and end of coaming, 5 point measurement each band
one band lower 1/3, one band i.e. end or side coaming
upper 2/3 of coaming
Topside ballast tanks a) watertight transverse
bulkheads:
- Lower 1/3 of bulkhead 5 point pattern over 1 sq. metre
of plating
- Upper 2/3 of bulkhead 5 point pattern over 1 sq. metre
of plating
- Stiffeners 5 point pattern over 1 metre
length
b) two representative swash
transverse bulkheads:
- Lower 1/3 of bulkhead 5 point pattern over sq. metre of
plating
- Upper 2/3 of bulkhead 5 point pattern over 1 sq. metre
of plating
- stiffeners 5 point pattern over 1 metre
length
c) three representative bays of
slope plating:
- Lower 1/3 of tank 5 point pattern over 1 sq. metre
of plating
- Upper 2/3 of tank 5 point pattern over 1 sq. metre
of plating
d) Longitudinals, suspect and 5 point pattern on both web and
adjacent flange over 1 metre length
Structure in double side spaces of double skin bulk carriers including wing void spaces of ore
carriers
minimum of two webs and both 5-point pattern over approx. two
transverse bulkheads square metre area
b) other strakes
2.4.10.5 The thickness measurements are to be 2.4.11.2 For CSR bulk carriers, the ship’s
carried out by a qualified company certified by longitudinal strength is to be evaluated by using
IRS. the thickness of structural members measured,
renewed and reinforced, as appropriate, during
2.4.10.6 In order to ensure necessary control the special surveys carried out after the ship
during the process of thickness measurements, reached 15 years of age (or during the special
these are normally to be carried out under the survey No.3, if this is carried out before the ship
supervision of the Surveyor. The Surveyor has reaches 15 years) in accordance with the criteria
the right to re-check the measurements as for longitudinal strength of the ship’s hull girder
deemed necessary to ensure acceptable for CSR bulk carriers specified in Ch.13 of CSR.
accuracy.
2.4.11.3 The final result of evaluation of the
2.4.10.7 In all cases the extent of thickness ship’s longitudinal strength required in 2.4.11.2
measurements is to be sufficient as to represent after renewal or reinforcement work of structural
the actual average condition. members, if carried out as a result of initial
evaluation, is to be reported as a part of the
2.4.10.8 A thickness measurement report is to Executive Hull Summary.
be prepared. The report is to give the location of
measurements, the thickness measured as well 2.4.11.4 An Executive Hull Summary of the
as corresponding original thickness. survey and results is to be issued to the Owner
Furthermore, the report is to give the date when and placed on board the vessel for reference at
the measurements were carried out, type of future surveys. The Executive Hull Summary is
measuring equipment, names of personnel and to be endorsed by IRS Head Office.
their qualifications and has to be signed by the
operator. The Surveyor is to review the report of 2.4.12 Compliance with IMO standards for
the final thickness measurement after repairs scantlings of aft transverse bulkhead of the
have been carried out and countersign the cover foremost cargo hold and allowable hold
page. loading for foremost cargo hold
2.4.11 Reporting and evaluation of survey 2.4.12.1 These requirements apply to all bulk
carriers of 150 [m] in length and above,
2.4.11.1 The data and information on the intending to carry cargoes having bulk density of
3
structural condition of the vessel collected 1.78 [t/m ] or above where:
during the survey is to be evaluated for
acceptability and continued structural integrity of a) The foremost hold is bounded by the side
the vessel. shell only in ships which were contracted for
construction prior to 1 July 1998 and
b) The foremost hold is of double skin iv) for ships which were less than 5 years
construction of less than 760 [mm] in of age on 1 July 1998, on or before the
breadth, measured perpendicular to the side date on which the ship reaches 10 years
shell, in ships, the keel of which were laid or of age.
were at a similar stage of construction,
before 1 July 1999. Completion prior to 1 July 2003 of an
intermediate or special survey with a due date
2.4.12.2 For existing bulk carriers of the type as after 1 July 2003, can not be used to postpone
mentioned in 2.4.12.1 a) and b) above which compliance.
have not yet complied with the IMO standards,
the compliance is to be achieved within the 2.4.12.3 For bulkcarriers described in 2.4.12.2,
following time limits: thickness measurement of vertically corrugated
aft transverse bulkhead of the foremost cargo
i) for ships which were 15 years of age or hold is to be carried out to determine the general
more on 1 July 1998, immediately condition of the structure and to define the
before continuance in service; extent of possible repairs and/or reinforcements
required to meet the above mentioned IMO
ii) for ships which were 10 years of age or standards. As a minimum, the thickness
more but less than 15 years of age on 1 measurement is to be carried out at the critical
July 1998, by the due date of the first locations given in Table 2.4.12 and Fig.2.4.12.
intermediate or special survey to be
held after the date on which the ship In addition, thickness measurement is to be
reaches 15 years of age but not later carried out at subsequent intermediate surveys
than the date on which the ship reaches (for ships over 10 years of age) and special
17 years of age; surveys for the purpose of verifying continuing
compliance with the above standards.
iii) for ships which were 5 years of age or
more but less than 10 years of age on 1 Where annual gauging has been adopted as an
July 1998, on or before the due date, alternative to steel renewal in accordance with
after 1 July 2003, of the first the IMO standards, thickness measurement is
intermediate or special survey after the also to be carried out at subsequent annual
date on which the ship reaches 10 years surveys.
of age; and
Table 2.4.12 : Critical levels at which thickness measurement is to be carried out for the
vertically corrugated aft transverse bulkhead of the foremost cargo hold of existing bulk carriers
to determine compliance with IMO standard
Notes:
1. To adequately assess the scantlings of each individual vertical corrugation, each corrugation flange,
web, shedder plate and gusset plate within each of the levels given above are to be gauged.
2. Where the thickness changes within the horizontal levels, the thinner plate is to be gauged.
3. Steel renewal/reinforcement is to comply with IMO standard.
2.4.13.2 Compliance with the requirements 2.4.14 Compliance with SOLAS regulation 12,
indicated in Table 2.4.13.1, as applicable is to Ch.XII : Hold, ballast and dry space water
be achieved within the following time limits: level detectors
st
i) For ships which will be 15 years of age Bulk carriers constructed before 1 July, 2004
or more on 1 January 2004 by the due are to be fitted with water level detectors as
date of the first intermediate or special described in Pt.5, Ch.1, 2.13 of the Rules, not
survey after that date; later than the date of the annual, intermediate or
special survey of the ship to be carried out after
st
ii) For ships which will be 10 years of age 1 July, 2004, whichever comes first.
or more on 1 January 2004 by the due
date of the first special survey after that 2.4.15 Compliance with SOLAS regulation 13,
date; Ch.XII : Availability of pumping systems ( for
dewatering of forward spaces)
iii) For ships which will be less than 10
st
years of age on 1 January 2004 by the Bulk carriers constructed before 1 July, 2004
date on which the ship reaches 10 years are to comply with this SOLAS regulation in
of age. accordance with details given in Pt.5, Ch.1, 2.14
of the Rules, not later than the date of the first
Completion prior to 1 January 2004 of an intermediate or special survey of the ship to be
st
intermediate or special survey with a due date carried out after 1 July, 2004, but in no case
st
after 1January 2004 cannot be used to postpone later than 1 July, 2007.
compliance. However, completion prior to 1
January 2004 of an intermediate survey the 2.5 Special Surveys – Machinery
window for which straddles 1 January 2004 can
be accepted. 2.5.1 Requirements for examination of
machinery and piping are given in Sec.8.
2.4.13.3 Ships which are required to comply with
UR S31 as indicated in Table 2.4.13.1 are
Renewal criteria for Bulk carriers with side S31 Cargo holds bounded by
side shell frames and frames and/or brackets single side shell
brackets not meeting the
requirements of Pt.5,
Ch.1 of the 1998 or
subsequent rules
Cargo hatch cover Bulk carriers where S30 Securing devices and
securing arrangements cargo hatch covers do stoppers for the fore
(except for pontoon not meet the most and the second
type hatchcover) requirements of Pt.3, foremost cargo hold
Ch.12 of the January, hatchways located wholly
2004 Rules or partially within 0.25L of
the fore perpendicular
Fore deck fittings: Bulk carriers, ore S27 Located on the exposed
Air pipes and carriers, general dry deck and serving spaces
ventilators and their cargo ships and wholly or partially forward
closing devices combination carriers of of the collision bulkhead
L ≥ 100 m contracted for
construction prior to
1 January, 2004
Strength of small Bulk carriers, ore S26 Located on the exposed
hatches on the fore carriers, general dry deck giving access to
deck and their cargo ships and spaces wholly or partially
securing devices (See combination carriers of forward of the collision
Pt.3, Ch.12, 7.2 for L ≥ 100 m contracted for bulkhead
definition of small construction prior to
hatches) 1 January, 2004.
Section 3
3.1.2 For vessels with class notation Ore or Oil 3.2.1.2 At Annual Surveys, the Surveyor is to
Carrier ESP and Oil or Bulk Carrier ESP, the examine the hull and machinery, so far as
relevant requirements given in Sec.2 are also to necessary and practicable, in order to be
be applied. satisfied as to their general condition.
for checking items of equipment and a) Examination of all pump room bulkheads for
installations for correct functioning. signs of oil leakage or fractures and, in
particular, the sealing arrangements of all
3.2.1.4 It is to be confirmed that no new penetrations of pump room bulkheads.
installation of material containing asbestos was
carried out since last survey. b) Examination of the condition of all piping
systems.
3.2.2 Hull and weather deck
3.2.2.3 All watertight doors in watertight
3.2.2.1 The survey is to consist of an bulkheads, to be examined and tested (locally
examination for the purpose of ensuring, as far and remotely) as far as practicable.
as practicable, that the hull, equipment, closing
appliances and related piping are maintained in 3.2.2.4 Suspect areas identified at previous
satisfactory and efficient condition. Special special or intermediate surveys are to be close-
attention is to be paid to the following: up surveyed. Thickness measurements are to
be taken in the area of substantial corrosion
a) Weather deck, ship side plating above water identified at previous surveys.
line.
3.2.2.5 Examination of Ballast Tank is to be
b) Openings on freeboard and superstructure carried out when required as a consequence of
decks; exposed casings; skylights and the results of the Special Survey or Intermediate
fiddley openings; deck houses; Survey. (See 3.4.5.1 and 3.3.3.3 respectively).
companionways and superstructure When considered necessary by the Surveyor or
bulkheads; side scuttles and dead lights; where extensive corrosion is found, thickness
flush deck scuttles; ash shoots and other measurement is to be carried out. When
openings. examination of ballast tanks reveals substantial
corrosion, additional thickness measurements
c) Weld connection between air pipes and are to be carried out to the extent given in Table
deck plating; air pipe heads on exposed 3.4.9.2a) or Table 3.4.9.2b).
decks (external examination); ventilators
and closing devices. For vessels built under IACS Common
Structural Rules, the identified substantial
d) Watertight bulkheads and their penetrations corrosion areas are required to be examined
as far as practicable. and additional thickness measurements are to
be carried out.
e) Scuppers and sanitary discharges as far as
practicable together with valves and their 3.2.2.6 Anchoring and mooring equipment is to
controls. be examined as far as is practicable. A general
examination of emergency towing arrangements
f) Guard rails, bulwarks, freeing ports, is to be carried out to ensure their ready
gangways, walkways and life lines. availability.
g) Cargo tank openings including gaskets, For vessels with single point mooring
covers, coamings and flame screens. arrangements where 'SPM' notation is assigned,
the following are to be generally examined:
h) Cargo tanks pressure/vacuum valves,
secondary means to prevent over or under a) Components of the single point mooring
pressure and devices to prevent passage of system (bow chain stoppers, bow fairleads,
flame. pedestal roller fairleads, winches and
capstans), to verify their satisfactory
i) Flame screens on vents to all bunker tanks. condition.
j) Examination of cargo, crude oil washing, b) Hull structures supporting and adjacent to
bunker and vent piping systems, including the components of the single point mooring
vent masts and headers. system, to verify that there is no deformation
or fracture.
3.2.2.2 Examination of pump room and pipe
tunnel, if fitted, is to be carried out including: 3.2.2.7 Where applicable Surveyor should
satisfy himself regarding the freeboard marks on
the ship's side.
3.2.3.9 All the means of communication 3.2.3.17 General examination visually and in
between the navigating bridge and the operation, as feasible, of the main electrical
machinery control positions, as well as the machinery, the emergency sources of electrical
bridge and the main alternative steering power, the switch gear, other electrical
position, if fitted, are to be tested. It is to be equipment including the lighting system is to be
confirmed that means of indicating the angular carried out.
position of the rudder are operating
satisfactorily. 3.2.3.18 Confirmation as far as practicable, the
operation of the emergency source(s) of
3.2.3.10 Confirmation that with ships having electrical power, including their starting
emergency steering positions there are means arrangement, the systems supplied, and when
of relaying heading information and, when appropriate, their automatic operation.
appropriate, supplying visual compass readings
to the emergency steering positions. 3.2.3.19 Examining in general, that the
precautions provided against shock, fire and
3.2.3.11 Confirmation that various alarms other hazards of electrical origin are being
required for hydraulic power operated, electric maintained.
and electro-hydraulic steering gears are,
operating satisfactorily and that the recharging 3.2.3.20 General Examination of automation
arrangements for hydraulic power operated equipment is to be carried out. Satisfactory
steering gears are being maintained. operation of safety devices, bilge level detection
and alarm systems and control systems is to be
3.2.3.12 Examining the means for the operation verified.
of the main and auxiliary machinery essential for
propulsion and the safety of the ship, including 3.2.3.21 Confirmation that machinery space
when applicable, the means of remotely ventilation systems are in good working
controlling the propulsion machinery from the condition.
navigating bridge and the arrangements to
operate the main and other machinery from a 3.2.3.22 Examination so far as is possible of
machinery control room. cargo, bilge, ballast and stripping pumps for
excessive gland seal leakage, verification of
3.2.3.13 Confirmation that the engine room proper operation of electrical and mechanical
telegraph, the second means of communication remote operating and shutdown devices and
between the navigation bridge and the operation of pump room bilge system, and
machinery space and the means of checking that pump foundations are intact.
communication with any other positions from
which the engines are controlled are operating 3.2.3.23 Checking the protection of cargo pump
satisfactorily. room and in particular:
3.2.3.14 Confirmation that the engineer's alarm a) Checking temperature sensing devices
is clearly audible in the engineer's accommo- for bulkhead glands and alarms;
dation.
b) Checking interlock between lighting and
3.2.3.15 The bilge pumping systems and bilge ventilation.
wells including operation of each bilge pump,
extended spindles and level alarms, where c) Checking gas detection system.
fitted, are to be examined as far as is
practicable. It is also to be confirmed that bilge d) Checking bilge level monitoring devices
pumping system for each watertight and alarms.
compartment is satisfactory.
3.2.3.24 Verification that installed pressure
It is also to be confirmed that drainage from gauges on cargo discharge lines and level
enclosed cargo spaces situated on freeboard indicating systems are operational.
deck is satisfactory.
3.2.3.25 Examination of emergency lighting in all
3.2.3.16 Examining visually the condition of any cargo pump rooms of tankers constructed after
expansion joints in sea water system. 1 July 2002.
a) verification that fire control plans are m) verification that the deck foam system and
properly posted; deck sprinkler system are in good operating
condition so far as is practicable;
b) examination as far as possible and testing
as feasible of the fire and/or smoke n) verification that all electrical equipment in
detection system(s); dangerous zones is in good condition and
has been properly maintained so far as is
c) examination of the fire main system and practicable;
verification that each fire pump including the
emergency fire pump can be operated o) checking the deck foam system, including
separately so that the two required powerful the supplies of foam concentrate and testing
jets of water can be produced that minimum number of jets of water at the
simultaneously from different hydrants; required pressure in the fire main is
obtained when the system is in operation;
d) verification that fire hoses, nozzles,
applicators and spanners are in good p) examination of the fire-extinguishing
working condition and situated at their systems for spaces containing paint and/or
respective locations; flammable liquids and deep fat cooking
equipment in accommodation and service
e) examination of fixed fire fighting system spaces;
controls, piping, instructions and marking,
checking for evidence of proper q) examination of the fire safety requirements
maintenance and servicing including date of of any helicopter facilities.
last systems tests;
Surveys carried out by the National Authority of
f) verification that all semi-portable and the country in which the ship is registered would
portable fire extinguishers are in their normally be accepted as meeting these
stowed positions, checking for evidence of requirements, at the discretion of the Surveyor.
proper maintenance and servicing,
conducting random check for evidence of 3.2.4.2 For tankers fitted with inert gas system,
discharged containers; examination of the inert gas system as detailed
in Section 12, Para 12.2.1 is to be carried out.
g) verification, as far as practicable, that the
remote controls for stopping fans and 3.2.4.3 Confirmation that the means of escape
machinery and shutting off fuel supplies in from accommodation, machinery spaces and
machinery spaces are in working order; other spaces are satisfactory.
Concurrent crediting to both Intermediate survey and additional thickness measurements are
and Special survey for surveys and thickness to be carried out.
measurements of spaces is not acceptable.
d) A general examination of electrical
3.3.1.2 The following requirements are equipment in dangerous zones and testing
applicable for vessels over five years of age. For of insulation resistance of the circuits. In
vessels below 5 years of age additional cases where a proper record of testing is
examination over and above the requirements of maintained, consideration may be given to
Annual survey may be required at the discretion accepting recent readings. These
of the Surveyors. measurements are not to be attempted until
the ship is in gas free condition and are to
3.3.1.3 For vessels over 10 years of age a be carried out within an acceptable time
specific survey program is to be worked out by period.
the owner in cooperation with the Surveyors
considering the requirements of the previous 3.3.3 Oil tankers between 5 and 10 years of
special survey, executive hull summary of that age
survey, later relevant survey records and taking
account of any amendments to the survey 3.3.3.1
requirements after the last special survey. The
survey program is to be submitted in written a) Single hull oil tankers:
format for approval and kept on board until the
intermediate survey has been completed. (See All ballast tanks are to be examined. When
3.4.2 for guidance on preparation of survey considered necessary by the Surveyor,
program). thickness measurement and testing are to be
carried out to ensure that the structural integrity
3.3.1.4 Prior to the commencement of any part remains effective.
of the intermediate survey, a survey planning
meeting is to be held between the attending b) Double hull oil tankers:
Surveyor(s), the owner’s representative in
attendance and where involved, the thickness For tanks used for water ballast, an Overall
measurement company representative and the Survey of Representative Tanks selected by the
master of ship or an appropriately qualified Surveyor is to be carried out. If such inspections
representative appointed by the master or reveal no visible structural defects, the
Company for the purpose to ascertain that all examination may be limited to a verification that
the arrangements envisaged in the survey the hard Protective Coating remains in GOOD
programme are in place, so as to ensure the condition.
safe and efficient conduct of the survey work to
be carried out. 3.3.3.2 In addition to the requirements above,
suspect areas identified at previous surveys are
3.3.2 Examination and testing to be close-up surveyed.
3.3.2.1 The following are to be carried out: 3.3.3.3 A ballast tank is to be examined at
subsequent annual intervals where:
a) The survey to the extent specified in 3.3.3 to
3.3.5 depending on the age and type of the a) a hard protective coating has not been
tanker. applied from the time of construction, or
b) For weather decks, an examination as far as b) a soft or semi-hard coating has been
applicable of cargo, crude oil washing, applied, or
bunker, ballast, steam and vent piping
systems as well as vent masts and headers. c) substantial corrosion is found within the
If upon examination there is any doubt as to tank, or
the condition of the piping, the piping may
be required to be pressure tested, thickness d) the hard protective coating is found to be in
measured or both. less than GOOD condition and the hard
protective coating is not repaired to the
c) For vessels built under IACS Common satisfaction of the Surveyor.
Structural Rules, the identified substantial
corrosion areas are required to be examined
3.4.1.8 The special survey is to include, in f) Relevant previous survey and inspection
addition to the requirements of the Annual reports of IRS and the Owners;
Survey, examination, tests and checks of
sufficient extent to ensure that the hull, g) Cargo and ballast history for the last 3 years,
equipment and related piping are in satisfactory including carriage of cargo under heated
condition and that the ship is fit for its intended conditions;
purpose for the next five (5) year class period,
subject to proper maintenance and operation h) Details of the inert gas plant and tank
and the periodical surveys being carried out at cleaning procedures;
the due dates.
i) Information and other relevant data regarding
A Docking Survey in accordance with the conversion or modification of the ship’s cargo
requirements of Sec.7 is to be carried out as and ballast tanks since the time of construction.
part of the Special Survey. Any remaining work
in respect of the overall and close-up surveys j) Description and history of the coating and
and thickness measurements and repairs corrosion protection system (including previous
applicable to the lower portions of cargo tanks class notations), if any;
and ballast tanks (i.e. parts below light ballast
water line) are to be completed in the dry-dock. k) Inspections by the Owner’s personnel during
the last 3 years with reference to structural
3.4.2 Planning and preparation for survey deterioration in general, leakages in tank
boundaries and piping and condition of the
3.4.2.1 A specific Survey Programme is to be coating and corrosion protection system if any;
worked out in advance of the Survey by the
Owner in cooperation with the Surveyors and l) Information regarding the relevant
submitted to IRS for approval. The Survey maintenance level during operation including
Programme is to be in a written format based on port state control reports of inspection
IMO Resolution MSC197(80). The survey is not containing hull related deficiencies. Safety
to commence until the survey programme has Management System non-conformities relating
been agreed. Prior to the development of the to hull maintenance, including the associated
survey programme, the survey planning corrective action(s); and
questionnaire based on IMO Resolution
MSC197(80) is to be completed by the owner m) Any other information that will help identify
and forwarded to IRS. The Survey Programme suspect areas and critical structural areas.
at Intermediate Survey may consist of the
Survey Programme at the previous Special 3.4.2.3 The Survey Programme submitted for
Survey supplemented by the Executive Hull approval is to account for and comply, as a
Summary of that Special Survey and later minimum, with the requirements of close-up
relevant survey reports. The survey program is survey, thickness measurement and tank testing
to be worked out taking into account any respectively, and to include relevant information
amendments to the survey requirements after including at least :
the last special survey.
a) Basic ship information and particulars;
3.4.2.2 In developing the Survey Programme,
the following documentation is to be collected b) Main structural plans (scantling drawings),
and consulted with a view to selecting tanks, including information regarding use of high
areas and structural areas for examination : strength steels, clad steel and stainless steel;
b) Documentation on board as per 3.4.3; d) List of tanks with information on use, extent of
coatings and corrosion protection systems;
c) Main structural plans (scantling drawings),
including information regarding use of high e) Conditions for survey (e.g. information like
strength steels, clad steel and stainless steel; tank cleaning, gas freeing, ventilation, lighting,
etc.);
d) Executive Hull Summary;
f) Provisions and methods of access to
e) Relevant previous damage and repair history; structures;
h) Identification of tanks and areas for close-up 3.4.2.4 IRS will advise the Owner of the
survey (As per Table 3.4.8.1a or Table 3.4.8.1b) maximum acceptable structural corrosion
diminution levels applicable to the vessel.
i) Identification of sections for thickness
measurement (As per Table 3.4.9.1) 3.4.2.5 The ship is to be prepared for overall
survey in accordance with the requirements of
j) Identification of tanks for testing Table 3.4.2.5. The preparation is to be of
sufficient extent to facilitate an examination to
k) Identification of the thickness measurement ascertain any excessive corrosion, deformation,
company. fractures, damages and other structural
deterioration.
l) Damage experience related to the ship in
question.
2) The steelwork is to be
exposed and cleaned as may
be required for its proper
examination by the Surveyor
and close attention is to be
paid to the parts of the
structure which are particularly
liable to excessive corrosion or
to deterioration due to other
causes.
3.4.2.6 Proper preparation and the close co- 3.4.3 Documentation on board
operation between the attending surveyor(s) and
the owner’s representatives onboard prior to and 3.4.3.1 The Owners are to obtain supply and
during the survey are an essential part in the maintain on board documentation as specified in
safe and efficient conduct of the survey. During 3.4.3.3, which is to be readily available for the
the survey on board safety meetings are to be Surveyor.
held regularly
3.4.3.2 The documentation is to be kept on
3.4.2.7 Prior to commencement of any part of board for the life time of the ship.
the special survey, a survey planning meeting is
to be held between the attending surveyor(s), 3.4.3.3 A Survey Report File is to be a part of
the owner’s representative in attendance, the the documentation on board consisting of
thickness measurement company representative
and the master of the ship or an appropriately - Reports of structural surveys
qualified representative appointed by the master
or Company for the purpose to ascertain that all - Executive Hull Summary
the arrangements envisaged in the survey
programme are in place, so as to ensure the - Thickness measurement reports.
safe and efficient conduct of the survey work to
be carried out. 3.4.3.4 The Survey Report File is to be available
also in the Owners management offices and
3.4.2.8 The following is an indicative list of items with IRS.
that are to be addressed in the meeting:
3.4.3.5 The following additional supporting
a) Schedule of the vessel (i.e. the voyage, documentation is to be available on board:
docking and undocking manoeuvres,
periods alongside, cargo and ballast - Main structural plans of cargo and ballast
operations, etc.); tanks (for CSR ships these plans are to
include for each structural element both the
b) Provisions and arrangements for thickness as-built and renewal thickness. Any
measurements (i.e. access, cleaning/de- thickness for voluntary addition is also to be
scaling, illumination, ventilation, personal clearly indicated on the plans. The midship
safety); section plan to be supplied on board the
ship is to include the minimum allowable hull
c) Extent of the thickness measurements; girder sectional properties for the tank
transverse section in all cargo tanks)
d) Acceptance criteria (refer to the list of
minimum thicknesses); - Previous repair history
b) a soft or semi-hard coating has been 3.4.6.4 Cargo piping on deck including crude oil
applied, or washing (COW) piping and cargo and ballast
piping systems within the above tanks and
c) substantial corrosion is found within the spaces are to be examined and operationally
tank, or tested to working pressure to attending
Surveyor's satisfaction to ensure that tightness
d) the hard protective coating is found to and condition remain satisfactory. Special
be in less than GOOD condition and the attention is to be given to ballast piping in cargo
hard protective coating is not repaired to tanks and cargo piping in Ballast Tanks and void
the satisfaction of the Surveyor. spaces and Surveyors are to be advised on all
occasions when the piping, including valves and
3.4.5.2 Where the hard protective coating in fittings are open during repair periods and can
tanks is found to be in GOOD condition, the be examined internally.
extent of close-up surveys and thickness
measurements may be specially considered.
Notes:
2) If a selection of tanks is accepted to be examined, then different tanks are to be examined at each
special survey, on a rotational basis.
3) Peak tanks (all uses) are subject to internal examination at each special survey.
4) At special survey No.III and subsequent special surveys, one deep tank for fuel oil is to be included, if
fitted.
3.4.6.7 The masts, standing rigging and anchors - Protection to the aft steering wheel and the
are to be examined. gear.
The Surveyor should satisfy himself that there 3.4.6.11 The chain cables are to be ranged and
are sufficient mooring ropes on board and also the anchors and the chain cables are to be
that a tow line is provided when this is a Rule examined. At special survey no. II and
requirement. subsequent special surveys, the chain cables
are to be gauged. Any length of chain cable
3.4.6.8 The steering gear, and its connections which is found to have reduced in mean
and control systems (main and alternative) are diameter at its most worn part by more than 12
to be examined. The auxiliary steering gear with per cent of its original rule diameter is to be
its various parts are to be examined in working renewed.
condition.
3.4.6.12 The windlass is to be examined.
3.4.6.9 The hand pumps and suctions, air and
sounding pipes are to be examined. The 3.4.6.13 A thorough examination of aft and
Surveyors are to ensure that striking plates are forward emergency towing arrangements is to
fitted under the sounding pipes whilst examining be carried out to ensure its ready availability and
the tanks internally. satisfactory condition.
Automatic air pipe heads are to be internally - examination of pick-up gear, towing pennant
examined at special surveys as indicated in and chafing gear for possible deterioration;
Table 3.4.6.10. For designs where the inner
parts cannot be properly inspected from outside, - examination of strong points, fairleads,
the head is to be removed from the air pipe. pedestal roller and their attachment to hull
Particular attention is to be paid to the condition structure.
of the zinc coating in heads constructed from
galvanised steel. The survey is to confirm that one of the towing
arrangements (aft or forward) are pre-rigged.
3.4.6.10 The Surveyor should satisfy himself
regarding the efficient condition of the following :
Table 3.4.6.10 : Requirements for internal examination of automatic air pipe heads
3.4.6.14 For vessels with single point mooring 3.4.6.18 Where fitted, the strums of the cargo
arrangements where 'SPM' notation is assigned, suction pipes are to be removed or lifted to
the following is to be carried out: facilitate examination of the shell plating and
bulkheads in the vicinity, unless other means for
a) A thorough examination of the components visual inspection of these parts are provided.
of the single point mooring system (bow
chain stoppers, bow fairleads, pedestal 3.4.6.19 The loading instrument is to be
roller fairleads, winches and capstans) to checked for accuracy by applying test load
verify their satisfactory condition. conditions in presence of the Surveyor.
b) A close-up examination of the hull structures
supporting and adjacent to the components 3.4.6.20 Examination of accommodation
of the single point mooring system to verify ladders, gangways and their winches are to be
that there is no deformation or fracture. carried out as required for annual surveys. In
Thickness determination and non- addition, the accommodation ladders and
destructive tests are to be carried out if gangways are to be operationally, tested with
required by the Surveyor. the specified maximum operation load.
3.4.6.15 The chain locker, hold fasts, hawse The tests are to be carried out with the load
pipes and chain stoppers are to be examined applied as uniformly as possible along the
and pumping arrangements of the chain locker length of the accommodation ladder or
tested. gangway, at an angle of inclination
corresponding to the maximum bending moment
3.4.6.16 Engine room structure is to be on the accommodation ladder or gangway.
examined. Particular attention being given to
tank tops, shell plating in way of tank tops, Accommodation ladder winch is to be
brackets connecting side shell frames and tank operationally tested at special surveys. The
tops and engine room bulkheads in way of tank brake system of the winch is to be tested for
tops and bilge wells. Where excessive areas of holding the maximum operational load on the
wastage are found, thickness measurements ladder.
are to be carried out and renewals of repairs
made when wastage exceeds allowable limits. For existing installations on board ships
constructed prior to 01 Jan 2010 where the
3.4.6.17 The attachment to the structure and maximum operational load is not known, load
condition of anodes in tanks is to be examined. nominated by the shipowner or operator may be
considered as the test load.
Table 3.4.7.1 : Table of minimum requirements for tank testing at special survey of oil tankers,
ore/oil ships and ore/bulk/oil ships (including double hull oil tankers)
2 Cargo tank boundaries facing ballast tanks, void 2 All Cargo tank bulkheads
spaces, pipe tunnels, pump rooms or cofferdams
3.4.7.4 Boundaries of fuel oil, lub.oil and fresh 3.4.8.2 The Surveyor may extend the Close-up
water tanks are to be tested with a head of liquid Survey as deemed necessary taking into
to the highest point that liquid will rise under account the maintenance of the tanks under
service conditions. Tank testing of fuel oil, lub.oil survey, the condition of the corrosion prevention
and fresh water tanks may be specially system and also in the following cases:
considered based on a satisfactory external
examination of the tank boundaries and a a) In particular, tanks having structural
confirmation from the Master stating that the arrangements or details which have
pressure testing has been carried out according suffered defects on similar tanks or on
to the requirement with satisfactory results similar ships according to available
information.
3.4.7.5 For double hull oil tankers the testing of b) In tanks which have structures approved
double bottom tanks and other spaces not with reduced scantlings due to an approved
designed for the carriage of liquid may be corrosion control system.
omitted, provided a satisfactory internal
examination together with an examination of the 3.4.8.3 For areas in tanks where coatings are
tank top is carried out. found to be in a GOOD condition, the extent of
Close-up Surveys according to Tables 3.4.8.1a
3.4.8 Close-up survey requirements and Table 3.4.8.1b may be specially considered
by the Surveyor.
3.4.8.1 The minimum requirements for Close-up
Surveys at Special Survey are given in Table
3.4.8.1a and Table 3.4.8.1b as applicable.
Table 3.4.8.1a : Minimum requirements to close-up surveys at special survey of oil tankers,
ore/oil ships, ore/bulk/oil ships other than double hull oil tankers
Special Survey
Special Survey No. I Special Survey No. II Special Survey No. III No. IV and
Age ≤ 5 5 < Age ≤ 10 10 < Age ≤ 15 subsequently
Age ≥ 15
A) One Web Frame Ring A) All Web Frame Rings - in a A) All Web Frame Rings - As Special Survey
- in a ballast wing tank, if ballast wing tank, if any, or a in all ballast tanks No.3
any, or a cargo wing tank cargo wing tank, used primarily
used primarily for water for water ballast
ballast
B) One Deck Trans- B) One Deck Transverse - in A) All Web Frame Rings - Additional
verse - in a cargo oil tank each of the remaining ballast in a cargo wing tank transverses as
tanks, if any deemed necessary
by the Surveyor
D) One Transverse B) One Deck Transverse - in a A). A minimum of 30% of
1)
Bulkhead - in a ballast cargo wing tank web frame rings in each
tank remaining cargo wing tank
A) Complete transverse web frame B) Deck transverse including C) Transverse bulkhead complete -
ring including adjacent structural adjacent deck structural members including girder system and adjacent
members members
D) Transverse bulkhead lower part E) Deck and bottom transverse F) Additional complete transverse
- including girder system and including adjacent structural web frame ring
adjacent structural members members
(1) : Web frame in a ballast tank means vertical web in side tank, hopper web in hopper tank, floor in double bottom
tank and deck transverse in double deck tank (where fitted), including adjacent structural members. In fore and aft
peak tanks web frame means a complete transverse web frame ring including adjacent structural members.
(2) : Deck transverse, including adjacent deck structural members (or external structure on deck in way of the tank,
where applicable).
(3) : Transverse bulkhead complete in cargo tanks, including girder system, adjacent structural members (such as
longitudinal bulkheads) and internal structure of lower and upper stools, where fitted.
(4) : Transverse bulkhead complete in ballast tanks, including girder system and adjacent structural members, such
as longitudinal bulkheads, girders in double bottom tanks, inner bottom plating, hopper side, connecting brackets.
(5) : Transverse bulkhead lower part in cargo tank, including girder system, adjacent structural members (such as
longitudinal bulkheads) and internal structure of lower stool, where fitted.
(6) : The knuckle area and the upper part (5 metres approximately), including adjacent structural members. Knuckle
area is the area of the web frame around the connections of the slope hopper plating to the inner hull bulkhead and
the inner bottom plating, upto 2 metres from the corners both on the bulkhead and the double bottom.
(7) : Web frame in a cargo oil tank means deck transverse, longitudinal bulkhead vertical girder and cross ties,
where fitted, including adjacent structural members.
Note 1 : Complete ballast tank : means double bottom tank plus double side tank plus double deck tank, as
applicable, even if these tanks are separate.
Note 2 : Where no centre cargo tanks are fitted (as in the case of centre longitudinal bulkhead), transverse
bulkheads in wing tanks are to be surveyed.
2) Within the cargo area: 2) Within the cargo area: 2) Within the cargo area: 2) Within the cargo area:
One section of deck a) Each deck plate a) Each deck plate a) Each deck plate
plating for the full beam of b) One Transverse b) Two Transverse b) Three Transverse
the ship (in way of a section sections sections
ballast tank, if any, or a c) All wind and water c) All wind and water
cargo tank used primarily strakes strakes
for water ballast) d) Each bottom plate
7) Representative expo-
sed superstructure deck
plating (poop, bridge,
forecastle deck)
3.4.10 Reporting and evaluation of survey 3.4.10.3 Where any structural renewal or
reinforcement work is carried out as a result of
3.4.10.1 The data and information on the the initial evaluation of the ship's longitudinal
structural condition of the vessel collected strength as required by 3.4.10.2, the final result
during the survey is to be evaluated for of the evaluations is to be included as a part of
acceptability and continued structural integrity of the Executive hull summary.
the vessel.
3.4.10.4 An Executive Hull Summary of the
3.4.10.2 In case of oil tankers of 130 [m] in survey and results is to be issued to the Owner
length and upwards (as defined in ILLC), the and placed on board the vessel for reference at
ship's longitudinal strength is to be evaluated future surveys. The Executive Hull Summary is
using the thickness of the structural members to be endorsed by IRS Head Office.
measured, renewed, reinforced, as appropriate,
during the renewal survey of cargo ship safety 3.5 Special Surveys - Machinery
construction certificate or the cargo ship safety
certificate carried out after the ship reached 10 3.5.1 Requirements for examination of
years of age in accordance with the criteria for machinery and systems are given in Sec.8.
longitudinal strength of the ship's hull girder
Section 4
For vessels which also carry products covered 4.2.1.3 Access to cargo tanks or other spaces
by the IGC Code it may be necessary in within the cargo area, necessitating gas freeing
accordance with Pt.5, Ch.4, Sec.1 to apply the will normally not be required unless necessary
survey requirements given in Sec.5 of this for checking items of equipment and
chapter. installations for correct functioning.
4.2.2 Hull and weather deck a) Examination of all pump room bulkheads for
signs of chemical leakage or fractures and
4.2.2.1 The survey is to consist of an in particular, the sealing arrangements of all
examination for the purpose of ensuring, as far penetrations of pump room bulkheads.
as practicable, that the hull, equipment, closing
appliances and related piping are maintained in b) Examination of the condition of all piping
satisfactory and efficient condition. Special systems.
attention is to be paid to the following:
4.2.2.3 All watertight doors in watertight
a) Weather decks, ships side plating above bulkheads, to be examined and tested (locally
waterline. and remotely) as far as practicable.
k) Verification that wheelhouse doors and 4.2.2.7 Where applicable, Surveyor should
windows, side scuttles and windows in satisfy himself regarding the freeboard marks on
superstructure and deckhouse ends facing the ship's side.
the cargo area are in good condition.
4.2.2.8 The Surveyor is to confirm that, where
4.2.2.2 Examination of pump room and pipe required, an approved loading instrument
tunnel, if fitted: together with its operation manual are available
on board, See Pt.3, Ch.5. It is to be verified by
the Surveyor that the loading instrument is
checked for accuracy at regular intervals by the dedicated ballast tanks, as appropriate, are
ship's staff by applying test loading conditions. recorded in the coating technical file.
position of the rudder are operating 4.2.3.18 Confirmation as far as practicable, the
satisfactorily. operation of the emergency source(s) of
electrical power, including their starting
4.2.3.10 Confirmation that with ships having arrangement, the systems supplied, and when
emergency steering positions there are means appropriate, their automatic operation.
of relaying heading information and, when
appropriate, supplying visual compass readings 4.2.3.19 Examining in general, that the
to the emergency steering positions. precautions provided against shock, fire and
other hazards of electrical origin are being
4.2.3.11 Confirmation that various alarms maintained.
required for hydraulic power operated, electric
and electro-hydraulic steering gears are, 4.2.3.20 General Examination of automation
operating satisfactorily and that the recharging equipment is to be carried out. Satisfactory
arrangements for hydraulic power operated operation of safety devices, bilge level detection
steering gears are being maintained. and alarm systems and control systems is to be
verified.
4.2.3.12 Examining the means for the operation
of the main and auxiliary machinery essential for 4.2.3.21 Examination so far as is possible of
propulsion and the safety of the ship, including cargo, bilge, ballast and stripping pumps for
when applicable, the means of remotely excessive gland seal leakage, verification of
controlling the propulsion machinery from the proper operation of electrical and mechanical
navigating bridge and the arrangements to remote operating and shutdown devices and
operate the main and other machinery from a remote operation of pump room bilge system,
machinery control room. and checking that pump foundations are intact.
4.2.3.13 Confirmation that the engine room 4.2.3.22 Verification that installed pressure
telegraph, the second means of communication gauges on cargo discharge lines including those
between the navigation bridge and the fitted outside the cargo pump room and level
machinery space and the means of indicating systems are operational.
communication with any other positions from
which the engines are controlled are operating 4.2.3.23 Verification that pumps, valves and
satisfactorily. pipelines are identified and distinctively marked.
4.2.3.14 Confirmation that the engineer's alarm 4.2.3.24 Confirmation that machinery space
is clearly audible in the engineer's acco- ventilation systems are in good working
mmodation. condition.
4.2.3.15 The bilge pumping systems and bilge 4.2.4 Fire protection, detection and
wells including operation of each bilge pump, extinction
extended spindles and level alarms, where
fitted, are to be examined as far as is 4.2.4.1 The arrangements for fire protection,
practicable. It is also to be confirmed that bilge detection and extinction are to be examined and
pumping system for each watertight are to include confirmation that no changes
compartment is satisfactory. have been made in the structural fire protection.
Following are to be examined / verified:
It is also to be confirmed that drainage from
enclosed cargo spaces situated on freeboard a) verification that fire control plans are
deck is satisfactory. properly posted;
4.2.3.16 Examining visually the condition of any b) examination as far as possible and testing
expansion joints in sea water system. as feasible of the fire and/or smoke
detection system(s);
4.2.3.17 General examination visually and in
operation, as feasible, of the main electrical c) examination of the fire main system and
machinery, the emergency sources of electrical verification that each fire pump including the
power, the switch gear, other electrical emergency fire pump can be operated
equipment including the lighting system is to be separately so that the two required powerful
carried out. jets of water can be produced
simultaneously from different hydrants;
d) verification that fire hoses, nozzles, that their means of operation are clearly
applicators and spanners are in good marked;
working condition and situated at their
respective locations; p) Confirming that potential sources of ignition
in or near the cargo pump room are
e) examination of fixed fire fighting system eliminated, such as loose gear, combustible
controls, piping, instructions and marking, materials etc., that there are no signs of
checking for evidence of proper undue leakage and that access ladders are
maintenance and servicing including date of in satisfactory condition;
last systems tests;
q) Confirming that the condition of portable fire
f) verification that all semi-portable and fighting equipment for the cargoes to be
portable fire extinguishers are in their carried in the cargo area is satisfactory;
stowed positions, checking for evidence of
proper maintenance and servicing, r) examination of the fire-extinguishing
conducting random check for evidence of systems for spaces containing paint and/or
discharged containers; flammable liquids and deep fat cooking
equipment in accommodation and service
g) verification, as far as practicable, that the spaces;
remote controls for stopping fans and
machinery and shutting off fuel supplies in s) examination of the fire safety requirements
machinery spaces are in working order; of any helicopter facilities;
4.4.2 for guidance on preparation of survey cargo holds, cofferdams, pipe tunnels, void
program). spaces within the cargo area and all ballast
tanks. However, testing of cargo and ballast
4.3.1.4 Prior to the commencement of any part tanks and survey of automatic air pipe heads
of the intermediate survey, a survey planning specified in 4.4.6.2 are not required unless
meeting is to be held between the attending deemed necessary by the attending surveyor.
Surveyor(s), the owner’s representative in Thickness measurement is to be carried out for
attendance and where involved, the thickness items 1) to 4) of Table 4.4.9.1.
measurement company representative and the
master of ship or an appropriately qualified 4.3.4.2 The intermediate survey may be
representative appointed by the master or commenced at the second annual survey and
Company for the purpose to ascertain that all be progressed during the succeeding year with
the arrangements envisaged in the survey a view to completion at the third annual survey
programme are in place, so as to ensure the in lieu of the application of 4.4.1.4.
safe and efficient conduct of the survey work to
be carried out. 4.3.4.3 An in-water survey complying with the
requirements of Sec.7.2 may be accepted in lieu
4.3.2 Examination tanks and spaces of the requirements of 4.4.1.10.
4.3.2.1 The survey of integral cargo tanks and 4.3.5 Chemical tankers exceeding 15 years of
ballast tanks depending on the age of the vessel age the following is to apply:
is to be carried out as specified in 4.3.3 to 4.3.5.
4.3.5.1 The requirements of the intermediate
4.3.3 Chemical tankers between 5 and 10 survey are to be to the same extent as the
years of age previous special survey as required in 4.4 for
hull structure and piping systems in way of
4.3.3.1 The following are to be carried out: cargo holds, cofferdams, pipe tunnels, void
spaces within the cargo area and all ballast
For ballast tanks, an Overall Survey of tanks. However, testing of cargo and ballast
Representative Tanks selected by the Surveyor tanks is not required unless deemed necessary
is to be carried out. If such inspections reveal no by the attending surveyor. Thickness
visible structural defects, the examination may measurement is to be carried out for items 1) to
be limited to a verification that the hard 4) of Table 4.4.9.1.
Protective Coating remains in GOOD condition.
4.3.5.2 For the application of 4.3.5.1 the
4.3.3.2 In addition to the requirements above, intermediate survey may be commenced at the
suspect areas identified at previous surveys are second annual survey and be progressed during
to be examined. the succeeding year with a view to completion at
the third annual survey in lieu of the application
4.3.3.3 A ballast tank is to be examined at of 4.4.1.4.
subsequent annual intervals where:
4.3.5.3 A survey in dry dock is to be part of the
a) a hard protective coating has not been intermediate survey. Any remaining work in
applied from the time of construction, or respect of the overall and close-up surveys and
b) a soft or semi-hard coating has been thickness measurements and repairs applicable
applied, or to the lower portions of cargo tanks and water
c) substantial corrosion is found within the ballast tanks (i.e. parts below light ballast
tank, or waterline) are to be completed in the dry-dock.
d) the hard protective coating is found to be in
less than GOOD condition and the hard 4.3.6 Safety arrangements related to cargo
protective coating is not repaired to the
satisfaction of the Surveyor. 4.3.6.1 The following are to be dealt with as
applicable:
4.3.4 Chemical tankers between 10 and 15
years of age a) Examination of vent line drainage
arrangements.
4.3.4.1 The requirements of the intermediate
survey are to be to the same extent as the b) Verification that the cargo heating/cooling
previous special survey as required in 4.4 for system is in good condition.
hull structure and piping systems in way of
f) A General Examination of the electrical r) Verifying from the Cargo Record Book that
equipment and cables in dangerous zones the pumping and stripping arrangements
such as cargo pump-rooms, and areas have been emptying the tanks efficiently
adjacent to cargo tanks for defective and all are in working order.
certified safe type equipment, improperly
installed wiring, non-approved lighting and s) Confirming, if possible, that the discharge
fixtures and dead end wiring. Testing outlets are in good condition.
insulation resistance of the circuits except
in cases where a proper record of the t) Confirming the satisfactory operation of the
testing is maintained, consideration is to be recording device, as fitted and verifying by
given to accepting recent readings by the an actual flow test that it has an accuracy
crew. If any of the readings are marginal or of ± 15% or better.
if the condition of the cables, fixtures or
equipments appears defective in any way, Surveys carried out by the National Authority of
verification measurements may be the country in which the ship is registered may
required. These measurements are not to be accepted at the discretion of the Surveyor as
be attempted until the ship is in a gas free meeting these additional requirements.
condition and are to be carried out within
an acceptable time period. 4.4 Special Surveys - Hull
date of the Special Survey, the period of class 4.4.2 Planning and preparation for survey
will start from the survey completion date.
4.4.2.1 A specific Survey Programme is to be
4.4.1.4 The Special Survey may be commenced worked out in advance of the Survey by the
at the 4th Annual Survey and be progressed Owner in cooperation with the Surveyors and
with a view to completion by the 5th anniversary submitted to IRS for approval. The Survey
date. When the special survey is commenced Programme shall be in a written format prior to
prior to the fourth annual survey, the entire the development of survey programme, the
survey is to be completed within 15 months if survey planning questionnaire in prescribed
such work is to be credited to the special survey format is to be completed by the owner and
and in this case the next period of class will start forwarded to IRS. The survey program is to be
from the survey completion date. worked out taking into account any amendments
to the survey requirements after the last special
Concurrent crediting to both Intermediate survey survey.
and Special survey for surveys and thickness
measurements of spaces is not acceptable. 4.4.2.2 In developing the Survey Programme,
the following documentation is to be collected
4.4.1.5 As part of the preparation for Special and consulted with a view to selecting tanks,
Survey, the proposed Survey Programme (See areas and structural areas for examination :
4.4.2) including the schedule for thickness
measurements (See 4.4.9) are to be submitted a) Survey status and basic ship information
at least 3 months in advance of the intended
commencement of the Special Survey. b) Documentation on board as per 4.4.3
4.4.1.6 Record of Special Survey will not be c) Main structural plans (scantling drawings),
assigned until the Machinery Survey has been including information regarding use of high
completed or postponed in agreement with IRS. strength steels, clad steel and stainless
steel
4.4.1.7 Ships which have satisfactorily passed a
Special Survey will have a record entered in the d) Executive hull summary
Supplement to the Register Book indicating the
assigned date of Special Survey. In addition a e) Relevant previous damage and repair
notation "ESP" will be entered for chemical history
tankers.
f) Relevant previous survey and inspection
4.4.1.8 The special survey is to include, in reports of IRS and the Owners
addition to the requirements of the Annual
Survey, examination, tests and checks of g) Information regarding the use of the ship's
sufficient extent to ensure that the hull, holds and tanks, typical cargoes and other
equipment and related piping are in satisfactory relevant data
condition and that the ship is fit for its intended
purpose for the next five (5) year class period, h) Details of the inert gas plant and tank
subject to proper maintenance and operation cleaning procedures
and the periodical surveys being carried out at
the due dates. i) Information and other relevant data
regarding conversion or modification of the
4.4.1.9 The special survey requirements to be ship’s cargo and ballast tanks since the time
applied in respect of independent cargo tanks of construction
are given in 4.4.11.
j) Description and history of the coating and
4.4.1.10 A Docking Survey in accordance with corrosion protection system (previous class
the requirements of Sec.7 is to be carried out as notations), if any
part of the Special Survey. Any remaining work
in respect of the overall and close-up surveys k) Inspections by the Owner’s personnel
and thickness measurements and repairs during the last 3 years with reference to
applicable to the lower portions of cargo tanks structural deterioration in general, leakages
and water ballast tanks (i.e. parts below light in tank boundaries and piping and condition
ballast water line) are to be completed in the of the coating and corrosion protection
dry-dock. system, if any
Special Survey No. I Special Survey No. II Special Survey No. Special Survey No. IV
Age ≤ 5 5 < Age ≤ 10 III and subsequently
10 < Age ≤ 15 Age ≥ 15
1) All tanks, peaks, bilges and 1) Requirements of 1) Requirements of 1) Requirements of
drain wells, engine and boiler Special Survey I to be Special Survey II to be Special survey III to be
spaces and other spaces are complied with complied with complied with
to be cleared out and cleaned
as necessary for examination. 2) The chain locker is to 2) Portions of wood
Floor plates in engine and be cleaned internally. sheathing, or other
boiler spaces are to be lifted The chain cables are to covering, on steel
as may be necessary for be ranged for inspection. decks are to be
examination of the structure The anchors are to be removed, as
underneath. Where necessary cleaned and placed in an considered necessary
ceiling, lining, casings and accessible position for by the Surveyor, in
loose insulation are to be inspection. order to ascertain the
removed as required by the condition of the plating.
Surveyor for examination of
the structure. Compositions on
the plating are to be examined
and sounded, but need not be
disturbed if found satisfactorily
adhering to the plating
2) The steelwork is to be
exposed and cleaned as may
be required for its proper
examination by the Surveyor
and close attention is to be
paid to the parts of the
structure which are particularly
liable to excessive corrosion or
to deterioration due to other
causes.
4.4.3.1 The Owners are to obtain supply and 4.4.4.1 See Sec.1.8.
maintain on board documentation as specified in
4.4.3.3, which is to be readily available for the 4.4.5 Space protection
Surveyor.
4.4.5.1 Where provided, the condition of the
4.4.3.2 The documentation is to be kept on corrosion prevention system of cargo tanks is to
board for the life time of the ship. be examined.
- Main structural plans of cargo holds, cargo 4.4.5.2 Where the hard protective coating in
and ballast tanks cargo tanks is found to be in GOOD condition,
- Previous repair history the extent of close-up surveys and thickness
- Cargo and ballast history measurements may be specially considered.
- Extent of use of inert gas plant and tank
cleaning procedures 4.4.6 Survey and examination
- Inspection by ship's personnel with
reference to 4.4.6.1 All spaces within the hull and
superstructure are to be examined.
- structural deterioration in general
4.4.6.2 All tanks other than cargo and ballast
- leakages in bulkheads and piping tanks are to be examined internally in
accordance with the requirements of Table
- condition of coating or corrosion 4.4.6.2.
prevention systems, if any
4.4.6.3 An overall survey of all cargo tanks,
- Any other information that will help identify ballast tanks including double bottom tanks, pipe
critical structural areas or Suspect Areas tunnels, cofferdams and void spaces bounding
requiring inspection cargo tanks, decks and outer hull is to be carried
out. This examination is to be supplemented by
- Survey Programme as required by 4.4.2 thickness measurement and testing as required
until such time as the Special Survey has by 4.4.9 and 4.4.7 to ensure that the structural
been completed. integrity remains effective. The aim of the
examination is to discover Substantial
4.4.3.6 Prior to survey, the Surveyor is to Corrosion, significant deformation, fractures,
examine the completeness of the documentation damages or other structural deterioration and if
on board, and its contents as a basis for the deemed necessary by the Surveyor, a suitable
survey. non-destructive examination may be required.
Notes:
4.4.6.4 Cargo piping on deck and cargo and 4.4.6.8 The steering gear, and its connections
ballast piping systems within the above tanks and control systems (main and alternative) are
and spaces are to be examined and to be examined. The auxiliary steering gear with
operationally tested to working pressure to its various parts are to be examined in working
attending Surveyor's satisfaction to ensure that condition.
tightness and condition remain satisfactory.
Special attention is to be given to ballast piping 4.4.6.9 The hand pumps and suctions, air and
in cargo tanks and cargo piping in Ballast Tanks sounding pipes are to be examined. The
and void spaces and Surveyors are to be Surveyors are to ensure that striking plates are
advised on all occasions when this piping, fitted under the sounding pipes whilst examining
including valves and fittings are open during the tanks internally.
repair periods and can be examined internally.
Automatic air pipe heads are to be internally
4.4.6.5 Where ballast tanks have been examined at special surveys as indicated in
converted to void spaces, the survey extent is to Table 4.4.6.9. For designs where the inner parts
be based upon ballast tank requirements. cannot be properly inspected from outside, the
head is to be removed from the air pipe.
4.4.6.6 All watertight bulkheads and watertight Particular attention is to be paid to the condition
doors are to be examined. All decks, casings of the zinc coating in heads constructed from
and superstructures are to be examined. galvanised steel.
Attention is to be given to the corners of
openings and other discontinuities in way of the 4.4.6.10 The Surveyor should satisfy himself
strength decks and top sides. regarding the efficient condition of the following :
4.4.6.7 The masts, standing rigging and anchors - Means of escape from machinery spaces,
are to be examined. crew and passenger spaces and spaces in
which crew are normally employed;
The Surveyor should satisfy himself that there - Means of communication between bridge
are sufficient mooring ropes on board and also and engine room and between bridge and
that a tow line is provided when this is a Rule alternative steering position;
requirement. - Helm indicator;
- Protection to the aft steering wheel and the
gear.
Table 4.4.6.9 : Requirements for internal examination of automatic air pipe heads
Location Special survey No.I Special survey No.II Special survey No.III
Age ≤ 5 5 < Age ≤ 10 and subsequent
Age > 10
1,2
forward Two air pipe heads one All air pipe heads on
0.25L port and one starboard on exposed decks
3
exposed decks All air pipe heads on
1,2
aft of 0.25L Two air pipe heads one At least 20% of air pipe exposed decks
1,2
from the port and one starboard on heads on exposed decks
forward exposed decks
perpendicular
Table 4.4.6.9 (Contd.)
Notes:
4.4.6.11 The chain cables are to be ranged and 4.4.6.15 For vessels with single point mooring
the anchors and the chain cables are to be arrangements where 'SPM' notation is assigned,
examined. At special survey no. II and the following is to be carried out:
subsequent special surveys, the chain cables
are to be gauged. Any length of chain cable a) A thorough examination of the components
which is found to have reduced in mean of the single point mooring system (bow
diameter at its most worn part by more than 12 chain stoppers, bow fairleads, pedestal
per cent of its original rule diameter is to be roller fairleads, winches and capstans) to
renewed. verify their satisfactory condition.
B) One Deck B) One Deck Transverse A) All Web Frames Rings Additional transverse
Transverse - in a cargo - in each of the remaining - in a cargo wing tank areas as deemed
tank or on deck ballast tank or on deck necessary by the Surveyor
D) One Transverse
Bulkhead – lower part in
each remaining ballast
tank
D) One Transverse
Bulkhead - lower part in a
cargo wing tank
D) One Transverse
Bulkhead - lower part in
two cargo centre tanks
(See Note 1)
Note 1) Where no center cargo tanks are fitted (as in the case of center longitudinal bulkhead), transverse
bulkheads in wing tanks are to be surveyed.
A-D are areas subjected to close-up surveys and thickness measurements (See Fig.4.4.8.1 to 4.4.8.3)
5) One Transverse
Bulkhead – in two cargo
centre tanks (See Note II)
5) One Transverse
Bulkhead – in cargo wing
tank
(1), (2), (3), (4), (5), (6) and (7) are areas to be subjected to close-up surveys and thickness measurements (See
Figs. 4.4.8.1 to 4.4.8.3).
(1) Web frame in a ballast tank means vertical web in side tank, hopper web in hopper tank, floor in double
bottom tank and deck transverse in double deck tank (where fitted), including adjacent structural members.
In fore and aft peak tanks web frame means a complete transverse web frame ring including adjacent
structural members.
(2) Deck transverse, including adjacent deck structural members (or external structure on deck in way of the
tank, where applicable).
(3) Transverse bulkhead complete in cargo tanks, including girder system, adjacent structural members (such
as longitudinal bulkheads) and internal structure of lower and upper stools, where fitted.
(4) Transverse bulkhead complete in ballast tanks, including girder system and adjacent structural members,
such as longitudinal bulkheads, girders in double bottom tanks, inner bottom plating, hopper side,
connecting brackets.
(5) Transverse bulkhead lower part in cargo tank, including girder system, adjacent structural members (such
as longitudinal bulkheads) and internal structure of lower stool, where fitted.
(6) The knuckle area and the upper part (3 metres approximately), including adjacent structural members.
Knuckle area is the area of the web frame around the connections of the slope hopper plating to the inner
hull bulkhead and the inner bottom plating, upto 2 metres from the corners both on the bulkhead and the
double bottom.
(7) Web frame in a cargo tank means deck transverse, longitudinal bulkhead vertical girder and cross ties,
where fitted, including adjacent structural members.
Note I : Ballast double hull tank : means double bottom tank plus double side tank plus double deck tank, as
applicable, even if these tanks are separate.
Note II : Where no center cargo tanks are fitted (as in the case of center longitudinal bulkhead), transverse
bulkheads in wing tanks are to be surveyed.
C, (3)
D, (5)
(4)
(6)
(7)
(6)
2) Within the cargo area : 2) Within the cargo area: 2) Within the cargo 2) Within the cargo area:
One section of deck area:
plating for the full beam of a) Each deck plate a) Each deck plate
the ship (in way of a b) One Transverse section a) Each deck plate b) Three Transverse
(1)
ballast tank, if any, or a b)Two Transverse sections
(1)
cargo tank used primarily sections c) All wind and water strakes
for water ballast) c) All wind and water d) Each bottom plate
strakes
7) Representative exposed
superstructure deck plating
(poop, bridge, forecastle
deck)
(1) At least one section is to include a ballast tank within 0.5L amidships
Table 4.4.9.2 : Requirements for extent of thickness measurements at those areas of substantial
corrosion, special survey of chemical tankers within the cargo area length
Structural member Extent of measurement Pattern of measurement
Bottom, inner bottom and hopper structure
Bottom, inner bottom and Minimum of three bays across 5-point pattern for each panel
hopper structure plating tank, including aft bay between longitudinals and floors
Measurements around and under
all suction bell mouths
Bottom, inner bottom and Minimum of three longitudinals in Three measurements in line
hopper structure longitudinals each bay where bottom plating across the flange and three
measured measurements on vertical web
Bottom girders, including the At fore and aft watertight floors Vertical line of single
watertight ones and in center of tanks measurements on girder plating
with one measurement between
each panel stiffener, or a
minimum of three
measurements.
Two measurements across face
flat where fitted
Bottom floors, including the Three floors in bays where 5-point pattern over two square
watertight ones bottom plating measured, with metre area
measurements at both ends and
middle
4.4.10.1 For chemical tankers exceeding 10 4.4.12.1 The data and information on the
years of age selected steel cargo pipes outside structural condition of the vessel collected
cargo tanks and ballast pipes passing through during the survey is to be evaluated for
cargo tanks are to be: acceptability and continued structural integrity of
the vessel.
Section 5
5.2.2 Hull and weather deck i) Confirming that any special arrangements to
survive conditions of damage are in order.
5.2.2.1 The survey is to consist of an
examination for the purpose of ensuring, as far 5.2.2.2 Examining the cargo compressor rooms
as practicable, that the hull, equipment, closing and electrical motor rooms.
appliances and related piping are maintained in
satisfactory/efficient condition. Special attention Examination of the electric motor room and
is to be paid to the following: compressor room bulkheads for signs of
leakage or fractures and in particular, the
a) Weather deck, shipside plating above sealing arrangements of all penetrations on
waterline. bulkheads.
5.2.2.8 Where applicable Surveyor should 5.2.2.15 When examining internal spaces, as far
satisfy himself regarding the freeboard marks on as practicable, the permanent means of access
the ship's side. where appropriate, are to be verified that they
remain in good condition.
5.2.2.9 The Surveyor is to confirm that, where
required, an approved loading instrument 5.2.2.16 For vessels subject to IMO PSPC (See
together with its operation manual are available Pt.3, Ch.2, 3.6) it is to be confirmed that the
on board, See Pt.3, Ch.5. It is to be verified by maintenance, repair and partial re-coating of
the Surveyor that the loading instrument is dedicated ballast tanks, as appropriate, are
checked for accuracy at regular intervals by the recorded in the coating technical file.
ship's staff by applying test loading conditions.
5.2.3 Machinery and systems
5.2.2.10 Accommodation ladders are to be
examined at annual surveys. Satisfactory 5.2.3.1 A general examination of the machinery,
condition of the following items is to be checked, boilers, all pressurised systems (steam,
in particular : hydraulic, pneumatic) and their associated
5.2.3.5 Confirmation that means are provided so 5.2.3.14 The bilge pumping systems and bilge
that machinery can be brought into operation wells including operation of each bilge pump,
from the dead ship condition without external extended spindles and level alarms, where
aid. fitted, are to be examined as far as is
practicable. It is also to be confirmed that bilge
5.2.3.6 All main and auxiliary steering pumping system for each watertight
arrangements and their associated equipment compartment is satisfactory.
and control systems are to be examined and
tested. Where applicable, Surveyors are to It is also to be confirmed that drainage from
verify that log entries have been made in enclosed spaces in cargo areas situated on
accordance with statutory requirements. freeboard deck is satisfactory.
5.2.3.7 Confirming, when appropriate, that 5.2.3.15 Examining visually the condition of any
requisite arrangements to regain steering expansion joints in sea water system.
capability in the event of the prescribed single
failure are being maintained. 5.2.3.16 General examination visually and in
operation, as feasible, of the main electrical
5.2.3.8 All the means of communication machinery, the emergency sources of electrical
between the navigating bridge and the power, the switch gear, other electrical
machinery control positions, as well as the equipment including the lighting system is to be
bridge and the main alternative steering carried out.
position, if fitted, are to be tested. It is to be
confirmed that means of indicating the angular 5.2.3.17 Confirmation as far as practicable, the
position of the rudder are operating operation of the emergency source(s) of
satisfactorily. electrical power, including their starting
arrangement, the systems supplied, and when
5.2.3.9 Confirmation that with ships having appropriate, their automatic operation.
emergency steering positions there are means
of relaying heading information and, when 5.2.3.18 Examining in general, that the
appropriate, supplying visual compass readings precautions provided against shock, fire and
to the emergency steering positions. other hazards of electrical origin are being
maintained.
5.2.3.10 Confirmation that various alarms
required for hydraulic power operated, electric 5.2.3.19 General Examination of automation
and electro-hydraulic steering gears are, equipment is to be carried out. Satisfactory
operating satisfactorily and that the recharging operation of safety devices, bilge level detection
arrangements for hydraulic power operated and alarm systems and control systems is to be
steering gears are being maintained. verified.
5.2.4 Fire protection, detection and j) examination of any manual and automatic
extinction fire doors and proving their operations;
5.2.4.1 The arrangements for fire protection, k) Examining the fixed fire fighting system for
detection and extinction are to be examined and the cargo pump room and confirming that its
are to include confirmation that no changes means of operation is clearly marked;
have been made in the structural fire protection.
Following are to be examined / verified: l) Examining the water spray system for
cooling, fire protection and crew protection
a) verification that fire control plans are and confirming that its means of operation is
properly posted; clearly marked;
b) examination as far as possible and testing m) Confirming that electrical equipment in gas
as feasible of the fire and/or smoke dangerous spaces and zones is in
detection system(s); satisfactory condition and properly
maintained;
c) examination of the fire main system and
verification that each fire pump including the n) Examining the dry chemical powder fire
emergency fire pump can be operated extinguishing system for the cargo area and
separately so that the two required powerful confirming that its means of operation is
jets of water can be produced clearly marked;
simultaneously from different hydrants;
testing the remote means for starting one o) Examining the fixed fire fighting system for
main fire pump; the cargo pump room and the deck foam
system for the cargo area and confirming
d) verification that fire hoses, nozzles, that their means of operation are clearly
applicators and spanners are in good marked.
working condition and situated at their
respective locations; p) examination of the fire-extinguishing
systems for spaces containing paint and/or
e) examination of fixed fire fighting system flammable liquids and deep fat cooking
controls, piping, instructions and marking, equipment in accommodation and service
checking for evidence of proper spaces;
maintenance and servicing including date of
last systems tests; q) examination of the fire safety requirements
of any helicopter facilities.
f) verification that all semi-portable and
portable fire extinguishers are in their Surveys carried out by the National Authority of
stowed positions, checking for evidence of the country in which the ship is registered would
proper maintenance and servicing, normally be accepted as meeting these
conducting random check for evidence of requirements, at the discretion of the Surveyor.
discharged containers;
5.2.4.2 On ships where inert gas systems are
g) verification, as far as practicable, that the installed, the requirements of Sec.12 are to be
remote controls for stopping fans and complied with.
machinery and shutting off fuel supplies in
machinery spaces are in working order; 5.2.4.3 Confirmation that the means of escape
from accommodation, machinery spaces and
h) examination of the closing arrangements of other spaces are satisfactory.
ventilators, funnel annular spaces, skylights,
doorways and tunnel, where applicable; 5.2.4.4 Examination of the arrangements for
gaseous fuel for domestic purposes.
i) confirmation that the fire fighters’ outfits and
emergency escape breathing devices
(EEBDs) are complete and in good
5.2.5 Other safety arrangements related to 5.2.5.7 Ventilation systems and air locks in
cargo / cargo area working spaces are to be checked for
satisfactory operation.
5.2.5.1 The ship's log and operational records
for the cargo containment system covering the 5.2.5.8 Cargo pipeline, valves and fittings are to
period from the previous survey are to be be generally examined, with special reference to
examined taking into consideration hours per expansion bellows, supports and vapour seals
day of the reliquefaction plant or the boil-off rate. on insulated pipes.
Any malfunction of the system entered in the log
is to be investigated, the cause ascertained, and 5.2.5.9 Examining the process piping including
that part of the system at fault is to be found or the expansion arrangements, insulation from
placed in good order. hull structure, pressure relief and drainage
arrangements.
5.2.5.2 Cargo liquid level indicating devices are
to be generally examined. The low level, high 5.2.5.10 Portable and/or fixed drip trays, or
level, and overfill alarms are to be examined and insulation for deck protection in the event of
tested to ascertain that they are in working cargo leakage, are to be examined for condition.
order. Consideration will be given to the
acceptance of simulated tests, provided that 5.2.5.11 Examining when applicable bow or
they are carried out at the cargo temperature, or stern loading and unloading arrangements with
comprehensive maintenance records, including particular reference to the electrical equipment,
details of tests held, in accordance with the fire- fighting arrangements and means of
cargo plant instrumentation maintenance communications between the cargo control
manual. The calibration status of the measuring room and the shore location.
instruments may also be verified.
5.2.5.12 Confirming that the cargo tank and
5.2.5.3 Cargo gas leakage detection systems interface pressure and relief valves, including
are to be examined and tested to ascertain that safety systems and alarms are satisfactory.
they are in working order and calibrated using
sample gas. 5.2.5.13 Confirming that all liquid and vapour
hoses are suitable for their intended purpose.
The gas detection arrangements for cargo
control rooms and the measures taken to 5.2.5.14 Confirming that any air drying system
exclude ignition sources where such spaces are and any inter barrier and hold space purging
not gas safe, are to be examined. inert gas system are satisfactory.
5.2.5.4 The correct functioning of the cargo For membrane containment systems, normal
containment system temperature and pressure operation of the nitrogen control system for
indicating equipment, together with any insulation and inter barrier spaces is to be
associated alarms, is to be verified. confirmed by the Master.
5.2.5.5 Control devices for the cargo 5.2.5.15 Confirming that two sets of portable gas
containment systems and cargo handling detection equipment suitable for the cargoes to
equipment, together with any associated be carried and a suitable instrument for
shutdown and/or interlock, are to be checked measuring oxygen levels have been provided.
under simulated working conditions and, if
necessary, recalibrated. 5.2.5.16 Electrical bonding of the cargo pipes
and tanks to the hull is to be verified.
5.2.5.6 The arrangements for manually operated
emergency shutdown system together with the 5.2.5.17 Confirming that when applicable
automatic shut down of the cargo pumps and arrangements are made for sufficient inert gas
compressors are to be checked to ascertain to be carried to compensate for normal losses
they are in working order. and that means are provided for monitoring the
spaces.
Alternatively, the log books may be examined
for verification that the emergency shutdown 5.2.5.18 Confirming that the use of inert gas has
system has been tested. not increased beyond that needed to
compensate for normal losses by examining
records of inert gas usage.
a) The machinery under working conditions. 5.2.8.2 Where the insulation arrangement is
such that the insulation cannot be examined
b) The shells of all pressure vessels in the during special surveys (See 5.4.6.9) the
system, externally, insulation need not be surrounding structures of wing tanks, double
removed for this examination, but any bottom tanks and cofferdams are to be
deterioration of insulation or evidence of examined for cold spots, prior to the survey.
dampness which could lead to external This examination is to be held at a convenient
corrosion of the vessels of their cargo discharge operation with the cargo tanks
connections, is to be investigated. loaded at approximately the minimum notation
temperature.
c) Primary refrigerant gas and liquid pipes,
cargo vapour and liquid condensate pipes 5.2.8.3 On application by the Owner,
and condenser cooling water pipes. consideration will be given to the cold spot
Insulation need not be removed, but any examination, where applicable, being carried out
deterioration or evidence of dampness is to by the ship's staff.
be investigated.
5.2.8.4 When tests are required after repairs,
d) The reliquefaction/refrigeration plant spare independent cargo tanks, other than
gear. independent tanks, type C, are to be tested by
hydraulic or hydropneumatic means as
5.2.7 Methane burning equipment and other appropriate. Test heads and pressures should
equipment components be as defined in Pt.5, Ch.4. Cargo tanks of the
membrane or semi-membrane type are to be
5.2.7.1 The following components are to be tested by means of a detectable gas in the inter-
generally examined externally. If insulation is barrier spaces and discolouring paint on the
fitted, this need not be removed, but any weld seams of the cargo tanks wall, or other
deterioration of insulation, or evidence of suitable means. Independent cargo tanks of
dampness which could lead to external type C are to be tested hydraulically at 1.25
corrosion of the vessels or their connections, is times the approved maximum vapour pressure.
to be investigated.
5.2.9 Personnel protection
a) Heat exchangers and pressure vessels for
use with methane burning in boilers or a) Verification that the requisite safety
machinery. equipment and associated breathing
apparatus with requisite air supplies and
b) Cargo heaters, vaporizers, masthead emergency escape respiratory and eye
heaters and other miscellaneous pressure protection, if required, are in good condition
vessels. and are properly stowed.
5.2.7.2 Controls and interlocks are to be b) Verification that medical first air equipment
checked. including stretchers and oxygen
resuscitation is in god condition and that
5.2.7.3 Alarm systems are to be checked to satisfactory arrangements are made for
ascertain they are in working order. antidotes for cargoes actually carried to be
on board.
5.2.7.4 Exhaust fans and/or pressurizing system
for gas trunking are to be tested. c) Verification that decontamination arrange-
ments are operational.
5.2.7.5 The relevant instruction and information
material such as cargo handling plans, filling
limit information, cooling down procedures etc.
are to be verified as being onboard.
Table 5.3.2.2 : Table of the minimum requirements for close-up survey of hull at intermediate
surveys of liquefied gas carriers
- all web frames and both transverse - all web frames and both transverse bulkheads
bulkheads in a representative ballast tank in two representative ballast tanks (1) and (2)
(1) and (2)
e) Generally examining the electrical 1.11. In such cases, the next period of class will
equipment and cables in dangerous zones start from the expiry date of the Special Survey
such as cargo pump rooms and areas before extension was granted.
adjacent to cargo tanks to check for
defective equipment, fixtures and wiring. Concurrent crediting to both Intermediate survey
The insulation resistance of the circuits is to and Special survey for surveys and thickness
be tested and in cases where a proper measurements of spaces is not acceptable.
record of testing is maintained,
consideration should be given to accepting 5.4.1.2 The interval between the Special
recent readings. Examination with reference Surveys may be reduced at the request of the
to the following is to be carried out: parties concerned or by IRS if considered
appropriate.
- Protective earthing (spot check).
5.4.1.3 For surveys completed within 3 months
- Integrity of flame proof enclosures. before the expiry date of the Special Survey, the
next period of class will start from the expiry
- Damage of outer sheath of cables. date of the Special Survey. For surveys
completed more than 3 months before the expiry
- Function testing of pressurized date of the Special Survey, the period of class
equipment and associated alarms. will start from the survey completion date.
- Testing of systems for de-energizing 5.4.1.4 The Special Survey may be commenced
non-certified safe electrical equipment at the 4th Annual Survey and be progressed
located in spaces protected by air locks, with a view to completion by the 5th anniversary
such as electrical motor-rooms, cargo date. When the special survey is commenced
control rooms, etc. prior to the fourth annual survey, the entire
survey is to be completed within 15 months if
f) Confirming that spares are provided for such work is to be credited to the special survey
cargo area mechanical ventilation fans. and in this case the next period of class will start
from the survey completion date.
g) Checking the provision of equipment for
personnel protection. 5.4.1.5 For the purpose of special survey,
results of thickness measurement carried out
h) Examining when applicable, the during or after the fourth annual survey only
arrangements for the use of cargo as fuel would be considered.
and testing as far as practicable, that the
gas supply to the machinery space is cut off 5.4.1.6 Record of Special Survey will not be
should the exhaust ventilation not be assigned until the Machinery Survey has been
functioning correctly and that the master gas completed or postponed in agreement with IRS.
fuel valve may be remotely closed from
within the machinery space. 5.4.1.7 Ships which have satisfactorily passed a
Special Survey will have a record entered in the
i) The emergency shutdown system is to be Supplement to the Register Book indicating the
tested without flow in the pipelines, to verify assigned date of Special Survey.
that the trip system stops the cargo pumps
and compressors. 5.4.1.8 The special survey is to include, in
addition to the requirements of the Annual
5.4 Special Surveys - Hull Survey, examination, tests and checks of
sufficient extent to ensure that the hull,
5.4.1 General equipment and related piping are in satisfactory
condition and that the ship is fit for its intended
5.4.1.1 All ships classed with IRS are to undergo purpose for the new period of class of five years
Special Surveys at 5 yearly intervals. The first to be assigned subject to proper maintenance
Special Survey is to be completed within 5 years and operation and the periodical surveys being
from the date of the initial classification survey carried out at the due dates.
and thereafter 5 years from the assigned date of
the previous Special Survey. However, an 5.4.1.9 The examinations of the hull are to be
extension of class of 3 months maximum supplemented by thickness measurements (See
th
beyond the 5 year may be granted in 5.4.4) and testing as deemed necessary, to
exceptional circumstances in accordance with ensure that the structural integrity remains
effective. The aim of the examination is to safe and efficient conduct of the survey work to
discover substantial corrosion, significant be carried out.
deformation, fractures, damages or other
structural deterioration, that may be present. 5.4.3 Examination and testing
5.4.1.10 A Docking Survey in accordance with 5.4.3.1 All spaces within the hull and
the requirements of Sec.7 is to be carried out as superstructure are to be examined.
part of the Special Survey. Any remaining work
in respect of the overall and close-up surveys 5.4.3.2 All tanks other than cargo and ballast
and thickness measurements and repairs tanks are to be examined internally in
applicable to the lower portions of ballast tanks accordance with the requirements of Table
(i.e. parts below light ballast waterline) are to be 5.4.3.2.
completed in the dry dock
All bilge and ballast piping systems are to be
5.4.2 Planning and preparation for survey examined and operationally tested to working
pressure to attending Surveyor’s satisfaction to
5.4.2.1 The ship is to be prepared for overall ensure that tightness remains satisfactory.
survey in accordance with the requirements of
Table 5.4.2.1. The preparation is to be of 5.4.3.3 An overall survey of all water ballast
sufficient extent to facilitate an examination to tanks including double bottom tanks, cargo
ascertain any excessive corrosion, deformation, compressor and electrical motor rooms, pipe
fractures, damages and other structural tunnels, cofferdams and void spaces bounding
deterioration. cargo tanks, decks and outer hull is to be carried
out. This examination is to be supplemented by
5.4.2.2 Prior to commencement of any part of thickness measurement and testing as deemed
the special survey, a survey planning meeting is necessary, to ensure that the structural integrity
to be held between the attending surveyor(s), remains effective. The aim of the examination is
the owner’s representative in attendance, the to discover Substantial Corrosion, significant
thickness measurement company representative deformation, fractures, damages or other
and the master of the ship or an appropriately structural deterioration and if deemed necessary
qualified representative appointed by the master by the Surveyor, a suitable non-destructive
or Company for the purpose to ascertain that all examination may be required.
the arrangements envisaged in the survey
programme are in place, so as to ensure the
Special Survey No. I Special Survey Special Survey No. III Special Survey
Age ≤ 5 No. II 10 < Age ≤ 15 No. IV and
5 < Age ≤ 10 subsequently
Age ≥ 15
1) All tanks, peaks, bilges and drain 1) Requirements of 1) Requirements of 1) Requirements of
wells, engine and boiler spaces and Special Survey I to be Special Survey II to be Special survey III to
other spaces are to be cleared out complied with complied with be complied with
and cleaned as necessary for
examination. Floor plates in engine 2) The chain locker is 2) Portions of wood
and boiler spaces are to be lifted as to be cleaned internally. sheathing, or other
may be necessary for examination The chain cables are to covering, on steel decks
of the structure underneath. Where be ranged for are to be removed, as
necessary ceiling, lining, casings inspection. The considered necessary by
and loose insulation are to be anchors are to be the Surveyor, in order to
removed as required by the cleaned and placed in ascertain the condition of
Surveyor for examination of the an accessible position the plating.
structure. Compositions on the for inspection.
plating are to be examined and
sounded, but need not be disturbed
if found satisfactorily adhering to the
plating
Notes:
2) If a selection of tanks is accepted to be examined, then different tanks are to be examined at each
special survey, on a rotational basis.
3) Peak tanks (all uses) are subject to internal examination at each special survey.
4) At special surveys No.III and subsequent special surveys one deep tank for fuel oil is to be included,
if fitted.
5.4.3.4 Where ballast tanks have been its various parts are to be examined in working
converted to void spaces, the survey extent is to condition.
be based upon ballast tank requirements.
5.4.3.10 The hand pumps and suctions, air and
5.4.3.5 For ballast tanks, excluding double sounding pipes are to be examined. The
bottom tanks, where a hard protective coating is Surveyors are to ensure that striking plates are
found in POOR condition and it is not renewed, fitted under the sounding pipes whilst examining
where soft or semi-hard coating has been the tanks internally.
applied, or where a protective coating was not
applied from the time of construction, the space Automatic air pipe heads are to be internally
in question is to be internally examined at examined at special surveys as indicated in
Annual Surveys. Thickness measurement is to Table 5.4.3.10. For designs where the inner
be carried out as deemed necessary by the parts cannot be properly inspected from outside,
Surveyor. the head is to be removed from the air pipe.
Particular attention is to be paid to the condition
5.4.3.6 For double bottom ballast tanks where a of the zinc coating in heads constructed from
protective coating is found in POOR condition galvanised steel.
and it has not been renewed or where soft or
semi-hard coating has been applied, or where a 5.4.3.11 The Surveyor should satisfy himself
protective coating was not applied from the time regarding the efficient condition of the following :
of construction, the spaces in question may be
examined at Annual Surveys. When considered - Means of escape from machinery spaces,
necessary by the Surveyor, thickness crew and passenger spaces and spaces in
measurement is to be carried out. which crew are normally employed;
5.4.3.7 All watertight bulkheads and watertight - Means of communication between bridge
doors are to be examined. All decks, casings and engine room and between bridge and
and superstructures are to be examined. alternative steering position;
Attention is to be given to the corners of
openings and other discontinuities in way of the - Helm indicator;
strength decks and top sides.
- Protection to the aft steering wheel and the
5.4.3.8 The masts, standing rigging and anchors gear.
are to be examined.
5.4.3.12 The chain cables are to be ranged and
The Surveyor should satisfy himself that there the anchors and the chain cables are to be
are sufficient mooring ropes on board and also examined. At special survey no. II and
that a tow line is provided when this is a Rule subsequent special surveys, the chain cables
requirement. are to be gauged. Any length of chain cable
which is found to have reduced in mean
5.4.3.9 The steering gear, and its connections diameter at its most worn part by more than 12
and control systems (main and alternative) are per cent of its original rule diameter is to be
to be examined. The auxiliary steering gear with renewed.
Table 5.4.3.10 : Requirements for internal examination of automatic air pipe heads
2) Within the cargo area : 2) Within the cargo area: 2) Within the cargo area: 2) Within the cargo area:
One section of deck a) Each deck plate a) Each deck plate a) Each deck plate
plating for the full beam of b) One Transverse section b) Two Transverse b) Three Transverse
the ship within 0.5L within 0.5L amidships in sections (1) sections (1)
amidships in way of a way of a ballast tank, if c) All wind and water c) All wind and water
ballast tank, if any. any strakes strakes
d) Each bottom plate
e) Duct keel or pipe tunnel
plating and internals
4) Selected wind and 4) Selected wind and 4) All wind and water
water strakes outside the water strakes outside the strakes outside the cargo
cargo area cargo area area
7) Representative
exposed superstructure
deck plating (poop, bridge,
forecastle deck)
(1) at least one section is to include a ballast tank within 0.5L amidships, if any.
survey, the condition of the corrosion prevention b) In tanks which have structures approved
system and also in the following cases: with reduced scantlings due to an approved
corrosion control system.
a) In particular, tanks having structural
arrangements or details which have 5.4.5.3 For areas in tanks where hard protective
suffered defects on similar tanks or on coatings are found to be in a GOOD condition,
similar ships according to available the extent of Close-up Surveys according to
information. Table 5.4.5.1 may be specially considered by
the Surveyor.
Special Survey No. I Special Survey No. II Special Survey No. III
Age ≤ 5 5 < Age ≤ 10 subsequent age > 10
One web frame in a All web frames in a ballast tank, All web frames in all ballast tanks
representative ballast tank of which is to be a double hull side (1)
the topside, hopper side and tank or a topside tank. If such
double hull side type (1) tanks are not fitted, another All transverse bulkheads in all
ballast tank is to be selected (1) ballast tanks (2)
One transverse bulkhead in a
ballast tank (3) One web frame in each
remaining ballast tank (1)
Notes :
a) Ballast tanks include topside, double hull side, double bottom, hopper side, or any combined
arrangement of the aforementioned and peak tanks where fitted.
b) For ships having independent tanks of type C, with a midship section similar to that of a general
cargo ship, the extent of close-up surveys may be specially considered by the Surveyor.
5.4.6 Cargo containment and systems records have not shown any abnormal
operation, cargo tanks do not require to be
5.4.6.1 All cargo tanks are to be examined hydraulically tested.
internally, also externally so far as is practicable,
particular attention being paid to the plating in 5.4.6.2 Non-destructive testing is to supplement
way of supports of securing arrangements, cargo tank inspection with special attention to be
tower structures, seatings and pipe connections. given to the integrity of the main structural
Attention is also to be paid to the sealing members, tank shell and highly stressed parts,
arrangements in way of the deck penetrations including welded connections as deemed
and the antiflotation arrangements for necessary by the Surveyor. However, for Type
independent tanks. The tightness of all cargo C independent tanks non-destructive testing can
tanks is to be verified by an appropriate not be dispensed with totally. The following
procedure. The ships gas detection equipment items are, inter alia, considered as highly
may be used for tightness test of independent stressed parts:
tanks below deck. Provided that the structural
examination is satisfactory, that the gas leakage - Cargo tank supports and anti-rolling/anti-
monitoring systems have been found to be pitching devices.
operating satisfactorily and that the voyage
suitable gas. Relief valves on cargo gas and 5.4.6.16 Sea connections associated with the
liquid pipelines are to have their pressure cargo handling equipment are to be opened out
settings checked. The valves may be removed when the ship is in dry-dock.
from the pipelines for the purpose.
5.4.6.17 The arrangements for discharging the
If the cargo tanks are equipped with relief valves cargo overboard in an emergency are to be
with non-metallic membranes in the main or pilot checked.
valves, then such non-metallic membranes are
to be replaced. If a proper record of continuous 5.4.6.18 Special Survey I (Ships five years old)-
overhaul and retesting of individually identifiable reliquefaction/refrigeration equipment
relief valves is maintained, then consideration
will be given to acceptance on the basis of a) Each reciprocating compressor is to be
opening, internal examination and testing of a opened out. Cylinder bores, pistons, piston
representative sampling of valves, including rods, connecting rods, valves and seats,
each size and type of liquefied gas or vapour glands, relief devices, suction filters and
relief valve in use, provided there is a logbook lubricating arrangements are to be
evidence that the remaining valves have been examined. Crankshafts are to be examined
overhauled and tested since crediting of the but crankcase glands and the lower half of
previous special survey. main bearings need not be exposed if the
Surveyor is satisfied with the alignment and
5.4.6.12 All cargo pumps, cargo booster pumps wear.
and cargo vapour pumps are to be opened out
for examination. If requested by the Owner, b) Where other than reciprocating type
these items may be examined on a Continuous compressors are fitted, or where there is a
Survey basis provided the interval between program of replacement instead of surveys
examination of each item does not exceed five on board, alternative survey arrangements
years. Pumping systems for inter-barrier spaces will be considered. Each case will be given
are to be checked and verified to be in good individual consideration.
working order.
c) The water end covers of condensers are to
5.4.6.13 Where considered necessary, insulated be removed for examination of the tubes,
cargo gas and liquid pipelines are to have tube plates and covers.
sections of insulation removed to ascertain the
condition of the pipes. If visual examination d) Refrigerant condenser cooling water pumps,
raises doubt as to the integrity of the pipe lines, including standby pump(s) which may be
then the pipe lines are to be pressure tested to used on other services, are to be opened
1.25 times MARVS. Care is to be taken that in out for examination.
the replacement of insulation the outer vapour
seal is made good. e) Where a pressure vessel is insulated,
sufficient insulation is to be removed,
5.4.6.14 Equipment for the production of inert especially in way of connections and
gas is to be examined and shown to be supports, to enable the vessel's condition to
operating satisfactorily within the gas be ascertained.
specification limits. Pipelines, valves, etc., for
the distribution of the inert gas are to be f) Insulated pipes are to have sufficient
generally examined. Pressure vessels for the insulation removed to enable their condition
storage of inert gas are to be examined to be ascertained. Vapour seals are to be
internally and externally and the securing specially examined for condition.
arrangements are to be specially examined.
Pressure relief valves are to be demonstrated to g) The Surveyor is to satisfy himself that all
be in good working order. Liquid nitrogen pressure relief valves and/or safety discs
storage vessels are to be examined, so far as is throughout the system are in good order. No
practicable, and all control equipment, alarms attempt, however, is to be made to test
and safety devices are to be verified as primary refrigerant pressure relief valves on
operational. board ship.
5.4.6.15 Gas tight bulkhead shaft seals are to be h) The items covered by (a) to (d) may, at the
opened out so that the sealing arrangements request of the Owner, be examined on a
may be checked. Continuous Survey basis provided the
interval between examination of each item shell are to have the end covers removed
does not exceed five years. and the shell pneumatically tested to a
pressure equal to the designed working
5.4.6.19 Special Survey I (ships five years old)- pressure.
Methane burning equipment
c) All other pressure vessels in the
a) Where methane is used as fuel for main reliquefaction/refrigeration system, methane
propulsion purposes, the associated burning system and other handling systems
compressors and heat exchangers are to be are to be pneumatically tested to a pressure
opened out and examined as for equal to the designed working pressure.
reliquefaction/refrigeration equipment. The
steam side of steam heaters is to be d) Liquid cargo pipes are to be tested by
hydraulically tested to 1.5 times the design approved means, to a pressure equal to
pressure. 1.25 times the working pressure.
Alternatively, selected representative
b) Methane gas pipe trunks or casings are to lengths may be removed for internal
be generally examined and the exhaust or examination and hydraulic testing.
inerting arrangements for these trunks are
to be verified. e) At Special Survey III and at each alternate
Special Survey thereafter, plating of
c) All alarms associated with the methane independent cargo tanks, and also the hull
burning systems are to be verified. structural plating surrounding cargo tanks,
where it is insulated on one side, is to be
5.4.6.20 Special Survey II and Special Surveys measured for thickness by a non-destructive
thereafter (ships 10 years old and over) method.
Section 6
- clamping devices, retaining bars, In the case of hatch covers / steel pontoons of
cleating; general dry cargo ships, a close-up survey of
hatch cover plating is to be carried out.
- chain or rope pulleys;
6.2.2.3 All watertight doors in watertight
- guides; bulkheads, to be examined and tested (locally
and remotely) as far as practicable.
- guide rails and track wheels;
6.2.2.4 Anchoring and mooring equipment is to
- stoppers, etc.; be examined as far as is practicable.
Special Survey or Intermediate Survey (See 6.2.2.13 The maintenance and inspection
6.4.3.1, 6.4.3.2 and 6.3.2, 6.3.3 respectively). records of accommodation ladders and
When extensive corrosion is found, thickness gangways are to be verified. It is to be confirmed
measurement is to be carried out. If the results that supporting wires are being renewed at
of these thickness measurements indicate intervals not exceeding 5 years.
substantial corrosion then the extent of
thickness measurements are to be increased to 6.2.2.14 When examining internal spaces, as far
determine the extent of areas of substantial as practicable, the permanent means of access
corrosion in accordance with Table 6.4.8.2. where appropriate, are to be verified that they
remain in good condition.
6.2.2.8 The Surveyor is to confirm that, where
required, an approved loading instrument 6.2.2.15 For vessels subject to IMO PSPC (See
together with its operation manual are available Pt.3, Ch.2, 3.6) it is to be confirmed that the
on board, (See Pt.3, Ch.5). It is to be verified by maintenance, repair and partial re-coating of
the Surveyor that the loading instrument is dedicated ballast tanks, as appropriate, are
checked for accuracy at regular intervals by the recorded in the coating technical file.
ship's staff by applying test loading conditions.
6.2.3 Examination of cargo holds of general
6.2.2.9 Accommodation ladders are to be dry cargo ships.
examined at annual surveys. Satisfactory
condition of the following items is to be checked, 6.2.3.1 For cargo ships of 10 – 15 years of age:
in particular :
a) Overall survey of one forward and one after
a) steps; cargo hold and their associated tween deck
b) platforms; spaces.
c) all support points such as pivots, rollers,
etc.; b) When considered necessary by the
d) all suspension points such as lugs, Surveyor or where extensive corrosion
brackets, etc.; exists, thickness measurement is to be
e) stanchions, rigid handrails, hand ropes and carried out. If the results of these thickness
turntables; measurements indicate substantial corro-
f) davit structure, wire and sheaves, etc. sion, then the extent of thickness
measurements is to be increased to
6.2.2.10 Gangways are to be examined at determine the extent of areas of substantial
annual surveys. Satisfactory condition of the corrosion in accordance with Table 6.4.8.2.
following items is to be checked, in particular :
6.2.3.2 For cargo ships over 15 years of age:
a) treads;
b) side stringers, cross-members, decking, a) Overall survey of all cargo holds and tween
deck plates, etc.; deck spaces.
c) all support points such as wheel, roller, etc.;
d) stanchions, rigid handrails, hand ropes. b) In a forward lower cargo hold and one other
selected lower cargo hold:
6.2.2.11 Winches of accommodation ladders
and gangways are to be examined to verify the - Close-up examination of sufficient
satisfactory condition of the following items: extent, minimum 25% of frames, to
establish the condition of the lower
a) brake mechanism including condition of region of the shell frames including
brake pads and band brake, if fitted; approx. lower one third length of side
b) remote control system, and frame at side shell, side frame end
c) power supply system for electric motor. attachment and the adjacent shell
plating.
6.2.2.12 Davits and fittings on the ship’s deck
associated with accommodation ladders and - Where this level of survey reveals the
gangways are to be examined for satisfactory need for remedial measures, the survey
condition at annual surveys. Fittings or is to be extended to include a close-up
structures for means of access to deck such as survey of all of the shell frames and
handholds in a gateway or bulwark ladder and adjacent shell plating of those cargo
stanchions are also to be examined. holds and associated tween deck
spaces (as applicable) as well as a
close-up survey of sufficient extent of all verify that log entries have been made in
remaining cargo holds and tween deck accordance with statutory requirements.
spaces (as applicable).
6.2.4.7 Steering chains are to be cleaned for
c) When considered necessary by the ascertaining wear and tear and lengths of chain
surveyor, or where extensive corrosion worn in mean diameter by more than 12 per
exists, thickness measurement is to be cent of the original rule diameter are to be
carried out. If the results of these thickness renewed.
measurements indicate substantial corro-
sion, then the number of thickness 6.2.4.8 All the means of communication
measurements are to be increased to between the navigating bridge and the
determine the extent of substantial corrosion machinery control positions, as well as the
in accordance with Table 6.4.8.2. bridge and the main alternative steering
position, if fitted, are to be tested. It is to be
d) Where the protective coating in cargo holds, confirmed that means of indicating the angular
as applicable, is found to be in a GOOD position of the rudder are operating
condition, the extent of close-up surveys satisfactorily.
may be specially considered.
6.2.4.9 Confirmation that with ships having
e) All piping and penetrations in cargo holds, emergency steering positions there are means
including overboard piping are to be of relaying heading information and, when
examined. appropriate, supplying visual compass readings
to the emergency steering positions.
6.2.4 Machinery and systems
6.2.4.10 Confirmation that various alarms
6.2.4.1 A general examination of the machinery, required for hydraulic power operated, electric
boilers, all pressurised systems (steam, and electro-hydraulic steering gears are,
pneumatic, hydraulic) and their associated operating satisfactorily and that the recharging
fittings, propulsion system and auxiliary arrangements for hydraulic power operated
machinery to see whether they are being steering gears are being maintained.
properly maintained and with particular attention
to the fire and explosion hazards. 6.2.4.11 Examining the means for the operation
of the main and auxiliary machinery essential for
6.2.4.2 Confirmation that machinery, boilers and propulsion and the safety of the ship, including
other pressure vessels, associated piping when applicable, the means of remotely
systems and fittings are so installed and controlling the propulsion machinery from the
protected as to reduce to a minimum any danger navigating bridge and the arrangements to
to persons on board, due regard being given to operate the main and other machinery from a
moving parts, hot surfaces and other hazards. machinery control room.
6.2.4.3 Confirmation that Periodical Surveys of 6.2.4.12 Confirmation that the engine room
boilers and other pressure vessels have been telegraph, the second means of communication
carried out as required by the Rules and the between the navigation bridge and the
safety devices have been tested. machinery space and the means of
communication with any other positions from
which the engines are controlled are operating
6.2.4.4 Confirmation that the normal operation of satisfactorily.
the propulsion machinery can be sustained or
restored even though one of the essential 6.2.4.13 Confirmation that the engineer's alarm
auxiliaries becomes inoperative. is clearly audible in the engineer's
accommodation.
6.2.4.5 Confirmation that means are provided so
that machinery can be brought into operation 6.2.4.14 The bilge pumping systems and bilge
from the dead ship condition without external wells including operation of each bilge pump,
aid. extended spindles and level alarms, where
fitted, are to be examined as far as is
6.2.4.6 All main and auxiliary steering practicable. It is also to be confirmed that bilge
arrangements and their associated equipment pumping system for each watertight
and control systems are to be examined and compartment is satisfactory.
tested. Where applicable, Surveyors are to
It is also to be confirmed that drainage from separately so that the two required powerful
enclosed cargo spaces situated on freeboard jets of water can be produced
deck is satisfactory. simultaneously from different hydrants;
6.2.4.15 Examining visually the condition of any d) verification that fire hoses, nozzles,
expansion joints in sea water system. applicators and spanners are in good
working condition and situated at their
6.2.4.16 General examination visually and in respective locations;
operation, as feasible, of the main electrical
machinery, the emergency sources of electrical e) examination of fixed fire fighting system
power, the switch gear, other electrical controls, piping, instructions and marking,
equipment including the lighting system is to be checking for evidence of proper
carried out. maintenance and servicing including date of
last systems tests;
6.2.4.17 Confirmation as far as practicable, the
operation of the emergency source(s) of f) verification that all semi-portable and
electrical power, including their starting portable fire extinguishers are in their
arrangement, the systems supplied, and when stowed positions, checking for evidence of
appropriate, their automatic operation. proper maintenance and servicing,
conducting random check for evidence of
6.2.4.18 Examining in general, that the discharged containers;
precautions provided against shock, fire and
other hazards of electrical origin are being g) verification, as far as practicable, that the
maintained. remote controls for stopping fans and
machinery and shutting off fuel supplies in
6.2.4.19 General Examination of automation machinery spaces are in working order;
equipment is to be carried out. Satisfactory
operation of safety devices, bilge level detection h) examination of the closing arrangements of
and alarm systems and control systems is to be ventilators, funnel annular spaces, skylights,
verified. doorways and tunnel, where applicable;
6.2.4.20 For single hold cargo ships which i) confirmation that the fire fighters’ outfits and
require fitment of hold water level detectors as emergency escape breathing devices
per Pt.4, Ch.3, Sec.3.6, the annual survey is to (EEBDs) are complete and in good
include an examination and a test of the water condition and that the cylinders, including
ingress detection system and their alarms. the spare cylinders, of any required self-
contained breathing apparatus are suitably
6.2.4.21 Confirmation that machinery space charged;
ventilation systems are in good working
condition. j) examination of any manual and automatic
fire doors and proving their operations;
6.2.5 Fire protection, detection and
extinction k) examination of the fire-extinguishing
systems for spaces containing paint and/or
6.2.5.1 The arrangements for fire protection, flammable liquids and deep fat cooking
detection and extinction are to be examined and equipment in accommodation and service
are to include confirmation that no changes spaces;
have been made in the structural fire protection.
Following are to be examined / verified: l) examination of the fire safety requirements
of any helicopter facilities;
a) verification that fire control plans are
properly posted; m) examination of the fire protection
arrangement in cargo, vehicle and ro-ro
b) examination as far as possible and testing spaces and confirmation, as far as
as feasible of the fire and/or smoke practicable and as appropriate, the
detection system(s); operation of the means of control provided
for closing the various openings;
c) examination of the fire main system and
verification that each fire pump including the n) Examination, when appropriate, of the
emergency fire pump can be operated special arrangements for carrying
6.2.5.3 Examination of the arrangements for - Hinges and bearings, thrust bearings;
gaseous fuel for domestic purposes.
- Hull and door side supports for securing,
6.2.6 Shell and inner doors of ro-ro ships supporting and locking devices;
Table 6.2.6.4 : Minimum requirements for close-up surveys of doors, locking, securing and
supporting devices and fittings
List of the devices and fittings and associated welding to be subject to close-up survey by the attending
Surveyor:
i) Cylinder securing pins, supporting brackets, back-up brackets (where fitted) and their welding
connections;
ii) Hinge pins, supporting brackets, back-up brackets (where fitted) and their welded connections;
iii) Locking hooks, securing pins, supporting brackets, back-up brackets (where fitted) and their
welded connections;
iv) Locking pins, supporting brackets, back-up brackets (where fitted) and their welded connections;
v) Locating and stopper devices and their welded connections.
- Device for locking the door in the open - Confirmation that power supply for
position; indicator system is supplied by the
emergency source or other secure power
- Securing, supporting and locking devices; supply and independent of the power
supply for operating the doors;
- Proper sequence of the interlock system
for the opening / closing system and the - Verification of proper condition of sensors
securing and locking devices; and protection from water, ice formation
and mechanical damage.
- Mechanical lock of the securing devices;
6.2.6.10 Test of water leakage detection system
- Proper locking of hydraulic securing (where fitted)
devices in the event of a loss of the
hydraulic fluid, according to the procedure The water leakage detection system is to be
provided by the OMM; tested including proper audible alarm on the
navigation bridge panel and on the engine
- Correct indication of open / closed position control room panel, according to the procedure
of doors and securing / locking devices at provided by the OMM.
navigation bridge and other control
stations; 6.2.6.11 Test of television surveillance system
(where fitted)
- Isolating of the hydraulic securing / locking
devices from other hydraulic systems; The television surveillance system is to be
tested including proper indication on the
- Confirmation that the operating panels are navigation bridge monitor and on the engine
inaccessible to unauthorized persons; control room monitor.
c) For double bottom ballast tanks, where a In lieu of the application of 6.4.1.4, the
protective coating is found to be in POOR intermediate survey may be commenced at the
condition and is not renewed, where a soft second annual survey and be progressed with a
or semi-hard coating has been applied or view to completion at the third annual survey.
where a hard protective coating was not
applied from the time of construction, the 6.4 Special surveys - Hull
tank(s) in question may be examined at
subsequent Annual surveys. 6.4.1 General
6.3.3.2 Cargo holds of general dry cargo ships: 6.4.1.1 All ships classed with IRS are to undergo
Special Surveys at 5 yearly intervals. The first
a) An overall survey of all cargo holds and Special Survey is to be completed within 5 years
tween deck spaces. from the date of the initial classification survey
and thereafter 5 years from the assigned date of
b) Areas found suspect at previous surveys the previous Special Survey. However, an
are to be surveyed in accordance with extension of class of 3 months maximum
6.2.2.6. beyond the 5th year may be granted in
exceptional circumstances in accordance with
c) When considered necessary by the 1.11. In such cases, the next period of class will
Surveyor or where extensive corrosion start from the expiry date of the Special Survey
exists, thickness measurement is to be before extension was granted.
carried out. If the results of these thickness
measurements indicate substantial 6.4.1.2 The interval between the Special
corrosion, then the extent of thickness Surveys may be reduced at the request of the
measurements are to be increased to parties concerned or by IRS if considered
determine the extent of areas of substantial appropriate.
corrosion in accordance with Table 6.4.8.2.
6.4.1.3 For surveys completed within 3 months
6.3.3.3 In the case of ships other than those before the expiry date of the Special Survey, the
engaged in the carriage of dry cargoes only, an next period of class will start from the expiry
internal examination of selected cargo spaces is date of the Special Survey. For surveys
to be carried out. completed more than 3 months before the expiry
date of the Special Survey, the period of class
6.3.4 Vessels of age more than 15 years will start from the survey completion date.
a) For vessels other than general dry cargo 6.4.1.4 The Special Survey may be commenced
ships, in addition to the requirements given at the 4th Annual Survey and be progressed
in 6.3.3, an internal examination of selected with a view to completion by the 5th anniversary
cargo holds is to be carried out. date. When the special survey is commenced
prior to the fourth annual survey, the entire
b) For general dry cargo ships, the survey is to be completed within 15 months if
requirements of the intermediate survey is such work is to be credited to the special survey
to be to the same extent as the previous and in this case the next period of class will start
special survey as required in 6.4 for hull from the survey completion date.
structure and piping systems in way of the
cargo holds, cofferdams, pipe tunnels, void Concurrent crediting to both Intermediate survey
spaces and fuel oil tanks in the cargo area and Special survey for surveys and thickness
and all ballast tanks. However, tank testing measurements of spaces is not acceptable.
specified in 6.4.6, survey of automatic air
pipe heads specified in 6.4.4.7 and internal 6.4.1.5 For the purpose of special survey,
examination of fuel oil, lub.oil and results of thickness measurement carried out
freshwater tanks specified in Table 6.4.4.1 during or after the fourth annual survey only
need not be carried out unless deemed would be considered.
necessary by the Surveyor. In water survey
complying with the requirements of 7.2 may 6.4.1.6 Record of Special Survey will not be
be accepted in lieu of docking survey assigned until the Machinery Survey has been
required by 6.4.1.11. Thickness completed or postponed in agreement with IRS.
measurement is to be carried out for items 1
to 4 of Table 6.4.8.1b except for item 2d). 6.4.1.7 Ships which have satisfactorily passed a
Special Survey will have a record entered in the
Supplement to the Register Book indicating the for the new period of class of five years to be
assigned date of Special Survey. assigned subject to proper maintenance and
operation and the periodical surveys being
6.4.1.8 For vessels other than general dry cargo carried out at the due dates.
ships, IRS may, at the request of the Owners,
accept a Special Survey of the hull on a 6.4.1.10 The examinations of the hull are to be
continuous basis spread over a period of 5 supplemented by thickness measurements (See
years. Proposals for such continuous Surveys 6.4.8) and testing as deemed necessary, to
are to be submitted for the consideration of IRS. ensure that the structural integrity remains
In general, approximately one-fifth of the Special effective. The aim of the examination is to
Survey is to be completed every year. All discover substantial corrosion, significant
compartments of the hull should be opened for deformation, fractures, damages or other
Survey and testing in rotation such that not more structural deterioration, that may be present.
than 5 years elapse between consecutive
examination of each part. 6.4.1.11 A Docking Survey in accordance with
the requirements of Sec.7 is to be carried out as
The Surveyor may extend the inspection at his part of the Special Survey. Any remaining work
discretion, to other items if the inspections in respect of the overall and close-up surveys
carried out reveal any defects. and thickness measurements, as applicable, of
the lower portions of cargo holds and ballast
The agreement for surveys to be carried out on tanks (i.e. parts below light ballast water line)
a continuous survey system basis may be are to be completed in dry dock.
withdrawn at the discretion of IRS or on the
request of Owners. 6.4.2 Preparation for survey
Ships on continuous survey system are not 6.4.2.1 The ship is to be prepared for overall
exempt from other periodical survey survey in accordance with the requirements of
requirements. For ships more than 10 years of Table 6.4.2.1. The preparation is to be of
age, the ballast tanks are to be internally sufficient extent to facilitate an examination to
examined twice in each five-year class period, ascertain any excessive corrosion, deformation,
i.e. once within the scope of the intermediate fractures, damages and other structural
survey and once within the scope of the deterioration.
continuous system for the hull special survey.
6.4.2.2 Prior to commencement of any part of
Ships which have completed satisfactorily the the special survey, a survey planning meeting is
Survey of all the items on such basis will have a to be held between the attending surveyor(s),
record entered in the supplement to the Register the owner’s representative in attendance, the
Of Ships indicating the date of completion of the thickness measurement company representative
Survey. and the master of the ship or an appropriately
qualified representative appointed by the master
6.4.1.9 The special survey is to include, in or Company for the purpose to ascertain that all
addition to the requirements of the Annual the arrangements envisaged in the survey
Survey, examination, tests and checks of programme are in place, so as to ensure the
sufficient extent to ensure that the hull, safe and efficient conduct of the survey work to
equipment and related piping as required in be carried out.
6.4.4.2 and 6.4.4.3 are in satisfactory condition
and that the ship is fit for its intended purpose
Special Survey No. I Special Survey No. II Special Survey Special Survey
Age ≤ 5 5 < Age ≤ 10 No. III No. IV and
10 < Age ≤ 15 subsequently
Age ≥ 15
1) The holds, tween decks, deep 1) Requirements of Special 1) Requirements of 1) Requirements of
tanks, peaks, bilges and drain Survey I to be complied with Special Survey II to be Special survey III to
wells, engine and boiler spaces, complied with be complied with
coal bunkers and other spaces
are to be cleared out and
cleaned as necessary for
examination. Floor plates in
engine and boiler spaces are to
be lifted as may be necessary
for examination of the structure
underneath. Where necessary
ceiling, lining, casings and loose
insulation are to be removed as
required by the Surveyor for
examination of the structure.
Compositions on the plating are
to be examined and sounded,
but need not be disturbed if
found satisfactorily adhering to
the plating.
2) In ships with single bottom, a 2) In ships having a single 2) Ceiling in the holds 2) Where holds are
sufficient amount of close ceiling bottom, a sufficient amount is to be removed in insulated for the
is to be lifted to enable of ceiling is to be lifted to order to ascertain that purpose of carrying
examination of the structure allow the examination of the the steel work is in refrigerated cargoes,
below. The ceilings to be lifted is structure underneath. The good condition, free limbers and hatches
to comprise of at least two lifting of the ceiling is to from rust and coated. If are to be lifted and a
strakes on each side of comprise of at least three the Surveyor is sufficient additional
centreline fore and aft and one strakes all fore and aft on satisfied, after removal amount of insulation
of these strakes is to be in way each side and one such of portions of the is to be removed in
of the bilges strake one each side to be in ceiling, than it need not each compartment to
way of the bilges. Where the all be removed enable the Surveyor
ceiling is fitted in hatches, to ascertain the
the whole of the hatches and condition of the
at least one strake of planks structure in way and
in way of the bilges on each to enable the
side are to be lifted. If the thickness of the shell
Surveyor considers it plating to be
necessary the whole of the ascertained
ceiling and the limber boards
are to be lifted
Special Survey No. I Special Survey No. II Special Survey Special Survey
Age ≤ 5 5 < Age ≤ 10 No. III No. IV and
10 < Age ≤ 15 subsequently
Age ≥ 15
3) In ships having double 3) In ships with double 3) Portions of wood
bottom, a sufficient amount of bottom, a sufficient amount sheathing, or other
ceiling is to be lifted from the of ceiling in the holds and covering, on steel
tank top and the bilges to enable other spaces is to be decks are to be
the condition of plating removed from the bilges and removed, as
underneath to be ascertain. If the inner bottom to enable considered necessary
the condition of the plating is the condition of the structure by the Surveyor, in
found to be satisfactory, lifting of in the bilges, the inner order to ascertain the
the remainder of the ceiling may bottom plating, pillar feet and condition of the plating
be dispensed with. All bilges are the bottom plating of
to be cleaned for examination. bulkheads and tunnel sides
Where the inner bottom plating to be examined. If the
is covered with cement or Surveyor considers it
asphalt the removal of such necessary, the whole of the
covering may be dispensed with ceiling is to be removed
provided it is found to be
adhering properly to the plating
when carefully examined by
hammering and chipping
4) Where holds are insulated for 4) The chain locker is to be 4) Where the holds are
the carriage of refrigerated cleaned internally. The chain insulated for the
cargoes and the hull in way was cables are to be ranged for purpose of carrying
examined by IRS Surveyors inspection. The anchors are refrigerated cargoes,
prior to the fitting of the to be cleaned and placed in the limbers and
insulation, it will be sufficient to an accessible position for hatches are to be lifted
remove the limbers and hatches inspection and sufficient insulation
for examination of the structure is to be removed in
in way. In all other cases each of the chambers
additional insulation will require to enable the Surveyor
to be removed as considered to satisfy himself of the
necessary to enable the condition of the framing
Surveyor to satisfy himself and plating
regarding condition of the
structure
Special Survey No. I Special Survey No. II Special Survey Special Survey
Age ≤ 5 5 < Age ≤ 10 No. III No. IV and
10 < Age ≤ 15 subsequently
Age ≥ 15
6.4.3.2 For double bottom ballast tanks where a - An overall survey of all cargo holds, pipe
hard protective coating is found in POOR tunnels, cofferdams and void spaces
condition and it has not been renewed or where bounding cargo holds, decks and outer hull
soft or semi-hard coating has been applied, or is to be carried out.
where a hard protective coating was not applied
from the time of construction, the spaces in - All piping systems within the above spaces
question may be examined at Annual Surveys. and in ballast tanks are to be examined and
When considered necessary by the surveyor, operationally tested to working pressure to
thickness measurements are to be carried out. attending Surveyor’s satisfaction to ensure
that tightness and condition remains
6.4.4 Survey and examination satisfactory.
6.4.4.1 All spaces within the hull and - The survey extent of ballast tanks converted
superstructure are to be examined. to void spaces is to be based on the
requirement for ballast tanks.
Notes:
2) If a selection of tanks is accepted to be examined, then different tanks are to be examined at each
special survey, on a rotational basis.
3) Peak tanks (all uses) are subject to internal examination at each special survey.
4) At special survey No.III and subsequent special surveys one deep tank for fuel oil in the cargo area is
to be included, if fitted.
6.4.4.4 All watertight bulkheads and watertight are to be carried out and renewals or repairs
doors are to be examined. made when wastage exceeds allowable limits.
6.4.4.5 All decks, casings and superstructures 6.4.4.7 The hand pumps and suctions, air and
are to be examined. Attention is to be given to sounding pipes are to be examined. The
the corners of openings and other discontinuities Surveyors are to ensure that striking plates are
in way of the strength decks and top sides. fitted under the sounding pipes whilst examining
the tanks internally.
Wooden decks or sheathings are to be
examined and if decay or rot is found or the For vessel other than passenger ships,
wood is excessively worn, the wood should be automatic air pipe heads are to be internally
renewed. examined at special surveys as indicated in
Table 6.4.4.7. For designs where the inner parts
Attention is to be given to the condition of the cannot be properly inspected from outside, the
plating under wood decks, sheathing or other head is to be removed from the air pipe.
deck coverings. Removal of such coverings may Particular attention is to be paid to the condition
be dispensed with if they are found to be sound of the zinc coating in heads constructed from
and adhering satisfactorily to the plating. galvanised steel.
6.4.4.6 Engine room structure is to be 6.4.4.8 The steering gear, and its connections
examined. Particular attention being given to and control systems (main and alternative) are
tank tops, shell plating in way of tank tops, to be examined. The auxiliary steering gear with
brackets connecting side shell frames and tank its various parts are to be examined in working
tops and engine room bulkheads in way of tank condition.
tops and bilge wells. Where excessive areas of
wastage are found, thickness measurements
Table 6.4.4.7 : Requirements for internal examination of automatic air pipe heads
Location Special survey No.I Special survey No.II Special survey No.III
Age ≤ 5 5 < Age ≤ 10 and subsequent
Age > 10
1,2
forward 0.25L Two air pipe heads one All air pipe heads on
port and one starboard on exposed decks
3
exposed decks All air pipe heads on
1,2
aft of 0.25L Two air pipe heads one At least 20% of air pipe exposed decks
1,2
from the port and one starboard on heads on exposed decks
forward exposed decks
perpendicular
6.4.4.9 The Surveyor should satisfy himself 6.4.4.12 The windlass is to be examined.
regarding the efficient condition of the following :
6.4.4.13 The chain locker, hold fasts, hawse
- Means of escape from machinery spaces, pipes and chain stoppers are to be examined
crew and passenger spaces and spaces in and pumping arrangements of the chain locker
which crew are normally employed; tested.
6.4.4.11 The chain cables are to be ranged and The tests are to be carried out with the load
the anchors and the chain cables are to be applied as uniformly as possible along the
examined. At special survey no. II and length of the accommodation ladder or
subsequent special surveys, the chain cables gangway, at an angle of inclination
are to be gauged. Any length of chain cable corresponding to the maximum bending moment
which is found to have reduced in mean on the accommodation ladder or gangway.
diameter at its most worn part by more than 12
per cent of its original rule diameter is to be Accommodation ladder winch is to be
renewed. operationally tested at special surveys. The
brake system of the winch is to be tested for
holding the maximum operational load on the
ladder.
b) checking the effectiveness of sealing 6.4.7.1 The minimum requirements for close-up
arrangements of all hatch covers by hose survey for general dry cargo ships are given in
testing or equivalent. Table 6.4.7.1.
c) checking the residual thickness of The surveyor may extend the close-up survey
coamings, steel pontoon or hatch cover as deemed necessary taking into account the
plating and stiffening members as deemed maintenance of the spaces under survey, the
necessary by the Surveyor. condition of the corrosion prevention system and
where spaces have structural arrangements or
For general dry cargo ships, thickness details which have suffered defects in similar
measurement of plating and stiffeners of hatch spaces or on similar ships according to available
cover and coaming is to be carried out as information.
required by Table 6.4.8.1b.
6.4.7.2 For areas in tanks and cargo holds
where coatings are found in GOOD condition,
the extent of close-up examination may be
specially considered.
Notes:
1) Thickness measurement locations are to be selected to provide the best representative sampling of areas likely
to be most exposed to corrosion considering cargo and ballast history and arrangement and condition of
protective coatings.
2) Thickness measurements of internals may be specially considered by the Surveyor if the hard protective
coating is in GOOD condition.
3) For ships less than 100 [m] in length, the number of transverse sections required at Special Survey No.III may
be reduced to one (1) and the number of transverse sections required at Subsequent Special Surveys may be
reduced to two (2).
4) For ships equal to or more than 100 [m] in length, at special survey No.III, additional thickness measurements
of exposed main deck plating within amidship 0.5L may be required.
Notes:
1. Thickness measurement locations should be selected to provide the best representative sampling of areas
likely to be most exposed to corrosion, considering cargo and ballast history and arrangement and condition of
protective coatings.
2. For ships less than 100 metres in length, the number of transverse sections required at Special Survey No. III
may be reduced to one and the number of transverse sections at Special Survey No. IV and subsequent
surveys may be reduced to two.
6.4.8.2 For general dry cargo ships, thickness measurements may be specially
representative thickness measurement to considered by the Surveyor.
determine both general and local levels of
corrosion in the shell frames and their end 6.4.8.4 Transverse sections are to be chosen
attachments in all cargo holds and ballast tanks where the largest reductions are suspected to
is to be carried out. occur or are revealed from deck plating
Thickness measurement is also to be carried out measurements.
to determine the corrosion levels on the
transverse bulkhead plating. 6.4.8.5 The thickness measurements are to be
carried out by a qualified firm certified by IRS.
The thickness measurements may be dispensed
with provided the surveyor is satisfied by the 6.4.8.6 In order to ensure necessary control
close-up examination, that there is no structural during the process of thickness measurements,
diminution and the hard protective coating these are normally to be carried out under the
where applied remains efficient. supervision of the Surveyor. The Surveyor has
the right to re-check the measurements as
6.4.8.3 For areas in tanks where coating are deemed necessary to ensure acceptable
found to be in a GOOD condition, the extent of accuracy.
Table 6.4.8.2 : Guidance for additional thickness measurements in way of substantial corrosion
Section 7
Docking Surveys
An extension of examination of the ship’s bottom 7.1.6 The propeller should be examined for
of 3 months beyond the due date can be erosion, pitting, cracking of blades or possible
granted in exceptional circumstances due to any contact damage. The clearance in the stern
of the following reasons: bush should be measured. In the case of
approved oil glands, measurements by poker
a) Non-availability of drydocking facilities, gauges or other devices for ascertaining the
repair facilities, essential materials, stern bush weardown may be accepted,
equipment or spare parts. provided the sealing arrangements appear
satisfactory.
b) Delays incurred by action taken to avoid
severe weather conditions or delays caused 7.1.7 For controllable pitch propellers, the
by severe weather conditions. Surveyor is to be satisfied with the fastenings
and tightness of hub and blade sealing.
7.1.2 The ship is to be placed on blocks of Dismantling need not be carried out unless
sufficient height in a drydock or on a slipway and considered necessary by the Surveyor.
proper staging is to be erected as may be
necessary. Shell plating, stern frame or stern 7.1.8 Exposed parts of steerable propellers,
post, rudder and sea inlet and discharge azimuth thrusters, side thrusters, vertical axis
openings are to be examined. Particular propellers and waterjet units are to be
attention is to be given to the bilge keels and examined.
their connection to the bilge strake, shell plating
in way of side, bow and stern doors, ash shoots, 7.2 In-water surveys
and other openings and to parts of the structure
particularly liable to excessive corrosion or to 7.2.1 Eligibility
deterioration from causes such as chafing and
lying on the ground and to any undue unfairness 7.2.1.1 For ships less than 15 years in age the
of the bottom plating. Important plate unfairness examination of the outside of ship's bottom and
or other deterioration which do not necessitate related items of ships may be carried out while
immediate repairs are to be recorded. the ship is afloat (inwater survey) in lieu of the
required intermediate docking between special
Visible parts of rudder, rudder pintles, rudder surveys provided following conditions are
shafts and couplings are to be examined. The satisfied.
clearances in the rudder bearings are to be
ascertained. The rudder is to be lifted for a) The ship has been assigned the class
examination of the pintles, if considered notation INWATER SURVEY as defined in
necessary by the Surveyor. Where applicable, Ch.1. However, on application by the owner
pressure test of the rudder may be required as and in special circumstances, such inwater
considered necessary by the Surveyor. survey may be considered for ships not
assigned with the class notation INWATER
7.1.3 When the chain cables are ranged the SURVEY.
anchors and cables should be examined by the
Surveyor. b) The ship does not have any outstanding
recommendations which require repair work
7.1.4 Sea chests and their gratings, sea in dry dock to the underwater part of the
connections and overboard discharge valves shell plating, the rudder, the propeller or the
and cocks and their fastenings to the hull or sea propeller shaft.
chests are to be examined. Valves and cocks
- rudder and fittings 7.2.3.1 The in-water survey is to provide all the
information normally obtained from a docking
- sternpost survey. However, special consideration may be
given to ascertaining rudder bearing clearances
- propeller, including the means used for and stern bush clearances of oil stern bearings
identifying each blade based on a review of the operating history, on
board testing and stern tube oil sample reports.
- anodes, including securing arrange- These details are to be included in the proposals
ments for in-water surveys which are to be submitted in
advance of the survey so that satisfactory
- bilge keels arrangements can be agreed with IRS.
- welded seams and butts. 7.2.3.2 The in-water survey is to be carried out
with the ship in as light condition as possible in
The plans are also to include the necessary sheltered water preferably with weak tidal
instructions to facilitate the divers' work, streams and currents. The in-water visibility and
especially for taking clearance measurements. the cleanliness of the hull below the waterline is
to be good enough to permit a meaningful
7.2.2.2 The plans for approval are also to examination which allows the Surveyor and
include the procedure for measurement or diver to determine the condition of the plating,
verification, as the case may be, of the following: appendages and the welding. IRS is to be
satisfied with the methods of orientation of the
- rudder pintle/bush clearance divers on the plating, which should make use
where necessary of permanent markings on the
- stern bush clearance plating at selected points.
- pintle securing arrangement in the 7.2.3.3 The in-water survey is to be carried out
socket. by a person who is a skilled diver and trained to
carry out in-water survey, or a qualified diver
7.2.2.3 As far as practicable, a photographic under surveillance of a Surveyor. The diver has
documentation, used as a reference during the to be employed by a firm approved by IRS.
in-water surveys, of the following hull parts is to
be submitted to IRS: The equipment, procedure for observing and
reporting the survey are to be discussed with the
- propeller boss parties involved prior to the in-water survey and
suitable time is to be allowed to enable the
- rudder pintles, where slack is measured diving company to test all equipment
beforehand.
- typical connections to the sea
7.2.3.4 When professional divers are employed,
- directional propellers, if any the Surveyor is to be satisfied with the method
of pictorial representation, and a good two-way
communication between the Surveyor and undertaken and the necessary repairs carried
divers is to be provided. out.
7.2.3.5 If the in-water survey reveals damage or 7.2.3.6 The condition of the coating is to be
a deterioration that requires early attention, the confirmed at every drydocking for continuance
Surveyor may require that the ship to be of the INWATER SURVEY notation.
drydocked in order that a detailed survey can be
Section 8
receiver is not practicable it is to be tested Surveyor. All safety devices for the foregoing
hydraulically to 1.3 times the working pressure. are to be examined.
8.4.2 Air compressors are to be opened up and 8.8.3 Non-metallic expansion joints in piping
coolers tested as considered necessary by the systems, if located in system which penetrates
Surveyor. Selected pipes in the starting air the ship's side and both the penetration and the
systems are to be removed for internal non-metallic expansion joint are located below
examination and hammer tested. If an the deepest load waterline, are to be examined
appreciable amount of lubricating oil is found in and replaced as necessary or at an interval
the pipes the starting air system is to be recommended by the manufacturer.
thoroughly cleaned by steaming or other
suitable means. Some of the pipes selected are 8.9 Survey requirements: Reduction gears,
to be those adjacent to the starting air valves at flexible couplings and clutch arrangements
the cylinders and to the discharges from the air
compressors. 8.9.1 Reduction gears, flexible couplings and
clutch arrangements are to be opened as
8.5 Survey requirements: Fresh water considered by the Surveyor in order to permit
generators and evaporators the examination of the gears, gear teeth,
spiders, pinions, shafts and bearings, reversing
8.5.1 To the extent applicable, these are to be gears, etc. Essential parts of other power
opened up and examined. After such Survey transmission arrangements are to be opened up
their relief valves are to be checked under and examined as considered necessary by the
working conditions, where practicable. Surveyor.
8.6 Survey requirements: Fuel tanks 8.10 Survey requirements: Securing arran-
gements
8.6.1 Fuel tanks which do not form part of the
ship's structure are to be examined externally 8.10.1 Holding down bolts and chocks of main
and, if considered necessary by the Surveyor and auxiliary engines, gear cases, thrust blocks
also internally. All mountings, fittings and remote and tunnel bearings are to be checked.
control devices are to be examined as far as
practicable. All such tanks are to be tested by 8.11 Survey requirements: Shafting
filling to maximum working level.
8.11.1 Intermediate shafts and bearings, thrust
8.7 Survey requirements: Pumps, heat bearings and their seating are to be examined.
exchangers, forced draught fans, etc. The lower halves of bearings need not be
exposed if alignment and wear are found
8.7.1 All pumps, heat exchangers, forced acceptable.
draught fans, etc. used for essential purposes
are to be opened up and examined as 8.12 Survey requirements: Sea connections
considered necessary by the Surveyor.
8.12.1 All openings to the sea including sanitary
8.8 Survey requirements: Pumping and and other overboard discharges in the
piping system machinery spaces and pump rooms together
with valves and cocks are to be examined
8.8.1 The valves, cocks and strainers of the internally and externally. The fastenings of
bilge system including bilge injection are to be valves and cocks to the hull are to be examined
opened up as considered necessary by the and are to be renewed when considered
Surveyor and, together with pipes, are to be necessary by the Surveyor. Particular attention
examined and tested under working conditions. is to be given to the sea suctions and sea water
If non-return valves are fitted in hold bilges, cooling pipes.
these be opened up for examination.
8.13 Survey requirements: Windlass and
8.8.2 The oil fuel, feed and lubricating systems steering machinery
and ballast connections and blanking
arrangements to deep tanks which may carry 8.13.1 These are to be examined to ascertain
liquid or dry cargoes, together with all pressure that they are in good working order. Any relief
filters, heaters and coolers used for essential valves fitted are to be included in the above
service, are to be opened up and examined or examination.
tested as considered necessary by the
8.19.5 Transformers are to be examined. 8.20.1 On ships which are electrically propelled,
Samples of oil are to be taken and tested for the main propulsion motors, generators, cables,
breakdown voltage, acidity and moisture in case together with all ancillary electrical gear, exciters
of oil immersed transformers or electrical and ventilating plant (including coolers) are to be
apparatus associated with supplies to essential examined and their insulation resistance to earth
services. The testing is to be carried out by a to be measured. Protective gear and alarm
competent testing authority and a certificate devices are to be checked as far as practicable
giving the test results is to be furnished to the and special attention should be given to
Surveyor. windings, commutators and slip rings. Safety
interlocks intended to prevent unsafe operation
8.19.6 Motors used for essential services or unauthorised access are to be checked to
including their starters are to be examined, and verify that they are functioning correctly.
under working conditions if considered Emergency over speed governors are to be
necessary by the Surveyors. tested. Where insulating oil is used, samples of
oil are to be taken and tested for breakdown
8.19.7 Generators and steering gear motors are voltage, acidity and moisture by a competent
to be examined under working conditions. Air testing authority and a certificate giving the test
gaps are to be checked for excessive wear results is to be furnished to the Surveyor.
down.
8.21 In service testing of large permanently found, hydraulic test to 1.25 x design
installed breathing gas containers onboard pressure to be carried out.
diving vessels - Special Requirements
At subsequent special surveys, following to be
8.21.1 At the first special survey, following is to carried out:
be carried out:
- External and internal survey, by intrascope if
- External and internal survey, by intrascope if necessary.
necessary.
- Hydraulic test to 1.25 x design pressure.
- If internal survey is not possible or if
corrosion or other items of concern are
Section 9
Boiler Surveys
9.1.2 At each Survey, the boilers, superheaters, 9.1.6 Principal boiler mountings and safety
economisers, air heaters, desuperheaters, and valves are to be examined at each Survey. The
other equipment are to be examined internally remaining mountings are to be opened if
(water/steam side) and externally (fire side) as considered necessary by the Surveyor. Manhole
considered necessary. and hand hole doors, are to be examined to
ensure that the joining faces are in good
In exhaust gas heated economizers of the shell condition and that the clearances at the spigot
type, all accessible welded joints are to be are satisfactory.
subjected to a visual examination for detection
of cracks. Nondestructive testing may be 9.1.7 In case where it is considered necessary,
required for this purpose. the parts subjected to pressure are to be
hydraulically tested and the thickness of plates
9.1.3 Boiler safety valve and its relieving gear and size of stays ascertained to determine the
are to be examined and tested to verify safe working pressure. Collision chocks, rolling
satisfactory operation. The adjustment of the stays and boiler stools are to be examined and
safety valves is to be verified during each boiler maintained in efficient condition. The shell
internal survey. Safety valves are to be adjusted plating in way of welded lugs or fabricated feet
to a pressure not greater than 3 percent of the are to be carefully examined at each Survey.
approved working pressure. Insulation and sheathing in way are to be
removed as considered necessary for this
9.1.4 Review of the following records since the purpose.
last boiler survey is to be carried out as part of
the survey: In fired boilers employing forced circulation the
pumps used for this purpose are to be opened
a) Operation and examined at each boiler Survey.
b) Maintenance
c) Repair history 9.1.8 The proper operation of the water level
d) Feed water chemistry indicators are to be confirmed at each Survey.
The oil fuel burning system is to be examined
9.1.5 External survey of boilers including test of under working conditions and a general
safety and protective devices and test of safety examination made of the fuel tank valves, pipe,
valve using its relieving gear, is to be carried out deck control gear and oil discharge pipes
annually, within the window of the Annual between pumps and burners.
Survey of a ship. For exhaust gas heated
9.1.9 An extension of the internal examination of 9.2.2 At each steam heated steam generator
the boiler upto 3 months beyond the due date survey the mountings and the safety valves are
can be granted in exceptional circumstances. to be examined. Manhole and hand hole doors
“Exceptional circumstances” means are to be examined to ensure that joining faces
unavailability of repair facilities, unavailability of are in good condition and that the clearances at
essential materials, equipment or spare parts or the spigot are satisfactory.
delays incurred by action taken to avoid severe
weather conditions. The extension may be 9.2.3 Where it is considered necessary, parts
granted by IRS after the following is subjected to pressure are to be hydraulically
satisfactorily carried out: tested and the thickness of plates and the sizes
of stays ascertained to determine the safe
a) External examination of the boiler working pressure.
b) Boiler safety valve relieving gear 9.2.4 The proper operation of the water level
(easing gear) is examined and indicators is to be confirmed at each Survey.
operationally tested. The safety valves of the steam heated steam
generator are to be adjusted to a pressure not
c) Boiler protective devices operationally greater than 3 per cent above the approved
tested. working pressure.
Section 10
Section 11
11.1.1 At tailshaft surveys, propeller shafts and 11.2.1 Conventional propeller shaft surveys
tube shafts, if any, are to be sufficiently drawn to
permit entire examination at intervals as detailed The survey, is normally to include complete
in Sec.1 of this Chapter. withdrawal of the propeller shaft and
examination of following, as applicable:
For the purpose of these requirements, “Tube-
shaft” means a detachable part of the propulsion - measurement of wear down;
shafting passing through the stern tube, which is
coupled to the intermediate shaft at the forward - propeller nut and propeller shaft threaded
end and to the propeller shaft at the aft end. end;
For vessels with Tailshaft Condition Monitoring - cone, key and keyway, including
(TCM) notation, the alternative requirements examination by an efficient crack detection
given in 11.5 are to be complied with. method of the after end of the cylindrical
part of the shaft and one third of the length
11.1.2 Where propeller shafts are fitted with of the taper from the big end;
approved oil glands or continuous liners, which
effectively prevent sea water from contacting the - where propeller is fitted by a solid flanged
steel shaft, or are made of approved corrosion coupling at the after end of the shaft, non-
resisting material; the tailshaft surveys can be destructive examination of the flange fillet
carried out at an interval of 5 years provided: area of the shaft may be required if the
visual examination of the area is not
a) In case of keyed propellers, the propeller satisfactory;
shafts are of a design having features which
would reduce stress concentrations in the shaft - propeller shaft bearing areas;
in way of the propeller assembly, or
- stern bushes/bearings;
b) the propellers are fitted to a solid flange
coupling at the end of the shaft, or - shaft sealing arrangements, including
lubricating oil system;
c) the propellers are fitted key less to the shaft
taper. 11.2.2 Steerable and azimuth thrusters
All other shafts are to be surveyed at intervals of The survey is to normally comprise of
2.5 years. examination of the following:
11.1.3 Upon application by the Owners, IRS a) Exposed parts including attachment to the
may consider, a modified survey as detailed in hull.
11.3 for shafting arrangements which have been
assigned TS(OG) notation and where new oil b) The following items upon removal of
seals can be fitted without removal of the propeller:
propeller (except in the case of keyed
propellers). On satisfactory completion of - propeller shaft threaded end and nut;
modified survey, notation TS(OGM) would be - cone, key and keyway including
assigned. examination by an efficient crack
detection method of fore part of the
11.1.4 Upon application by the Owners, IRS shaft cone;
may consider, for shafting arrangements where - sealing glands.
modified survey is applicable, a postponement
of the survey for a maximum period of half the c) Lubricating oil analysis (to include wear
specified survey cycle provided a partial survey particle analysis) records to detect possible
as detailed in 11.4 is held. wear of internal gears and bearings.
d) Internal gears and control gears as far as a) Analysis of hydraulic oil including wear
practicable through hand holes or limited particle analysis.
opening of controlling device.
b) Propeller blades and hub including crack
If the above checks are not satisfactory, detection of blade root, flange and blade
complete dismantling of the internal parts may securing arrangements.
be required.
c) Examination of seals, carrier bearings,
11.2.3 Vertical axis propellers crank pin ring, fillets, blade openings in the
boss and blade bolts, upon removal of at
The survey is to normally comprise of lest one blade.
examination of the following:
d) Examination of distribution box seal and
a) Exposed parts. bearings.
b) Tightness of the oil glands and the backlash e) Verification upon re-assembly of,
of the gears from outside by action on the servomechanism and hydraulic test of hub
blades. and hydraulic piping including pitch controls
together with limit stops.
c) Gears, as far as practicable through hand
holes and observation ports. 11.3 Modified survey
d) Control gear for proper functioning. 11.3.1 The modified survey is accepted at
alternate surveys, provided that the clearances
e) Lubricating oil analysis (to include wear of the aft bearing are found in order and the oil
particle analysis) records to detect possible and the oil sealing arrangements have proved
wear of internal gears and bearings. effective.
If the above checks are not satisfactory, 11.3.2 The modified survey consists of:
complete dismantling of the internal parts may
be required. - drawing the shaft to expose the aft bearing
contact area of the shaft,
11.2.4 Water jet systems
- examining the forward bearing as far as
The survey is to normally comprise of possible and all accessible parts of the shaft
examination of the following: including the propeller connection to the
shaft, and
a) Impeller, shaft and bearing clearances.
- for keyed propellers, performing a non-
b) Sealing glands. destructive examination by an approved
crack detection method of about one third of
c) Nozzle assembly. the length of the taper from the big end, for
which dismantling of the propeller will be
d) Control and reversing gear. required,
The propellers are fitted to a solid flange c) For shafts with controllable pitch propeller
coupling at the end of the shaft, or mounted on solid flange coupling:
The propellers are fitted keyless to the shaft - Verification of tightness in way of blade
taper. glands and distribution box
Section 12
12.1 General
- high water level in scrubber;
12.1.1 Inert gas systems installed on board - failure of the inert gas blowers;
ships intended for the carriage of oil or liquid - failure of the power supply to the automatic
chemicals in bulk or liquefied gases are to be control system for the gas regulating valve
surveyed periodically as detailed in Sec.1 of this and to the instrumentation for continuous
Chapter. indication and permanent recording of
pressure and oxygen content in the inert
12.2 Annual surveys gas main;
- high pressure of gas in the inert gas main.
12.2.1 Following are to be examined at each - Surveys carried out by the National
Annual Survey: Authority of the country in which the ship is
registered would normally be accepted as
a) external examination of the condition of all meeting these requirements, at the
piping and components for signs of discretion of the Surveyor.
corrosion or gas/effluent leakage.
12.2.2 Checking when practicable, the proper
b) verification of the proper operation of both operation of the inert gas system on completion
inert gas blowers. of the checks listed in 12.2.1 h).
Section 13
13.4.7 Primary refrigerant cooler coils and grids bearings need not be exposed if the Surveyor is
are to be examined whilst under the refrigerant satisfied as to alignment and wear.
pressure prevailing in the system at the time of
the Survey with the plant at rest and the 13.5.2 For screw-type compressors, the period
regulating valves opened just sufficient to obtain before opening up may be extended to 6 years
an approximate balance of pressure throughout or 25000 running hours, whichever is the earlier.
the system and to avoid accumulation of liquid in
the coils or grids. 13.5.3 Where there is a programme of
replacement instead of Surveys on board,
13.4.8 The shells of condensers, evaporators, alternative Survey arrangements will be
separators, receivers, and other pressure considered. Each case will be given individual
vessels are to be examined as far as consideration.
practicable. Any evidence of excessive
corrosion of water end covers of "shell and tube" 13.5.4 Refrigerant condenser cooling water
and "double-pipe" type condensers is to be pumps, including standby pump(s) which may
investigated. be used on other services, are to be opened up
and their working parts exposed.
13.4.9 Primary refrigerant gas and liquid pipes,
condenser cooling water piping and valves are 13.5.5 Brine and primary refrigerant pumps are
to be examined as far as possible. to be opened up and their working parts
exposed. Special consideration will be given to
13.4.10 Any evidence of dampness or Survey requirements for primary refrigerant
deterioration of the insulation which could lead pumps of the hermetically sealed type.
to external corrosion of the vessels or other
parts mentioned, is to be investigated and 13.5.6 The water end covers of "shell and tube"
necessary measures are to be taken to correct and "double-pipe" type condensers are to be
the defects thus ascertained. removed for examination of the tubes, tube
plates and covers.
13.4.11 A general examination is to be made of
the fans, their motors, control gear and the 13.5.7 The shells and connections of "shell-and-
insulation resistance is to be measured. The tube" and "double-pipe" type condensers and
insulation resistance is not to be less than evaporators, separators, receivers, driers, filters
100,000 ohms. The generating plant supplying and other pressure vessels, and the coil
electric power is to be examined generally with a terminals of "coil-in-casing" type condensers
view to ascertaining that the plant is being and evaporators, are to be examined as far as
efficiently maintained. practicable.
13.4.12 The thermometers for measuring the 13.5.8 In the case of pressure vessels covered
chamber air suction and air delivery by insulation, any evidence of dampness or
temperatures are to be examined. If repairs and deterioration of the insulation which could lead
renewals are carried out, the thermometers are to external corrosion of the vessels or their
afterwards to be checked for accuracy. connections is to be investigated.
13.4.13 A Survey book or other permanent 13.5.9 Sufficient insulation is to be stripped from
record is to be kept on board the ship to show insulated pressure vessels to allow the condition
the date of examination of various parts. This is of the vessels and their connections to be
to be available to the Surveyor at all times and is ascertained. Care is to be taken that in
to be signed by the Surveyor on each occasion replacement of the insulation, the vapour sealing
after the Survey. of the outer covering is made good.
suitably coated and taped, after pressure 13.5.19 Due consideration is to be given to the
testing, to prevent corrosion. On replacement of type of insulation used in the holds and
the insulation, the vapour sealing of the outer chambers when determining the amount of
covering is to be made good. insulation lining to be removed as detailed in
13.5.17 and 13.5.18. Where organic foam
13.5.11 The Surveyor is to satisfy himself that all insulants have been used, including foamed "in
pressure relief valves and/or safety discs situ", or other insulants in slab form, the
throughout the refrigerating plant are in good Surveyor should use his discretion regarding the
order. However, no attempt is to be made to test removal of linings if he is able to satisfy himself
primary refrigerant pressure relief valves on that the condition of the insulation is good by
board ship. means of test bore holes.
13.5.16 All automatic controls and alarms are to 13.7.2 In the case of ships engaged on voyages
be tested. of less than two months duration, a loading port
certificate will be considered as valid for two
13.5.17 Sufficient air trunking and insulation months, provided the cargoes carried are of
lining is to be stripped from the chamber's such a nature as not to damage the insulation or
overhead and vertical surfaces to allow the appliances in the insulated chambers, nor to
condition of the insulation, insulation linings, affect by taint or mould the refrigerated cargoes
grounds, supports, hangers and fixtures which loaded during that period.
support the insulation, grids, meat rails, etc., to
be ascertained. Care is to be taken that on 13.7.3 If a vessel loads at more than one port,
replacement the ducts and linings are sealed Loading Port Survey at the first Loading Port
against air blowing into the insulation, or against would only be required provided all the
moisture ingress from refrigerated cell or space chambers which are intended to be loaded with
atmosphere. refrigerated cargo during the voyage are offered
for examination and no general cargo is
13.5.18 Sufficient tank top insulation is to be subsequently loaded in these chambers prior to
stripped to allow the condition of the grounds loading of refrigerated cargo.
and inner insulation lining to be ascertained.
Ammonia (NH3) or
Dichlorodifluoro-
Item Monochlorodifluoro- Carbondioxide (CO2)
methane (R12)
methane R22)
"Shell and tube" type 7 bar 14 bar -
gas condensers or gas
evaporators (brine Water or brine end covers to be removed and shell pneumatically tested with
coolers) (primary the refrigerant or air or a mixture of inert gas and refrigerant to the above
refrigerant in the shell) pressures
17 bar 70 bar 140 bar
"Coil in casing" type
gas condensers Where it is impracticable to remove the coils they may be examined and
tested in place
"Coil in casing" type 14 bar 35 bar 105 bar
gas evaporators (brine Where it is impracticable to remove the coils they may be examined and
coolers) tested in place
Primary refrigerant
chamber grids or air 7 bar 10 bar 70 bar
cooler coils
"Shell and tube" type Primary refrigerant end covers are to be removed and tested
gas evaporators (brine
coolers) (brine is in the Shell to be hydraulically tested to twice the design pressure but not less than 3
shell) bar
Section 14
full power trials are carried out at the time of - Independent gas generators.
the survey in the presence of a Surveyor.
- M.E. driven pumps, e.g. bilge, lubricating oil, 14.3 Machinery not acceptable for Survey by
cooling water. Chief Engineers
- Independently driven pumps and associated
motors and cables where insulation - Main engine crankshaft and bearings in
resistance readings are supplied e.g. bilge, single engine installations where special
ballast, fresh water cooling, sea water requirements in 14.2.1 are not complied with
cooling, lubricating oil, oil fuel transfer. - Reduction/increase gearing, flexible coup-
- M.E. fresh water and lubricating oil coolers. lings and clutches.
- Low pressure heaters used in fuel oil - Holding down bolts and chocks
systems of internal combustion engines - Crankcase doors, crankcase and scavenge
- Main and auxiliary condensers/drain relief devices
coolers. - Boilers and all other pressure vessels
- Air compressors including their safety - Boiler fuel oil heaters
devices. - Steam pipes and starting air pipes
- Windlass and windlass machinery. - Maneuvering valves and bulkhead stop
- Forced or induced draught fans. valves
- Auxiliary oil and steam engines including - Steering machinery
their coolers and pumps (provided the - Pumping arrangements for Bilge/Ballast/
number of generating sets is such that all Fuel Oil/Fresh Water/Sea water/Lub.Oil/ Fire
services essential to the propulsion and - Electrical equipment other than that defined
safety of the ship, also the preservation of in 14.2.1
refrigerated cargo, can be supplied when - Propellers
any two sets are not working. One of these - Screwshafts
sets can be overhauled while the other - Sea connections
remains as "stand-by"). - M.E. controls, bridge, centralised or
- Intermediate shafts. automatic and controls in unmanned
- Main engine thrust bearing. machinery spaces
- Engine trial
Note : In cases where torsional vibration - First start arrangements trial.
characteristics indicate that there is no
susceptibility to damage as a result of Ships fitted with Approved Inert Gas Systems
uneven firing and the condition monitoring
equipment defined in 14.8.1.1 is installed, a - All other I.G. system components not listed
special arrangement may be granted in 14.2.1.
whereby the Chief Engineer is permitted to
survey the main engine crankshafts and 14.4 System Administration
bearings on single engine installations
provided a modified confirmatory survey is 14.4.1 The Owner is to make a formal request to
carried out by IRS Surveyors at the time of IRS providing the documentation and
the annual audit as follows: information detailed in 14.4.2 below for approval
of the system.
- Check condition-monitoring records.
(See 14.8.1.1) 14.4.2 The documentation and information to be
- Check bearing clearances where submitted is to include the following:
possible.
- Check for signs of wiped or broken a) A description of the system and its
white metal in crankcase. application onboard and organizational
- Check witness marks of shrink fits. interface identifying the areas of
responsibility ashore and the people
- Check bed plate structure inside and responsible for the PMS onboard.
outside.
- Obtain Chief Engineer's statements b) The list of items of machinery, equipment
regarding crankpins, journals and bearings. and components to be considered for
inclusion in the PMS. The list is to be same
Ships fitted with Approved Inert Gas Systems in terms of description and identification with
the identification system adopted by IRS.
- Scrubber units
- Blowers
This is to include a system for reporting to 14.5.3 The PMS is retained throughout the class
Owners, records to be maintained onboard period of the vessel provided that :
and at Owner’s head quarters.
a) An annual report covering the year’s service
f) A list of all personnel likely to be in-charge is submitted to IRS detailing the list of items
of the PMS system. of machinery and components which were
subjected to preventive maintenance in the
14.4.3 Computerized system requirement period under review, together with
preventive maintenance sheets, the
14.4.3.1 The access to and updating the condition monitoring data including all data
maintenance documentation and the since last dismantling and any changes to
maintenance program is to be permitted by the PMS documentation.
Chief Engineer or other authorized person only.
b) An annual audit of the PMS is carried out.
14.4.3.2 The system is to be suitably protected
by suitable password access w.r.t. alterations to c) Any change to the PMS is submitted to IRS
maintenance schedules, list of items under PMS for approval.
and noting of damages.
14.5.4 The survey agreement for machinery
14.4.3.3 The computerized system is to include according to PMS will be withdrawn by IRS if the
a backup procedure, which is activated at PMS is not satisfactorily operated in terms of
regular intervals. improperly maintained records or unsatisfactory
condition of machinery or failure to observe the
14.4.3.4 The functional applications of these agreed intervals between overhauls.
computerized systems are to be approved by
IRS. 14.5.5 The Owner may discontinue the PMS at
any time by informing IRS in writing. In such a
14.4.4 Information to be available onboard. case the items that have been inspected under
the PMS since last annual audit may be credited
a) All the documentation listed in 14.4.2, duly for IRS records at the discretion of the attending
updated. surveyor carrying out confirmatory surveys.
14.5.6 In case of sale or change of management d) The attending surveyor after verification of
of the ship the PMS will require to be re- records on board for the identification details
approved. of the Chief Engineers who have
undertaken the maintenance activity and
14.6 System Surveys prepared the reports given in c), for
compliance with the approved PMS, and
14.6.1 Confirmation Survey is to be carried out upon satisfactory general examination and
by an IRS Surveyor within one year from the confirmatory surveys will credit the items for
date of the documentation approval. The scope survey.
of this survey is to verify that :
e) Where condition monitoring equipment is in
a) The PMS is implemented as per the use, function tests, confirmatory inspections
approved documentation and is suitable to and random check readings are to be
the type and complexity of machinery and carried out as far as practicable and
systems onboard. reasonable at the discretion of the surveyor.
Where the condition and performance of the
b) The documentation required for the annual items are within specified approved limits,
audit is available and the adopted system is these items can be credited for survey
able to produce such a report. without opening up.
c) The requirements of surveys and testing for f) Written reports of break down or malfunction
continuing the class status are complied are to be made available.
with.
g) If the surveyor is not satisfied with results of
d) The shipboard personnel are familiar with the PMS i.e. with degree of accuracy as
the PMS procedures including regards the maintenance records and/or the
documentation. general condition of the machinery, a report
will be forwarded to IRS recommending that
14.6.2 Annual Audit is to be carried out once the special arrangements dealing with
the PMS is implemented and approved, to verify machinery surveys be suspended.
the continued compliance with the documented
PMS. The annual audit is carried out in h) Upon satisfactory completion of the annual
conjunction with the annual class surveys. The audit the surveyor confirms the validity of
scope of the audit is to be as given in the the PMS by crediting the PMS Annual audit.
following :
14.7 Damage and repairs
a) The Surveyor is to verify that the PMS is
correctly operated and that all items (due for 14.7.1 Damage to components or items of
survey in the relevant period) have actually machinery covered by the PMS which may
been surveyed in due time. affect the class is to be reported to IRS
immediately. A surveyor will attend on board,
b) The Surveyor is to verify that the machinery survey the damage and on the basis of the
has been functioning satisfactorily upon survey results decide whether condition of class
review of the maintenance and performance is to be recommended.
records since the previous survey or audit
and where needed necessary measures 14.7.2 All parts of machinery or components,
have been taken in response to machinery which need to undergo substantial repairs, are
operating parameters exceeding acceptable to be surveyed by IRS before, during and after
limits and that the overhaul intervals have the repairs, as deemed appropriate by the
been observed. attending surveyor.
14.8.1.1 For the main propulsion diesel engine - Exhaust gas temperatures for each cylinder
the following parameters are to be monitored. and before and after turbochargers
- Engine cooling system temperatures and
- Shaft horse power pressures
- Engine and shaft RPM - Engine lubricating oil system temperatures
- Indicator diagrams (both power and injection and pressures
timing), where applicable - Turbocharger RPM and vibration
- Fuel oil temperature and/or viscosity - Lubricating oil analysis data
- Charge air pressure - Crankshaft deflections.
- Exhaust gas temperatures for each cylinder
and before and after turbochargers 14.8.1.4 For other auxiliary machinery the
- Engine cooling system temperatures and following parameters are to be monitored.
pressures
- Engine lubricating oil system temperatures - Cooler inlet and outlet temperatures and
and pressures efficiencies
- Turbocharger RPM and vibration - Inlet and outlet temperatures of heaters
- Lubricating oil analysis data - Pumps and fans vibration and performance
- Crankshaft deflections data
- Main bearing temperatures. - Differential pressures across filters serving
essential systems.
14.8.1.2 For the main and auxiliary steam
turbines the following parameters are to be
monitored.
Section 15
15.1 For tankers and combination carriers cargoes and electrical continuity / bonding
with notation VCS1 arrangements.
At each annual survey, the vapour emission Confirmation of the proper operation of the
control system is to be generally examined for vapour manifold isolating valve, including
ensuring its satisfactory condition. The survey is manual operation.
also to include:
c) Vapour connection flanges
a) Components and piping
Confirmation of the continuing effectiveness of
External examination of all components and the “lug and hole” construction of the vapour
piping, including isolating / relief valves, means connection flange(s), or other approved means
of collecting and draining condensate, means for of preventing misconnection of the loading hose
separation of vapours from non-compatible to the vapour collection system.
f) Cargo gauging system All valves, including cargo tank isolating valves,
main vapour line cross-over valves (where fitted
Correct operation of the closed cargo gauging for vapour segregation), condensate drain
system for each tank, which is connected to the valves, manifold isolating valves, pressure /
vapour collection system. Where portable vacuum relief valves and spill valves / rupture
gauging devices are used, the number of disks (where fitted as additional overfill control
devices available are to be equal to the number devices) are to be examined.
of tanks that can be simultaneously loaded plus
two (2) additional units. b) Gauging system
g) Cargo tank venting system The closed gauging system, including portable
gauging devices where applicable, is to be
Examination of the cargo tank venting system, examined.
including flame screens, where fitted.
c) Alarms
h) Alarms and safety devices
The independent cargo tank overfill alarms,
Verification of the satisfactory operation of the where fitted, are to be examined.
following alarms and safety devices using
simulated conditions, where necessary. d) Hoses
- High vapour pressure in main vapour Vapour collection system hoses are to be tested
collection line(s) (not required for tank for electrical continuity or non-conductivity, as
barges). applicable.
- Cargo tank overfill (high-high liquid level), 15.2 For tankers and combination carriers
where fitted. with notation VCS2
b) Vapour manifold
15.2.2 Special surveys
Confirmation that a means of electrical
insulation (insulating flange or non-conductive At each Special Survey – Machinery, in addition
hose, etc.) is provided for the vapour manifold to the requirements of 15.1.2 and 15.2.1, the
connection. following items of the vapour emission control
system are to be examined for ensuring its
c) Fixed oxygen analyzer satisfactory condition:
Confirmation of the accuracy of the fixed oxygen a) Vapour Blowers / Compressors and
analyzer (required to be fitted within 3 [m] (10 detonation flame arresters
feet) of the vessel’s vapour manifold connection)
by means of a calibration gas. Vapour blowers / compressors and detonation
flame arresters, where fitted, are to be
d) Vapour blowers / compressors examined, including isolating and relief valves,
as applicable.
General examination of any devices (such as
compressors or blowers) used to increase the
vapour flow rate.
Section 16
− Oil fired thermal oil heater/s and 16.2.4 All mountings are to examined externally
Economiser/s are to be examined externally and internally, if considered necessary by the
including the heat exchanger coils, surveyor.
insulation and fuel oil burning arrangement
16.2.5 Fuel oil burning arrangements are to be
− Circulating pumps examined for proper operation including
− Dump cooler operation of safety cut-outs.
16.5.2 Pipe fittings and valves are to be - Expansion tank low level and low-low
examined externally and internally, if considered level alarm and safety cut out
necessary by the surveyor. - Fire Extinguishing arrangements.
16.6 Expansion tank
16.8 Thermal oil analysis
16.6.1 Expansion tank including associated
save-alls is to be visually examined. 16.8.1 Thermal oil is to be analysed at regular
intervals – atleast annually.
16.6.2 Arrangement to limit the temperature of
thermal oil in the expansion tanks (in open vent 16.8.2 The thermal oil shall be free from harmful
systems) such as ‘Temperature Blocking Pipe” contaminants and signs of oxidation or
are to be examined for proper operation. deterioration.
Section 17
17.2.1 The annual survey is to consist of general 17.2.3 Self Protection of the Vessel
examination / verification of the items indicated
in 17.2.2 to 17.2.7. Agni 1 :
End of Chapter
Part 2
Inspection and Testing of Materials
January 2014
Indian Register of Shipping
Part 2
Contents
Chapter 10 Equipment
Contents
2.5 Procedure for tensile testing at elevated 4.6 Ring tensile test
temperatures
Indian Register of Shipping
Part 2
Page 2 of 10 Contents
1.11 Special quality plate material (‘Z’ quality) 4.5 Mechanical tests
5.1 General
Section 2 : Normal Strength Steels for Ship
Structures 5.2 Deoxidation and chemical composition
6.1 General
Section 7 : Steels for Machinery Structures Section 10 : Normal and Higher Strength
Corrosion Resistant Steels for Cargo Oil
7.1 General Tanks
10.1 Scope
Section 8 : Plates with Specified minimum
through Thickness Properties (‘Z’ Quality) 10.2 Testing and approval
Section 2 : Hull and Machinery Steel 4.4 Dimensions, dimensional and geometrical
Castings for General Applications tolerances
Section 3 : Ferritic Steel Castings for Low 4.10 Welding procedure qualification test
Temperature Services
Section 5 : Austenitic Stainless Steel
3.1 General Castings
4.2 Manufacture
Section 6 : Castings for other Applications
4.3 Visual examination
6.1 General
Section 3 : Ferritic Steel Forgings for Low Section 4 : Austenitic Stainless Steel
Temperature Service Forgings
1.1 Scope
Section 3 : Castings for Propellers
2.9 Rectification of defective castings 3.10 Acceptance criteria for dye penetrant
examination
2.10 Identification
3.11 Metallographic examination
4.10 Identification
Section 4 : Tubes
4.11 Certification
4.1 Scope
Section 1 : General
2.15 Visual and non-destructive examination
1.1 Scope
2.16 Rectification of defects
Chapter 10 : Equipment
Section 1 : Anchors Section 3 : Short Link Chain Cables
4.5 Identification
Section 2 : Stud Link Chain Cables
2.1 Scope
Section 5 : Offshore Mooring Chains
2.2 Manufacture
5.1 Scope
2.3 Design and tolerances
5.2 Chain grades
2.4 Material for welded chain cables and
5.3 Approval of chain manufacturers
accessories
5.4 Approval of quality system at chain and
2.5 Material for cast chain cables and
accessory manufacturers
accessories
5.5 Approval of steel mills - rolled bar
2.6 Material for forged chain cables and
accessories 5.6 Approval of forge shops and foundries -
accessories
2.7 Heat treatment of completed chain cables
5.7 Rolled steel bars
2.8 Materials and welding of studs
5.8 Forged steel
2.9 Testing of completed chain cables
5.9 Cast steel
2.10 Accessories for chain cables
5.10 Materials for studs
2.11 Identification
5.11 Design
6.2 Butt weld tests 8.2 Initial approval tests for manual, semi-
automatic and automatic multi-run techniques
6.3 Annual tests
8.3 Deposited metal test assemblies
6.4 Upgrading and uprating
8.4 Butt weld test assemblies
Section 7 : Welding Consumables for High
Strength Quenched and Tempered and 8.5 Fillet weld test assemblies
TMCP Steels for Welded Structures
8.6 Initial approval tests for two-run technique
7.1 General
8.7 Annual tests
7.2 Testing of the weld metal
End of Chapter
Chapter 1
General Requirements
Contents
Section
1 Conditions for Manufacture, Survey and Certification
2 Quality Assurance Scheme for Materials
Section 1
examinations not completed are to be carried specific requirements. It is, however, in the
out in consultation with the Surveyors, at a interests of manufacturers to provide additional
subsequent stage of manufacture. material for any retests which may be
necessary, as insufficient or unacceptable test
1.4.5 In the event of any material proving material may be a cause for rejection.
unsatisfactory, during subsequent working,
machining or fabrication, it is to be rejected, not 1.7.2 The test material is to be representative of
withstanding any previous certification. the item or batch and is not to be separated until
all the specified heat treatment has been
1.5 Chemical composition completed, except where provision for an
alternative procedure is made in the subsequent
1.5.1 The chemical composition of the ladle chapters of this Part.
samples is to be determined by the
manufacturer in an adequately equipped and In case of castings where separately cast test
competently staffed laboratory. The samples are accepted, the test samples are to
manufacturer's analysis will be accepted, but be cooled down under the same conditions as
may be subject to occasional independent the castings.
checks if required by the Surveyors.
1.7.3 All test material is to be selected by the
1.5.2 At the discretion of the Surveyors, a check surveyor and identified by suitable markings
chemical analysis of suitable samples from which are to be maintained during the
products may also be required. These samples preparation of the test specimen.
are to be taken from the material used for
mechanical tests, but where this is not 1.8 Mechanical tests
practicable an alternative procedure for
obtaining a representative sample is to be 1.8.1 The number and direction of test
agreed with the manufacturer. specimens and their dimensions are to be in
accordance with the requirements of
1.6 Heat treatment subsequent chapters of this Part and the
specific requirements for the product.
1.6.1 Materials are to be supplied in the
condition specified in, or permitted by the Rules. 1.8.2 Where Charpy impact tests are required, a
Heat treatment is to be carried out in properly set of three test specimens are to be prepared
constructed furnaces which are efficiently and the average energy value is to comply with
maintained and have adequate means for the requirements of subsequent Chapters of this
control and recording of temperature. The part. One individual value may be less than the
furnace dimensions are to be such as to allow required average value provided that it is not
the whole item to be uniformly heated to the less than 70 per cent of that value.
necessary temperature. In the case of very large
components which require heat treatment, 1.8.3 Where metric or imperial units are to be
alternative methods will be specially considered. used for acceptance testing, the specified
values are to be converted in accordance with
1.7 Test material the appropriate conversions given in Table
1.8.1.
1.7.1 Sufficient test material is to be provided for
the preparation of the tests detailed in the
Notes :
1.10.1 Where the result of any test, other than 1.10.3 The additional tests detailed in 1.10.1
an impact test, does not comply with the and 1.10.2 are, where possible, to be taken from
requirements, two additional tests of the same material adjacent to the original tests. For
type may be taken. For acceptance of the castings, however, where insufficient material
material satisfactory results are to be obtained remains in the original test samples, the
from both of these tests. additional tests may be prepared from other test
samples representative of the castings.
1.10.4 When unsatisfactory results are obtained and the rectification has been completed in
from tests representative of a batch of material, accordance with applicable requirements of
the item or piece from which the tests were subsequent chapters of this Part and to the
taken is to be rejected. The remainder of the satisfaction of Surveyors.
batch may be accepted provided that two further
items or pieces are selected and tested with 1.12.2 The repair of defects by welding can be
satisfactory results. If the tests from one or both accepted only when permitted by the
of these additional items or pieces give appropriate specific requirements and provided
unsatisfactory results, the batch is to be that the agreement of the Surveyor is obtained
rejected. before the work is commenced. When a repair
has been agreed, it is necessary in all cases to
1.10.5 When a batch is rejected, the remaining prove by suitable methods of non-destructive
items or pieces in the batch may be re- examination that the defects have been
submitted individually for test, and those which completely removed before welding is
give satisfactory results may be considered for commenced. Welding procedures and
acceptance by the Surveyors. inspection on completion of the repair are to be
in accordance with the appropriate specific
1.10.6 At the option of the manufacturer, requirement and are to be to the satisfaction of
rejected material may be re-submitted as the Surveyor.
another grade and may then be considered for
acceptance by the Surveyors, provided that the 1.13 Identification of materials
test results comply with the appropriate
requirements. 1.13.1 The manufacturer is to adopt a system of
identification which will enable all finished
1.10.7 When material which is intended to be material to be traced to the original cast, and the
supplied in the ''as rolled" or "hot finished" Surveyors are to be given all facilities for so
condition fails test, it may be suitably heat tracing the material when required. When any
treated and re-submitted for test, with the prior item has been identified by the personal mark of
concurrence of the ship or machinery builder. a Surveyor, or his deputy, this is not to be
Similarly materials supplied in the heat-treated removed until an acceptable new identification
condition may be re-heat treated and re- mark has been made. Failure to comply with this
submitted for test. condition will render the item liable to rejection.
1.11 Visual and non-destructive examination 1.13.2 Before any item is finally accepted it is to
be clearly marked by the manufacturer in at
1.11.1 Prior to the final acceptance of materials, least one place with the particulars detailed in
surface inspection, verification of dimensions the appropriate specific requirements.
and non-destructive examination are to be
carried out in accordance with the requirements 1.13.3 Hard stamping is to be used except
detailed in subsequent chapters of this Part. where this may be detrimental to the material, in
which case stenciling, painting or electric
1.11.2 When there is visible evidence to doubt etching is to be used. Paints used to identify
the soundness of any material or component, alloy steels are to be free from lead, copper,
such as flaws in test specimens or suspicious zinc or tin, i.e., the dried film is not to contain
surface marks, the manufacturer is expected to any of these elements in quantities more than
prove the quality of the material by any 250 ppm.
acceptable method.
1.13.4 Where a number of identical items are
1.12 Rectification of defective material securely fastened together in bundles, the
manufacturer need only brand the top of each
1.12.1 Small surface imperfections may be bundle. Alternatively a durable label giving the
removed by mechanical means provided that, required particulars may be attached to each
after such treatment, the dimensions are bundle.
acceptable, the area is proved free from defects
Section 2
2.1.1 Alternative procedures for survey and 2.3.3 An outline description of all important
testing may be accepted by IRS at works where manufacturing plant and equipments. This is to
materials are manufactured under closely include a production flow chart indicating all
control rolled conditions by semi-continuous or stages where testing and inspection are carried
continuous processes. out along with details of equipments used for
measuring and testing.
2.1.2 IRS will consider the extent to which the
manufacturing and quality control procedures 2.3.4 A controlled copy of company's Quality
employed by a manufacturer ensure compliance Manual prescribing a quality system generally in
of the materials with the requirements of the compliance with the applicable requirements of
Rules. ISO 9000 series of standards.
2.1.3 Where it is considered that compliance 2.3.5 The system used for the identification and
with Rule requirements can be satisfactorily traceability of raw materials, semi-finished and
achieved, IRS will issue a Quality Assurance finished Products.
Approval Certificate to the manufacturer.
2.3.6 Number and qualification of personnel
2.1.4 Approval by another organization will not engaged in quality control and quality
normally be acceptable as sufficient evidence assurance.
that a manufacturer's arrangements comply with
IRS requirements. 2.3.7 Information on the system of procurement
and acceptance of materials e.g. ingots, billets
2.1.5 The quality system procedures and or blooms for further processing where the
practices of a manufacturer who has been manufacturer does not produce such raw
granted approval will be kept under continuous materials.
review.
2.3.8 Consolidated test results, physical,
2.2 Requirements for approval chemical, non-destructive tests etc. for a period
of preceding three months of products, if
2.2.1 The manufacturer is required to have possible, covering the full range of thickness,
necessary manufacturing and testing facilities weight range and grades for which approval is
supervised by suitably qualified and trained sought. The data is to include the number of
personnel to the satisfaction of IRS. samples, minimum, maximum, average value
and standard deviation. For high strength ship
2.2.2 The manufacturer is to demonstrate that steels, the carbon equivalent values are also
the firm has experience consistent with the required. The data is to also include numbers of
technology and complexity of the product type rejections during manufacture as well as after
for which approval is sought and that the firm's delivery and reasons thereof.
product has been of a consistently high
standard. 2.4 Assessment and approval
2.2.3 The manufacturer is required to establish 2.4.1 After receipt and appraisal of the
and maintain a quality system in line with the information required by 2.3 an assessment of
requirements of ISO 9000 series of standards to the Works would be carried out by the
ensure that IRS requirements for certification of Surveyors to ensure compliance with the Quality
materials and components are met consistently. Manual and examine in detail Quality Control
Procedures in relation to the process, products,
2.3 Information required for approval inspections, tests and certification. Where the
proposed quality control procedures are
2.3.1 Manufacturers applying for approval under considered to be inadequate the Surveyors may,
this scheme are to submit the information in consultation with Head Office, advise as to
required by 2.3.2 to 2.3.8. how these may be revised to be acceptable to
IRS.
2.5.1 The Certificate will be valid for three years 2.6.1 After issue of the Quality Assurance
subject to surveillance assessment being carried Approval Certificate, the manufacturer would be
out every six months or at more frequent authorized to issue certificate of products on
intervals as deemed necessary by IRS behalf of IRS subject to the Certificates being
depending on the type of product, the rate of countersigned by IRS Surveyors. Arrangements
production and standard of the Work's quality for this will be specially advised by IRS.
control procedures.
End of Chapter
Chapter 2
Contents
Section
1 General Requirements
2 Tensile Testing
3 Impact Tests
4 Ductility Testing of Pipes and Tubes
5 The Brittle Crack Arrest Toughness Test
Section 1
General Requirements
1.1 General are to be from the same cast and in the same
condition of heat treatment.
1.1.1 All tests are to be carried out by competent
personnel. The machines are to be maintained 1.3 Preparation of test specimens
in satisfactory and accurate condition and are to
be recalibrated at approximately annual 1.3.1 If test samples are cut from material by
intervals. This calibration is to be carried out by flame cutting or shearing, a reasonable margin
a nationally recognized Authority or other is required to enable sufficient material to be
organization of standing and is to be carried out removed from the cut edges during final
to the satisfaction of Surveyors. The accuracy of machining.
test machines is to be within ± one per cent. A
record of all calibrations is to be kept available in 1.3.2 Test specimens are to be cut and
the test house. prepared in a manner which does not affect their
properties, i.e. not subjected to any significant
Testing machines are to be calibrated in cold straining or heating.
accordance with the following or other
equivalent recognized standards: 1.3.3 Where possible, test specimens from
rolled materials are to retain their rolled surface
a) Tensile / compression testing : ISO 7500-1 on both sides.
b) Impact testing : ISO 148-2
1.4 Discarding of test specimens
1.2 Selection of test samples
1.4.1 If a test specimen fails because of faulty
1.2.1 Test samples are to be selected by the manufacture, visible defects, or incorrect
Surveyor unless otherwise agreed. operation of the testing machine, it may be
discarded at the Surveyor's discretion and
1.2.2 All materials in a batch presented for replaced by a new test specimen prepared from
testing are to be of the same product form (e.g. material adjacent to the original test.
plates, sections, bars). Normally, the materials
Section 2
Tensile Testing
2.1 Dimensions of tensile test specimens three different types of test specimens may be
used :
2.1.1 Generally, proportional test specimens
with a gauge length of 5.65√So (where So is the - Round test specimens;
cross-sectional area of the test length) are to be
used. Where it is not possible to use such - Flat test specimens; and
specimens, non-proportional specimens may be
considered. - Full cross-section test specimens.
2.1.2.1 The following symbols have been used 2.1.2.2 The gauge length may be rounded off to
in the figure and in subsequent paragraphs:- the nearest 5 [mm] provided that the difference
between this length and Lo is less than 10% of
d =diameter Lo.
a =thickness of specimen
b =width 2.1.2.3 For plates with thickness equal to and
Lo = Original gauge length greater than 3 [mm], test specimen according to
Lc = Parallel length alternatives A or B given below are to be used.
So = Original cross-sectional area Where the capacity of the available testing
R = Transition radius machine is insufficient to allow the use of a test
D =External tube diameter specimen of full thickness, this may be reduced
t = plate thickness by machining one of the rolled surfaces.
Alternatively for materials over 40 [mm] thick, 2.1.2.7 For forgings, castings (excluding grey
proportional round test specimens with cast iron) and bars round test specimens with
dimensions as specified in C below may be dimensions as specified in alternative C of
used. 2.1.2.3 are usually to be used.
Alternative A, Non-proportional flat test 2.1.2.8 If for special reasons, other dimensions
specimen are to be used, they will have to conform with
the following geometric relationship:
a=t
b =25 [mm] Lo =5d;
Lo =200 [mm]
Lc =Lo + d:
Lc ≥ 212.5 [mm]
R =25 [mm]
R=10 [mm], except for materials with a specified
Alternative B, Proportional flat test specimen minimum elongation A ≤ 10 per cent, where R is
to be 1.5 x d.
a=t
2.1.2.9 For tubes, test specimen according to
b =25 [mm] alternative A or B below are to be used:
6892-98 or other recognised standards as simplification the term "Yield Stress" is used
appropriate. throughout when requirements are specified for
acceptance testing at ambient temperature.
c) a load/extension diagram using the value of stress at elevated temperatures are to have an
load measured either at the commencement extensometer gauge length of not less than 50
of plastic deformation or yield or at the first [mm] and a cross sectional area of not less than
2
peak obtained during yielding even when 65 [mm ]. Where, however, this is precluded by
that peak is equal to or less than any the dimensions of the product or by the test
subsequent peaks observed. equipment available, the test specimen is to be
of the largest practical dimensions.
2.4.5 The 0.2 or 1.0 per cent proof stress (non-
proportional elongation) is to be determined 2.5.2 The heating apparatus is to be such that
from an accurate load/extension diagram by the temperature of the specimen during testing
drawing a line parallel to the straight elastic does not deviate from that specified by more
portion and distant from it by an amount than ± 5°C.
representing 0.2 or 1.0 per cent of extensometer
gauge length. The point of intersection of this 2.5.3 The straining rate when approaching the
line with the plastic portion of the diagram lower yield or proof load is to be controlled
represents the proof load, from which 0.2 or 1.0 within the range 0.1 to 0.3 per cent of the
per cent proof stress can be calculated. extensometer gauge length per minute.
2.5 Procedure for tensile testing at elevated 2.5.4 The time intervals used for estimation of
temperatures strain rate from measurements of strain are not
to exceed 6 seconds.
2.5.1 The test specimens used for the
determination of lower yield or 0.2 per cent proof
Section 3
Impact Tests
Table 3.1.1 : Dimensions and tolerances for charpy V-notch impact test specimens
Fig.3.1.1
Table 3.1.2: Dimensions and tolerances for charpy U-notch impact test specimens
Table 3.2.4
Section 4
4.4.1 The test specimens are to be cut with the 4.6 Ring tensile test
ends perpendicular to the axis of the tube. The
length of the specimens is to be approximately 4.6.1 The ring is to have a length of about 15
1.5D. The length may be shorter provided that [mm] with plain and smoothed ends cut
after testing the remaining cylindrical portion is perpendicular to the tube axis. The ring is to be
not less than O.5D (Reference ISO 8494). The drawn to fracture by means of two mandrels
edges of the end to be tested may be rounded placed inside the ring and pulled in tensile
by filing. The rate of penetration shall not testing machine. The rate shall not exceed 5
exceed 50 [mm]/minute. [mm]/second. (Reference ISO 8496).
Section 5
5.1 Scope
5.2 Symbols
The standard ESSO test method described in
this section is used to estimate the brittle crack
arrest toughness value Kca of rolled steel plates
for hull of thickness not greater than100 [mm].
2
σ N/mm Gross stress in tested part ( load / W S.tS)
3/2
Kca N/mm Brittle crack arrest toughness value
5.3 Purpose
5.4.3 The test specimens are to be taken from
The purpose of this test is to assess brittle crack the same steel plate.
arrest toughness with temperature gradient and
to obtain the corresponding brittle crack arrest 5.4.4 Test specimens are to be taken in such a
toughness value Kca. way that the axial direction of the load is parallel
to the rolling direction of the steel plate.
5.4 Standard test specimen
5.4.5 The thickness of the test specimen is to be
5.4.1 Fig.5.4.1 shows the shape and size of the the same as the thickness of the steel plate to
standard test specimen. be used in the vessel structure.
5 5 Test equipment
0.8ts≤ tr ≤ 1.5ts W s ≤ W r ≤ 2W s
(See Notes 1 and 2)
Note 2: If the tab plate has a thickness smaller than the test specimen, the reflection of stress wave will
be on the safer side for the assessment; therefore, considering the actual circumstances for conducting
the test, the lower limit of thickness is taken as 0.8ts.
more than 10 minutes, after which the specified
5.6.2 Thermocouples are to be fitted at 50 mm test load may then be applied.
pitch on the notch extension line of the test
specimen. 5.7.5 After maintaining the test load for at least
30 seconds, a brittle crack is to be generated by
5.6.3 If the brittle crack is estimated to deviate impact. The standard impact energy is taken as
from its presumed course, thermocouples are to 20 to 60 [J] per 1 [mm] plate thickness. If the
be fitted at two points separated by 100 mm on brittle crack initiation characteristics of the base
the line of load from the notch extension line at metal are high, and it is difficult to generate a
the centre of width of the test specimen. brittle crack, the impact energy may be
increased to the upper limit of 120 [J] per 1 [mm]
5.6.4 If dynamic measurements are necessary, plate thickness.
strain gauges and crack gauges are to be fitted
at specific locations. 5.7.6 Loading is stopped when the initiation,
propagation, and arrest of crack have been
5.6.5 The test specimen is to be fixed to the confirmed. Normal temperature is restored, and
testing machine together with the tab plate after if necessary, the ligament is broken by gas
welding and the pin load jig. cutting and forcibly the specimen is broken by
using the testing machine. Or, after the ductile
5.6.6 The impact equipment is to be mounted. crack has been propagated to an adequate
The construction of the impact equipment is to length with the testing machine, the ligament is
be such that the impact energy is correctly broken by gas cutting.
transmitted. An appropriate jig is to be arranged
to minimize the effect of bending load due to the 5.7.7 After forcing the fracture, photos of the
impact equipment. fractured surface and the propagation route are
to be taken, and the crack length is to be
5.7 Test method measured.
End of Chapter
Chapter 3
Contents
Section
1 General Requirements
2 Normal Strength Steels for Ship Structures
3 Higher Strength Steels for Ship Structures
4 High Strength Quenched and Tempered Steels for Welded Structures
5 Steel for Low Temperature Service
6 Steels for Boilers and Pressure Vessels
7 Steels for Machinery Structures
8 Plates with Specified minimum through Thickness Properties (‘Z’ quality)
9 Austenitic and Duplex Stainless Steels
10 Rolled Steel Plates, Strips, Sections and Bars
Section 1
General Requirements
agreement, to be grounds for rejection. Where 1.4.7 The tolerance on nominal thickness are
necessary, suitable methods of non-destructive not applicable to areas repaired by grinding
examination may be used for the detection of which are to be in accordance with a recognized
harmful surface and internal defects. The extent standard.
of this examination, together with appropriate
acceptance standards, is to be agreed between 1.4.8 For materials intended for applications as
the purchaser, manufacturer and Surveyors. detailed in Sec. 5 and 6, no minus tolerance is
permitted in the thickness of plates and strip.
1.4 Thickness tolerance of plates and wide
flats with width ≥ 600 [mm] 1.4.9 The responsibility for verification and
maintenance of the production within the
1.4.1 The tolerance on thickness of a given required tolerance rests with the manufacturer.
product are defined as follows: The Surveyor may require to witness some
measurements.
a) Minus tolerance is the lower limit of the
acceptable range below the nominal 1.4.10 The responsibility for storage and
thickness. maintenance of the delivered products with
acceptable level of surface conditions rests with
b) Plus tolerance is the upper limit of the the shipyard before the products are used in
acceptable range above the nominal fabrication.
thickness.
1.4.11 Where zero minus tolerance is applied in
Note : Nominal thickness is defined by the accordance with Class C of ISO 7452, the
purchaser at the time of enquiry and order. requirements of 1.4.12 to 1.4.14 need not be
applied.
1.4.2 The minus tolerance for products for
normal strength, higher strength and high Additionally, if ISO 7452 is applied, it is required
strength quenched and tempered steels is 0.3 that the steel mill demonstrate to the satisfaction
[mm] irrespective of nominal thickness. of IRS that the number of measurements and
measurement distribution is appropriate to
1.4.3 The minus tolerance for products intended establish that the mother plates produced are at
for machinery structures are to be in accordance or above the specified nominal thickness.
with Table 1.4.3.
1.4.12 Average thickness
1.4.5 The plus tolerance on nominal thickness is 1.4.13.2 Automated method or manual method
to be in accordance with a recognized national may be applied to the thickness measurements.
or international standard or as specified.
1.4.13.3 The procedure and the records of
1.4.6 The tolerance on sections (except for wide measurements are to be made available to the
flats) are to be in accordance with the Surveyor and copies provided on request.
requirements of recognized international or
national standard. 1.4.14 Thickness measuring locations
Line 1
A1 A2 A3
Line 2
B1 B2 B3
C1 C2 C3
Line 3
: Measurement points
Rolling direction
Fig. 1.4.14.2a) : Locations of Thickness Measuring Points for the Original Steel Plates
Fig. 1.4.14.2b) : Locations of Thickness Measuring Points for the Cut Steel Products
Line 1
A1 A2 A3
(i) Line 2 B1 B2 B3
C1 C2 C3
Line 3
: Measurement points
Rolling direction
Line 1
A1 A2 A3
B1 B2 B3
(ii) Line 2
C1 C2 C3
Line 3
: Measurement points
Rolling direction
Line 1
Line 2
Line 3
: Measurement points
Rolling direction
1.5 Heat treatment, condition of supply coolant for the purpose of hardening the
microstructure. Tempering subsequent to
1.5.1 All materials are to be supplied in the heat quenching is a process in which the steel is
treated conditions described in the subsequent reheated to an appropriate temperature not
sections of this chapter unless supply in the as- higher than the Ac1 to restore toughness
rolled condition is allowed. properties by improving the microstructure.
1.5.3.2 The conditions of supply and the impact 1.6.3.1 Plates and flats with a width ≥ 600
test requirements are detailed in subsequent [mm] : The test samples are to be taken from
sections of the Chapter. one end at a position approximately midway
between the axis in the direction of the rolling
1.6 Test material and the edge of the rolled product (See Fig.1.6.1
a). Unless otherwise agreed the tensile test
1.6.1 All material in a batch presented for specimens are to be prepared with their
acceptance tests are to be of the same product longitudinal axis transverse to the final direction
form e.g. plates, flats, sections. etc., from the of rolling.
same cast and in the same condition of supply.
1.6.3.2 Flats with a width < 600 [mm], bulb
1.6.2 Test samples flats and other sections : For flats having a
width of 600 [mm] or less, bulb flats and other
a) The test samples are to be fully sections the test specimens are to be taken from
representative of the material and, where one end at a position approximately one third
appropriate, are not to be cut from the from the outer edge (See Figs.1.6.1 b,c,d), or in
material until heat treatment has been the case of small sections as near as possible to
completed. this position. In the case of channels, beams or
bulb angles the test samples may alternatively
b) The test specimens are not to be be taken from a position approximately one
separately heat treated in any way. quarter of the width from the web centreline or
axis (See Fig.1.6.1 c). The tensile test
1.6.3 Unless otherwise agreed, the test samples specimens may be prepared with their
are to be taken from the following position : longitudinal axis either parallel or transverse to
the final direction of rolling.
1.6.3.3 Bars and other similar products: The a) for non-cylindrical sections, at one third of
test specimens are to be taken so that the axis the half diagonal from the outside.
of the test specimen is parallel to the direction of
rolling. For small sizes, the test specimen may b) for cylindrical sections, at one third of the
consist of a suitable length of the full cross radius from outside (See Fig.1.6.1 e).
section of the product (the impact test specimen
receiving nevertheless the necessary 1.6.3.4 For plates and flats with thicknesses in
machining). For larger sizes, the test samples excess of 40 [mm], full thickness specimens
are to be taken so that the axis of the test may be prepared, but when instead a machined
specimen lies as near as possible to the round specimen is used then the axis is to be
following : located at a position lying one-quarter of the
product thickness from the surface as shown in
Fig.1.6.1.f.
concerning freedom from harmful internal less than their average breadth to each
defects. other are to be regarded as one single area.
The repairs are to be agreed with the
1.9 Freedom from defects Surveyor in each case and are to be carried
out under his supervision unless otherwise
1.9.1 All products must have a workmanlike agreed. Complete elimination of the defects
finish and must be free from defects and may be verified by a magnetic particle or
imperfections which may impair their proper dye penetrant test procedure at the
workability and use. This may however, include Surveyors' discretion.
some discontinuties of a harmless nature, minor
imperfections e.g. pittings, rolling in scale, f) Where necessary the entire surface may be
indentations, roll marks, scratches and grooves ground to a depth as given by the under
which cannot be avoided completely despite thickness tolerances of the product.
proper manufacturing and which will not be
objected to provided they do not exceed the 1.10.2 Surface defects which cannot be dealt
acceptable limits contained herein. with as in 1.10.1 may be repaired by chipping
and/ or grinding followed by welding subject to
1.9.2 Imperfections : Notwithstanding this, the Surveyor's consent and under his supervision
products may have imperfections exceeding the provided:
discontinuities inherent to the manufacturing
process, as defined under 1.9.1. In such cases, a) And single welded area shall not exceed
limits for their acceptability are to be agreed with 0.125 [m] and the sum of all areas shall not
IRS, taking the end use of the product into exceed 2 per cent of the surface side in
consideration. question. The distance between two welded
areas is not to be less than their average
1.9.3 Defects : Cracks, shells, sand patches width.
and sharp edged seams are always considered
defects which would impair the end use of the b) The weld preparation must not reduce the
product and which require rejection or repair, thickness of the product below 80 per cent
irrespective of their size and number. The same of the nominal thickness. For occasional
applies to other imperfection exceeding the defects with depths exceeding the 80 per
acceptable limits. cent limit, special consideration at the
Surveyors' discretion will be necessary.
1.10 Repairs
c) The repair shall be carried out by qualified
1.10.1 Surface defects in structural steel may be welders using an approved procedure for
removed by local grinding, provided that the appropriate steel grade. The electrodes
shall be of low hydrogen type and must be
a) the nominal product thickness will not be dried in accordance with manufacturer's
reduced by more than 7 per cent or 3 [mm], requirements and protected against
whichever is the less. rehumidification before and during welding.
b) each single ground area does not exceed d) The welds are to be of reasonable length
2
0.25 [m ]. and must have at least 3 parallel welding
beads. The deposited metal must be sound
c) each single ground area does not exceed 2 without any lack of fusion, undercut, cracks
per cent of the total surface in question. and other defects which could impair the
workability or use of the product. Welding is
Ground areas lying in a distance less than to be performed with one layer of beads in
their average breadth to each other are to excess of which is subsequently to be
be regarded as one single area. ground smooth to the surface level.
d) Ground area lying opposite each other on e) Products which are to be supplied in a heat
both surfaces must not decrease the treated condition are to be welded prior to
product thickness by values exceeding the the heat treatment; otherwise, a new heat
limits as stated above in a, b and c. treatment may be required.
e) the ground area must have smooth f) Products supplied in the controlled rolled or
transition to the surrounding surface of the as rolled condition may require a suitable
product. Ground areas lying in a distance heat treatment after welding. however, the
1.11.1 When plate material, intended for welded 1.13 Test certificates or shipping statements
construction, will be subject to significant strains
in a direction perpendicular to the rolled 1.13.1 The Surveyor is to be supplied, in
surfaces, it is recommended that consideration duplicate, copies of the test certificates or
be given to the use of special plate material with shipping statements for all accepted materials,
specified through thickness properties. These IRS may require separate documents for each
strains are usually associated with thermal grade of steel. These documents are to contain,
contraction and restraint during welding, in addition to the description, dimensions, etc. of
particularly for full penetration "T"- butt welds, the material at least the following particulars:
but may also be associated with loads applied in
service or during construction. Requirements for a) Purchaser's order number and if known the
these materials are detailed in Sec. 8 and it is ship number for which the material is
the responsibility of shipbuilder or fabricator to intended;
make provision for the use of this material.
b) Identification number and/or initials;
1.12 Branding of materials
c) Identification of steel works;
1.12.1 Every finished item is to be clearly
marked by the manufacturer in at least one d) Identification of the grade of steel;
place with IRS brand IR and the following
particulars: e) Cast number and ladle analysis;
a) The manufacturer's name or trade mark; f) Condition of supply when other than as
rolled e.g. normalized or controlled rolled;
b) Identification mark for the grade of steel,
(material supplied in the thermo- g) If the material is of rimming quality, this
mechanically controlled process condition is should be stated;
to have the letter TM added after the
identification mark) ; h) Test results.
c) Cast or identification number and/or initials In the case of ‘Z’ quality steel, notation ‘Z25’ or
which enable the full history of the item to ‘Z35’ as appropriate, is to be indicated with the
be traced; steel grade and test results are to include
through thickness reduction in area (%).
d) If required by the purchaser, his order
number or other identification marks.
1.13.2 Before the test certificates or shipping "We hereby certify that the material has been
statements are signed by the Surveyor, the made by an approved process in accordance
manufacturer is required to furnish him with a with the Rules of Indian Register of Shipping
written declaration stating that the material has and has been tested satisfactorily in the
been made by an approved process and that it presence of the surveyors of Indian Register of
has been subjected to and has withstood Shipping".
satisfactorily the required tests in the presence
of the Surveyor or his authorized deputy. The 1.13.3 When steel is not produced at the works
following form of declaration will be accepted if at which it is rolled a certificate is to be supplied
stamped or printed on each test certificate or to the Surveyor at the rolling mill stating the
shipping statement with the name of steelworks process by which it was manufactured and the
and initialed by the makers or an authorized name of the manufacturer, the number of cast
deputy: from which it was made and the ladle analysis.
The Surveyors are to have access to the works
at which the steel was produced and the works
must be approved by IRS.
Section 2
2.1.1 Normal strength hot-rolled steel plates, 2.3.1 All materials are to be supplied in a
wide flats, sections and bars intended for use in condition complying with Table 2.3.1 and Table
hull construction, is to comply with the following 2.3.2. Where alternative arrangements are
requirements. Steel differing in chemical permitted these are at the option of the
composition, deoxidation practice, heat steelmaker, unless otherwise expressly stated in
treatment or mechanical properties may be the order for the material.
accepted, subject to special agreement by IRS.
2.4 Mechanical tests
2.1.2 These requirements are primarily intended
to apply to steel plates not exceeding 100 [mm] 2.4.1 Sizes and orientation of test specimens
in thickness and sections and bars not are to be in Accordance with the requirements of
exceeding 50 [mm] in thickness. For greater Sec. 1.
thickness, certain variations in the requirements
may be allowed or required in particular cases 2.4.2 For each batch presented. except where
after consideration of the technical specially agreed by IRS. one tensile test is to be
circumstances involved. made from one piece unless the weight of
finished material is greater than 50 tonnes in
2.1.3 Additional approval tests may be required which case one extra test piece is to be made
to verify the suitability for forming and welding of from a different piece from each 50 tonnes or
Grade E plate exceeding 50 [mm] in thickness. fraction thereof. Additional tests are to be made
for every variation of 10 [mm] in thickness of
2.2 Deoxidation and chemical composition plate or diameter of products from the same
cast. For sections the thickness to be
2.2.1 The method of deoxidation and the considered is the thickness of the product at the
chemical composition of ladle samples are to point at which samples are taken for mechanical
comply with the requirements of Table 2.2.1. tests.
2.2.2 When any grade of steel is supplied in the 2.4.3 For plates of thickness exceeding 50 [mm]
thermo-mechanically controlled processed in Grade E steel, one tensile test is to be made
condition, deviations in the specified chemical on each piece.
composition may be allowed by IRS.
2.4.4 For each batch presented, except where
specially agreed by IRS at least one set of three
Charpy V-notch test specimens is to be made
from one piece unless the weight of finished tonnes or fraction thereof. However, for Grade
material is greater than 50 tonnes in which case 'A' steel over 50 [mm] thickness when supplied
one extra set of three test specimens is to be in the "as rolled" condition, one set of three
made from a different piece from each 50 charpy V-notch test specimens may be taken
tonnes or fraction thereof. The piece selected for from each batch of 50 tonnes or fraction thereof.
the preparation of test specimen is to be the
thickest of each batch. Where steel plates 2.4.6 For plates in Grade E steel, one set of
except for Grade 'A' steel over 50 [mm] in three impact test specimens is to be made from
thickness is supplied in the controlled rolled each piece.
condition, the frequency of impact test is to be
made from a different piece from each 25 2.4.7 For Grade E sections, except where
tonnes or fraction thereof. specially agreed, for each batch presented, one
set of three impact test specimens is to be made
2.4.5 When subject to the special approval of for each 25 tonnes of normalised material and
IRS, material is supplied in the as rolled for each 15 tonnes of materials which are not
condition the frequency of impact tests is to be normalised.
increased to one set from each batch of 25
Grade A B D E
1
Deoxidation Any method Any method except For t ≤ 25 [mm] killed, Fully killed fine
practice rimmed steel For t > 25 [mm] fully grain treated
killed and fine grain
2
treated
6,7,8
Chemical composition per cent
4
Carbon max. 0.21 0.21 0.21 0.18
5
Manganese 2.5 x Carbon % 0.80 0.60 0.70
min
Silicon max 0.50 max. 0.35 max. 0.35 max. 0.10 - 0.35
Phosphorus 0.035 max. 0.035 max. 0.035 max. 0.035 max.
max
Sulphur max 0.035 max. 0.035 max. 0.035 max. 0.035 max.
2
Aluminium - - 0.015 0.015
3
(acid soluble)
Carbon + 1/6 of the manganese content is not to exceed 0.40 per cent
Notes :
1 For grade A, rimmed steel may be accepted upto 12.5 [mm] thick inclusive provided that it is stated
on the test certificates or shipping statements to be rimmed steel and is not excluded by the
purchaser's order.
2 Aluminium is required for thickness above 25 [mm].
3 The total aluminium content may be determined instead of the acid soluble content. In such cases
the total aluminium content is to be not less than 0.020 per cent.
4 Max. 0.23% for sections.
5 For grade B, when the silicon content is 0.10% or more (killed steel), the minimum manganese
content may be reduced to 0.60%.
6 IRS may limit the amount of residual/trace elements which may have an adverse effect on the
working and use of the steel, e.g. copper and tin.
7 Where additions of any other element have been made as part of the steelmaking practice, the
content is to be specified.
8 When any grade of steel is supplied in the thermo-mechanically rolled condition, variation in the
specified chemical composition may be allowed or required by IRS.
1) These conditions of supply and the impact test requirements are summarised in Table 2.3.2
2) Subject to the special approval of IRS, Grades A and B steel plates may be supplied in the as
rolled condition.
3) Subject to the special approval of IRS, sections in Grade D steel may be supplied in the as rolled
condition provided satisfactory results are consistently obtained from Charpy V-notch impact tests.
Similarly sections in Grade E steel may be supplied in the as rolled or controlled rolled condition.
For the frequency of impact tests see 2.4.4, 2.4.5, 2.4.6 and 2.4.7.
2.4.8 Results of mechanical testing are to applications where transverse test specimens
comply with Table 2.4.1. For impact tests, one may be required. Transverse test results are to
individual value may be less than the required be guaranteed by the manufacturer. The
average value provided that it is not less than 70 tabulated values are for standard specimens 10
per cent of this average value. See also Ch. 1. [mm] x 10 [mm]. For plate thicknesses lower
than 10 [mm], sub-size specimens may be used
2.4.9 Minimum average energy values are with reduced requirements as follows :
specified for Charpy V-notch impact test
specimens taken in either the longitudinal or Specimen 10 x 7.5 [mm] : 5/6 of tabulated
transverse directions. energy
Specimen 10 x 5 [mm] : 2/3 of tabulated
Generally only longitudinal test specimens need energy.
be prepared and tested except for special
Table 2.3.2 : Required condition of supply and number of impact tests for normal strength steels
1. Condition of Supply
One set of impact tests is to be taken from each batch of the specified weight in ( ) in tones or fraction thereof.
Impact Test
Yield Elon-
Tensile Average impact energy (J) min.
strengt gation
Gra- strength Test 50 < t ≤ 70 70 < t ≤ 100
h ReH t ≤ 50 mm
de
[N/mm ]
2 Rm 5.65 So Temp. mm mm
2
min.
[N/mm ] A5 (%) °C Long Trans Long Trans Long Trans
(3) (3) (3) (3) (3) (3)
A +20 - - 34(5) 24(5) 41(5) 27(5)
B 400/520 0 27(4) 20(4) 34 24 41 27
235 22(2)
D (1) -20 27 20 34 24 41 27
E -40 27 20 34 24 41 27
Notes:
1) For all thicknesses of Grade A sections the upper limit for the specified tensile strength range may
be exceeded at the discretion of IRS.
2) For full thickness flat tensile test specimens with a width of 25 mm and a gauge length of 200 mm
the elongation is to comply with the following minimum values:
4) Charpy V-notch impact tests are generally not required for Grade B steel with thickness of 25 mm or
less.
5) Impact tests for Grade A over 50 mm thick are not required when the material is produced using fine
grain practice and furnished normalised. TM rolling may be accepted without impact testing at the
discretion of IRS.
Section 3
3.1 General
3.1.3 The requirements of this section are
3.1.1 Higher strength steel, supplied in three primarily intended to apply to plates not
strength levels, 32, 36 and 40, intended for use exceeding 100 [mm] in thickness in general, and
in hull construction, is to comply with following sections and bars not exceeding 50 [mm] in
requirements. thickness. For greater thickness, these
requirements may be applied with certain
Steel differing in chemical composition, variations, as may be agreed by IRS.
deoxidation practice, heat treatment or
mechanical properties may be accepted, subject The additional requirements for high strength
to special approval by IRS. Such steel is to be plates having specified minimum yield point of
2
given special designation. 460 [N/mm ] with thickness over 50 [mm] and
not greater than 100 [mm] for use in longitudinal
3.1.2 Each strength level is subdivided into four structural members in the upper deck region of
grades, AH, DH, EH and FH differing in the container ships (such as hatch side coaming,
required levels of notch toughness. hatch coaming, hatch coaming top and attached
longitudinal) and denoted by Grade EH47 are input welding, special consideration must be
also given in this section. given to the possibility of a consequent
reduction in mechanical properties.
3.1.4 It should be noted that when fatigue
loading is present, the effective fatigue strength 3.2 Deoxidation and chemical composition
of a welded construction of higher strength
steels may not be greater than that of a 3.2.1 The method of deoxidation and chemical
construction fabricated from the normal strength analysis of ladle samples are to comply with the
steels. Precautions against corrosion fatigue requirements of Table 3.2.1.
may also be necessary.
The chemical composition of EH 47 steel plates
Note: Before subjecting steels produced by would be specially considered.
thermo-mechanical rolling to further heating for
forming or stress relieving or using high heat-
Table 3.2.1 : Chemical composition and deoxidation practice for higher strength steels
AH32/DH32/EH32 FH32
1)
Grade AH36/DH36/EH36 FH36
AH40/DH40/EH40 FH40
Deoxidation
Fully killed and fine grain refined
practice
2)
Chemical Composition per cent (Ladle sample)
C max. 0.18 0.16
3)
Mn 0.90 - 1.60 0.90 - 1.60
Si max. 0.50 0.50
P max. 0.035 0.025
S max. 0.035 0.025
5)
Grain refining elements
Al (acid soluble) 4)
0.015
min.
Nb 0.02 - 0.05
V 0.05 - 0.10
Ti max. 0.02
Total (Nb + V + Ti) 0.12 max.
Residual elements
Cu max. 0.35 0.35
Cr max. 0.20 0.20
Ni max. 0.40 0.80
Mo max. 0.08 0.08
Notes:
1) The number following the grade designation indicates the yield point to which the steel is ordered
2
or produced in [Kg/mm ].
2) Where additions of any other element have been made as part of the steel making practice, the
content is to be indicated.
3) For thickness upto and including 12.5 [mm] the minimum manganese content may be reduced to
0.70 percent.
4) The total aluminium content may be determined instead of the acid soluble content. In such
cases the total aluminium content is to be not less than 0.020 percent
5) The steel is to contain aluminium, niobium, vanadium or other suitable grain refining elements,
either single or in combination. When used singly the steel is to contain the specified minimum
content of the grain refining element. When used in combination, the specified minimum content
of atleast one refining element is applicable.
3.2.5.1 For TM (TMCP) steels the following 3.3.1 All materials are to be supplied in a
special requirements apply: condition complying with the requirements given
in Table 3.3.1. Where alternative conditions are
i) The carbon equivalent value is to be permitted, these are at the option of the
calculated from the ladle analysis using the steelmaker, unless otherwise expressly stated in
following formula and to comply with the the order for material.
requirements of the following table:
3.4 Mechanical tests
Carbon equivalent for higher strength steels
upto 100 mm in thickness produced by TM 3.4.1 Sizes and orientation of test specimens
are to be in accordance with the requirements of
Carbon 1)
Max. (%) Sec. 1.
Grade equivalent
t ≤ 50 50 < t ≤ 100 3.4.2 For each batch presented, except where
AH32, DH32, specially agreed by IRS, one tensile test is to be
0.36 0.38
EH32, FH32 made from one piece unless the weight of
AH36, DH36, finished material is greater than 50 tonnes in
0.38 0.40
EH36, FH36 which case one extra test piece is to be made
AH40, DH40, from a different piece from each 50 tonnes or
0.40 0.42
EH40, FH40 fraction thereof. Additional tests are to be made
EH47 NA 0.49 for every variation of 10 [mm] in thickness of
t = thickness [mm] plate or diameter of products from the same
cast. For sections, the thickness to be
considered is the thickness of the product at the
point at which samples are taken for mechanical iii) When, subject to special approval of IRS,
tests. material is supplied in the as rolled condition,
the frequency of impact tests is to be increased
3.4.3 For plates of thickness exceeding 50 [mm] to one set from each batch of 25 tonnes or
in Grade E steel, one tensile test is to be made fraction thereof.
on each piece.
iv) The piece selected for the preparation of test
3.4.4 For each batch of plates presented, specimens is to be the thickest in each batch.
(except for Grades EH32, EH36, EH40, EH47,
FH32, FH36 and FH40) the number of Charpy 3.4.5 For each batch of Grade EH32, EH36,
V-notch impact tests is to be as follows : EH40 and EH47 steel presented, the number of
Charpy V- notch impact tests is to be as follows:
i) Except where otherwise specified or specially
agreed by IRS, for each batch presented, at i) For plates one set of three Charpy V-notch
least one set of three Charpy V-notch impact impact test specimens is to be taken from each
test specimens is to be made from one piece piece.
unless the weight of finished material is greater
than 50 tonnes, in which case one extra set of ii) For sections one set of impact tests is to be
three test specimens is to be made from a taken from each batch of 25 tonnes or fraction
different piece from each 50 tonnes or fraction thereof.
thereof.
iii) When, subject to special approval of IRS,
ii) For steel plates of Grades AH40 and DH40 sections are supplied in the as-rolled condition,
with thickness over 50 [mm] in normalized or TM one set of impact tests is to be taken from each
condition, one set of impact test specimens is to batch of 15 tonnes or fraction thereof.
be taken from each batch of 50 tonnes or
fraction thereof. For those in QT condition, one iv) For (ii) and (iii) above the piece selected for
set of impact test specimens is to be taken from the preparation of test specimens is to be the
each length as heat treated. thickest in each batch.
Table 3.3.1 : Required condition of supply and number of impact tests for higher strength steels
(1)(2)
Grade Deoxi- Grain Products Condition of supply (Batch for impact tests
dation refining Thickness [mm]
practice elements
10 12.5 20 25 30 35 40 50 100
N(Each piece)
Plates TM(Each piece) Not applicable
Killed and QT(Each length as heat treated)
FH32
fine grain Any N(25)
FH36 treated TM(25)
Section Not applicable
QT(25)
CR*(15)
N(Each piece)
Plates TM(Each piece) Not applicable
Killed and QT(Each length as heat treated)
FH40 fine grain Any
treated N(25)
Sections TM(25) Not applicable
QT(25)
Remarks
1. Condition of Supply
A - Any (Not Specified)
N - Normalised Condition
CR - Controlled Rolled Condition
TM - Thermo-Mechanical Rolling
QT - Quenched and Tempered Condition
AR* - As Rolled Condition subject to special approval of IRS
CR* - Controlled Rolled Condition subject to special approval of IRS.
2. Number of Impact Tests
One set of impact tests is to be taken from each batch of the "specified weight" in ( ) in tones or fraction
thereof.
For Grades A32 and A36 steels charpy impact tests are not generally required provided that satisfactory
results are obtained from occasional check tests selected by the Surveyor.
- Additionally at each location, Charpy V- 3.4.7.3 Brittle fracture initiation test (CTOD) or
notch impact tests are to be carried out deep notch test is to be carried out.
with appropriate temperature intervals to The test method and results are to be
properly define the full transition range. acceptable to IRS.
3.4.6.2 The Deep Notch Test or Crack Tip 3.4.8 One set of Charpy V-notch impact test
Opening Displacement (CTOD) test is to be specimens are to be tested from each rolled
carried out. The test method and results are to length for Grades FH32, FH36 and FH40 of
be acceptable to IRS. steel plates supplied in the normalised or
thermo-mechanically controlled process
3.4.6.3 The Naval Research Laboratory (NRL) condition.
drop weight test is to be carried out in
compliance with ASTM E208 or equivalent 3.4.9 For steels in the quenched and tempered
method. condition, one tensile and one set of three
Nil Ductility Transition Temperature (NDTT) is to Charpy V- notch impact tests are to be made on
be reported for reference. each plate as heat treated.
Impact Test
Yield
Tensile Elon- Average impact energy (J) min.
stren-
strengt gation Test 50 < t ≤ 70 70 < t ≤ 100
Grade gth ReH t ≤ 50 mm
2 h Rm 5.65 √So Temp. mm mm
[N/mm ] 2
min.
[N/mm ] A5 (%) °C Long Trans Long Trans Long Trans
(2) (2) (2) (2) (2) (2)
AH32 315 440/570 22(1) 0 31(3) 23(3) 38 26 46 31
DH32 -20 31 22 38 26 46 31
EH32 -40 31 22 38 26 46 31
FH32 -60 31 22 38 26 46 31
AH36 355 490/630 21(1) 0 34(3) 24(3) 41 27 50 34
DH36 -20 34 24 41 27 50 34
EH36 -40 34 24 41 27 50 34
FH36 -60 34 24 41 27 50 34
AH40 390 510/660 20(1) 0 39 27 46 31 55 37
DH40 -20 39 27 46 31 55 37
EH40 -40 39 27 46 31 55 37
FH40 -60 39 27 46 31 55 37
t = thickness [mm]
NOTES:
1) For full thickness flat tensile test specimens with a width of 25 [mm] and a gauge length of 200
[mm] the elongation [%] is to comply with the following minimum values:
Thickness [mm]
>5 > 10 > 15 > 20 > 25 > 30 > 40
Grade
≤5 ≤ 10 ≤ 15 ≤ 20 ≤ 25 ≤ 30 ≤ 40 ≤ 50
AH32, DH32, EH32 & FH32 14 16 17 18 19 20 21 22
2) See 2.4.9.
3) For Grades A32 and A36 steels a relaxation in the number of impact tests for acceptance
purposes may be permitted by special agreement with IRS provided that satisfactory results are
obtained from occasional check tests.
Table 3.4.2: Conditions of supply, grade and mechanical properties for EH47 steel plates
Section 4
4.1.2 Steel differing from the requirements in 4.3.2 The chemical composition is to be
this section in respect of chemical composition, determined by the steel maker, in an adequately
deoxidation practice, heat treatment or equipped competently staffed laboratory, from
mechanical properties may be accepted, subject each cast or ladle and is to comply with the
to special approval by IRS. requirements of the approved specifications and
limits given in Table 4.3.1.
4.1.3 The steel covered by the scope of these
requirements are divided into six yield strength 4.3.3 The cold cracking susceptibility Pcm for
levels of 420, 460, 500, 550, 620 and 690 evaluating weldability should be calculated from
2
[N/mm ]. For each yield strength level four the ladle analysis in accordance with the
grades AH, DH, EH and FH are specified, based following formula.
on the impact test temperature.
Si Mn Cu Ni Cr Mo V
Pcm = C + + + + + + + + 5B
4.1.4 Special consideration may be given to the 30 20 20 60 20 15 10
supply of those steels in thickness upto 50 [mm]
in the TMCP condition subject to approval of The maximum Pcm to be achieved is to be
IRS. agreed with IRS and included in the approved
specification.
4.2 Approval
4.4 Heat treatment
4.2.1 The steels must be approved by IRS and
for this purpose the steel maker is to submit a 4.4.1 All materials are to be supplied in the
specification containing such details as chemical quenched and tempered condition. This
composition, manufacturing process, requirement excludes precipitation hardening
mechanical properties, delivery condition, steels.
recommendation for welding, cold and hot
forming and heat treatment. In addition, IRS
T = transverse.
Note 1 : Where the yield stress is not marked in the tensile test, the 0.2% proof stress is applicable.
Note 2 : For full thickness flat test specimens with a width of 25 [mm] and a gauge length of 200 [mm]
the elongation is to comply with the minimum values shown in Table 4.5.2
Note 3 : For A grade steels, a reduction in the number of impact tests required for acceptance
purpose may be permitted by special agreement with IRS provided that satisfactory results are
obtained from occasional check tests.
Table 4.5.2 : Elongation minimum values for a width of 25 [mm] and a 200 [mm] gauge length
Section 5
1 N = Normalized
TMCP = Thermo-mechanically controlled process
QT = Quenched and tempered
5.4 Mechanical tests test specimen required. For plates, these are to
be cut with their principal axis perpendicular to
5.4.1 Test pieces for tensile testing of plates are the final direction of rolling and for sections.
to be cut with their principal axes transverse to these are to be taken longitudinally.
the final direction of rolling.
5.4.5 The results of all tensile tests are to
5.4.2 For each batch of plate presented, one comply with appropriate requirements given in
tensile test is to be made from one end of each Table 5.4.1. The ratio between the yield stress
piece unless the mass and length of the piece and the tensile strength is not to exceed 0.9 for
exceeds 5 tonnes and 15 m in which case test normalized and TMCP steels and 0.94 for Q & T
pieces are to be taken from both ends of each steels.
piece.
5.4.6 The average energy value from each set
5.4.3 Sections and bars are to be presented for of three impact tests are to comply with
acceptance test in batches containing not more appropriate requirements given in Table 5.4.1.
than 50 lengths, as supplied. The material in
each batch is to be of the same section size, 5.4.7 When standard subsidiary impact
from the same cast and in the same condition of specimens are necessary (See Sec. 2).
supply. One tensile test specimen is to be taken
from material representative of each batch, 5.4.8 When steel with improved through
except that additional tests are to be taken when thickness properties is required or specified in
the mass of a batch exceeds 10 tonnes. the order, the materials are to be tested as
detailed in Sec. 8.
5.4.4 One set of three Charpy V-notch impact
test specimens are to be taken for each tensile
1 These requirements are applicable to products not exceeding 40 [mm] in thickness. The
requirements for thicker products are subject to agreement.
2 The minimum design temperatures at which plates of different thicknesses in the above grades
may be used are given in Pt.3, Ch.2, Table 2.4.1 and Pt.5, Ch.4, Table 6.1.2 and Table 6.1.3.
Consideration will be given to the use of thicknesses greater than those in the table or to the use
of temperatures below - 165°C
Section 6
Grade of
Chemical composition per cent
steel
Deoxidation
C and C-Mn P Residual
C max. Si Mn S max. Al
steel max. elements
360 AR 0.18 0.50 max. 0.40-1.30 0.040 0.04 -
Any method
410 AR except 0.21 0.50 max. 0.40-1.30 0.040 0.040 -
460 AR rimmed steel 0.23 0.50 max. 0.80-1.50 0.040 0.040 - Cr 0.25
360 0.17 0.35 max. 0.40-1.20 0.035 0.035 max.
Any method - Cu 0.30
410 except 0.20 0.35 max. 0.50-1.30 0.035 0.035 max.
rimmed steel -
460 0.20
1
0.40 max. 0.80-1.40 0.035 0.035 Mo 0.10
1
- max.
490 Killed 0.20 0.10-0.50 0.90-1.60 0.035 0.035 Ni 0.30
360 FG 0.17 0.35 max. 0.40-1.20 0.035 0.035 See note 2 max.
Total 0.70
410 FG 0.20 0.35 max. 0.50-1.30 0.035 0.035 See note 2 max.
Killed fine
1
460 FG grained 0.20 0.40 max. 0.80-1.50 0.035 0.035 See note 2
1
490 FG 0.20 0.10-0.50 0.90-1.60 0.035 0.035 See note 2
Deoxi- P S Residual
Alloy steels C Si Mn Al Cr Mo
dation max. max. elements
1 Cr 1/2 Mo 0.10- 0.15- See 0.70- 0.40-
0.4-0.8 0.035 0.035 Cu 0.30
470 0.18 0.35 note 3 1.30 0.60
Killed max. Ni
2 1/4 Cr 1 0.08- 0.15- See 2.00- 0.90-
0.4-0.8 0.035 0.035 0.30 max.
Mo 480 0.18 0.50 note 3 2.50 1.10
Notes:
1 For thickness greater than 30 [mm], carbon 0.22 percent max.
2 Aluminium (acid soluble) 0.015 per cent min, or Aluminium (total) 0.018 percent min. Niobium, Vanadium or
other suitable grain refining elements may be used either in place of or in addition to aluminium.
3 Aluminium (acid soluble or total) 0.020 percent max.
Table 6.4.2 : Mechanical properties for acceptance purposes : carbon and carbon-manganese
steels-normalized or controlled rolled
Note:
For thicknesses greater than 63 [mm], the minimum values for yield stress may be reduced by 1 per
cent for each 5 [mm] increment in thickness over 63 [mm]. The minimum elongation values may also
be reduced one unit, e.g. 20 percent reduced to 19 percent for all thicknesses over 63 [mm]. For
thicknesses over 100 [mm], the above values are to be agreed.
Note:
For thicknesses greater than 63 [mm], the minimum values for yield stress may be reduced by 1 per
cent for each 5 [mm] increment in thickness over 63 [mm]. The minimum elongation values may also
be reduced one unit, e.g. 20 percent reduced to 19 percent for all thicknesses over 63 [mm]. For
thicknesses over 100 [mm], the above values are to be agreed.
6.5 Mechanical properties for design Table 6.5.3 Alloy steels. Normalized and
purposes at elevated temperatures tempered.
6.5.1 Nominal values for the minimum lower 6.5.2 These values are intended for design
yield or 0.2 per cent proof stress at purposes only and verification is not required
temperatures of 50°C and higher are given in except for materials complying with National or
the following tables : proprietary specifications where the elevated
temperature properties used for design
Table 6.5.1 Carbon and carbon manganese purposes are higher than those given in Table
steels - As rolled (applicable 6.5.1 to Table 6.5.3. The extent of testing in
only when the design such cases would have to be specially agreed
temperature does not exceed by IRS.
350°C).
6.5.3 Values for the estimated average stress to
Table 6.5.2 Carbon and carbon-manganese
rupture in 100,000 hours are given in Table
steels normalized or controlled
6.5.4 and may be used for design purposes.
rolled.
Table 6.5.1 : Mechanical properties for design purposes - Carbon and carbon -
manganese steels - as rolled
Table 6.5.2 : Mechanical properties for design purposes - carbon and carbon - manganese
steels - normalized or controlled rolled
Note : For thicknesses greater than 63 [mm], the values for lower yield or 0.2 percent stress are to be reduced
by 1 percent for each 5 [mm] increment in thickness upto 100 [mm]. For thicknesses over 100 [mm], the
values are to be agreed and verified by test.
Table 6.5.3 : Mechanical properties for design purposes : alloy steels-normalized tempered
Table 6.5.4 : Mechanical properties for design purposes : estimated average values for stress
2
to rupture in 100,000 hours [N/mm ]
Grades of steel
Carbon and carbon-manganese Alloy Steels
Temp. °C 360 FG 360 490
410 FG 410 490 FG 1 Cr 1/2 Mo 470 2 1/4 Cr 1 Mo 480
460 FG 460 510 FG
380 171 219 227 - -
390 155 196 203 - -
400 141 173 179 - -
410 127 151 157 - -
420 114 129 136 - -
430 102 109 117 - -
440 90 92 100 - -
450 78 78 85 - 221
460 67 67 73 - 204
470 57 57 63 - 186
480 47 48 55 210 170
490 36 - 47 177 153
500 - - - 146 137
510 - - - 121 122
520 - - - 99 107
530 - - - 81 93
540 - - - 67 79
550 - - - 54 69
560 - - - 43 59
570 - - - 35 51
580 - - - - 44
Section 7
7.1 General
b) Any grade of carbon or carbon-manganese
7.1.1 Steel plates, strips, sections or bars steel as detailed in Sec. 6 except that for
intended for use in the construction of welded this application batch testing is acceptable
machinery structures are to comply with one of and the same is to be carried out in
the following alternatives: accordance with the requirements of Sec. 2.
Section 8
8.1.1 Following requirements are for special 8.2.1 All plates are to be manufactured at works
quality plate material with improved ductility in which have been approved by IRS for this
the through thickness or "Z direction. quality of material.
8.1.2 The use of this material known as ‘Z’ 8.2.2 The sulphur content is not to exceed 0.008
quality steel, is recommended when plate per cent, as determined by ladle analysis. It is
material, intended for welded construction, will recommended that the steel should be efficiently
be subject to significant strain in a direction vacuum de-gassed.
perpendicular to the rolled surfaces. These
strains are usually associated with thermal 8.3 Test material
contraction and restraint during welding,
particularly for full penetration "T"- butt welds but 8.3.1 Unless otherwise agreed, through
may also be associated with loads applied in thickness tensile tests are only required for plate
service or during construction. Where these materials where the thickness exceeds 15 [mm].
strains are of sufficient magnitude, lamellar A test sample large enough to provide six test
tearing may occur. Two ‘Z’ quality steels are specimens are to be cut from the centre of one
specified; Z25 for normal ship applications and end of each rolled piece representing the batch.
‘Z35’ for more severe applications. (See Fig.8.3.1). Where appropriate the end
selected should be representative of the top end
Through thickness properties are characterized of an ingot or the start of a concast strand.
by specified values for reduction of area in a Generally three through thickness tensile test
through thickness tensile test. specimens are to be prepared while the rest of
the sample remains for possible retests.
8.1.3 This special quality material is to comply
with the requirements of Sec. 2, 3, 4, 5, 6 and 7 8.3.2 The batch size is to be determined
as appropriate and the following additional depending on the product and sulphur content
requirements. as given in Table 8.3.2.
8.5 Mechanical tests direction are given in Table 8.5.1. Only one
individual value may be below the minimum
8.5.1 The acceptable minimum average value average, but not less than the minimum
for the reduction of area of the three tensile test individual value for the appropriate grade.
specimens taken in the through thickness
Table 8.5.1 : Reduction of area acceptance 8.5.3 Depending on the test results, retest may
values be permitted in the cases shown in Fig.8.5.3. In
Grade Z25 Z35 these instances, three more tensile tests are to
be taken from the remaining test sample. The
Minimum average 25% 35% average of all 6 tensile tests is to be greater
Minimum individual 15% 25% than the required minimum average with not
more than two results below the minimum
8.5.2 A value less than minimum individual average.
value will require rejection of the piece.
However, in case of batch testing each In case of failure after retest, either the batch
remaining piece in the batch may be individually represented by the piece is rejected or each
tested. piece within batch may be retested.
Section 9
9.1.3 Austenitic stainless steels are also suitable 9.1.6 A specification giving details of the
for service at elevated temperatures and for chemical composition, heat treatment and
such applications the proposed specification mechanical properties, including for the
should contain, in addition to the requirements austenitic grades, both the 0.2 and 1.0 percent
of 9.1.6, minimum values for 0.2 and 1.0 per proof stresses, is to be submitted for
cent proof stresses at the design temperature. consideration and approval.
9.2.1 The chemical composition of ladle 9.3.1 All materials are to be supplied in the
samples is to comply with the requirements solution treated condition.
given in Table 9.2.1.
Austenitic
304L 0.03 } } } } 17.0-20.0 8.0-13.0 - 0.10 -
304LN “ } } } } 17.0-20.0 3.0-12.0 - 0.10-0.22 -
316L “ } } } } 16.0-18.5 10.0-15.0 2.0-3.0 0.10 -
316LN “ 1.0 2.0 0.045 0.03 16.0-18.5 10.0-14.5 2.0-3.0 0.10-0.22 -
317L “ } } } } 18.0-20.0 11.0-15.0 3.0-4.0 0.10 -
317LN “ } } } } 18.0-20.0 12.5-15.0 3.0-4.0 0.10-0.22 -
321 0.06 } } } } 17.0-19.0 9.0-12.0 - 0.10 5xC≤Ti≤0.7
347 0.06 } } } } 17.0-19.0 9.0-13.0 - 0.10 10xC≤Nb≤1.0
Duplex
UNS S31803 0.03 1.0 2.0 0.03 0.02 21.0-23.0 4.5-6.5 2.5-3.5 0.08-0.20 -
UNS S32750 0.03 0.80 1.2 0.035 0.02 24.0-26.0 6.0-8.0 3.0-5.0 0.24-0.32 Cu 0.50 max.
Type and grade 0.2% proof stress 1% proof stress Tensile strength Elongation on
2 2 2
of steel [N/mm ] [N/mm ] [N.mm ] 5.65 √So
minimum minimum minimum % minimum
Austenitic
304L 170 210 485 40
304LN 205 245 515 40
316L 170 210 485 40
316LN 205 245 515 40
317L 205 245 515 40
317LN 240 280 550 40
321 205 245 515 40
347 205 245 515 40
Duplex
UNS S 31803 450 - 620 25
UNS S 32750 550 - 795 15
Section 10
10.1.1These requirements apply to normal and 10.2.1 All materials are to be manufactured at
higher strength corrosion resistant steels when works which have been approved by IRS. .
such steel is used as the alternative means of
corrosion protection for cargo oil tanks as 10.2.2 The corrosion tests and assessment
specified in the performance standard MSC.289 criteria are to be in accordance with the
(87) of Regulation 3-11, Part A-1, Chapter II-1 of Appendix of the Annex to Performance Standard
the SOLAS Convention (See Pt.3, Ch.2, Sec.3) for Alternative Means of Corrosion Protection for
Cargo Oil Tanks of Crude Oil Tankers (MSC.289
10.1.2 The requirements are primarily intended (87)). Approval can be given for application in
to apply to steel products with a thickness as one of the following areas of a cargo oil tank:
follows:
a) Lower surface of strength deck and
- For steel plates and wide flats; surrounding structures.
- All Grades: Up to 50 [mm] in
thickness b) Upper surface of inner bottom plating
and surrounding structures.
- For sections and bars;
- All Grades: Up to 50 [mm] in c) For both strength deck and inner bottom
thickness plating.
10.1.3 Normal and higher strength Corrosion 10.2.3 The manufacturer has to submit to IRS a
Resistant steels as defined within this section, request for approval, which is to include the
are steels whose corrosion resistance following:
performance in the bottom or top of the internal
cargo oil tank is tested and approved to satisfy a) Corrosion test plan and details of
the requirements in MSC.289 (87) in addition to equipment and test environments.
other relevant requirements for ship material,
structural strength and construction. It is not b) Technical data related to product
intended that such steels be used for corrosion assessment criteria for confirming
resistant applications in other areas of a vessel corrosion resistance.
that are outside of those specified in the
performance standard MSC.289 (87) of
Regulation 3-11, Part A-1, Chapter II-1 of the c) The technical background explaining
SOLAS Convention. how the variation in added and
controlled elements improves corrosion
10.1.4 The basic requirements for ship steels resistance.
specified in this chapter apply to corrosion
resistant steels except where modified by this d) The grades, the brand name and
section. maximum thickness of corrosion
resistant steel to be approved.
10.1.5 The welding requirements specified in Designations for corrosion resistant
Ch.11 for approval of consumables for welding steels are given in Table 10.1.
normal and higher strength hull structural steels
also apply except as modified by this section. e) The welding processes and the brand
Welding procedures are to be approved name of the welding consumables to be
according to Pt.3, Ch.17, Sec.2.5. used for approval.
10.2.6 In addition to paragraph 10.2.5 above, 10.2.7 The manufacturer is to carry out the
IRS may require additional tests in the following approval test in accordance with the approved
cases: test plan.
a) When IRS determines that the control 10.2.8 IRS's Surveyor is to be present, as a rule,
range is set by the theoretical analysis when the test samples for the approval test are
of each element based on existing data, being identified and for approval tests, see also
the number of corrosion resistance tests 10.2.4.
conducted in accordance with the
Appendix of the Annex to Performance 10.2.9 After completion of the approval test, the
Standard for Alternative Means of manufacturer is to produce the report of the
Corrosion Protection for Cargo Oil approval test and submit to IRS.
Tanks (MSC.289 (87)) is too few to
adequately confirm the validity of the 10.2.10 IRS will give approval for corrosion
control range of chemical composition. resistant steel where approval tests are
considered by IRS to have given satisfactory random checks as required by the Surveyor.
results based on the data submitted in The carbon equivalent is to be in accordance
accordance with the provisions of this section. with Sec. 2 for normal strength steels and Sec 3
for high strength steel.
10.2.11 The results will be assessed by IRS in
accordance with the acceptance criteria 10.5 Condition of supply
specified in the Appendix of the Annex to
Performance Standard for Alternative Means of 10.5.1 All materials are to be supplied in one of
Corrosion Protection for Cargo Oil Tanks the supply conditions mentioned in Sec. 2 for
(MSC.289 (87)). normal strength steels and Sec 3 for high
strength steel.
10.2.12 It is the manufacturer’s responsibility to
assure that effective process and production
controls in operation are adhered to within the 10.6 Mechanical Tests
manufacturing specifications. If the process or
production controls are changed in any way, or 10.6.1 Tensile testing and Charpy V-notch
any product fails to meet specifications, the impact testing is to be carried out in accordance
manufacturer is to issue a report explaining the with Sec. 2 for normal strength steels and Sec 3
reasons, and, in the instance of product which for high strength steel.
fails to meet specifications, the measures to
prevent recurrence. 10.7 Freedom from defects
The complete report is to be submitted to the
Surveyor along with such additional information 10.7.1 The steel is to be reasonably free from
as the Surveyor may require. Each affected segregations and non-metallic inclusions. The
piece is to be tested to the Surveyor’s finished material is to have a workmanlike finish
satisfaction. The frequency of testing for and is to be free from internal and surface
subsequent products is at the discretion of IRS. defects prejudicial to the use of the material for
the intended application.
10.2.13 The certificate is to contain the
manufacturer’s name, the period of validity of 10.7.2 The acceptance criteria for surface finish
the certificate, the grades and thickness of the and procedures for the repair of defects, as
steel approved, welding methods and detailed in Sec1.8 and Sec.1.9 are to be
consumables approved. observed.
10.3.1 The method of manufacture, deoxidation 10.8.1 Unless otherwise agreed or specially
process and rolling practice is to be in required the thickness tolerances in Sec1 are
accordance with Sec. 2 for normal strength applicable.
steels and Sec 3 for high strength steel.
10.9 Identification of materials
10.4 Chemical Composition
10.9.1 The steelmaker is to adopt a system for
10.4.1 The chemical composition of the samples the identification of ingots, slabs and finished
taken from each ladle of each cast is to be pieces which will enable the material to be
determined by the manufacturer in an traced to its original cast. The Surveyor is to be
adequately equipped and competently staffed given full facilities for so tracing the material
laboratory and is to be in accordance with the when required.
appropriate requirements mentioned in Sec. 2
for normal strength steels and Sec 3 for high 10.10 Inspection and testing
strength steel.
10.10.1 Facilities for Inspection
10.4.2 The manufacturer will establish a
relationship of all the chemical elements which The manufacturer is to afford the Surveyor all
affect the corrosion resistance, the chemical necessary facilities and access to all relevant
elements added or controlled to achieve this are parts of the works to enable him to verify that
to be specifically verified for acceptance. the approved process is adhered to, for the
Verification is to be based on the ladle analysis selection of test materials, and the witnessing of
of the steel. The manufacturer's declared tests, as required by the Rules, and for verifying
analysis will be accepted subject to periodic the accuracy of the testing equipment.
End of Chapter
Chapter 4
Steel Castings
Contents
Section
1 General Requirements
2 Hull and Machinery Steel Castings for General Applications
3 Ferritic Steel Castings for Low Temperature Services
4 Steel Castings for Propellers
5 Austenitic Stainless Steel Castings
6 Castings for other applications
Section 1
General Requirements
1.2.3 All flame cutting, scarfing or arc-air 1.4.1 All castings are to be made from killed
gouging to remove surplus metal is to be steel and the chemical composition is to be
appropriate for the type of steel and the 1.7 Rectification of defective castings
mechanical properties specified for the castings.
The chemical composition of each heat is to be 1.7.1 General
determined by the manufacturer on a sample
taken preferably during the pouring to the heat. i) Steel casting defects are to be removed with
When multiple heats are tapped into a common or without weld repair before considering
ladle, the ladle analysis shall apply. suitable for use subject to approval of IRS.
iii) Welding s to be done under cover in positions 1.8.2 Before acceptance, all castings which
free from draughts and adverse weather have been tested and inspected with
conditions by qualified welders with adequate satisfactory results are to be clearly marked by
supervision. As far as possible, all welding is to the manufacturer with the following particulars:
be carried out in the downhand (flat) position.
i) Steel quality.
iv) The welding consumables used are to be of
an appropriate composition, giving a weld ii) Identification number, cast number or other
deposit with mechanical properties similar and in marking which will enable the full history of the
no way inferior to those of the parent castings. casting to be traced.
Welding procedure tests are to be carried out by
the manufacturer to demonstrate that iii) Manufacturer’s name or trade mark.
satisfactory mechanical properties can be
obtained after heat treatment as detailed in iv) The IRS brand name ‘IR’.
Sec.2.
v) Abbreviated name of the IRS local office.
v) After welding has been completed the
castings are to be given either a suitable heat vi) Personal stamp of Surveyors responsible for
treatment in accordance with the requirements inspection.
of Sec.2 or a stress relieving heat treatment at a
temperature of not less than 550°C. The type of vii) Where applicable, test pressure.
heat treatment employed will be dependent on
the chemical composition of the casting and he 1.8.3 When small castings are manufactured in
dimensions, positions and nature of the repairs. large numbers, modified arrangements for
identification may be specially agreed with IRS.
vi) Subject to the prior agreement of IRS special
consideration may be given to the omission of 1.9 Certification
postweld heat treatment or to the acceptance of
local stress relieving heat treatment where the 1.9.1 The manufacturer is to provide the
repaired area is small and machining of the Surveyor with a test certificate or shipping
casting has reached an advanced stage. statement giving the following particulars for
each casting or batch of castings which has
vii) On completion of heat treatment the weld been accepted:-
repairs and adjacent material are to be ground
smooth and examined by magnetic particle or a) Purchaser's name and order number;
liquid penetrant testing. Supplementary
examination by ultrasonics or radiography may b) Description of castings and steel quality;
also be repaired depending on the dimensions
and nature of the original defect. Satisfactory c) Identification number;
results are to be obtained from all forms of non-
destructive testing used. d) Steel making process, cast number and
chemical analysis of ladle samples;
1.8 Identification of castings
e) Results of mechanical testing;
1.8.1 The manufacturer is to adopt a system of
identification which will enable all finished f) General details of heat treatment;
castings to be traced to the original cast and
Surveyors are to be given full facilities for so g) Where applicable, test pressure.
tracing the castings when required.
Section 2
2.1.2 These requirements are applicable only to 2.2.1 For carbon and carbon-manganese steel
steel castings where the design and acceptance castings the chemical composition is to comply
tests are related to mechanical properties at with the overall limits given in Table 2.2.1 or
ambient temperature. For other applications, where applicable, the requirements of the
additional requirements may be necessary, approved specification.
especially when the castings are intended for
service at low or elevated temperatures. 2.2.2 Unless otherwise required, suitable grain
refining elements such as aluminium may be
used at the discretion of the manufacturer. The
content of such elements is to be reported.
Table 2.2.1 : Chemical composition limits for hull and machinery steel castings (%)
Steel Applications C Si Mn S P Residual elements (max.) Total
type (max.) (max.) (max.) (max.) Cu Cr Ni Mo residuals
(max.)
Castings for 0.40 0.60 0.50 – 0.040 0.040 0.30 0.30 0.40 0,15 0.80
non-welded 1.60
construction
C,
C-Mn
Castings for 0.23 0.60 1.60 0.040 0.040 0.30 0.30 0.40 0.15 0.80
welded max.
construction
2.3.3 Heat treatment is to be carried out in
2.3 Heat treatment properly constructed furnaces which are
efficiently maintained and have adequate means
2.3.1 Castings are to be supplied in one of the for control and recording of temperature. The
following conditions: furnace dimensions are to be such as to allow
the whole casting to be uniformly heated to the
Fully annealed necessary temperature. In the case of very large
Normalised castings alternative methods for heat treatment
Normalised and tempered will be specially considered by IRS. Sufficient
Quenched and tempered thermocouples are to be connected to the
furnace charge to measure and record that its
The tempering temperature is not less than temperature is adequately uniform unless the
550°C. temperature uniformity of the furnace is verified
at regular intervals.
2.3.2 Castings or component such as
crankshafts and engine bedplates, where 2.3.4 If a casting is locally reheated or any
dimensional stability and freedom from internal straightening operation is performed after the
stresses are important are to be given a stress final heat treatment, a subsequent stress
relief heat treatment. This is to be carried out at relieving heat treatment may be required in
a temperature of not less than 550°C followed order to avoid the possibility of harmful residual
by furnace cooling to 300°C or lower. stresses.
2.4.6 The test samples are not to be detached Specified Yield Elongation Reduction
from the casting until the specified heat minimum stress on 5.65 of area
2
treatment has been completed and they have tensile [N/mm ] √So (%) (%) min.
been properly identified. strength min. min.
(1)
2
2.4.7 One tensile test specimen is to be taken [N/mm ]
from each test sample. 400 200 25 40
440 220 22 30
2.4.8 The preparation of test specimens and the 480 240 20 27
procedures used for mechanical testing are to 520 260 18 25
comply with the relevant requirements of Ch.2. 560 300 15 20
Unless otherwise agreed all tests are to be 600 320 13 20
carried out in the presence of the Surveyors. Note:
2
(1) A tensile strength range of 150 [N/mm ] may
2.5 Mechanical properties additionally be specified.
2.5.1 Table 2.5.1 gives the minimum
requirements for yield stress, elongation and
Section 3
Table 3.2.1 : Chemical composition of ferritic steel castings for low temperature service
Chemical composition %
Type of Residual
steel C max. Si max. Mn S max. P max. Ni elements
max.
Carbon- 0.25 0.60 0.70-1.60 0.030 0.030 0.80 max.
manganese
2 14 Ni 0.25 0.60 0.50-0.80 0.025 0.030 2.00-3.00 Cr 0.25
Cu 0.30
3 12 Ni 0.15 0.60 0.50-0.80 0.020 0.025 3.00-4.00 Mo 0.15
V 0.03
Total 0.60
be carried out at the temperature specified in the
3.3 Heat treatment table.
3.3.1 Castings are to be supplied in one of the 3.4.3 The average energy value from a set of
following conditions : three charpy V-notch impact test specimens is
not to be lower than the required average value
a) normalized. given in Table 3.4.1. One individual value may
b) normalized and tempered. be less than the required average value
c) quenched and tempered. provided that it is not less than 70 per cent of
this average value.
3.4 Mechanical tests
3.5 Non-destructive testing
3.4.1 The mechanical properties of steel
castings are to comply with requirements given 3.5.1 The non-destructive examination of
in Table 3.4.1. castings is to be carried out in accordance with
the appropriate requirements of 1.7 and
3.4.2 The tensile test is to be carried out at additionally agreed between the manufacturer,
ambient temperature and the impact tests are to purchaser and Surveyor.
Table 3.4.1 : Mechanical properties for acceptance purposes : ferritic steel castings for low
temperature service
Charpy V-notch
Yield Elongation
Tensile Reduction impact test
Type of stress on
Grade 2 strength of area % Average
steel [N/mm ] 2 5.65√So% Test
[N/mm ] min. o energy J
min. min. temp. C
min.
Carbon- 400 200 400 - 550 25 40 -60
manganese 430 215 430 - 580 23 35 (see 27
450 230 460 - 610 22 30 Note)
2 14 Ni 490 275 490 - 640 20 35 -70 34
3 12 Ni 490 275 490 - 640 20 35 -95 34
o
Note : The temperature for carbon-maganese steels may be 5 C below the design temperature if the
o o
latter is above -55 C, with a maximum test temperature of -20 C.
Section 4
4.1 Scope
4.2.4 Heat treatment
4.1.1 These requirements are applicable to the
manufacture of cast steel propellers, blades and Martensitic castings are to be austenitized and
bosses. tempered. Austenitic castings should be solution
treated.
4.1.2 Where the use of alternative alloys is
proposed, particulars of chemical composition, 4.2.5 Mechanical tests
mechanical properties and heat treatment are to
be submitted for approval. 4.2.5.1 The mechanical properties are to meet
the requirements in Table 4.2.2. These values
4.1.3 These requirements may also be used for refer to the test specimens machined from
the repair of propellers damaged in service, integrally cast test bars attached to the hub or
subject to prior approval of IRS. on the blade.
All castings are to have a workmanlike finish 4.2.5.4 Separately cast test bars may be used
and are to be free from imperfections that could subject to prior approval of IRS. The test bars
be considered to impair in-service performance. are to be cast from the same heat as the
castings represented and heat treated with the
4.2.3 Chemical composition castings represented.
1) Not required for general service and the lowest ice class notations. For other ice class notations,
o
tests are to be made -10 C.
2
2) Rp1.0 value is 205 [N/mm ].
4.5.3 For all propellers, separately cast blades Relevant indication : an indication that is caused
and hubs, the surfaces covered by severity by a condition or type of discontinuity that
Zones A, B and C are to be liquid penetrant requires evaluation. Only indications which have
tested. Testing of Zone A is to be undertaken in any dimension greater than 1.5 [mm] shall be
the presence of the Surveyor, whilst testing of considered relevant.
Zone B and C may be witnessed by the
Surveyor upon his request. 4.5.6 For the purpose of evaluating indications,
the surface is to be divided into reference areas
2
4.5.4 If repairs have been made either by of 100 [cm ], which may be square or
grinding or by welding, the repaired areas are rectangular with the major dimension not
additionally to be subjected to the liquid exceeding 250 [mm]. The area shall be taken in
penetrant testing independent of their location the most unfavorable location relative to the
and/or severity Zone. Weld repairs are, indication being evaluated.
independent of their location, always to be
assessed according to Zone A. 4.5.7 The indications detected may, with respect
to their size and number, not exceed the values
4.5.5 The following definitions relevant to liquid given in the Table 4.5.1.
penetrant indications apply:
4.5.8 Where serious doubt exists that the
Indication : the presence of detectable bleed-out castings are not free from internal defects,
of the penetrant liquid from the material further non-destructive inspections are to be
discontinuities appearing at least 10 minutes carried out upon request of the Surveyor, e.g.
after the developer has been applied; radiographic and/or ultrasonic tests. The
acceptance criteria are then to be agreed
Linear indication : an indication in which the between the manufacturer and IRS in
length is at least three times the width; accordance with the recognised standard.
Table 4.5.1 : Allowable number and size of indications depending on severity zones
Severity zone Max. total Indication type Max. number for Max. dimension
1),2)
number of each type of indication
indications [mm]
Non-linear 5 4
A 7 Linear 2 3
Aligned 2 3
Non-linear 10 6
B 14 Linear 4 6
Aligned 4 6
Non-linear 14 8
C 20 Linear 6 6
Aligned 6 6
Notes:
1) Single non-linear indications less than 2 [mm] in Zone A and less than 3 [mm] in other zones may
be disregarded.
2) The total number of non-linear indications may be increased to the maximum total number, or part
thereof, represented by the absence of linear or aligned indications.
4.6.1 Defective castings are to be repaired in 4.7.1 The scope of the procedure tests involved
accordance with the requirements given in 4.6.2 in the qualification is given in 4.10.
to 4.6.7 and, where applicable, the requirements
of 4.7. Before welding is started, a detailed welding
procedure specification is to be submitted
4.6.2 In general the repairs are to be carried out covering the weld preparation, welding
by mechanical means, e.g. by grinding or positions, welding parameters, welding
milling. The resulting grooves are to be blended consumables, preheating, post weld heat
into the surrounding surface so as to avoid any treatment and inspection procedures.
sharp contours. Complete elimination of the
defective material is to be verified by liquid 4.7.2 All weld repairs are to be made by
penetrant testing. qualified welders using qualified procedures.
4.6.3 Weld repairs are to be undertaken only 4.7.3 Welding is to be done under controlled
when they are considered to be necessary and conditions free from draughts and adverse
have prior approval of the Surveyor. All weld weather.
repairs are to be documented by means of
sketches or photographs showing the location 4.7.4 Metal arc welding with electrodes or filler
and major dimensions of the grooves prepared wire used in the procedure tests is to be used.
for welding. The documentation is to be The welding consumables are to be stored and
presented to the Surveyor prior to repair handled in accordance with the manufacturer's
welding. recommendations.
4.6.4 The excavations are to be suitably shaped 4.7.5 Slag, undercuts and other imperfections
to allow good access for welding. The resulting are to be removed before depositing the next
grooves are to be subsequently ground smooth run.
and complete elimination of the defective
material is to be verified by liquid penetrant 4.7.6 The martenistic steels are to be furnace
2
testing. Welds having an area less than 5 [cm ] re-tempered after weld repair. Subject to prior
are to be avoided. approval, however, local stress relieving may be
considered for minor repairs.
4.6.5 Grinding in severity Zone A may be carried
out to an extent that maintains the blade 4.7.7 On completion of heat treatment the weld
thickness. Repair welding is generally not repairs and adjacent material are to be ground
permitted in severity Zone A and will only be smooth. All weld repairs are to be liquid
allowed after special consideration. penetrant tested.
4.6.6 Defects in severity Zone B that are not 4.7.8 The manufacturer is to be maintain
deeper than t/40 [mm] ("t" is the minimum local records of welding, subsequent heat treatment
thickness according to the Rules) or 2 [mm], and inspections traceable to each casting
whichever is greatest, are to be removed by repaired. These records are to be reviewed by
grinding. Those defects that are deeper may be the Surveyor.
repaired by welding subject to prior approval
from IRS. 4.8 Identification
4.6.7 Repair welding is generally permitted in 4.8.1 Castings are to be clearly marked by the
severity Zone C. manufacturer in accordance with the
requirements of Ch.1. The following details are 4.10 Welding procedure qualification test
to be marked on all castings which have been
accepted: 4.10.1 Preparation of test assembly
a) Heat number or other marking which will A test assembly of minimum 30 [mm] thickness
enable the full history of the casting to be is to be welded. The types of specimens to be
traced; prepared are shown in Fig.4.10.1.
4.8.2 The IR stamp is to be put on when the Two macro-sections shall be prepared and
casting has been accepted. etched on one side to clearly reveal the weld
metal, the fusion line and the heat affected
4.9 Certification zone. The sections are to be examined by eye
(aided by low power hand lens if desired) for any
4.9.1 The manufacturer is to provide the imperfections present in the weld metal and
Surveyor with an inspection certificate giving the HAZ. Cracks or crack-like imperfections, slag
following particulars for each casting which has inclusions and pores greater than 3 [mm] are not
been accepted: permitted.
b) Vessel identification, where known; Two flat transverse tensile test specimens shall
be prepared. Testing procedures shall be in
c) Description of the casting with drawing accordance with Ch.4 Sec.1 requirements. The
number; tensile strength shall meet the specified
minimum value of the base material. The
d) Diameter, number of blades, pitch, direction location of fracture is to be reported, i.e. weld
of turning; metal, HAZ or base material.
e) Skew angle for high skew propellers; 4.10.5 Charpy V-notch testing
Section 5
Table 5.4.2 : Mechanical properties for acceptance purposes : austenitic stainless steel castings
5.5.1 Where corrosive conditions are anticipated 5.6.1 The non-destructive examination of
in service, intergranular corrosion tests are castings is to be carried out in accordance with
required on castings in grades 304, 316 and the appropriate requirements of Classification
317. Such tests may not be required for grades Notes “Guidelines for non-destructive
304L, 316L and 347. examination of steel castings for marine
application” and additionally agreed between the
5.5.2 Where an intergranular corrosion test is manufacturer, purchaser and Surveyor.
specified, it is to be carried out in accordance
with the standard referred in 9.6.2 of Chapter 3.
Section 6
End of Chapter
Chapter 5
Steel Forgings
Contents
Section
1 General Requirements
2 Hull and Machinery Steel Forgings for General Applications
3 Ferritic Steel Forgings for Low Temperature Service
4 Austenitic Stainless Steel Forgings
Section 1
General Requirements
1.1.1 All important steel forgings, as defined in 1.2.1 Forgings are to be made at the works
the relevant construction Rules, are to be approved by IRS.
manufactured and tested in accordance with the
requirements of this Chapter. 1.2.2 The steel used in the manufacture of
forgings is to be made by a process approved
1.1.2 Where required by the relevant Rules by IRS.
dealing with design and construction, forgings
are to be manufactured and tested in 1.2.3 Adequate top and bottom discards are to
accordance with Ch.1 and 2, together with the be made to ensure freedom from piping and
general requirements given in this Chapter. harmful segregations in the finished forgings.
1.1.3 Alternatively, forgings which comply with 1.2.4 The plastic deformation is to be such as to
National or proprietary specifications may be ensure soundness, uniformity of structure and
accepted provided such specifications give satisfactory mechanical properties after heat
reasonable equivalence to these requirements treatment. The reduction ratio is to be in
or are otherwise specially approved for a accordance with the following Table:
specific application by IRS.
1 L and D are the length and diameter respectively of the part of the forging under consideration.
2 the reduction ratio is to be calculated with reference to the average cross-sectional area of the
ingot. Where an ingot is initially upset, this reference area may be taken as the average cross-
sectional area after this operation.
3 For rolled bars used as a substitute for forgings (see 1.1.1) the reduction ratio is not to be less
than 6 : 1
4 For forgings made by upsetting, the length after upsetting is to be not more than one-third of the
length before upsetting or, in the case of an initial forging reduction of at least 1.5:1, not more
than one half of the length before upsetting.
1.2.8 When two or more forgings are joined by 1.5.3 Alternatively, alloy steel forgings may be
welding to form a composite component the supplied in the normalized and tempered
proposed welding procedure specification is to condition, in which case the specified
be submitted for approval. Welding procedure mechanical properties are to be agreed with
qualification tests may be required. IRS.
1.9.2 Where small forgings are manufactured in c) Steel making process, cast number and
large numbers, modified arrangements for chemical analysis of ladle sample;
identification may be specially agreed with IRS.
d) Results of mechanical tests;
1.10 Certification
e) General details of heat treatment;
1.10.1 The manufacturer is to provide the
Surveyor, in duplicate, with a test certificate or f) Identification number.
shipping statement giving the following
particulars for each forging or batch of forgings
which has been accepted:
Section 2
2.1 Scope
2.2 Chemical Composition
2.1.1 The requirements given in this section are
applicable to steel forgings intended for hull and 2.2.1 The chemical composition is to comply
machinery applications such as rudder stocks, with the overall limits given in Tables 2.2.1 and
pintles, propeller shafts, crankshafts, connecting Table 2.2.2 or, where applicable, the
rods, piston rods, gearing etc. Where relevant, requirements of the approved specification.
these requirements are also applicable to
material for forging stock and to rolled bars 2.2.2 At the option of the manufacturer, suitable
intended to be machined into components of grain refining elements such as aluminium,
simple shape. niobium or vanadium may be added. The
content of such elements is to be reported.
2.1.2 These requirements are applicable only to
steel forgings where the design and acceptance 2.2.3 Elements designated as residual elements
tests relate to mechanical properties at ambient in the individual specifications are not to be
temperature. For other applications, additional intentionally added to the steel. The content of
requirements may be necessary especially such elements is to be reported.
when the forgings are intended for service at low
or elevated temperatures.
1) 6)
Table 2.2.1 : Chemical composition limits for hull steel forgings
4)
Steel C Si Mn P S Cr Mo Ni Cu Total
type residuals
2), 3) 4) 4) 4)
C, C-Mn 0.23 0.45 0.20- 0.035 0.035 0.30 0.15 0.40 0.30 0.85
1.50
5) 5) 5) 5) 5)
Alloy 0.45 0.035 0.035 0.30 -
1)
Composition in percentage mass by mass maximum unless shown as a range.
2)
The carbon content may be increased above this level provided that the carbon equivalent (Ceq) is
not more than 0.41%, calculated using the following formula:
Mn Cr + Mo + V Ni + Cu
Ceq = C + + + (%)
6 5 15
3)
The carbon content of C and C-Mn steel forgings not intended for welded construction may be 0.65
maximum.
4)
Elements are considered as residual elements.
5)
Specification is to be submitted for approval.
6)
Rudder stocks and pintles should be of weldable quality.
1)
Table 2.2.2 : Chemical composition limits for machinery steel forgings
3)
Steel C Si Mn P S Cr Mo Ni Cu Total
type residuals
2) 3) 3) 3)
C, C-Mn 0.65 0.45 0.30- 0.035 0.035 0.30 0.15 0.40 0.30 0.85
1.50
4)
Alloy 0.45 0.45 0.30- 0.035 0.035 Min Min Min 0.30 -
5) 5) 5)
1.00 0.40 0.15 0.40
1)
Composition in percentage mass by mass maximum unless shown as a range or as a minimum.
2)
The carbon content of C and C-Mn steel forgings intended for welded construction is to be 0.23
maximum. The carbon content may be increased above this level provided that the carbon equivalent
(Ceq) is not more than 0.41%.
3)
Elements are considered as residual elements unless shown as a minimum.
4)
Where alloy steel forgings are intended for welded constructions, the proposed chemical composition
is subject to approval by IRS.
5)
One or more of the elements is to comply with the minimum content.
2.3 Mechanical tests direction are to be taken from the end of the
journal (test position C in Fig.2.3.5d). If however,
2.3.1 Adequate number of test coupons are to the journal diameter is 200 [mm] or less the
be provided for carrying out tests including for tests are to be taken in a longitudinal direction
retest purposes, with a cross-sectional area of (test position A in Fig.2.3.5d). Where the
not less than that part of the forging which it finished length of the toothed portion exceed
represents. This test material is to be integral 1.25 [m], one set of tests is to be taken from
with each forging except as provided in 2.3.7 each end.
and 2.3.10. Where batch testing is permitted
according to 2.3.10 the test material may c) Small pinions - Where the finished diameter
alternatively be a production part or separately of the toothed portion is 200 [mm] or less one
forged. Separately forged test material is to set of tests is to be taken in a longitudinal
have a reduction ratio similar to that used for the direction (test position A in Fig.2.3.5d).
forgings represented.
d) Gear wheels - One set of tests is to be taken
2.3.2 For the purpose of these requirements a from each forging in tangential direction (test
set of tests is to consist of one tensile test position A or B in Fig.2.3.5e).
specimen and when required in other sections of
Rules three Charpy V-notch impact test e) Gear wheel rims (made by expanding)
specimens. One set of tests is to be taken from each forging
in a tangential direction (test position A or B in
2.3.3 Test specimens are normally to be cut with Fig.2.3.5.f). Where the finished diameter
their axes either parallel (longitudinal test) or exceeds 2.5 [m] or the mass (as heat treated
tangential (tangential test) to the principal axial excluding test material) exceeds 3 tonnes, two
direction of each product. sets of tests are to be taken from diametrically
opposite positions (test positions A and B in Fig.
2.3.4 Unless otherwise agreed, the longitudinal 2.3.5f). The mechanical properties for
axis of test specimens is to be positioned as longitudinal test are also to be applied.
follows:
f) Pinion sleeves - One set of tests is to be taken
a) for thickness or diameter upto maximum 50 from each forging in tangential direction (test
[mm], the axis is to be at the mid-thickness position A or B in Fig.2.3.5g). Where the finished
or the center of the cross section. length exceeds 1.25 [m] one set of tests is to be
b) for thickness or diameter greater than 50 taken from each end.
[mm], the axis is to be at one quarter
thickness (mid-radius) or 8- [mm], whichever g) Crankwebs
is less, below any heat treated surface. One set of tests is to be taken from each forging
in a tangential direction.
2.3.5 Except as provided in 2.3.10 the number
and direction of tests is to be as follows: h) Solid open die forged crankshafts
One set of tests is to be taken in a longitudinal
a) Hull components such as rudder stocks, direction from the driving shaft end of each
pintles etc. General machinery components forging (test position A in Fig.2.3.5h).
such as shafting, connecting rods, etc. Where the mass (as heat treated but excluding
One set of tests is to be taken from the end of test material) exceeds 3 tonnes tests in a
each forging in a longitudinal direction except longitudinal direction are to be taken from each
that, at the discretion of the manufacture the end (test positions A and B in Fig.2.3.5h).
alternative directions or positions as shown in Where, however, the crankthrows are formed by
Fig.2.3.5a, Fig.2.3.5b and Fig.2.3.5c may be machining or flame cutting, the second set of
used. Where a forging exceeds both 4 tonnes in tests is to be taken in a tangential direction from
mass and 3 [m] in length one set of tests is to be material removed from the crankthrow at the
taken from each end. These limits refer to the end opposite the driving shaft end (test position
‘as forged’ mass and length but excluding the C in Fig.2.3.5h).
test material.
2.3.6 For closed die crankshaft forgings and
b) Pinions - Where the finished machined crankshaft forgings where the method of
diameter of the toothed portion exceeds 200 manufacture has been specially approved in
[mm] one set of tests is to be taken from each accordance with 1.2.5, the number and position
forging in a tangential direction adjacent to the of test specimens is to be agreed with IRS
toothed portion (test position B in Fig.2.3.5d). having regard to the method of manufacture
Where the dimensions preclude the preparation employed.
of tests from this position, tests in a tangential
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2.3.10 Normalized forgings with mass upto 1000 2.4.4 At the discretion of IRS hardness tests
[kg] each and quenched and tempered forgings may be required in the following cases:
with mass upto 500 [kg] each may be batch
tested. A batch is to consist of forgings of similar i) Gear forgings after completion of heat
shape and dimensions, made from the same treatment and prior to machining the gear teeth:
heat of steel, heat treated in the same furnace
charge and with a total mass not exceeding 6 The hardness is to be determined at four
tonnes for normalized forgings and 3 tonnes for positions equally spaced around the
quenched and tempered forgings respectively. circumference of the surface where teeth will
subsequently be cut. Where the finished
2.3.11 A batch testing procedure may also be diameter of the toothed portion exceeds 2.5 [m],
used for hot rolled bars. A batch is to consist of the above number of test positions is to be
either: increased to eight. Where the width of a gear
wheel rim forging exceeds 1.25 [m], the
i) material from the same rolled ingot or hardness is to be determined at eight positions
bloom provided that where this is cut at each end of the forging.
into individual lengths, these are all heat
treated in the same furnace charge, or ii) Small crankshaft and gear forgings which
have been batch tested:
ii) bars of the same diameter and heat,
heat treated in the same furnace charge In such cases at least one hardness test is to be
and with a total mass not exceeding 2.5 carried out on each forging.
tonnes.
The results of hardness tests are to be reported
2.3.12 The preparation of test specimens and and, for information purposes, typical Brinell
the procedures used for mechanical testing are hardness values are given in Table 2.4.2.
to comply with the relevant requirements of Pt.2,
Ch.2. Unless otherwise agreed all tests are to 2.4.5 Hardness tests may also be required on
be carried out in the presence of the Surveyor. forgings which have been induction hardened,
nitrided or carburized. For gear forgings these
2.4 Mechanical properties tests are to be carried out on the teeth after,
where applicable, they have been ground to the
2.4.1 Table 2.4.1 and Table 2.4.2 gives the finished profile. The results of such tests
minimum requirements for yield stress, including depth of hardening are to comply with
elongation, reduction of area and impact test the approved specifications. (See 1.5.6).
energy values corresponding to different
strength levels but it is not tended that these 2.4.6 Where the result of a tensile test does not
should necessarily be regarded as specific comply with the requirements, two additional
grades. Where it is proposed to use a steel with tests may be taken. If satisfactory results are
a specified minimum tensile strength obtained from both of these additional tests the
intermediate to those given, corresponding forging or batch of forgings is acceptable. If one
minimum values for the other properties may be or both retests fail the forging or batch of
obtained by interpolation. forgings is to be rejected.
2.4.2 Forgings may be supplied to any specified 2.4.7 Where the results from a set of three
minimum tensile strength selected within the impact test specimens do not comply with the
general limits detailed in Table 2.4.1 and Table requirements an additional set of three impact
2.4.2 but subject to any additional requirements test specimens may be taken provided that not
of the relevant construction rules. more than two individual values are less than
the required average value and of these not
2.4.3 The mechanical properties are to comply more than one is less than 70% of this average
with the requirements of Table 2.4.1 and Table value. The results obtained are to be combined
2.4.2 appropriate to the specified minimum with the original results to form a new average
tensile strength or, where applicable the which, for acceptance of the forgings or batch
requirements of the approved specification. forgings, is to be not less than the required
average value.
Steel type Tensile Yield stress Elongation as min. % Reduction of area Z min.
1)
strength Re min. %
2
Rm min. [N/mm ] Long. Tang. Long. Tang.
2
[N/mm ]
C and 400 200 26 19 50 35
C-Mn 440 220 24 18 50 35
480 240 22 16 45 30
520 260 21 15 45 30
560 280 20 14 40 27
600 300 18 13 40 27
Alloy 550 350 20 14 50 35
600 400 18 13 50 35
650 450 17 12 50 35
1) The following ranges for tensile strength may be additionally specified:
specified minimum tensile strength : < 600 [N/mm ] ≥ 600 [N/mm ]
2 2
2 2
tensile strength range : 120 [N/mm ] 150 [N/mm ]
2)
Table 2.4.2 : Mechanical properties for machinery steel forgings
Section 3
3.1.1 The requirements for carbon-manganese 3.4.1 At least one tensile and three V-notch
and nickel steels suitable for low temperature impact test specimens are to be taken from
service are detailed in this section. They are each forging or each batch of forgings. Where
applicable to all forgings with material thickness the dimensions and shape allow, the test
up to and including 50 [mm] used for the specimens are to be cut in a longitudinal
construction of cargo tanks, storage tanks and direction.
process pressure vessels for liquefied gases
and where the design temperature is less than 3.4.2 The impact tests are to be carried out at a
0°C, to forgings for the piping systems. temperature appropriate to the type of steel and
for the proposed application. Where forgings are
3.1.2 The requirements are also applicable to intended for ships for liquefied gases the test
forgings for other pressure vessels and pressure temperature is to be in accordance with the
piping systems where the use of steels with requirements given in Table 5.4.1 of Ch.3,
guaranteed impact properties at low Sec.5.
temperatures is required.
3.4.3 The results of all tensile tests are to
3.2 Chemical composition comply with the approved specification.
3.2.1 The chemical composition of ladle 3.4.4 The average energy values for impact
samples is, in general, to comply with the tests are also to comply with the approved
requirements given in Table 3.2.1 of Ch.3. specification and generally with the
requirements of Ch.3, Sec.5. See also Ch.2.
3.3 Heat treatment
3.4.5 For material thickness above 50 [mm], the
3.3.1 Forgings are to be normalized, normalized material properties are to be agreed.
and tempered or quenched and tempered in
accordance with the approved specification. 3.5 Pressure tests
Section 4
Table 4.2.1 : Mechanical properties for design purposes : austenitic stainless steels
End of Chapter
Chapter 6
Contents
Section
1 General Requirements
2 Seamless Pressure Pipes
3 Welded Pressure Pipes
4 Boiler and Superheater Tubes
5 Tubes and Pipes for Low Temperature Services
6 Austenitic Stainless Steel Pressure Pipes
Section 1
General Requirements
1.1.4 Steels, intended for the cargo and process 1.2.1 Pipes for Class I and II pressure systems,
piping systems of ships for liquefied gases boilers and superheater tubes are to be
where the design temperature is less than 0°C, manufactured at works approved by IRS. The
are to comply with specific requirements of steel used is to be manufactured in accordance
Sec.5. with Ch.3, Sec.1.
1.1.5 Pipes and tubes, which comply with 1.2.2 Unless a particular method is requested by
national or proprietary specifications may be the purchaser, pipes and tubes may be
accepted provided that these specifications give manufactured by any of the following methods:-
reasonable equivalence to the requirements of
this Section or are otherwise specially approved a) hot finished seamless;
for a specific application and provided that
1.4.1 The requirements for the chemical 1.8.1 All pipes for Class I and II pressure
composition of the ladle sample and the systems, boiler and superheater tubes are to be
acceptable method of de-oxidation is to comply presented for visual examination and verification
with the requirements detailed in the relevant of dimensions. The manufacturer is to provide
Section of this Chapter. adequate lighting conditions to enable an
internal and external examination of the pipes
1.5 Heat treatment and tubes to be carried out.
1.5.1 All pipes and tubes are to be supplied in 1.8.2 For welded pipes and tubes the
the condition detailed in the relevant specific manufacturer is to employ suitable non-
requirements. destructive methods for the quality control of the
welds. It is preferred that this examination is
1.6 Test material carried out on a continuous basis.
1.6.1 Pipes and tubes are to be presented for 1.9 Hydraulic tests
test in batches. The size of a batch and the
number of tests to be performed are dependent 1.9.1 Each pipe and tube is to be subjected to a
on the application. hydraulic test at the manufacturer's works.
1.6.2 Where heat treatment has been carried 1.9.2 The hydraulic test pressure is to be
out, a batch is to consist of pipes or tubes of the determined by the following formula, except that
same size, manufactured from the same type of the maximum test pressure need not exceed 14
2
steel and subjected to the same finishing [N/mm ].
treatment in a continuous furnace, or heat
2st
P=
D
1.11.1 Pipes and tubes are to be clearly marked 1.12.3 The chemical composition stated on the
by the manufacturer in accordance with the certificate is to include the content of all the
requirements of Ch.1. The following details are elements detailed in the specific requirements.
to be shown on all materials which have been Where rimmed steel is supplied, this is to be
accepted:- stated on the certificate.
Section 2
2.1.1 Following requirements are applicable for 2.2.1 Tubes are to be manufactured by a
seamless pressure pipes in carbon, carbon- seamless process and may be hot or cold
manganese and low alloy steels. finished.
2.1.2 Where pipes are used for the manufacture 2.2.2 The method of de-oxidation and the
of pressure vessel shells and headers, the chemical composition of ladle samples are to
requirements of forgings in Ch.5 are applicable comply with the appropriate requirements given
where the wall thickness exceeds 40 [mm]. in Table 2.2.1.
2 14 Cr 1 Mo
Grade 410 Fully annealed
Grade 490 Normalized and tempered 650-750°C
1
Cr 1
Mo 1
V Normalized and tempered
2 2 4
Notes:
1. Provided that the finishing temperature is sufficiently high to soften the material.
2. Normalized and tempered at the option of the manufacturer.
Table 2.4.1 : Mechanical properties for acceptance purposes : Seamless pressure pipes
(maximum wall thickness 40 mm)
Type of Grade Yield stress Tensile Elongation Flattening Bend test
2
steel [N/mm ] strength on test diameter of
2
min. [N/mm ] 5.65√So% constant C former
min. (t=
thickness)
Carbon and 320 195 320-440 25 0.10 4t
carbon-
360 215 360-480 24 0.10 4t
manganese
410 235 410-530 22 0.08 4t
460 265 460-580 21 0.07 4t
490 285 490-610 21 0.07 4t
1 Cr
1 440 275 440-590 22 0.07 4t
2
Mo
1
410 135 410-560 20 0.07 4t
2 14 Cr
2
1 Mo 490 275 490-640 16 0.07 4t
1 1
2
Cr 2
Mo
460 275 460-610 15 0.07 4t
1
4
V
Notes:
1 Annealed condition
2 Normalized and tempered condition
Table 2.5.1 : Mechanical properties for design purposes : Seamless pressure pipes
Notes:
1 Annealed condition
Table 2.5.2 : Mechanical properties for design purposes : Seamless pressure pipes - estimated
2
values for stress to rupture in 100 000 hours (units [N/mm ])
1 1
2
Cr 2 Mo
1 1
Carbon and carbon-manganese 1 Cr 2 Mo 2 4 Cr 1 Mo
1
V
Temperature 4
°C Grade 490
Grade 320, 360, Grade 410 Normalized
Grade 460, 490 Grade 440 Grade 460
410 Annealed and tempered
(see Note)
380 171 227 - - - -
390 155 203 - - - -
400 141 179 - - - -
410 127 157 - - - -
420 114 136 - - - -
430 102 117 - - - -
440 90 100 - - - -
450 78 85 - 196 221 -
460 67 73 - 182 204 -
470 57 63 - 168 186 -
480 47 55 210 154 170 218
490 36 47 177 141 153 191
500 - 41 146 127 137 170
510 - - 121 115 122 150
520 - - 99 102 107 131
530 - - 81 90 93 116
540 - - 67 78 79 100
550 - - 54 69 69 85
560 - - 43 59 59 72
570 - - 35 51 51 59
580 - - - 44 44 46
Note : When tempering temperature exceeds 750°C, the values for Grade 410 are to be used.
Section 3
Table 3.3.1 : Heat treatment : Welded 3.4.3 The results of all mechanical tests are to
pressure pipes comply with the appropriate requirements given
in Table 3.4.1.
Type of steel Condition of supply
Carbon and Normalized (Normalized 3.5 Mechanical properties for design
carbon- and tempered at
manganese the option of the 3.5.1 The mechanical properties at elevated
manufacturer) temperature for carbon and carbon-manganese
2 2
steels in Grades 320 [N/mm ] to 460 [N/mm ]
1 Cr 1
Mo Normalized and tempered 1
2 and 1 Cr 2 Mo steel can be taken from the
appropriate Tables in Sec.2.
3.4 Mechanical tests
3.5.2 Where rimmed steel is used, the design
3.4.1 All pipes are to be presented in batches as temperature is limited to 400°C.
defined in Sec.1.
Table 3.4.1 : Mechanical properties for acceptance purposes : Welded pressure pipes
1 Cr 1
Mo 440 275 440 - 590 22 0.07
2
Section 4
4.1.1 The following requirements are applicable 4.4.1 Tubes are to be presented for test in
for boiler and superheater tubes in carbon, batches as defined in Sec.1.
carbon-manganese and low alloy steels.
4.4.2 Each boiler and superheater tube selected
4.1.2 Austenitic stainless steels may also be for test is to be subjected to at least the
used for this type of service. Where such following:
applications are proposed, details of the
chemical composition, heat treatment and a) Tensile test;
mechanical properties are to be submitted for
consideration and approval. b) Flattening or bending tests at the
manufacturer's option;
4.2 Manufacture and chemical composition
c) Expanding or flanging tests at the
4.2.1 Tubes are to be seamless or welded and manufacturer's option.
are to be manufactured in accordance with the
requirements of Sec.2 and 3 respectively. 4.4.3 The results of all mechanical tests are to
comply with the appropriate requirements given
4.2.2 The method of de-oxidation and the in Table 4.4.1.
chemical composition of ladle samples are to
comply with the requirements given in Table 4.5 Mechanical properties for design
2.2.1 or Table 3.2.1, as appropriate.
4.5.1 The mechanical properties at elevated
4.3 Heat treatment temperature for carbon and carbon-manganese
2 2
steels in Grades 320 [N/mm ] to 460 [N/mm ], 1
4.3.1 All tubes are to be supplied in accordance Cr 12 Mo and 2 14 Cr 1 Mo steels can be taken
with the requirements given in Table 2.3.1 or
from the appropriate Tables in Sec.2.
Table 3.3.1 as appropriate, except that 1 Cr
1
2
Mo steel may be supplied in the normalized 4.5.2 Where rimmed steel is used, the design
only condition when the carbon content does not temperature is limited to 400°C.
exceed 0.15 per cent.
Table 4.4.1 : Mechanical properties for acceptance purposes : Boilers and superheater tubes
1 1
2 4
Cr 410 135 410-560 20 0.07 4t 8 10 15
2
1 Mo 490 275 490-640 16 0.07 4t 8 10 15
Notes:
1. Annealed condition
2. Normalized and tempered condition
Section 5
5.1.1 This Section gives the requirements for 5.2.1 The pipes are to be manufactured
seamless and welded carbon, carbon- seamless or by a welding process, and may be
manganese and nickel alloy steel pipes not hot or cold finished.
exceeding 25 [mm] in thickness intended for use
in liquefied gas piping systems where the design 5.3 Chemical composition
temperature is lower than 0°C and also for other
pressure piping systems where guaranteed 5.3.1 The chemical composition of ladle
impact properties at low temperature is required. samples is in general to comply with the
requirements given in Table 5.3.1. Steels for the
production of tubes and pipes are to be killed.
Note : Where a minimum Almet of 0.015% is specified, the determination of the total aluminium is
acceptable provided that the result is not less than 0.018%.
5.5.1 All pipes are to be presented for test in 5.5.4 Ring tensile test may be carried out in
batches as defined in Sec.1 pressure piping conformity with ISO 8495 or other equivalent
systems. standard.
5.5.2 At least two percent of the number of 5.5.5 The impact tests are to consist of a set of
lengths in each batch is to be selected at three Charpy V-notch test specimens cut in the
random for the preparation of the tests. longitudinal direction with the notch
perpendicular to the original surface of the pipe.
5.5.3 Each pipe or tube selected for test is to be The dimension of the test specimens are to be
subjected to following tests: in accordance with the requirements of Ch.2.
Impact testing is not required for wall thickness
- Seamless pipes and tubes: below 6 [mm].
Section 6
6.5 Intergranular corrosion tests subjected to a bend test through 90° over a
mandrel of diameter equal to twice the thickness
6.5.1 For materials used for piping systems for of the test specimen.
chemicals, intercrystalline corrosion tests are to
be carried out on one per cent of the number of 6.6 Fabricated pipework
pipes in each batch, with a minimum of one
pipe. 6.6.1 Fabricated pipework is to be produced
from material manufactured in accordance with
6.5.2 For pipes with an outside diameter not 6.2, 6.3, 6.4 and 6.5.
exceeding 40 [mm], the test specimens are to
consist of a full cross section. For larger pipes, 6.6.2 Welding is to be carried out in accordance
the test specimens are to be cut as with an approved and qualified procedure by
circumferential strips of full wall thickness and suitably qualified welders.
having a width of not less than 12.5 [mm]. In
both cases, the total surface areas is to be 6.6.3 Fabricated pipework may be supplied in
2
between 15 and 35 [cm ]. the as-welded condition without subsequent
solution treatment provided that welding
6.5.3 When required, one test of this type is to procedure tests have demonstrated satisfactory
be carried out for each tensile test. The testing material properties including resistance to
is to be carried out in accordance with ASTM intercrystalline corrosion.
A262, practice E, copper-copper sulphate-
sulphuric acid or another recognized standard. 6.6.4 In addition, butt welds are to be subjected
The bent specimen is to be free from cracks to 5 per cent radiographic examination for Class
indicating the presence of intergranular attack. I and 2 per cent for Class II pipes.
The material for the test is to be taken adjacent
to that for the tensile test. 6.6.5 Fabricated pipework in the as-welded
condition and intended for systems located on
6.5.4 After immersion, the full cross-section test deck is to be protected by a suitable corrosion
specimens are to be subjected to a flattening control coating.
test in accordance with the requirements of
Chapter 2. The strip test specimens are to be
End of Chapter
Chapter 7
Iron Castings
Contents
Section
1 General Requirements
Section 1
General Requirements
1.1.3 As an alternative to 1.1.2, castings which 1.3.1 Castings are to be free from surface or
comply with National or Proprietary internal defects which could be prejudicial to
specifications may be accepted, provided that their proper application in service. The surface
such specifications give reasonable equivalence finish is to be in accordance with good practice
to these requirements or otherwise are specially and any specific requirements of the approved
approved or required by IRS. plan.
strength and impact test are to undergo two tonnes of fettled castings and a single
ferritizing heat treatment. casting will constitute a batch if its mass is two
tonnes or more.
1.5.3 Where it is proposed to locally harden the
surface of castings, full details of the proposed 1.6.4 For continuous melting of same grade of
procedure and specifications are to be cast iron in large tonnages the mass of the
submitted for approval by IRS. batch may be increased to the output of two
hours of pouring. If production is carefully
1.6 Mechanical tests monitored by systematic checking of the melting
process, such as chill testing, chemical analysis
1.6.1 Separately cast test samples are to be or thermal analysis, test samples may be taken
used unless otherwise agreed between the at longer intervals.
manufacturer and the purchaser. The test
samples are generally to be one of the standard 1.6.5 For large castings where more than one
types detailed in Fig.1.6.1, Fig.1.6.2 and ladle of treated metal is used, additional test
Fig.1.6.3 with a thickness of 25 [mm]. Test samples are to be provided so as to be
samples of dimensions, other than as detailed in representative of each ladle used.
Fig.1.6.1 to Fig.1.6.3 may, however, be specially
required for some components. For grey cast 1.6.6 All test samples are to be suitably marked
iron the test samples are to be in the form of to identify them with the castings which they
cylindrical bars of 30 [mm] diameter and of represent.
suitable length. When two or more test samples
are cast simultaneously in a single mould, the 1.6.7 Where castings are supplied in the heat
bars are to be at least 50 [mm] apart as treated condition, the test samples are to be
indicated in Fig.1.6.4. heat treated together with the castings which
they represent.
1.6.2 Integrally cast samples may be used when
a casting is more than 20 [mm] thick and its 1.6.8 The test samples are to be cast in moulds
mass exceeds 200 [kgs] subject to agreement made from the same type of material as used for
between the manufacturer and the purchaser. the castings and are not to be stripped from the
The type and location of the test sample are to moulds until the metal temperature is below
be selected to provide approximately the same 500°C.
cooling conditions as for the casting it
represents. 1.6.9 One tensile test specimen is to prepared
from each test sample. The dimensions of the
1.6.3 At least one test sample is to be provided test specimens and the testing procedures used
for each casting or batch of castings. A batch are to be in accordance with Ch.2.
consists of castings poured from a single ladle
of metal provided they are all of similar type and
dimensions. A batch should not normally exceed
Table 1.7.1 : Mechanical properties for acceptance purposes (spheroidal or nodular graphite iron)
1. For intermediate values of specified minimum tensile strength, the minimum values for 0.2% proof and
elongation may be obtained by interpolation.
2. The average value measured on 3 Charpy V-notch specimens. One result may be below the average value but
not less than the minimum shown in brackets.
3. In the case of integrally cast samples, the elongation may be 2 percentage points less.
1.11.1 The manufacturer is to adopt a system of 1.11.3 Where small castings are manufactured
identification which will enable all finished in large numbers, modified arrangements for
castings to be traced to the original ladle of identification may be specially agreed with IRS.
treated metal and the Surveyor is to be given full
facilities for so tracing the castings when 1.12 Certification
required.
1.12.1 The manufacturer is to provide the
1.11.2 Before acceptance, all castings which Surveyor with a written statement giving the
have been tested and inspected with following particulars for each casting or batch of
satisfactory results are to be clearly marked by castings which has been accepted:-
the manufacturer with the following particulars:-
a) Purchaser's name and order no;
a) Grade of cast iron;
b) Description of castings and quality of cast
b) Identification number, or other marking iron;
which will enable the full history of the
casting to be traced; c) Identification number;
d) IR and the abbreviated name of the local e) Where applicable, details of heat treatment;
office of IRS;
f) Where specially required, the chemical
e) Personal stamp of the Surveyor responsible analysis of the ladle sample;
for inspection;
g) Where applicable, test pressure.
f) Where applicable, test pressure;
End of Chapter
Chapter 8
Copper Alloys
Contents
Section
1 General Requirements
2 Castings for Valves and Fittings
3 Castings for Propellers
4 Tubes
Section 1
General Requirements
Section 2
2.1 Scope
2.4 Chemical composition
2.1.1 Following requirements make provision for
copper alloy castings for valves, liner bushes 2.4.1 The chemical composition is to comply
and other fittings intended for use in ship and with the appropriate requirements of Table
machinery construction. 2.4.1.
Chemical composition %
Designation
Cu Sn Zn Pb Ni Mn P Fe Al
90/10 Cu-Sn 9.0- 0.5 0.75 0.5 0.50
Remainder - - -
Phosphor-bronze 11.0 max. max. max. max.
85/5/10 Leaded 2.0 9.0- 2.0 0.10
Remainder 4.0-6.0 - - -
bronze max. 11.0 max. max.
8.5- 1.5 1.0
88/10/2 Gunmetal Remainder 1.0-3.0 - - - -
11.0 max. max.
87/7/3/3 Leaded 2.0
Remainder 6.0-8.0 1.5-3.0 2.5-3.5 - - - -
Gunmetal max.
85/5/5/5 Leaded 2.0
Remainder 4.0-6.0 4.0-6.0 4.0-6.0 - - - -
Gunmetal max.
29.0- 0.5-
70/30 Cu-Ni-Fe Remainder - - - - 0.4-1.0 -
32.0 1.50
9.0-
90/10 Cu-Ni-Fe Remainder - - - 0.5-1.0 - 1.0-1.8 -
11.0
0.10 1.0 0.03 7.0-
Ni-Al-bronze Remainder 3.0-6.0 0.5-4.0 - 2.0-6.0
max. max. max. 11.0
2.5.1 At the option of the manufacturer castings 2.7.1 All castings must be supplied in a clean
may be supplied in the 'as cast' or heat treated fettled condition.
condition.
2.7.2 Before acceptance, all castings are to be
2.6 Mechanical tests presented for visual examination by the
Surveyor. This is to include the examination of
2.6.1 The test material may be separately cast internal surfaces where applicable.
as a keel block sample in accordance with
Fig.3.6.1 or as otherwise agreed with the 2.7.3 The accuracy and verification of
Surveyor. For liners and bushes, the test dimensions are the responsibility of the
material may be cut from the ends of the manufacturer, unless otherwise agreed.
casting.
2.8 Pressure testing
2.6.2 Where castings are supplied in a heat
treated condition, the test samples are to be 2.8.1 Where required by the relevant
similarly heat treated prior to the preparation of construction Rules, castings are to be pressure
the tensile specimens. tested before final acceptance. Unless otherwise
agreed, these tests are to be carried out in the
2.6.3 The results of all tests are to comply with presence of the Surveyors and are to be to their
the appropriate requirements given in Table satisfaction.
2.6.1.
Note:
The 0.2% proof stress values are given for information purposes only and, unless otherwise agreed, are
not required to be verified by test.
2.9.1 Minor surface defects may be removed by c) Personal stamp of the Surveyor responsible
grinding provided that the dimensional for inspection;
tolerances are not exceeded.
d) Test pressure, where applicable;
2.9.2 Proposal to repair a defective casting by
welding are to be submitted to the Surveyor for e) Date of final inspection.
approval before this work is commenced. Such
proposals are to include details of the extent and 2.10.2 Where small castings are manufactured
positions of all defects. The Surveyor is to in large numbers, modified arrangements for
satisfy himself the number and size of the identification may be specially agreed with the
defects are such that castings can be efficiently Surveyor.
repaired.
2.11 Certification
2.9.3 A statement and/or sketch detailing the
extent and position of all weld repairs is to be 2.11.1 The manufacturer is to provide the
prepared by the manufacturer as permanent Surveyor with a written statement giving the
record. following particulars for each casting or batch of
castings which has been accepted:-
2.9.4 Weld repairs to liners in copper alloys
containing more than 0.5 per cent lead are not a) Purchaser's name and order no.;
permitted.
b) Description of castings and alloy type;
2.10 Identification
c) Identification number
2.10.1 Before acceptance, all castings which
have been tested and inspected with d) Type of heat treatment, where applicable;
satisfactory results are to be clearly marked with
the following details: e) Ingot or cast analysis.
a) Identification number, cast number or other 2.11.2 In addition to 2.11.1 the manufacturer is
markings which will enable the full history of to provide a signed statement and/or sketch
the casting to be traced; detailing the extent and position of all weld
repairs made to each casting.
Section 3
3.5.1 At the option of the manufacturer, castings 3.6.1 Test samples are to be provided from each
may be supplied in the 'as cast' or heat treated cast used for the manufacture of propeller or
condition. propeller blade castings.
Note:
The mechanical properties of other alloys meeting the above limiting values are to be in accordance
with a specification approved by IRS.
3.7.1 All castings are to be fettled, cleaned and 3.7.3 The dimensions are to be checked by the
adequately prepared for inspection. manufacturer and the report on the dimensional
inspection is to be given to the Surveyor, who
3.7.2 Propeller castings are to be inspected at may require checks to be made in his presence.
all stages of manufacture and the whole surface
including the bore is to be subjected to a
comprehensive visual examination in the
finished condition by the Surveyor. The
Surveyor may require areas to be etched (e.g.
3.8.1 Dye penetrant inspection All defects requiring welding repair on the
castings are to be documented preferably on
a) The severity zones "A" are to be subjected drawings or special sketches showing their
to a dye penetrant inspection in the dimensions and locations. Furthermore, the
presence of the Surveyor. For the inspection inspection procedure is to be documented. The
and acceptance standard, see 3.10. In documentation is to be presented to the
zones "B" and "C" the dye penetrant Surveyor prior to any repair welding.
inspection is to be performed by the
manufacturer and may be witnessed by the 3.9 Definition of skew, severity zones
Surveyor upon his request. See 3.9 for
definitions of severity zones. 3.9.1 Skew : The skew of a propeller is defined
as follows:
b) If repairs have been made either by grinding
or by welding the repaired areas are The maximum skew angle of a propeller blade is
additionally to be subjected to the dye defined as the angle, in projected view of the
penetrant inspection independent of their blade, between a line drawn through the blade
location and/or severity zone. tip and the shaft centreline and a second line
through the shaft centreline which acts as a
3.8.2 Radiographic and ultrasonic exami- tangent to the locus of the mid-points of the
nation helical blade section. See Fig.3.9.1.
Where serious doubts exist that the castings are High skew propellers have a skew angle greater
not free from internal defects further non- than 25°, low skew propellers a skew angle of
destructive examination is to be carried out upon up to 25°.
request of the Surveyor, e.g. radiographic and/or
ultrasonic testing. Acceptance criteria are to be
agreed between the manufacturer and IRS in
accordance with a recognized standard.
Guidance
In order to relate the degree of examination to a) Zone A is in the area on the pressure side of
the criticality of defects in propeller blades and the blade, from and including the fillet to
to help reduce the risk of failure by fatigue 0.4R and bounded on either side by lines at
cracking after repair, propeller blades are a distance 0.15 times the chord length Cr
divided into the three zones designated A, B and from the leading edge and 0.2 times Cr from
C. the trailing edge, respectively. See
Fig.3.9.2.
Zone A is the region carrying the highest
operating stresses and which, Where the hub radius (Rb) exceeds 0.27R,
therefore, requires the highest the other boundary of Zone A is to be
degree of inspection. Generally, the increased to 1.5Rb. Zone A also includes
blade thicknesses are greatest in the parts of the separate cast propeller hub
this area giving the greatest degree which lie in the area of the windows as
of restraint in repair welds and this described in Fig.3.9.4 and the flange and
in turn leads to the highest residual fillet area of controllable pitch and built-up
stresses in and around any repair propeller blades as described in Fig.3.9.5.
welds. High residual tensile
stresses frequently lead to fatigue b) Zone B is on the pressure side the
cracking during subsequent service remaining area upto 0.7R and on the
so that relief of these stresses by suction side the area from the fillet to 0.7R.
heat treatment is essential for any See Fig.3.9.1.
welds made in this zone. Welding
is generally not permitted in Zone A c) Zone C is the area outside 0.7R on both
and will only be allowed after sides of the blade. It also includes the
special consideration by the surface of the hub of a monobloc propeller
Classification Society. Every effort and all the surfaces of the hub of
should be made to rectify a controllable pitch propeller other than those
propeller which is either defective designated Zone A above.
or damaged in this area without
recourse to welding even to the 3.9.2.2 High-skew propellers
extent of reducing the scantlings, if
this is acceptable. If a repair using a) Zone A is the area on the pressure face
welding is agreed, post-weld stress contained within the blade root-fillet and a
relief heat treatment is mandatory. line running from the junction of the leading
edge with the root fillet to the trailing edge at
Zone B is a region where the operation 0.9R and at passing through the mid-point
stresses may be high. Welding of the blade chord at 0.7R and a point
should preferably be avoided but situated at 0.3 of the chord length from the
generally is allowed subject to prior leading edge at 0.4R. It also includes an
approval from the Classification area along the trailing edge on the suction
Society. Complete details of the side of the blade from the root to 0.9R and
defect/damage and the intended with its inner boundary at 0.15 of the chord
repair procedure are to be lengths from the trailing edge.
submitted for each instance in
order to obtain such approval. b) Zone B constitutes the whole of the
remaining blade surfaces.
Zone C is a region in which the operation
stresses are low and where the c) Zone A and B are illustrated in Fig.3.9.3.
blade thicknesses are relatively
small so that repair welding is safer 3.10 Acceptance criteria for dye penetrant
and, if made in accordance with an examination
approved procedure is freely
permitted. 3.10.1 Inspection procedure
2
Table 3.10.1 : Allowable number and size of indications in a reference area of 100 [cm ],
depending on severity zones
1) Singular circular indications less than 2 [mm] for zone A and less than 3 [mm] for the other zones
may be disregarded.
2) The total number of circular indications may be increased to the max. total number, or part thereof,
represented by the absence of linear/aligned indications.
3.10.3.1 For the judgement, the surface to be a) In zone A, repair welding will generally not
inspected is to be divided into reference areas of be allowed unless specially approved by
2
100 [cm ] as given in the definitions, see para IRS.
3.10.2. The indications detected may, with
respect to their size and number, not exceed the b) Grinding may be carried out to an extent
values given in the Table 3.10.1. which maintains the blade thickness of the
approved drawing.
The area is to be taken in the most unfavourable
location relative to the indication being c) The possible repair of defects which are
evaluated. deeper than those referred to above will be
specially considered by IRS.
3.10.3.2 Areas which are prepared for welding
are, independent of their location, always to be 3.12.4 Repair of defects in zone B
assessed according to Zone A. The same
applies to the welded areas after being finished a) Defects that are not deeper than dB = (t/40)
machined and/or ground. [mm] (t = minimum local rule thickness
[mm]) or 2 [mm] (whichever is greater)
3.11 Metallographic examination below minimum local rule thickness should
be removed by grinding.
3.11.1 Samples for metallographic examination
are to be prepared from propellers and propeller b) Those defects that are deeper than
blade castings for Grades Cu1 and Cu2. These allowable for removal by grinding may be
samples are to be representative of each cast, repaired by welding.
and may conveniently be taken from the tensile
test specimen. The proportion of alpha-phase 3.12.5 Repair of defects in zone C
determined from the average of at least five
counts is to be not less than 25 percent. In zone C, repair welds are generally permitted.
3.12.1 Indications exceeding the acceptance 3.13.1 Static balancing is to be carried out on all
standard of Table 3.10.1, cracks, shrinkage propellers. Dynamic balancing is necessary for
cavities, sand, slag and other non-metallic propellers running above 500 [rpm].
inclusions, blow holes and other discontinuities
which may impair the safe service of the 3.14 Repair welding
propeller are defined as defects and must be
repaired. 3.14.1 General requirements
3.14.1.3 Before welding is started, Welding Arc welding with coated electrodes and gas-
Procedure Qualification Tests are to be carried shielded metal arc process (GMAW) are
out and witnessed by the Surveyors. Each generally to be applied. Argon-shielded tungsten
welder/operator is to demonstrate his ability to welding (GTAW) is to be used with care due to
carry out the proposed welding using the same the higher specific heat input of this process.
process, consumable and position which are to
be used in actual repair (for the scope of tests Adequate pre-heating is to be carried out with
see 3.18). care to avoid local overheating.
For material thickness less than 30 [mm], gas Slag, undercuts and other defects are to be
welding may give a satisfactory weldment for removed before depositing the next run.
Cu1 and Cu2 materials.
Table 3.14.3(b) : Soaking times for stress relief heat treatment of copper alloy propellers
Alloy grade Cu1 and Cu2 Alloy grade Cu3 and Cu4
Max. Max.
Stress relief Hours per 25 Hours per 25
recommended recommended
temp.°C [mm] thickness [mm] thickness
total time hours total time hours
350 5 15 - -
400 1 5 - -
450 1/2 2 5 15
500 1/4 1 1 5
1) 1)
550 1/4 1.2 1/2 2
1) 1)
600 - - 1/4 1
Note 1) 550°C and 600°C only applicable for Cu4 alloys
3.14.3.3 All welding work is to be carried out The heating is to be slow and uniform and the
preferably in the shop free from draughts and concentrated flames such as oxy-acetylene and
influence of the weather. oxy-propane are not to be used. Sufficient time
is be allowed for the temperature to become
3.14.3.4 With the exception of alloy Cu3 (Ni-Al- fairly uniform through the full thickness of the
bronze) all weld repairs are to be stress relief blade section. The temperature is to be
heat treated, in order to avoid stress corrosion maintained within the suggested range
cracking. However, stress relief heat treatment throughout the straightening operation. A
of alloy Cu3 propeller castings may be required thermocouple instrument or temperature
after major repairs in zone B (and specially indicating crayons are to be used for measuring
approved welding in Zone A) or if a welding the temperature.
consumable susceptible to stress corrosion
cracking is used. In such cases the propeller is 3.15.3 Cold straightening
to be either stress relief heat treated in the
temperature 450 to 500°C or annealed in the Cold straightening should be used for minor
temperature range 650 - 800°C, depending on repairs of tips and edges only. Cold
the extent of repair, see Table 3.14.3(a). straightening on Cu1, Cu2 and Cu4 bronze is
always to be followed by a stress relieving heat
3.14.3.5 The soaking times for stress relief heat treatment, See Table 3.14.3(a).
treatment of copper alloy propellers is to be in
accordance with Table 3.14.3(b). The heating 3.16 Identification
and cooling is to be carried out slowly under
controlled conditions. The cooling rate after any 3.16.1 Castings are to be clearly marked by the
stress relieving heat treatment shall not exceed manufacturer in accordance with the
50°C/hr until the temperature of 200°C is requirements of Ch.1. The following details are
reached. to be marked on all the castings which have
been accepted:
3.15 Straightening
a) Heat number, casting number or other
3.15.1 Application of load identification mark which will enable the full
history of the item to be traced;
For hot and cold straightening purposes, static
loading only is to be used. b) Alloy grade;
Section 4
Tubes
1)
Table 4.4.1 : Chemical composition of tubes
Chemical composition %
Designation
Cu Fe Ni Zn As Al Mn P Pb
Phosphorus 2)
99.90 0.013-
deoxidised non- - - - - - - -
min. 0.050
arsenical copper
Phosphorus 2)
99.20 0.30- 0.013-
deoxidised - - - - - -
min. 0.50 0.050
arsenical copper
0.02- 1.8-
Al-brass 76.0-79.0 - - Remainder - - -
0.06 2.3
Copper-nickel 9.0-
Remainder 1.0-1.8 - - - 0.5-1.0 - -
90/10 11.0
Copper-nickel 30.0-
Remainder 0.4-1.0 - - - 0.5-1.5 - -
70/30 32.0
Notes:
5 x t x Rm
P=
D
4.11.1 The manufacturer is to provide the e) Mechanical test results and results of stress
Surveyor with a written statement giving the cracking tests where applicable.
End of Chapter
Chapter 9
Aluminium Alloys
Contents
Section
1 General
2 Wrought Aluminium Alloys
3 Aluminium Alloy Castings
4 Aluminium/Steel Transition Joints
Section 1
General
1.1.3 These requirements are applicable to 1.1.6 Consideration may be given to aluminium
wrought aluminium alloy products within a alloys not specified in this chapter and to
thickness range of 3 [mm] and 50 [mm] alternative temper conditions, complying with
inclusive. The application of aluminium alloys recognized national or international standards
products outside this thickness range requires with specifications equivalent to the
prior agreement of IRS. requirements of this chapter.
Section 2
2.1.1 This Section deals with wrought aluminium 2.3.1 Materials are to be free from surface or
alloys for structural applications including plates, internal defects of such a nature as would be
sections, tubes, bars and rivet bars and rivets. harmful in service.
2.1.3 The alloy grades 6005A, 6061 of the 6000 2.4.2 Dimensional tolerances other than those
series should not be used in direct contact with given in Table 2.4.1, Table 2.4.2 and Table 2.4.3
sea water unless protected by anodes and/or are to comply with a recognized national or
paint system. international standard.
2.2.1 Aluminium alloys are to be manufactured 2.5.1 Samples for chemical analysis are to be
at Works approved by IRS. taken representative of each cast, or the
equivalent where a continuous melting process
2.2.2 The alloys may be cast either in ingot is involved.
moulds or by an approved continuous casting
process. Plates are to be formed by rolling and 2.5.2 The chemical composition of these
may be hot or cold finished. Bars and sections samples is to comply with the requirements of
may be formed by rolling, extrusion or drawing. Table 2.5.1.
Oth- Oth-
Al Si Fe Cu Mn Mg Cr Zn Ti
ers (2) ers (2)
Grade Misc.
Each Total
% % % % % % % % %
% %
0.40-
Remain 0.6- 5.0-
5059 0.45 0.50 0.25 0.25 0.90 0.20 0.05 3) 0.15 4)
der 1.2 6.0
Remain 0.4- 4.0- 0.05-
5083 ≤ 0.40 ≤ 0.40 ≤ 0.10 ≤ 0.25 ≤ 0.15 ≤ 0.05 ≤ 0.15
der 1.0 4.9 0.25
Remain 0.20- 3.5- 0.05-
5086 ≤ 0.40 ≤ 0.50 ≤ 0.10 ≤ 0.25 ≤ 0.15 ≤ 0.05 ≤ 0.15
der 0.7 4.5 0.25
4.0-
Remain 0.7-
5383 0.25 0.25 0.20 5.2 0.25 0.40 0.15 0.05 3) 0.15 3)
der 1.0
0.10 ≤
Remain ≤ 2.6- Mn +
5754 ≤ 0.40 ≤ 0.40 ≤ 0.50 ≤ 0.30 ≤ 0.20 ≤ 0.15 ≤ 0.05 ≤ 0.15
der 0.10 3.6 Cr ≤
0.60
Remain
0.50 – 4.7 – 0.05 –
5456 der 0.25 0.40 0.10 0.25 0.20 0.05 0.15
1.0 5.5 0.20
0.12 ≤
Remain 0.50- 0.040- Mn +
6005-A ≤ 0.35 ≤ 0.30 ≤ 0.50 ≤ 0.30 ≤ 0.20 ≤ 0.10 ≤ 0.05 ≤ 0.15
der 0.9 0.7 Cr ≤
0.50
Remain 0.40- 0.15- 0.8- 0.04-
6061 ≤ 0.7 ≤ 0.15 ≤ 0.25 ≤ 0.15 ≤ 0.05 ≤ 0.15
der 0.8 0.40 1.2 0.35
Remain 0.7- 0.40- 0.6-
6082 ≤ 0.50 ≤ 0.10 ≤ 0.25 ≤ 0.20 ≤ 0.10 ≤ 0.05 ≤ 0.15
der 1.3 1.0 1.2
Notes:
1. Slight variations in the content of some elements, compared with values indicated in this Table may be accepted with IRS's
agreement.
2. Other metallic elements such as Ni, Ga.V are considered as impurities. The regular analysis need not be made for these
elements.
3. Zr: maximum 0.20. The total for other elements does not include Zirconium.
4. Zr: 0.05-0.25. The total for other elements does not include Zirconium.
2.5.4 When the aluminium alloys are not cast in 2.7.1 All materials in a lot forwarded for
the same works in which they are manufactured sampling are to be of the same alloy, production
into semi finished products, the works is to give batch and product form (plates, sections etc.).
a certificate detailing the chemical composition The materials in one lot are to be of the same
and heat number. dimensions and in the same delivery condition.
Artificially aged grades are to be from the same 2.8.3.3 The test specimens are to be cut with
furnace batch. the ends perpendicular to the axis of the profile.
The edges of the end may be rounded by filing.
2.7.2 Wherever practicable, the tensile test
pieces for rolled and extruded sections are to be 2.8.3.4 The length of the specimen is to be in
of full section of material. Otherwise, the pieces accordance with details given in Chapter 2.
are to be taken in the range one third to half the
distance from the edge to center of the 2.8.3.5 Testing is to be carried out at ambient
predominant or thickest part of the section. temperature and is to consist of expanding the
end of the profile by means of a hardened
2.8 Testing and inspection conical steel mandrel having an included angle
of at least 60°.
2.8.1 Testing procedures
2.8.3.6 The sample is considered to be
The test specimens and procedures are to be in unacceptable if the sample fails with a clean
accordance with Ch.2. split along the weld line which confirms lack of
fusion.
2.8.2 Verification of proper fusion of press welds
for closed profiles. 2.8.4 Requirements of mechanical properties for
rolled products in different delivery conditions
The Manufacturer has to demonstrate by are given in Table 2.8.1 and are applicable for
macrosection tests or drift expansion tests of thickness within the range 3 [mm] to 50 [mm].
closed profiles performed on each batch of For thickness above 10 [mm], however, lower
closed profiles that there is no lack of fusion at mechanical properties may be accepted.
the press welds.
2.8.5 Requirements of mechanical properties for
2.8.3 Drift expansion tests extruded products in different delivery conditions
are given in Table 2.8.2 and are applicable for
2.8.3.1 Every fifth profile is to be sampled after thickness within the range 3 [mm] to 50 [mm].
final heat treatment.
One sample is to be selected from the batches 2.8.6 Requirements of mechanical properties
of five profiles or less. and delivery conditions for extruded closed
profiles are given in Table 2.8.3.
Every profile is to be selected if the length
exceeds 6 [m]. 2.8.7 Other delivery conditions with related
mechanical properties may be accepted by IRS,
2.8.3.2 Two samples are to be cut from the front in each particular case.
and back end of each production profile.
O 3 ≤ t ≤ 50 mm 125 275-350 16 14
O 3 ≤ t ≤ 50 mm 145 290 - 17
5383
H111 3 ≤ t ≤ 50 mm 145 290 - 17
O 3 ≤ t ≤ 50 mm 95 240-305 16 14
H111 3 ≤ t ≤ 50 mm 95 240-305 16 14
2)
H116 3 ≤ t ≤ 50 mm 195 275 10 9
O 3 ≤ t ≤ 50 mm 80 190-240 18 17
5754
H111 3 ≤ t ≤ 50 mm 80 190-240 18 17
Designation Condition
F As fabricated
O Annealed, soft
H1 Strain hardened only
H2 Strain hardened and partially annealed
H3 Strain hardened and thermally stabilized
H321 Strain hardened and stabilized
H11 Strain hardened to specified strength
H12 Strain hardened to specified strength
H13 Strain hardened to specified strength
H111 Less strain hardened than H11 e.g. by straightening or stretching
H112 No controlled strain hardening, but there are mechanical property limits
H116 Treatment against exfoliation corrosion
Cooled from an elevated temperature shaping process and then artificially
T5
aged
T6 Solution heat treated and then artificially aged.
O 3 ≤ t ≤ 50 mm 110 270-350 14 12
O 3 ≤ t ≤ 50 mm 145 290 17 17
5383 H111 3 ≤ t ≤ 50 mm 145 290 17 17
H112 3 ≤ t ≤ 50 mm 190 310 13
5059 H112 3 ≤ t ≤ 50 mm 200 330 10
O 3 ≤ t ≤ 50 mm 95 240-315 14 12
H112 3 ≤ t ≤ 50 mm 95 240 12 10
T5 3 ≤ t ≤ 50 mm 215 260 9 8
6005A
3 ≤ t ≤ 10 mm 215 260 8 6
T6
10 ≤ t ≤ 50 mm 200 250 8 6
T5 3 ≤ t ≤ 50 mm 230 270 8 6
6082
3 ≤ t ≤ 50 mm 250 290 6
T6
3 ≤ t ≤ 50 mm 260 310 10 8
Notes:
1) The values are applicable for longitudinal and transverse tensile test specimens as well.
2) Elongation in 50 mm applies for thicknesses upto and including 12.5 mm and in 5d for
thicknesses over 12.5 mm.
2.9.2 Slight surface imperfections may be Other test methods may also be accepted at the
removed by smooth grinding or machining as discretion of IRS.
long as the thickness of the material remains
within the tolerances given in 2.4. 2.10.3 For batch acceptance of 5xxx-alloys in
the H116 and H321 tempers, metallographic
2.10 Corrosion testing examination of one sample selected from mid
width at one end of a coil or random sheet or
2.10.1 Rolled 5xxx-alloys of type 5083, 5383, plate is to be carried out. The microstructure of
5059, 5086 and 5456 in the H111, H112, H116 the sample is to be compared to the reference
and H321 tempers intended for use in marine photomicrograph of acceptable material in the
hull construction or in marine applications where presence of the Surveyor. A longitudinal section
frequent direct contact with seawater is perpendicular to the rolled surface is to be
expected, are to be corrosion tested with prepared for metallographic examination under
respect to exfoliation and intergranular corrosion the conditions specified in ASTM B928, Section
resistance. 9.6.1. If the microstructure shows evidence of
continuous grain boundary network of
2.10.2 The manufacturers are to establish the aluminium-magnesium precipitate in excess of
relationship between microstructure and the reference photomicrographs of acceptable
resistance to corrosion when the above alloys material, the batch is either to be rejected or
are approved. A reference photomicrograph tested for exfoliation-corrosion resistance and
taken at 500x under the conditions specified in intergranular corrosion resistance subject to the
ASTM B928, Section 9.4.1, is to be established agreement of the Surveyor. The corrosion tests
for each of the alloy-tempers and relevant are to be in accordance with ASTM G66 and
thickness ranges. The reference photographs G67 or equivalent standards. Acceptance
are to be taken from samples which have criteria are as noted below:
exhibited no evidence of exfoliation corrosion
and a pitting rating of PB or better, when i) The sample is to exhibit no evidence of
subjected to the test described in ASTM G66 exfoliation corrosion
“Standard test method for visual assessment of ii) The pitting rating of the sample is to be
exfoliation, corrosion susceptability of 5xxx PB or better when subjected to ASTM
series aluminium alloys” (ASSET Test). The G66 ASSET test
samples are also to have exhibited resistance iii) The sample is to exhibit resistance to
to intergranular corrosion at a mass loss not intergranular corrosion at a mass loss
2 2
greater than 15 [mg/cm ], when subjected to no greater than 15 [mg/cm ] when
tests described in ASTM G67 “Standard test subjected to ASTM G67 NAMLT test.
method for determining the susceptibility to
intergranular corrosion of 5xxx series aluminium If the results from testing satisfy the acceptance
alloys by mass loss after exposure to nitric acid” criteria the batch is accepted, else it is to be
(NAMLT). Upon satisfactory establishment of rejected.
2.11.2 The test samples are to be taken - For the products with a nominal weight
of less than 1 [kg/m], one tensile test
- at one third of the width from a specimen is to be taken from each 1000
longitudinal edge of rolled products. [kg], or fraction thereof, in each batch.
For nominal weights between 1 and 5
- in the range 1/3 to 1/2 of the distance [kg/m], one tensile test specimen is to
from the edge to the centre of the be taken from each 2000 [kg] or fraction
thickest part of extruded products. hereof, in each batch. If the nominal
weight exceeds 5 [kg/m], one tensile
2.11.3 Test samples are to be taken so that the test specimen is to be taken for each
orientation of test specimens is as follows: 3000 [kg] of the product or fraction
thereof, in each batch.
a) Rolled products
2.13.2 Corrosion tests
Normally, tests in the transverse direction
are required. If the width is insufficient to For rolled plates of grade 5083, 5383, 5059 and
obtain transverse test specimen, or in the 5086 delivered in the tempers H116 or H321,
case of strain hardening alloys, tests in the one sample is to be tested per batch.
longitudinal direction will be permitted.
2.14 Retest procedures
b) Extruded products
2.14.1 When the tensile test from the first piece
The extruded products are tested in selected in accordance with Sec.11 fails to meet
longitudinal direction. the requirements, two further tensile tests may
be made from the same piece. If both of these
2.11.4 After removal of test samples, each test additional tests are satisfactory, this piece and
specimen is to be marked in order that its the remaining pieces from the same batch may
original identity, location and orientation is be accepted.
maintained.
2.14.2 If one or both the additional tests referred to be reduced by more than 20 per cent. The
to above are unsatisfactory, the piece is to be welding is to be carried out by approved
rejected, but the remaining material from the welders. The weld is to be ground flush with the
same batch may be accepted provided that two surrounding piece surface. Before repair welding
of the remaining pieces in the batch selected in is commenced and after grinding the weld bead,
the same way, are tested with satisfactory suitable non destructive testing may be required
results. If unsatisfactory results are obtained at the discretion of the Surveyor.
from either of these two pieces then the batch of
material is to be rejected. 2.17 Identification
2.14.3 In the event of any material bearing the 2.17.1 The manufacturer is to adopt a system of
Classification Society's brand failing to comply identification which will ensure that all finished
with the test requirements, the brand is to be material in a batch presented for test is of the
unmistakably defaced by the manufacturer. same nominal chemical composition.
2.15 Visual and non-destructive examination 2.17.2 Products are to be clearly marked by the
manufacturer in accordance with the
2.15.1 Surface inspection and verification of requirements of Ch.1. The following details are
dimensions are the responsibility of the to be shown on all materials which have been
manufacturer, and acceptance by the Surveyors accepted:
of material later found to be defective shall not
absolve the manufacturer from this a) Manufacturer's name or trade mark;
responsibility.
b) Grade of alloy;
2.15.2 In general, the non-destructive
examination of materials is not required for c) Identification mark which will enable the full
acceptance purposes. Manufacturers are history of the item to be traced;
expected, however to employ suitable methods
of non-destructive examination for the general d) Abbreviated designation of temper condition
maintenance of quality standards. in accordance with para 2.6;
2.15.3 For applications where the non- e) Personal stamp of the Surveyor responsible
destructive examination of materials is for the final inspection and also IRS’s
considered to be necessary, the extent of this stamp.
examination, together with appropriate
acceptance standards, are to be agreed f) Tempered grades that are corrosion tested
between the purchaser, manufacturer and in accordance with 2.12 are to be marked
Surveyor. “M” after the temper condition, e.g. 5083
H321 M.
2.16 Rectification of defects
2.17.3 When extruded products are bundled
2.16.1 Local surface defects may be removed together or packed in crates for delivery, the
by machining or grinding, provided the thickness marking specified in para 2.17.2 are to be
of the material remains within the tolerances affixed by a securely fastened tag or label.
given in para 2.4. The extent of repairs is to be
agreed upon with the Surveyor, and all repairs 2.18 Certification
are to be carried out under Surveyor's
supervision, unless otherwise arranged. 2.18.1 Each test certificate or shipping
statement is to include the following particulars :
2.16.2 Surface defects which cannot be dealt
with as in 2.12.1 are not allowed to be repaired, a) Purchaser's name and order number;
unless it can be ensured that repair by welding
does not affect the strength and stability of the b) Contract number;
piece for the intended purpose. Any case of
repair by welding is to be specified in detail for c) Address to which material is to be
consideration and approval by the Surveyor. dispatched;
Prior to any such repair welding, the defect is to
be removed by machining or grinding. After d) Description and dimensions;
complete removal of the defect and before
welding the thickness of the piece at no place is e) Specification or grade of alloys;
f) Identification mark which will enable the full j) Corrosion test results (if any).
history of the item to be traced;
2.18.2 Where the alloy is not produced at the
g) Chemical composition; works at which it is wrought, a certificate is to be
supplied by the Manufacturer of the alloy stating
h) Mechanical test results (Not required on the cast number and chemical composition. The
shipping statement); works at which alloys are produced must be
approved by IRS.
i) Details of heat treatment, where applicable;
and
Section 3
3.1.1 Provision is made in this section for 3.3.1 All castings are to be free from surface or
aluminium alloy castings intended for use in the internal defects which would be prejudicial to
construction of ships, ships for liquid chemicals their proper application in service.
and other marine structures, liquefied gas piping
systems where the design temperature is not 3.4 Chemical composition
lower than minus 165°C. These materials should
not be used for piping outside cargo tanks 3.4.1 The chemical composition of a sample
except for short lengths of pipes attached to from each cast is to comply with the
cargo tanks in which case fire resisting requirements given in Table 3.4.1. Suitable grain
insulation should be provided. refining elements may be used at the discretion
of the Manufacturer. The content of such
3.1.2 Castings are to be manufactured and elements is to be reported in ladle analysis.
tested in accordance with Ch.1 and Ch.2 and
also with the requirements of this Section. 3.4.2 Where it is proposed to use alloys not
specified in Table 3.4.1 details of chemical
3.1.3 As an alternative to 3.1.2, castings which composition, heat treatment and mechanical
comply with National/International and properties are to be submitted for approval.
proprietary specifications may be accepted
provided that these specifications give 3.4.3 When a cast is wholly prepared from
reasonable equivalence to the requirements of ingots for which an analysis is already available,
this Section or are approved for a specific and provided that no significant alloy additions
application. Generally survey and certification are made during melting, the ingot maker's
are to be carried out in accordance with the certified analysis can be accepted subject to
requirements of Ch.1. occasional checks as required by the Surveyor.
3.2 Manufacture
Grade
Alloy Element %
AlMg3 AlSi12 AlSi10Mg AlSi7 High purity
Copper 0.1 max 0.1 max. 0.1 max. 0.1 max.
Magnesium 2.5 - 4.5 0.1 max. 0.15 - 0.4 0.25 - 0.45
Silicon 0.5 max. 11.0 - 9.0 - 11.0 6.5 - 7.5
13.5
Iron 0.5 max. 0.7 max. 0.6 max. 0.2 max.
Manganese 0.6 max. 0.5 max. 0.6 max. 0.1 max.
Zinc 0.2 max. 0.1 max. 0.1 max. 0.1 max.
Chromium 0.1 max. - - -
Titanium 0.2 max. 0.2 max. 0.2 max. 0.2 max.
Others
each 0.05 max. 0.05 max. 0.05 max. 0.05 max.
Total 0.15 max. 0.15 max. 0.15 max. 0.15 max.
Aluminium Remainder Remainder Remainder Remainder
3.6.1 At least one tensile specimen is to be 3.6.5 The results of all tensile tests are to
tested from each cast, where heat treatment is comply with the appropriate requirements given
involved, for each treatment batch from each in Table 3.6.1 and/or Table 3.6.2.
cast. Where continuous melting is employed 500
Table 3.6.1 : Minimum mechanical properties for acceptance purpose of sand cast and
investment cast reference test pieces
3.7.2 The accuracy and verification of 3.9.1 Where required by the relevant
dimensions are the responsibility of the construction rules, castings are to be pressure
manufacturer, unless otherwise agreed. tested before final acceptance. Unless otherwise
agreed, these tests are to be carried out in the
3.7.3 Before acceptance, all castings are to be presence and to the satisfaction of the Surveyor.
presented to the Surveyor for visual
examination. 3.10 Identification
3.8.2 Where appropriate, repair by welding may 3.10.2 All castings which have been tested and
be accepted at the discretion of the Surveyor. inspected with satisfactory results are to be
clearly marked with following details :
3.11 Certification
a) Identification number, cast number or other
numbers which will enable the full history of 3.11.1 The manufacturer is to provide the
the casting to be traced; Surveyor with a written statement giving the
following particulars for each casting or batch of
b) IR and the abbreviated name of local office castings which have been accepted :
of IRS;
a) Purchaser name and order number;
c) Personal stamp of the surveyor responsible
for the inspection; b) Description of castings and alloy type;
3.10.3 Where small castings are manufactured e) General details of heat treatment where
in large numbers, modified arrangements for applicable;
identification may be specially agreed with the
Surveyor. f) Results of mechanical tests; and
Section 4
4.1.2 Each design is to be separately approved 4.3 Visual and non-destructive examination
by IRS.
4.3.1 Each composite plate is to be subjected to
4.2 Manufacture 100 per cent visual and ultrasonic examination
in accordance with a relevant National/
4.2.1 Transition joints are to be manufactured by International standard to determine the extent of
an approved producer in accordance with an any unbounded areas. The unbounded areas
approved specification which is to include the are unacceptable and any such area and the
maximum temperature allowable at the interface surrounding 25 [mm] area is to be discarded.
during welding.
4.4 Mechanical tests
4.2.2 The aluminium material is to comply with
the requirements of Sec.1 and the steel is to be 4.4.1 Two shear test specimens and two tensile
of an appropriate grade complying with the test specimens are to be taken from each end of
requirements of Ch.3. each composite plate for tests to be made on
bond strength. One shear and one tensile test
4.2.3 Alternative materials which comply with specimen from each end are to be tested at
International, National or proprietary ambient temperature after heating to the
specifications may be accepted provided that maximum allowable interface temperature; the
they give reasonable equivalence to the other two specimens are to be tested without
requirements of 4.2.2 or are approved for a heat treatment.
specific application.
Table 4.4.1 : Bend tests on explosion bonded aluminium / steel transition joints
Type of test Minimum bend, degrees Diameter of former
Aluminium in tension 90 3T
Steel in tension 90 3T
Side bend 90 6T
4.5 Identification
b) The contract number for which the material
4.5.1 Each acceptable transition strip is to be is intended, if known;
clearly marked with IRS brand IR and the
following particulars : c) Address to which the material is dispatched;
4.6.1 Each test certificate or shipping statement h) Mechanical test results (not required on the
is to include the following particulars : shipping statement).
End of Chapter
Chapter 10
Equipment
Contents
Section
1 Anchors
2 Stud Link Chain Cables
3 Short Link Chain Cables
4 Steel Wire Ropes
5 Offshore Mooring Chains
Section 1
Anchors
- the clearance either side of the shank within c) For high holding power anchors - a nominal
the shackle jaws is not to be more than 3 mass equal to 1.33 times the actual mass of
[mm] for anchors upto 3000 [kg] mass, 4 the anchor;
[mm] for anchors upto 5000 [kg] mass, 6
[mm] for anchors upto 7000 [kg] mass and d) For super high holding power anchors - a
12 [mm] for larger anchors. nominal mass equal to 2.0 times the actual
mass of the anchor.
- the shackle pin is to be push fit in the eyes
of the shackle, which are to be chamfered 1.4.3 The proof load is to be applied on the arm
on the outside to ensure tightness when the or on the palm at a spot which, measured from
pin is clenched over. The shackle pin to hole the extremity of the bill, is one-third of the
clearance is not to be more than 0.5 [mm] distance between it and the centre of the crown.
for pins upto 57 [mm] and not more than 1
[mm] for pins of larger diameter In the case of the stockless anchors, both arms
are to be tested at the same time, first on one
- the anchor crown pin is to be snug fit within side of the shank, then reversed and tested on
the chamber and long enough to prevent the other.
horizontal movement. The gap is not to be
more than 1% of the chamber length. 1.4.4 Before application of proof test load the
anchors are to be examined to be sure that
- The lateral movement of the shank should castings are reasonably free of surface
not exceed 3 degrees. imperfections of harmful nature.
1.4 Proof test of anchors On completion of the proof load tests the
anchors are to be examined for cracks and other
1.4.1 Anchors of all sizes are to be proof load defects and for anchors made in more than one
tested with the load specified in Table 1.4.1. piece, the anchors are to be examined for free
Anchors having a mass of 75 [kgs] or more rotation of their heads over the complete angle.
inclusive of stock (56 [kgs] in case of high
holding power anchors) are to be tested at a In every test the difference between the gauge
proving establishment recognized by IRS. lengths (shown in Fig.1.4.4), where one-tenth of
the required load was applied first and where
1.4.2 The proof test load is to be as given in the load has been reduced to one-tenth of the
Table 1.4.1. The mass to be used in the Table is required load from the full load, is not to exceed
to be as follows:- one percent (1%).
a) For stockless anchors - the total mass of the 1.4.5 In addition to the requirements given in
anchor; this Chapter attention must be given to any
relevant statutory requirements of the National
b) For stocked anchors - the mass of the Authority of the country in which the ship is to be
anchor excluding the stock; registered.
Mass of anchor Proof test load Mass of anchor Proof test load Mass of anchor Proof test load
[kg] [kN] [kg] [kN] [kg] [kN]
(1) (2) (3) (4) (5) (6)
50 23.2 2000 349.0 7000 804.0
55 25.2 2100 362.0 7200 818.0
60 27.1 2200 376.0 7400 832.0
65 28.9 2300 388.0 7600 845.0
70 30.7 2400 401.0 7800 861.0
75 32.4 2500 414.0 8000 877.0
80 33.9 2600 427.0 8200 892.0
90 36.3 2700 438.0 8400 908.0
100 39.1 2800 450.0 8600 922.0
120 44.3 2900 462.0 8800 936.0
140 49.0 3000 474.0 9000 949.0
160 53.3 3100 484.0 9200 961.0
180 57.4 3200 495.0 9400 975.0
200 61.3 3300 506.0 9600 987.0
225 65.8 3400 517.0 9800 998.0
250 70.4 3500 528.0 10000 1010.0
275 74.9 3600 537.0 10500 1040.0
300 79.5 3700 547.0 11000 1070.0
325 84.1 3800 557.0 11500 1090.0
350 88.8 3900 567.0 12000 1110.0
375 93.4 4000 577.0 12500 1130.0
400 97.9 4100 586.0 13000 1160.0
425 103.0 4200 595.0 13500 1180.0
450 107.0 4300 604.0 14000 1210.0
475 112.0 4400 613.0 14500 1230.0
500 116.0 4500 622.0 15000 1260.0
550 125.0 4600 631.0 15500 1270.0
600 132.0 4700 638.0 16000 1300.0
650 140.0 4800 645.0 16500 1330.0
700 149.0 4900 653.0 17000 1360.0
750 158.0 5000 661.0 17500 1390.0
800 166.0 5100 669.0 18000 1410.0
850 175.0 5200 677.0 18500 1440.0
900 182.0 5300 685.0 19000 1470.0
950 191.0 5400 691.0 19500 1490.0
1000 199.0 5500 699.0 20000 1520.0
1050 208.0 5600 706.0 21000 1570.0
1100 216.0 5700 713.0 22000 1620.0
1150 224.0 5800 721.0 23000 1670.0
1200 231.0 5900 728.0 24000 1720.0
1250 239.0 6000 735.0 25000 1770.0
1300 247.0 6100 740.0 26000 1800.0
1350 255.0 6200 747.0 27000 1850.0
1400 262.0 6300 754.0 28000 1900.0
1450 270.0 6400 760.0 29000 1940.0
1500 278.0 6500 767.0 30000 1990.0
1600 292.0 6600 773.0 31000 2030.0
1700 307.0 6700 779.0 32000 2070.0
1800 321.0 6800 786.0 34000 2160.0
1900 335.0 6900 794.0 36000 2250.0
Mass of anchor Proof test load Mass of anchor Proof test load Mass of anchor Proof test load
[kg] [kN] [kg] [kN] [kg] [kN]
(1) (2) (3) (4) (5) (6)
38000 2330.0 42000 2490.0 46000 2650.0
40000 2410.0 44000 2570.0 48000 2730.0
Proof loads for intermediate masses are to be determined by linear interpolation
Notes
Where ordinary anchors have a mass exceeding 48 000 [kg], the proof loads are to be taken as 2.059 (mass of anchor in kg)2/3
[kN].
Where high holding power anchors have a mass exceeding 38 000 [kg], the proof loads are to be taken as 2.452 (actual mass of
anchor in kg)2/3 [kN].
1.5 Inspections and other tests 1.5.2 Drop test is to be carried out by dropping
each anchor component individually from a
1.5.1 Inspection and testing of anchor height of 4 [m] to an iron or steel slab. The iron
components is to be carried out as per the or steel slab should be able to resist the impact.
following: The component under test should not fracture.
a) Cast components are to be tested as per
1.5.3 Hammering test is to be carried on each
Test Programme A fluke and shank, after the drop test, by
hammering the component, hung clear off the
or ground using a non-metallic sling, with a
hammer of not less than 3 [kg] mass, to check
Test Programme B, where the Charpy V notch the soundness.
energy average of the cast material at 0°C is not
less than 27J. 1.5.4 Visual inspection is to be carried out of all
accessible surfaces after the proof load test.
b) Forged / fabricated components are to be
tested as per Test Programme B. 1.5.5 General non-destructive examination is to
be carried out, after proof load testing, as per
Test Programme A is to consist of Drop Test, Table 1.5.5.
Hammering Test, Visual Inspection and General
NDE as described below. 1.5.6 Extended non-destructive examination is
to be carried out, after proof load testing, as per
Test Programme B is to consist of Visual Table 1.5.6.
Inspection, general NDE and Extended NDE as
described in 1.5.5 and 1.5.6 below.
Table 1.5.6 : Extended NDE for ordinary, HHP and SHHP anchors
1.6.1 All identification marks are to be stamped f) Personal stamp of Surveyor responsible for
on one side of the anchor, on the shank and the inspection.
fluke, at locations reserved solely for this
purpose. g) Manufacturer’s mark
1.6.2 The following details are to be marked on h) Unique cast identification number of shank
all the anchors:- and fluke, if applicable.
a) IR and abbreviated name of local office of 1.6.3 In addition to the markings detailed in
IRS issuing the certificate; 1.6.2, each important part of the anchor is to be
plainly marked with the words 'forged steel' or
b) Number of the certificate; 'cast steel' as appropriate.
d) Mass (also the letters 'HHP/SHHP', when 1.7.1 Anchors are to be painted only on
approved for as high holding power completion of all inspections and tests.
anchor/super high holding power anchor);
Section 2
provided that all of the final link parts fit shown in Fig.2.4.1. For smaller diameters the
together properly; test specimens are to be taken as close as
possible to these positions.
c) Studs must be located in the links centrally
and at right angles to the sides of the link, 2.4.6 The cross-sectional area of the tensile test
2
although the studs at each end of any length specimen is to be not less than 150 [mm ].
may also be located off-centre to facilitate Alternatively, the tensile test specimen may be a
the insertion of the joining shackle. The suitable length of bar tested in full cross-section.
following tolerances are regarded as being
inherent in the method of manufacture and 2.4.7 The impact test specimens are to be
will not be objected to provided the stud fits notched in the radial direction as shown in
snugly and its ends lie practically flush Fig.2.4.1.
against the inside of the link.
2.4.8 The results of all the mechanical testing
Maximum off- 10 per cent of the are to comply with the requirements of Table
centre distance 'X' nominal diameter d 2.4.1.
Maximum deviation 4°
"α" from the 90° 2.4.9 The average value obtained from one set
position of three impact test specimens is to comply with
the requirements given in Table 2.4.1. One
The tolerances are to be measured in individual value only may be below the specified
accordance with Fig.2.3.7. average value provided it is not less than 70% of
that value.
2.3.3 The following tolerances are applicable to
accessories : If the Charpy V-notch impact test requirements
are not achieved, a retest of three further
Nominal diameter : + 5 per cent, - 0 per cent specimens selected from the same sample as
Other diameter : ± 2.5 per cent. per 1.10.2 of Chapter 1 shall be permissible.
Failure to meet the requirements will result in
2.4 Material for welded chain cables and rejection of the test unit represented unless it
accessories can be clearly attributable to improper simulated
heat treatment.
2.4.1 Bar material intended for the manufacture
of welded chain cables is to be in accordance If the tensile test requirements are not achieved,
with the appropriate requirements of Ch.3. a retest of two further specimens selected from
Rimming steel is not acceptable for this the same sample shall be permissible. Failure to
application. meet the specified requirements in either of the
additional tests will result in rejection of the test
2.4.2 Bars of the same nominal diameter are to unit represented unless it can be clearly
be presented for test in batches of 50 tonnes or attributable to improper simulated heat
fraction thereof from the same cast. A suitable treatment.
length from one bar in each batch is to be
selected for test purposes. 2.4.10 If failure to pass the tensile test or the
Charpy V-notch impact test is definitely
2.4.3 In order to evaluate the suitability of the attributable to improper heat treatment of the
bar material the sample selected from each test sample, a new test sample may be taken
batch is to be tested in a heat treatment from the same piece and re-heat treated. The
condition equivalent to that of the finished chain complete test (both tensile and impact test) is to
cable and accessories. For this purpose only the be repeated and the original results obtained
sample need be heat treated. may be disregarded.
2.4.4 For all grades, one tensile test is to be 2.4.11 The chemical composition of the steel
taken from each sample selected. Additionally bars is to be generally within the limits given in
one set of three Charpy V-notch impact test Table 2.4.2.
specimens is to be prepared and tested as
required in Table 2.4.1. 2.4.12 The tolerances on diameter and
roundness of rolled steel bars are to be within
2.4.5 Where the dimensions allow, the test the limits specified in Table 2.4.3 unless
specimens are to be taken at approximately otherwise agreed.
one-third of the radius from the outer surface as
Table 2.4.1 : Mechanical properties of rolled steel bars for acceptance purposes
1 The impact test of grade CC2 material may be waived, if the chain is to be supplied in a heat treated
condition as per Table 2.9.1.
Chemical Composition
1
Designation C Si Mn P S Al (Total)
max. max. max. min.
Grade CC1 0.20 0.15 - 0.35 min. 0.40 0.040 0.040 -
2
Grade CC2 0.24 0.15 - 0.55 max. 1.60 0.035 0.035 0.020
3
Grade CC3 To be specially considered in each case
NA = Not Applicable.
c) The welds, preferably in the horizontal requirements of this Chapter, attention must be
position, are to be executed by qualified given to any relevant statutory requirements of
welders using suitable welding the National Authority of the country in which the
consumables; ship is to be registered.
d) All the welds are to be completed before the 2.9.2 Each length of chain is to be subjected to
final heat treatment of the chain cable; and a proof loading test in an approved testing
machine and is to withstand the load given in
e) The welds are to be free from defects liable Table 2.9.1 for the appropriate grade and size of
to impair the proper use of the chain. cable. On completion of the test, each length of
cable is to be examined and is to be free from
2.9 Testing of completed chain cables significant defects.
2.9.1 Finished chain cables are to be tested in Should a proof load test fail, the defective link(s)
the presence of a Surveyor, at a proving is (are) to be replaced, a local heat treatment to
establishment recognized by IRS. For this be carried out on the new link(s) and the proof
purpose the chain cables must be free from load test is to be repeated. In addition, an
paint and anti-corrosive media. Special attention investigation is to be made to identify the cause
would be given to the visual inspection of the of the failure.
flash-butt-weld, if present. In addition to the
Table 2.9.1 : Formulae for proof load and breaking load tests
Table 2.9.2 : Number of mechanical test specimens for finished chain cables and accessories
NR = Not required
NA = Not applicable
2.9.3 Sample lengths comprising of at least 2.9.7 An additional link (or where the links are
three links are to be taken from every four small, several links) for mechanical test
lengths or fraction of chain cables and tested at specimen removal is to be provided in a length
the breaking loads given in Table 2.9.1. The of chain cable not containing the specimen for
breaking load is to be maintained for a minimum the breaking test. The specimen link must be
of 30 seconds. The links concerned are to be manufactured and heat treated together with the
made in a single manufacturing cycle together length of chain cable.
with the chain cable and must be welded and
heat treated together with it. Only after this 2.10 Accessories for chain cables
these may be separated from the chain cable in
the presence of the Surveyor. 2.10.1 End and joining shackles, attachment
links, adapter pieces, swivels and other fittings
2.9.4 Where a breaking load test specimen fails, are to be subjected to the proof and breaking
a further specimen is to be cut from the same loads appropriate to the grade and size of cable
length of cable and subjected to test. If this re- for which they are intended in accordance with
test fails, the length of cable from which it was the requirements of Table 2.9.1.
taken is to be rejected. When this test is also
representative of other lengths, each of the 2.10.2 The breaking load is to be applied to at
remaining lengths in the batch is to be least one item out of every 25 (one in 50 for
individually tested and is to meet the lugless shackles). The items need not
requirements of the breaking load test. necessarily be representative of each heat of
steel or individual purchase order. Enlarged
2.9.5 For large diameter cables where the links and end links need not be tested provided
required breaking load is greater than the that they are manufactured and heat treated
capacity of the testing machines, special together with the chain cable. The tested item is
consideration will be given to acceptance of to be destroyed and not used as part of an outfit,
other alternative testing procedure. in general. However, the accessories, which
have been successfully tested at the prescribed
2.9.6 Mechanical test specimens required in breaking load appropriate to the chain, may be
Table 2.9.2 are to be taken from every four used in service at the discretion of IRS where
lengths in accordance with 2.9.7. For forged or the accessories are manufactured with the
cast chain cables where the batch size is less following:
than four lengths, the sampling frequency is to
be by heat treatment charge. Mechanical tests a) material having higher strength
are to be carried out in the presence of the characteristics than those specified for the
Surveyor. The test specimens and their location part in question (e.g. grade 3 material for
are to be according to 2.4.5 to 2.4.7 and accessories for grade 2 chain).
Fig.2.4.1. Testing and re-testing are to be
carried out as given in 2.4.9. b) or alternatively, same grade material as the
chain but with increased dimensions and it
is verified by procedure tests that such tensile test specimen and the Charpy V-notch
accessories are so designed that the impact test specimens are to be taken in
breaking strength is not less than 1.4 times accordance with Table 2.9.2. Mechanical tests
the prescribed breaking load of the chain for are to be carried out in the presence of the
which they are intended. Surveyor. Location of test specimens and test
procedure are to be as given in 2.4.5 to 2.4.7
2.10.3 The breaking load test may be waived if – and Fig.2.4.1. Testing / re-testing is to be carried
out as per 2.4.9. Enlarged links and end links
a) The breaking load has been demonstrated need not be tested provided they are
on the occasion of the approval testing of manufactured and heat treated together with the
parts of the same design, and chain cable.
2.10.4 Unless otherwise specified, the forging or a) IR and the abbreviated name of the local
casting must at least comply with the office of IRS issuing the certificate;
mechanical properties given in Table 2.9.3, b) Number of certificate;
when properly heat treated. For test sampling, c) Date of test;
forgings or castings of similar dimensions d) Proof load and grade of chain;
originating from the same heat treatment charge e) Personal stamp of the Surveyor responsible
and the same heat of steel are to be combined for inspection.
into one test unit. From each test unit, one
Section 3
3.2.2 For chain of diameter less than 12.5 [mm], 3.2.7 The total elongation of the breaking load
other than steering chains, the manufacturer's sample at fracture, expressed as a percentage
tests will be accepted. of the original inside length of the sample after
proof loading, is to be not less than 20 per cent.
Table 3.2.1 : Mechanical test requirements for short link chain cables
Section 4
4.1 General
4.2 Materials
4.1.1 Steel wire ropes are to be manufactured at
Works approved by IRS. 4.2.1 The wire used in the manufacture of the
rope is to be drawn from steel made in
4.1.2 The wire ropes are to be of six strand type accordance with the requirements of Ch.3.
with minimum of 16 wires in each strand. In
addition to complying with the requirements of
this Chapter, the details regarding form of Table 4.2.1 : Torsion test - Speed of testing
construction and minimum breaking strength are
to be in accordance with IS: 2266-1989. Diameter of Maximum speed of
Alternative type of wire ropes will be specially coated wire [mm] testing twists per minute
considered on the basis of an equivalent < 1.5 90
breaking load and the suitability of the ≥ 1.5 < 3.0 60
construction for the purpose intended. ≥ 3.0 < 4.0 30
4.1.3 It is recommended that the wire ropes 4.2.2 The tensile strength is generally to be
intended for stream wires, towlines and mooring 2
within the ranges 1420 to 1570 [N/mm ]; 1570 to
lines be of fiber core construction and wire ropes 2 2
1770 [N/mm ] or 1770 to 1960 [N/mm ].
for towlines and mooring lines used in
association with mooring winches be of wire
rope core.
4.3.2 The uniformity of the zinc coating is to be diameter of the mandrel and that of the wire is to
determined by a dip test carried out in be as in Table 4.3.2. After wrapping on the
accordance with the requirements of a appropriate mandrel the zinc coating is to have
recognized standard. neither flaked nor cracked to such an extent that
any zinc can be removed by rubbing with bare
4.3.3 The adhesion of the coating is to be tested fingers.
by wrapping the wire round a cylindrical mandrel
for 10 complete turns. The ratio between the
Coating Diameter coated wire [mm] Max. ratio of mandrel to wire diameter
Grade 1 and 2 < 1.5 4
≥ 1.5 6
Grade 3 < 1.5 2
≥ 1.5 3
4.4 Test on completed ropes 4.4.2 The actual breaking load is not to be less
than that given in the appropriate approved
4.4.1 The breaking load is to be determined by standard.
testing to destruction a sample cut from the
completed rope. This sample is to be of 4.5 Identification
sufficient length to provide a clear test length of
at least 36 times the rope diameter between the 4.5.1 All completed ropes are to be identified
grips. with attached labels detailing the rope type,
diameter and length.
Section 5
5.1.1 Following requirements apply to the 5.2.1 Depending on the nominal tensile strength
materials, design, manufacture and testing of of the steels used for manufacture, chains are
offshore mooring chain and accessories subdivided into five grades, namely R3, R3S,
intended to be used for application such as: R4, R4S and R5.
mooring of mobile offshore drilling units,
mooring of floating production units, mooring of 5.2.2 Manufacturers propriety specifications for
offshore loading systems and mooring of gravity R4S and R5 may vary subject to design
based structures during fabrication. conditions and acceptance of IRS.
5.1.2 Mooring equipment covered by these 5.2.3 Each Grade is to be individually approved.
requirements are common stud and studless Approval for a higher grade does not constitute
links, connecting common links (splice links), approval of a lower grade.
enlarged links, end links, detachable connecting
links (shackles), end shackles, swivels and 5.3 Approval of chain manufacturers
swivel shackles.
5.3.1 Offshore mooring chain are to be
5.1.3 Studless link chain is normally to be manufactured only by works approved by IRS.
deployed only once, being intended for long- For this purpose approval tests are to be carried
term permanent mooring systems with pre- out, the scope of which is to include proof and
determined design life. breaking load tests, measurements and
mechanical tests including fracture mechanics f) proof and break loading including
tests. method/machinery, means of horizontal
support (if applicable), method of
5.3.2 Manufacturers are to submit for review and measurement and recording;
approval the sequence of all operations from
receiving inspection of raw materials to the g) non-destructive examination procedures.
shipment of finished products along with details
of the following manufacturing processes: h) the manufacturer’s surface quality
requirement of mooring components.
a) bar heating and bending including the
method, temperatures, temperature control 5.3.3 For initial approval CTOD (Crack Tip
and recording; Opening Displacement) tests are to be carried
out on the particular mooring grade of material.
b) flash welding including current, force, time CTOD tests are to be conducted in accordance
and dimensional variables as well as control with a recognized standard such as BS 7448
and recording of parameters; Parts 1 and 2. The CTOD test piece is to be a
standard 2 x 1 single edge notched bend piece,
c) flash removal including method and test location as shown in Fig.5.3.1. The
inspection; minimum test piece size is to be 50 x 25 [mm]
for chain diameter less than 120 [mm] and 80 x
d) stud insertion method for stud link chain; 40 [mm] for diameter 120 [mm] and above.
CTOD specimens are to be taken from both the
e) heat treatment including furnace types, side of the link containing the weld and from the
means of specifying, controlling and opposite side. Three links are to be selected for
recording of temperature and chain speed testing, i.e, a total of six CTOD specimens. The
and allowable limits, quenching bath and tests are to be taken at minus 20°C and meet
agitation, cooling method after exit; the minimum values indicated below:
5.3.4 Calibration of furnaces is to be verified by For Grade R4, R4S and R5 chain the steel is to
measurement and recording of a calibration test contain a minimum of 0.20 per cent
piece with dimensions equivalent to the molybdenum.
maximum size of link manufactured.
Thermocouples are to be placed both on the 5.5.3 A heat treatment sensitivity study
surface and in a drilled hole located at the mid simulating chain production conditions is to be
thickness position of the calibration block. applied in order to verify mechanical properties
and establish limits for temperature and time
5.3.5 For R4S and R5 chain and accessories, combinations. All test details and results are to
prior to approval, the manufacturer is to have be submitted to IRS.
undertaken experimental tests or have relevant
supporting data to develop the chain and 5.5.4 The bar manufacturer is to provide
accessory material. The tests and data may evidence that the manufacturing process
include: fatigue tests, hot ductility tests (no produces material that is resistant to strain
internal flaws are to develop whilst bending in ageing, temper embrittlement and for R3S, R4,
the link forming temperature range), welding R4S and R5, hydrogen embrittlement. All test
parameter research, heat treatment study, strain details and results are to be submitted to IRS.
age resistance, temper embrittlement study,
stress corrosion cracking (SCC) data and 5.6 Approval of forge shops and foundries -
hydrogen embrittlement (HE) study, using slow accessories
strain test pieces in hydrated environments.
Reports indicating the results of experimental 5.6.1 Forge shops and foundries intending to
tests are to be submitted. supply finished or semi-finished accessories are
to be approved by IRS. A description of
5.4 Approval of quality system at chain and manufacturing processes and process controls
accessory manufacturers is to be submitted to IRS. The scope of approval
is to be approved by IRS. The approval is to be
5.4.1 Chain and accessory manufacturers are to limited to a nominated supplier of forged or cast
have a documented and effective quality system material. If an accessory manufacturer wishes to
approved by IRS. The provision of such a quality use material from a number of suppliers, a
system is required in addition to, and not in lieu separate approval must be carried out for each
of, the witnessing of tests by a Surveyor as supplier.
specified in 5.7 to 5.14.
5.6.2 Approval will be given only after successful
5.5 Approval of steel mills - rolled bar testing of the completed accessory. The
approval will normally be limited to the type of
5.5.1 Bar material intended for chain and accessory and the designated mooring grade of
accessories are to be manufactured only by material upto the maximum diameter or
works approved by IRS. The approval is limited thickness equal to that of the completed
to a nominated supplier of bar material. If a accessory used for qualification. Qualification of
chain manufacturer wishes to use material from accessory pins to maximum diameters is also
a number of suppliers, separate approval tests required. Individual accessories of complex
must be carried out for each supplier. geometries will be specially considered.
Approval will be given only after successful 5.6.3 For forgings – The forging reduction ratio,
testing of the completed chain. The approval will used in the qualification tests, from cast ingot /
normally be limited upto the maximum diameter slab to forged component is to be recorded. The
equal to that of the chain diameter tested. The forging reduction ratio used in production can be
rolling reduction ratio is to be recorded and is to higher, but should not be lower than that
be at least 5:1. The rolling reduction ratio used qualified.
in production can be higher, but should not be
lower than that qualified. 5.6.4 The forge shop or foundry is to submit a
specification of chemical composition of the
5.5.2 The bar manufacturer is to submit a forged or cast material, which must be approved
specification of the chemical composition of the by IRS. For Grade R4, R4S and R5 chain the
bar material, which must be approved by IRS steel should contain a minimum of 0.20 per cent
and by the chain manufacturer. molybdenum.
5.6.5 Forges and foundries are to provide quantified and assessed to be sure inclusion
evidence that the manufacturing process levels are acceptable for the final product.
produces material that is resistant to strain
ageing, temper embrittlement and for R4S and b) A sample from each heat is to be macro
R5 grades, hydrogen embrittlement. A heat etched according to ASTM E381 or equivalent to
treatment sensitivity study simulating accessory be sure there is no injurious segregation or
production conditions shall be applied in order to porosity.
verify mechanical properties and establish limits
for temperature and time combinations. (Cooling c) Jominy hardenability data, according to ASTM
after tempering shall be appropriate to avoid A255, or equivalent, is to be supplied with each
temper embrittlement). All test details and heat.
results are to be submitted to IRS.
5.7.2 Chemical composition
5.6.6 For initial approval CTOD tests are to be
carried out on the particular mooring grade of For acceptance tests, the chemical composition
material. Three CTOD tests are to be tested in of ladle samples of each heat is to be
accordance with a recognized standard such as determined by the bar manufacturer and is to
BS 7448 Parts 1 and 2. The CTOD test piece is comply with the approved specification (see
to be a standard 2 x 1 single edge notched bend 5.5.2).
specimen taken from the quarter thickness
location. The minimum test piece size shall be 5.7.3 Mechanical tests
50 x 25 [mm] for chain diameters less than 120
[mm] and 80 x 40 [mm] for diameters 120 [mm] .1 Bars of the same nominal diameter are
and above. The tests are to be taken at minus to be presented for test in batches of 50 tonnes
20°C and the results submitted for review. or fraction thereof from the same heat. Test
specimens are to be taken from material heat
5.6.7 Calibration of furnaces shall be verified by treated in the same manner as intended for the
measurement and recording of a calibration test finished chain.
piece with dimensions equivalent to the
maximum size of link manufactured. .2 Each heat of Grade R3S, R4, R4S and
Thermocouples are to be placed both on the R5 steel bars is to be tested for hydrogen
surface and in a drilled hole located to the mid embrittlement. In case of continuous casting,
thickness position of the calibration block. test samples representing both the beginning
and the end of the charge are to be taken. In
5.6.8 For R4S and R5 refer to additional case of ingot casting, test samples representing
requirements in 5.3.5. two different ingots are to be taken.
5.7 Rolled steel bars a) Two tensile test specimens are to be taken
from the central region of bar material which
5.7.1 Steel manufacture has been subjected to the heat treatment
cycle intended to be used in production.
5.7.1.1 The steels are to be manufactured by The specimens are to preferably have a
basic oxygen, electric furnace or such other diameter of 20 mm, alternatively 14 mm.
process as may be specially approved. All steels One specimen is to be tested within max. 3
are to be killed and fine grain treated. The hours (1 1/2 hours for 14 mm diameter
austenitic grain size is to be 6 or finer in specimen) after machining. Where this is
accordance with ASTM E112. not possible, the specimen is to be cooled to
-60°C immediately after machining and kept
5.7.1.2 Steel for bars intended for R4S and R5 at that temperature for a period of maximum
chain is to be vacuum degassed. 5 days.
5.7.1.3 For R4S and R5 the following The second specimen is to be tested after
information is to be supplied by the bar baking at 250°C for 4 hours (2 hours for 14
manufacturer to the mooring chain manufacturer mm diameter specimen).
and the results included in the chain
documentation: b) A slow strain rate < 0.0003 per second is to
be used during the entire test, until fracture
a) Each heat is to be examined for non-metallic occurs. (This is approx. 10 minutes for a 20
inclusions. The level of micro inclusions is to be mm diameter specimen).
Notes:
2 At the option of IRS the impact test of Grade R3 and R3S may be carried out at either 0°C or
minus 20°C.
3 Reduction of area of cast steel is to be for Grades R3 and R3S: min. 40%, for R4, R4S and R5 :
min. 35% (see 5.9.4).
5.8.1.2 Steel for forgings intended for R4S and 5.8.2 Chemical composition
R5 chain is to be vacuum degassed.
For acceptance tests, the chemical composition
5.8.1.3 For steel intended for R4S and R5 of ladle samples of each heat is to be
accessories the following information is to be determined by the bar manufacturer and is to
supplied by the steel manufacturer to the comply with the approved specification (see
mooring accessory manufacturer and the results 5.5.2).
included in the accessory documentation:
For test sampling, forgings of similar dimensions b) A sample from each heat is to be macro
(diameters do not differ by more than 25 mm) etched according to ASTM E381 or equivalent to
originating from the same heat treatment charge be sure there is no injurious segregation or
and the same heat of steel are to be combined porosity.
into one test unit. From each test unit one
tensile and three impact test specimens are to c) Jominy hardenability data, according to ASTM
be taken and tested. For the location of the test A255, or equivalent is to be supplied with each
specimens see Sec. 2, Fig.2.4.1. heat.
5.8.6.3 The forgings are to be subjected to 100 The castings are to comply with the mechanical
percent ultrasonic examination at an appropriate properties given in Table 5.7.1. The requirement
stage of manufacture and in compliance with the for reduction of area is, however, reduced to 40
standard approved by IRS. per cent for grades R3 and R3S and 35 per cent
for grade R4, R4S and R5.
5.8.7 Marking
5.9.5 Mechanical tests
Marking is to be similar to that specified in 5.7.6.
For test sampling, castings of similar dimensions
5.9 Cast steel originating from the same heat treatment charge
and the same heat of steel are to be combined
5.9.1 Manufacture into one test unit. From each test unit one
tensile and three impact test specimens are to
5.9.1.1 Cast steels used for the manufacture of be taken and tested. For the location of the test
accessories are to be in compliance with specimens see Sec. 2, Fig.2.4.1.
approved specifications and the submitted test
reports approved by IRS. Steel is to be 5.9.6 Ultrasonic examination
manufactured by basic oxygen, electric furnace
or such other process as may be specially 5.9.6.1 Non-destructive examination is to be
approved. All steel is to be killed and fine grain performed in accordance with recognized
treated. The austenitic grain size is to be 6 or standards and the non-destructive examination
finer in accordance with ASTM E112.
procedures, together with rejection / acceptance 5.12 Chain cable manufacturing process
criteria are to be submitted to IRS.
5.12.1 General
5.9.6.2 Non-destructive examination operators
are to be appropriately qualified (to a minimum Offshore mooring chains are to be manufactured
level II in accordance with a recognized in continuous lengths by flash butt welding and
standard such as ISO 9712, SNT-TC-1A, EN are to be heat treated in a continuous furnace;
473 or ASNT Central Certification Program) in batch heat treatment is not permitted. The use
the method of non-destructive examination. of joining shackles to replace defective links is
subject to the written approval of the end
5.9.6.3 The castings are to be subjected to 100 purchaser in terms of the number and type
percent ultrasonic examination in compliance permitted. The use of connecting common links
with the standard approved by IRS. is restricted to 3 links in each 100 m of chain.
Marking is to be similar to that specified in 5.7.6. Records of bar heating, flash welding and heat
treatment are to be made available for
5.10 Materials for studs inspection by the Surveyor.
5.10.1 The studs intended for stud link chain 5.12.3 Bar heating
cable are to be made of steel corresponding to
that of the chain or in compliance with a) For electric resistance heating, the heating
specifications approved by IRS. In general, the phase is to be controlled by an optical heat
carbon content is not to exceed 0.25 per cent if sensor. The controller is to be checked at
the studs are to be welded in place. least once every 8 hours and the records
are to be maintained.
5.11 Design
b) For furnace heating, the heat is to be
5.11.1 Plans with design calculations, giving controlled and the temperature continuously
detailed design of chain and accessories made recorded using thermocouples in close
by or supplied through the chain manufacturer proximity to the bars. The controls are to be
are to be submitted for approval. Typical checked at least once every 8 hours and the
designs are given in ISO 1704 (see Sec. 2, records are to be maintained.
Fig.2.3.1 to 2.3.6). For studless chain the shape
and proportions are to comply with the 5.12.4 Flash welding
requirements of this section. Other studless
proportions are to be specially approved. It The following welding parameters are to be
should be considered that new or non-standard controlled during welding of each link:
designs of chain, shackles or fittings, may
require a fatigue analysis and possible a) Platen motion;
performance, fatigue or corrosion fatigue testing.
b) Current as a function of time;
5.11.2 In addition for stud link chain, plans
showing the detailed design of the stud are to be c) Hydraulic pressure.
submitted for information. The stud is to give an
impression in the chain link which is sufficiently The controls are to be checked at least every 4
deep to secure the position of the stud, but the hours and records are to be maintained.
combined effect of shape and depth of the
impression is to be such as not to cause any 5.12.5 Heat treatment
harmful notch effect or stress concentration in
the chain link. a) Chain is to be austenitized, above the upper
transformation temperature, at a combina-
5.11.3 Machining of Kenter shackles is to result tion of temperature and time within the limits
in fillet radius of minimum 3 per cent of nominal established.
diameter.
b) When applicable, chain is to be tempered at
a combination of temperature and time
within the limits established. Cooling after
Table 5.12.1 : Formulae for proof and break test loads, weight and length over 5 links
All chains are to have a workmanlike finish The form and proportion of links and
consistent with the method of manufacture and accessories are to be in accordance with the
be free from defects. Each link is to be approved design. The tolerances given in Sec.
examined in accordance with 5.15.5 using 2, Cl. 2.3 are applicable, in general.
approved procedures.
In addition, the tolerances for stud link and
studless common links are to be measured in
accordance with Fig.5.12.9a) and b).
a) Stud Link – The internal link radii (R) and external radii should be uniform
1)
Designation Description Nominal Minus Tolerance Plus Tolerance
Dimension of the
Link
a Link length 6d 0.15d 0.15d
b Link half length a*/2 0.1d 0.1d
c Link width 3.6d 0.09d 0.09d
e Stud angular 0 degrees 4 degrees 4 degrees
misalignment
R Inner radius 0.65d 0 ----
b) Studless – The internal link radii (R) and external radii should be uniform.
1)
Designation Description Nominal Minus Tolerance Plus Tolerance
Dimension of the
Link
a Link length 6d 0.15d 0.15d
b Link width 3.35d 0.09d 0.09d
R Inner radius 0.60d 0 ----
c) The stud ends must be a good fit inside the g) The welds are to be of good quality and free
link and the weld is to be confined to the from defects such as cracks, lack of fusion,
stud end opposite to the flash butt weld. The gross porosity and undercuts exceeding 1
full periphery of the stud end is to be welded mm.
unless otherwise approved.
h) All stud welds are to be visually examined. manufacturer has a procedure to record
At least 10 per cent of all stud welds within proof loads and the Surveyor is satisfied
each length of chain are to be examined by with the adequacy of the recording system,
dye penetrant or magnetic particles after he may not witness all proof load tests. The
proof load testing. If cracks or lack of fusion Surveyor is to satisfy himself that the testing
are found, all stud welds in that length are to machines are calibrated and maintained in a
be examined. satisfactory condition.
5.12.11 Connecting common links (splice links) c) Prior to testing and inspection chains are to
be free from scale, paint or other coating.
.1 Single links to substitute for test links or The chains are to be sand- or shot blasted
defective links without the necessity for to meet this requirement.
re-heat treatment of the whole length
are to be made in accordance with an 5.13.2 Proof and break load tests
approved procedure. Separate
approvals are required for each grade of a) The entire length of chain is to withstand
chain and the tests are to be made on the proof load specified in Table 5.12.1
the maximum size of chain for which without fracture and without crack in the
approval is sought. flash weld. The load applied is not to
exceed the proof load by more than 10
.2 Manufacture and heat treatment of per cent when stretching the chain.
connecting common link is not to affect Where plastic straining is used to set
the properties of the adjoining links. The studs, the applied load is not to be
temperature reached by these links is greater than that qualified in approval
nowhere to exceed 250°C. tests.
5.13.3 Dimensions and dimensional tolerances provided that every cast is represented.
Mechanical properties are to be as specified
After proof load testing, measurements are to be in Table 5.7.1.
taken on at least 5 per cent of the links in
accordance with 5.12.9. c) The frequency of impact testing in the bend
may be reduced at the discretion of the
The entire chain is to be checked for the length, Surveyor provided it is verified by statistical
five links at a time. By the five link check the first means that the required toughness is
five links are to be measured. In the next set of consistently achieved.
five links, at least two links from the previous
five links set are to be included. This procedure 5.13.5 Non-destructive examination
is to be followed for the entire chain length. The
measurements are to be taken preferably while a) After proof load testing, all surfaces of every
the chain is loaded to 5 - 10 per cent of the link are to be visually examined. Burrs,
minimum proof load. The links held in the end irregularities and rough edges are to be
blocks may be excluded from this measurement. contour ground. Links are to be free from
mill defects, surface cracks, dents and cuts,
5.13.4 Mechanical tests especially in the vicinity where gripped by
clamping dies during flash welding. Studs
a) Links of samples detached from finished, are to be securely fastened. Chain is to be
heat treated chain are to be sectioned for positioned in order to have good access to
determination of mechanical properties. A all surfaces.
test unit is to consist of one tensile and nine
impact specimens. The tensile specimen is b) Testing is to be performed in accordance
to be taken in the side opposite the flash with a recognized standard and the
weld. Three impact specimens are to be procedures, together with acceptance /
taken across the flash weld with the notch rejection criteria are to be submitted to IRS
centered in the middle. Three impact for review. Operators are to be appropriately
specimens are to be taken across the qualified, in the method of inspection, to at
unwelded side and three impact specimens least level II in accordance with a
are to be taken from the bend region. recognized standard such as ISO 9712,
SNT-TC-1A, EN 473 or ASNT Central
b) The test frequency is to be based on tests at Certification Program.
sampling intervals according to Table 5.13.1
The marking is to be permanent and legible b) Prior to test and inspection the chain
throughout the expected lifetime of the accessories are to be free from scale, paint or
chain. other coating.
.2 The chain is to be marked on the studs as c) All accessories are to be subjected to proof
follows: load tests sample, break load tests and sample
mechanical tests after final heat treatment in the
- Chain grade presence of a Surveyor. Where the
manufacturer has a procedure to record proof
- Certificate No. loads and the Surveyor is satisfied with the
adequacy of the recording system, he may not
- IRS stamp witness all proof load tests. The Surveyor is to
satisfy himself that the testing machines are
The Certificate number may be exchanged calibrated and maintained in a satisfactory
against an abbreviation or equivalent, in condition.
which case the details are to be stated in
the certificate.
5.14.2 Proof and break load tests Mechanical tests are to be taken from proof
loaded full size accessories that have been heat
a) All accessories are to be subjected to the treated with the production accessories they
proof load specified for the corresponding represent. The use of separate representative
stud link chain. coupons is not permitted except as indicated in
d) below.
b) Chain accessories are to be tested to the
break test loads prescribed for the grade b) Test location of forged shackles. Forged
and size of chain for which they are shackle bodies and forged Kenter shackles are
intended. At least one accessory out of to have a set of three impact tests and a tensile
every 25 accessories is to be tested. test taken from the crown of the shackle. Tensile
tests on smaller diameter shackles can be taken
For individually produced accessories or from the straight part of the shackle, where the
accessories produced in small batches (less geometry does not permit a tensile specimen
than 5), alternative testing will be subject to from the crown. The tensile properties and
special consideration. A batch is defined as impact values are to meet the requirements of
accessories that originate from the same heat Table 5.7.1 in the locations specified in Fig.2.4.1
treatment charge and the same heat of steel. of Section 2 with the Charpy pieces on the
Accessories which have been subjected to a outside radius.
break test are to be scrapped, in general.
However, where the accessories are of c) The locations of mechanical tests of cast
increased dimensions or alternatively a material shackles and cast Kenter shackles can be taken
with higher strength characteristics is used, they from the straight part of the accessory. The
may be included in the outfit at the discretion of tensile properties and impact values are to meet
IRS provided that: the requirements of Table 5.7.1 in the locations
specified in Fig.2.4.1 of Section 2.
i) the accessories are successfully tested
at the prescribed breaking load d) The locations of mechanical tests of other
appropriate to the chain for which they accessories with complex geometries are to be
are intended, and agreed with IRS.
ii) it is verified by procedure tests that such e) For individually produced accessories or
accessories are so designed that the accessories produced in small batches, (less
breaking strength is not less than 1.4 than 5), alternative testing can be proposed to
times the prescribed breaking load of IRS. Each proposal for alternative testing is to
the chain for which they are intended. be detailed by the manufacturer in a written
procedure.
5.14.3 Dimensions and dimensional tolerances
f) A batch is defined as accessories that
a) After proof load testing, at least one originate from the same heat treatment charge
accessory (of the same type, size and and the same heat of steel.
nominal strength) out of 25 is to be checked
for dimensions in accordance with 5.12.9. g) Mechanical tests of pins are to be taken as
The manufacturer is to provide an adequate per Fig.2.4.1 of Section 2 from the mid length of
evidence indicating compliance with the a sacrificial pin of the same diameter as the final
purchaser's requirements. pin. For oval pins the diameter taken is to
represent the smaller dimension. Mechanical
b) The following tolerances are applicable to tests may be taken from an extended pin of the
accessories: same diameter as the final pin that incorporates
a test prolongation and a heat treatment buffer
- Nominal diameter : +5 percent, -0 percent prolongation, where equivalence with mid length
- Other dimensions : ± 2 ½ percent. test values have been established. The length of
the buffer is to be at least equal to 1 pin
These tolerances do not apply to machined diameter dimension which is removed after the
surfaces. heat treatment cycle is finished. The test coupon
can then be removed from the pin. The buffer
5.14.4 Mechanical tests and test are to come from the same end of the
pin as per Fig.5.14.4 below:
a) Accessories are to be subjected to
mechanical testing as described in 5.8 and 5.9.
In the event of a failure of any test the entire 5.15.2 Approval of manufacturing
batch represented is to be rejected unless the
cause of failure is determined and it is The chafing chain is to be manufactured by
demonstrated to the Surveyor's satisfaction that works approved by IRS according to 5.3 of this
the condition causing the failure is not present in chapter.
any of the remaining accessories.
5.15.3 Materials
5.14.7 Marking
The materials used for the manufacture of the
.1 Each accessory is to be marked as follows: chafing chain are to satisfy the requirements of
5.7 to 5.10 of this chapter.
- Chain grade
5.15.4 Design, manufacturing, testing and
- Certificate No. certification
c) The common link is to be of the stud link e) The chain lengths shall be proof load tested
type and of Grade R3 or R4. in accordance with 5.13.2. The proof test
loads for Grade R3 and Grade R4 are to be
d) The chafing chain is to be capable of 3242 [kN] and 4731 [kN] respectively.
withstanding the breaking test loads of 4884
[kN] (Grade R3) and 6001 [kN] (Grade R4).
End of Chapter
c) The common link is to be of the stud link e) The chain lengths shall be proof load tested
type and of Grade R3 or R4. in accordance with 5.13.2. The proof test
loads for Grade R3 and Grade R4 are to be
d) The chafing chain is to be capable of 3242 [kN] and 4731 [kN] respectively.
withstanding the breaking test loads of 4884
[kN] (Grade R3) and 6001 [kN] (Grade R4).
End of Chapter
Chapter 11
Contents
Section
1 General
2 Electrodes for Normal Penetration Manual Welding
3 Deep Penetration Electrodes for Manual Welding
4 Wire-flux Combinations for Submerged Arc Automatic Welding
5 Wires and Wire-gas Combinations for Semi-automatic and Automatic Welding
6 Consumables for use in Electro-slag and Electro-gas Vertical Welding
7 Welding Consumables for High Strength Quenched and Tempered Steels for
Welded Structures
8 Consumables for Welding of Aluminium Alloys
Section 1
General
d) Higher strength steels for ship structures for These consumables are divided into 3 strength
low temperature application : Grades FH32, groups each of which is further graded as per
FH36 and FH40 (See Ch.3). the Charpy V-notch impact test requirements as
shown below:
Groups Grading
Normal strength steel 1, 2, 3
2
Higher strength steel : yield strength upto 355 [N/mm ] 1Y, 2Y, 3Y, 4Y
2
Higher strength steels : yield strength upto 390 [N/mm ] 2Y40, 3Y40, 4Y40
Hydrogen marks
Welding consumables of Grades 2 and 3; and of Grades 2Y, 3Y and 4Y and of Grades 2Y 40, 3Y 40
and 4Y 40, for which hydrogen content has been controlled in accordance with Sec.2.5 are identified
by the mark H, HH or HHH
The following suffixes are added after the Grade mark as applicable:
S : Semi-automatic
T : Two-run technique
M : Multi-run technique
TM : Both two-run and multi-run technique
V : Vertical
See Table 1.3.1 for correlation of welding 1.3.3 For grading of consumables for welding
consumables to hull structural steel grades. aluminium alloys indicated in 1.1.1f) above, refer
to Sec.8.
1.3.2 For grading of consumables for welding
higher strength quenched and tempered steels
indicated in 1.1.1e) above, refer to Sec.7.
1) Requirements for other grades of steels given in ch.3 but not included here will be specially considered.
2) See Note d)
3) See Note e)
a) When joining normal to higher strength structural steel, consumables of the lowest acceptable grade for either material being
joined may be used.
b) When joining steels of same strength level but of different toughness grade, consumables of the lowest acceptable grade for
either material being joined may be used.
c) It is recommended that controlled low hydrogen type consumables are to be used when joining higher strength structural
steels to the same or lower strength level, except that other consumables may be used when the carbon equivalent is below
or equal to 0.41%. When other than controlled low hydrogen type electrodes are used appropriate procedure test for
hydrogen cracking may be conducted subject to approval of IRS.
d) The welding consumables approved for steel Grades AH40, DH40, EH40 and/or FH40 may also be used for welding of the
corresponding grades of normal strength steels subject to the approval of IRS.
e) When joining higher strength steels using Grade 1Y welding consumables, the material thicknesses is not to exceed 25
[mm].
1.4.4 IRS may require, in any particular case, 1.8.1 Deposited metal tensile test specimens
such additional tests or spacing requirements as are to be machined to the dimensions shown in
may be necessary. Fig.1.8.1. Care is to be taken to ensure that the
longitudinal axis of the test piece coincides with
1.5 Test assemblies the centre of the weld and midthickness of the
plates. The test piece may be heated to a
1.5.1 The test assemblies are to be prepared temperature not exceeding 250°C for a period
and tested under the supervision of the not exceeding 16 hours for hydrogen removal,
Surveyor(s). prior to testing.
Section 2
2.2 Deposited metal tests 2.2.4 The chemical analysis of the deposited
weld metal in each test assembly is to be
2.2.1 Two deposited metal test assemblies are supplied by the manufacturer and is to include
to be prepared in the downhand position as the content of all significant alloying elements.
shown in Fig.2.2.1, one using 4 [mm] electrodes
and the other using the largest size 2.2.5 The results of all tests are to comply with
manufactured. If an electrode is manufactured in the requirements of Table 2.2.1 as appropriate.
one diameter only, one test assembly is
sufficient. Any grade of ship structural steel may
2.3.2 Where the electrode is only to be or 6 [mm] diameter and the remaining runs with
approved in the downhand position an additional the largest size of electrode manufactured.
test assembly is to be prepared in that position.
HORIZONTAL-VERTICAL
2.3.3 The grades of steels used for the
preparation of the test assemblies are to be as First run with 4 [mm] or 5 [mm] diameter
follows: electrode, subsequent runs with 5 [mm]
diameter electrodes.
Grade 1 electrodes A
VERTICAL UPWARDS AND OVERHEAD
Grade 2 electrodes A, B, D
First run with 3.25 [mm] diameter electrode.
Grade 3 electrode A, B, D, E Remaining runs with 4 [mm] diameter electrodes
or possibly 5 [mm] diameter electrodes if this is
Grade 2Y electrode AH32, AH36, recommended by the manufacturer for the
D32, D36 positions concerned.
be seen on the outer surface of the test a) Diamond Pyramid Hardness (98 N load) =
specimen. 150 minimum
The first side is to be welded using the 2.5.1 At the request of the manufacturer,
maximum size of electrode manufactured and electrodes may be submitted to a hydrogen test.
the second side is to be welded using the A suffix H, HH or HHH will be added to the
minimum size of electrode manufactured and grade number to indicate compliance with the
recommended for fillet welding. The fillet size requirements of this test.
will in general be determined by the electrode
size and the welding current employed during 2.5.2 The mercury method as specified in the
testing. Standard ISO 3690-2000, or any method which
correlates to that method may be used.
2.4.3 The assembly is to be sectioned to form Alternatively, the glycerine method as described
three macro sections each about 25 [mm] thick below is to be used.
and the hardness readings are to be made in
each section as indicated in Fig.2.4.2. The 2.5.3 Glycerine method
hardness of the weld is to be determined and is
to meet the following listed equivalent values:- a) Four test specimens are to be prepared
measuring 12 x 25 [mm] in cross- section by
about 125 [mm] in length. The parent metal
may be any grade of ship building steel and, electrodes are to be carried out using the
before welding, the specimens are to be process for which the electrode is recommended
weighed to the nearest 0.1 gram. On the 25 by the manufacturer.
[mm] surface of each test specimen a single
bead of welding is to be deposited about 2.6.2 Where an electrode is submitted for
100 [mm] in length by a 4 [mm] electrode approval for use in contact welding using
using about 150 [mm] of the electrode. The automatic gravity or similar welding devices in
welding is to be carried out with as short an addition to normal manual welding, fillet weld
arc as possible and with a current of about tests (see 2.4) and, where appropriate, butt weld
150 amperes. The electrode prior to tests (see 2.3) similar to those for normal
welding, can be submitted to the normal manual electrodes are to be carried out using
drying process recommended by the the process for which the electrode is
manufacturer. recommended by the manufacturer and these
tests are to be in addition to the normal approval
b) Within thirty seconds of the completion of tests.
welding of each specimen the slag is to be
removed and the specimen quenched in 2.6.3 In the case of approval of a fillet welding
water at approximately 20°C. After a further electrode using automatic gravity or similar
thirty seconds the specimens are to be contact welding devices, the fillet welding is to
cleaned and placed in an apparatus suitable be carried out using the welding process
for the collection of hydrogen by recommended by the manufacturer, with the
displacement of glycerine. The glycerine is longest size of electrode manufactured. The
to be kept at a temperature of 45°C during manufacturer's recommended current range is
the test. All the four specimens are to be to be reported for each electrode.
welded and placed in the hydrogen
collecting apparatus within 30 minutes. 2.6.4 Where approval is requested for the
welding of both normal strength and higher
c) The specimens are to be kept immersed in tensile steels, the assemblies are to be prepared
the glycerine for a period of 48 hours and, using higher tensile steel.
after removal, are to be cleaned in water
and spirit, dried and weighed to the nearest 2.7 Annual tests
0.1 gram to determine the amount of weld
deposited. The amount of gas evolved is to 2.7.1 For normal penetration electrodes, the
3
be measured to the nearest 0.05 [cm ] and annual tests are to consist of two deposited
corrected for temperature and pressure to metal test assemblies. These are to be prepared
20C and 760 [mm] Hg. and tested in accordance with 2.2. If an
electrode is available in one diameter only, one
2.5.4 The individual and average diffusible test assembly is sufficient.
hydrogen contents of the four specimens are to
3
be reported, and the average value in [cm ] per 2.7.2 Where an electrode is approved solely for
100 grams is not to exceed the following: gravity or contact welding, the annual test is to
consist of one deposited metal test assembly
Mark Mercury Glycerine using the gravity or other contact device as
method (ISO Method recommended by the manufacturer.
3690-1977)
H 15 10 2.8 Upgrading and uprating
HH 8 5
HHH 5 2.8.1 Upgrading and uprating will be considered
Note : For HHH mark, only mercury method is only at the manufacturer's request and
to be used preferably at the time of annual testing. Tests on
butt weld assemblies, in addition to the
2.6 Covered electrodes for gravity or contact requirements of annual testing, are to be carried
welding out.
Section 3
3.1.1 Where an electrode is designed solely for 3.2.1 Two plates of thickness equal to twice the
the deep penetration welding of downhand butt diameter of the core of the electrode plus 2 [mm]
joints and horizontal-vertical fillets, only the test are to be butt welded together with one
detailed in 3.2 and 3.3 are required for initial downhand run of welding from each side. The
approval purposes. plates are to be not less than 100 [mm] wide
and of sufficient length to allow the cutting out of
3.1.2 Deep penetration electrodes will only be the test specimens of the correct number and
approved as complying with Grade 1 size as shown in Fig.3.2.1. Grade A steel is to
requirements. The suffix D.P. will be added. be used for these test assemblies. The joint
edges are to be prepared square and smooth
3.1.3 Where a manufacturer recommends that and, after tacking, the gap is not to exceed 0.25
an electrode having deep penetrating properties [mm].
can also be used for downhand butt welding of
thicker plates with prepared edges, the 3.2.2 The test assembly is to be welded using a
electrode will be treated as normal penetration 8 [mm] diameter electrode or the largest
electrode, and the full series of tests in the diameter size manufactured if this is less than 8
downhand position is to be carried out as per [mm].
normal penetration electrode, together with deep
penetration tests given in 3.2 and 3.3. 3.2.3 After welding the test assembly is to be cut
to form two transverse tensile test pieces, two
3.1.4 Where a manufacturer desires to bend test pieces and three Charpy V-notch test
demonstrate that an electrode in addition to its pieces as shown in Fig.3.2.1. The results of
use as normal penetration electrode also has tensile and impact testing are to comply with the
deep penetrating properties when used for requirements of Table 2.3.1 for Grade 1
downhand butt welding and horizontal - vertical electrodes.
fillet welding, the additional tests given in 3.2
and 3.3 are to be carried out. 3.2.4 The discards at the end of the welded
assemblies are to be not more than 35 [mm]
3.1.5 Where the manufacturer prescribes a wide. The joints of these discards are to be
different welding current and procedure for the polished and etched and must show complete
electrode when used as a deep penetration fusion and interpenetration of the welds. At each
electrode and a normal penetration electrode, cut in the test assembly the joints are also to be
the recommended current and procedure are to examined to ensure that complete fusion has
be used when making the test specimens in taken place.
each case.
35 mm
Discard
Charpy V-notch
30 mm 30 mm
Face bend
Root bend
50 mm
Transverse tensile
50 mm
Transverse tensile
35 mm
Discard
0.25 mm
max.
100 mm min. 100 mm min.
3.3 Deep penetration fillet weld test 3.3.2 The fillet weld on one side of the assembly
is to be carried out with 4 [mm] electrode and
3.3.1 A fillet weld assembly is to be prepared as that on the other side with the maximum size of
shown in Fig.3.3.1 with plates about 12.5 [mm] the electrode manufactured. The welding current
in thickness. The welding is to be carried out used is to be within the range recommended by
with one run for each fillet with plate A in the the manufacturer and the welding is to be
horizontal plane during the welding operations. carried out using normal welding practice.
The length of the fillet is to be 160 [mm] and the
gap between the plates is to be not more than 3.3.3 The welded assembly is to be cut by
0.25 [mm]. Grade A steel is to be used for these sawing or machining within 35 [mm] of the ends
test assemblies. of the fillet welds and the joints are to be
polished and etched. The welding of the fillet
made with a 4 [mm] electrode is to show a
penetration of 4 [mm] (See Fig.3.3.1) and the
corresponding penetration of the fillet made with
the maximum size of electrode manufactured is
to be reported.
Section 4
b) For use with two-run technique. 4.1.4 The welding current may be either a.c. or
d.c. (electrode positive or negative) according to
Where wire-flux combinations are suitable for the recommendation of the manufacturer. If both
welding with both the techniques, tests are to be a.c. and d.c. are recommended, a.c. is to be
carried out for each technique. used for the tests.
cutting. In the latter case any remaining scale is 4.3.6 Two longitudinal tensile and three impact
to be removed from the bevelled edges. test specimens are to be taken from each test
assembly as shown in Fig.4.3.1. Care is to be
4.3.3 The direction of deposition of each run is taken that the axes of the tensile test specimens
to alternate from each end of the plate and after coincide with the centre of the weld and the
completion of each run the flux and welding slag midthickness of the plates. The impact test
is to be removed. Between each run the specimens are to be cut perpendicular to the
assembly is to be left in still air until it has cooled weld with their axes 10 [mm] from the upper
to 250°C but not below 100°C, the temperature surface. The notch is to be positioned in the
being taken in the centre of the weld, on the centre of the weld and cut in the face of the test
surface of the seam. The thickness of the layer specimen perpendicular to the surface of the
is to be not less than the diameter of the wire plate.
but not less than 4 [mm].
4.3.7 The results of all tests are to comply with
4.3.4 The welding conditions (amperage, requirements of Table 4.3.1 as appropriate. The
voltage and rate of travel) are to be in chemical analysis of the deposited weld metal
accordance with the recommendations of the including the content of the significant alloying
manufacturer and are to conform with normal elements is to be submitted by the
good welding practice for multi-run welding. manufacturer.
200
10° Table 4.3.1 : Requirements for deposited
metal tests (wire-flux combinations)
20
Elon- Charpy V-
gation notch impact
12
Tensile on 50
Tack weld Yield Avg.
16
stren- mm
Grade stress Test ener
gth gauge
[N/mm2] temp. gy -
50 [N/mm2] length
°C J
%
min.
min.
1 20
400 -
2 305 22 0 34
560
Tensile 3 -20
1Y 20
2Y 490 - 0
375 22 34
3Y 660 -20
4Y -40
2Y40 0
510 -
30
12 to 15 [mm] and 20
For Grades 1 and 1Y
to 25 [mm]
30 For Grades 2, 2Y, 3, 20 to 25 [mm] and 30
3Y and 4Y to 35 [mm]
All dimensions in mm unless otherwise indicated
For Grades 2Y40, 20 to 25 [mm] and 30
3Y40 and 4Y40 to 35 [mm]
Fig. 4.3.1 : Deposited metal test assembly
4.5.3 Welding is to be carried out in the still air until it has cooled to less than 250°C but
downhand position, and the direction of not below 100°C, the temperature being taken in
deposition of each run is to alternate from each the centre of the weld, on the surface of the
end of the plate. After completion of each run, seam. The thickness of the layer is to be not
the flux and welding slag is to be removed. less than the diameter of the wire nor less than
Between each run the assembly is to be left in 4 [mm].
Section 5
Table 5.1.6 : Compositional limits of designated groups of gas types and mixtures
2) Approval covers gas mixtures with equal or higher Helium contents only.
5.2 Approval tests for two-run automatic prepared using plates approximately 20 [mm] in
welding thickness and the other using plates of
maximum thickness for which approval is
5.2.1 Approval tests for two-run automatic requested.
welding are to be carried out generally in
accordance with the requirements of Sec.4 5.2.4 The edge preparation of test assemblies is
using the two-run automatic welding technique to be as shown in Fig.5.2.1. Small deviations in
for the preparation of all test assemblies. the edge preparation may be allowed, if
requested by the manufacturer. For assemblies
using plates over 25 [mm] in thickness, the edge
preparation is to be reported for information.
5.4 Approval tests for multi-run automatic a) For deposited metal assemblies: One
welding tensile and three impact tests;
5.4.1 Approval tests for multi-run automatic b) For butt weld assemblies: One transverse
welding are to be carried out generally in tensile, two bend and three impact tests.
accordance with the requirements of Sec.4 One longitudinal tensile test is also required
using the multi-run automatic welding technique where the wire is approved solely for two-
for the preparation of all test assemblies. run automatic welding.
5.4.2 One deposited metal test assembly is to 5.6 Upgrading and uprating
be prepared as shown in Fig.4.3.1. Welding is to
be as detailed in Sec.4 except that thickness of 5.6.1 Requests for upgrading and uprating will
each layer is to be not less than 3 [mm]. generally be considered at the time of annual
testing and additional tests in accordance with
5.4.3 A butt weld assembly is to be prepared, as the requirements of 2.8 would be required.
shown in Fig.4.5.1.
Section 6
1500 mm min
(centre line)
tensile steel. Two assemblies prepared using
normal strength steel may also be required at 1 set of 3 charpy
V-notch test specimen
the discretion of IRS. (2 mm from fusion line)
6.2.3 Test series - 1 set with the notch at 2 [mm] from the
fusion line in the deposited metal; and
- Each assembly shall be cut to give test
specimens according to Fig.6.2.1. - 2 macro-sections of the weld (towards
the middle of the weld and towards one
The length of the assembly should be sufficient end).
to allow the selection of all the following test
specimens : 6.2.4 Results to be obtained
Section 7
7.1 General
Y69 for welding steels with minimum yield
2
7.1.1 Scope strength 690 [N/mm ]
7.1.1.1 These requirements supplement the Wire-flux combinations for single or two-run
requirements of Sections 1 to 6 and give the technique are subject to special consideration of
conditions of approval and inspection of welding IRS.
consumables used for high strength quenched
and tempered or TMCP steels for welded 7.1.2.2 Each of the six (yield) strength groups is
structures according to Ch.3, Sec.4 with yield further divided into three main grades in respect
2
strength levels from 420 [N/mm ] upto 690 of charpy V-notch impact test requirements (test
2
[N/mm ] and impact grades AH, DH, EH and temperatures):
FH.
Grade Test temperature
Where no special requirements are given, those 3 - 20°C
of Sections 1 to 6 apply in analogous manner.
4 - 40°C
7.1.1.2 The welding consumables preferably to 5 - 60°C
be used for the steels concerned are divided
into several categories as follows:
7.1.2.3 Analogously to the designation scheme
used in Section 1 to 6 the welding consumables
- covered electrodes for manual welding,
for high strength quenched and tempered steels
are subject to additional designation and
- wire-flux combinations for multirun sub- approval as follows:
merged arc welding,
- According to 7.1.2.2 with the quality grades
- solid wire-gas combinations for arc welding
3, 4 or 5.
(including rods for gas tungsten arc
welding), - With the added symbol Y and an appended
code number designating the minimum yield
- flux cored wire with or without gas for arc
strength of the weld metal corresponding to
welding.
7.1.2.1 : Y42, Y46, Y50, Y55, Y62 and Y69.
7.1.2 Grading, Designation
- With the added symbol HH or HHH for
controlled hydrogen content of the weld
7.1.2.1 Based on the yield strength of the weld
metal.
metal, the welding consumables concerned are
divided into six (yield) strength groups:
- With the added symbol S (= semi-automatic)
for semi-mechanised welding.
Y42 for welding steels with minimum yield
2
strength 420 [N/mm ] - With the added symbol M designating
multirun technique and is applicable only to
Y46 for welding steels with minimum yield
2 welding consumables for fully mechanised
strength 460 [N/mm ]
welding).
Y50 for welding steels with minimum yield
2 7.1.2.4 Each higher quality grade includes the
strength 500 [N/mm ]
one (or those) below, AH, DH steels according
to Ch.3, Sec.4 are to be welded using welding
Y55 for welding steels with minimum yield
2 consumables of at least quality grade, 3, grade
strength 550 [N/mm ]
EH steels using at least quality grade 4 and
grade FH steels using at least quality grade 5,
Y62 for welding steels with minimum yield
2 as per the following table:
strength 620 [N/mm ]
7.1.3.2 Testing and approval procedure shall be 7.3.2 Depending on the type of the welding
in accordance with Sec.1 and as required in consumables (and according to the welding
Section 1 to 6 for the individual categories process), the butt-weld test pieces called for in
(types) of welding consumables mentioned in para 7.3.1 shall be welded in a manner
7.1.1.2 above. analogous to that prescribed in Sections 1 to 6.
The base metal used shall be a high-strength
7.2 Testing of the weld metal fine-grained structural steel with an appropriate
minimum yield strength and tensile strength and
7.2.1 For testing the deposited weld metal, test compatible with the added symbol for which
pieces analogous to those called for in Sections application is made.
1 to 6 respectively shall be prepared, depending
on the type of the welding consumables (and 7.3.3 Depending on the type of the welding
according to the welding process). The base consumables (and according to the welding
metal used shall be a fine-gained structural steel process), the test specimens described in
compatible with the properties of the weld metal, Sections 1 to 6 shall be taken from the butt-weld
or the side walls of the weld shall be buttered test pieces.
with a weld metal of the same composition.
7.3.4 The mechanical properties must meet the
7.2.2 The chemical composition of the deposited requirements stated in Table 7.3.1. The
weld metal shall be determined and certified in a provisions of Sections 1 to 6 apply in analogous
manner analogous to that prescribed in Sec.2, manner to the performance of the tests,
Cl.2.2.4. The results of the analysis shall not including in particular the maintenance of the
exceed the limit values specified in the test temperatures in the notched bar impact test
standards or by the manufacturer, the narrower and the requirements regarding the retest
tolerances being applicable in each case. specimens.
1) The tensile strength of the weld metal may be upto 10% below the requirements, provided that the
results obtained with the transverse tensile specimens taken from the welded joints meet the
minimum tensile strength requirements stated in Table 7.3.1. The elongation is to be stated in the
test report.
Note: For welding very large plate thicknesses where the "supporting effect" of the base material on
either side of the weld no longer applies and the tensile strength of the weld metal also determines the
tensile strength of the welded joint, it may be necessary, when applying footnote 1), to chose welding
consumables of the next higher strength category (next higher added symbol).
Table 7.2.3 : Required strength properties for deposited metal used to weld high strength
extremely thick steel plates of thickness more than 50[mm] but not exceeding 100[mm], of EH47
grade used in container carriers,
7.3.5 Where the bending angle required in Table 7.3.6 Mechanical Properties for Butt weld tests
7.3.1 is not achieved, the specimen may be for high strength extremely thick steel plates of
considered as fulfilling the requirements, if the thickness more than 50[mm] but not exceeding
bending elongation on a gauge length Lo fulfills 100[mm], of EH47 grade used in container
the minimum elongation requirements stated in carriers are to be as per Table 7.3.2
Table 7.2.2. The gauge length Lo = Ls + t (Ls =
width of weld, t = specimen thickness), see
Fig.7.3.1.
Quality Added Min. tensile Min. notch impact Minimum Bend ratio
2)
Grade symbol strength energy, test bending D/t
2 1)
[N/mm ] temperature angle
Y42 530 4
Depending on the
3 to 5 in Y46 570 4
quality grade and
accordance Y50 610 4
yield strength in 120°
with Table Y55 670 5
accordance with
7.2.1 Y62 720 5
Table 7.2.1
Y69 770 5
1) Bending angle attained before the first incipient crack, minor pore exposures upto a maximum
length of 3 mm allowed.
Table 7.3.2 : Mechanical Properties for Butt weld tests for high strength extremely thick steel
plates of thickness more than 50[mm] but not exceeding 100[mm], of EH47 grade used in
container carriers
Section 8
8.1.2 The welding consumables are divided into 8.1.3 Approval will be indicated by the grade as
two categories as follows: shown in Table 8.1.3.
Table 8.1.3 : Consumables grades and base materials for the approval test
8.1.4 The welding technique will be indicated in 8.1.6 Approval of a wire or a rod will be granted
the approval grading by a letter as under: in conjunction with a specific shielding gas
according to Table 8.1.6 or defined in terms of
m - manual multi-run welding (GTAW); composition and purity of "special" gas to be
S - semi-automatic multi-run welding (GMAW); designated with group sign "S". The composition
M - automatic multi-run welding (GTAW or of the shielding gas is to be reported. Where a
GMAW); wire in combination with any particular gas has
T - automatic two-run welding (GMAW). been approved, usage of the same wire with
another gas in the same group as defined in
8.1.5 The compositions, of the shielding gas and Table 8.1.6 may be considered.
the filler/electrode wire are to be reported.
1) Gases of other chemical composition (mixed gases) may be considered as "special gases" and
covered by a separate test.
8.1.7 On completion of welding, assemblies specimens must not be subjected to any heat
must be allowed to cool naturally to ambient treatment after welding except for the alloy
temperature. Welded test assemblies and test Grades 6005A, 6061 and 6082. These are to be
allowed to naturally age at ambient temperature 8.2.2 The welding current and power
for a period of 72 hours from the completion of requirements are to be within the range
welding, before the testing is carried out. A recommended by the manufacturer and are to
second solution heat treatment is not permitted. be reported.
The time and temperature of any ageing
treatment is to be reported in detail. 8.2.3 Welded assemblies are to be prepared
and tested in accordance with 8.3, 8.4 and 8.5.
8.2 Initial approval tests for manual, semi-
automatic and automatic multi-run 8.3 Deposited metal test assemblies
techniques
8.3.1 One assembly is to be prepared in the
8.2.1 Plate of the corresponding type of downhand position as shown in Fig.8.3.1.
aluminium alloy and of appropriate thickness is
to be used for the preparation of the weld test 8.3.2 The chemical composition of the plate
assemblies. used for the assembly is to be compatible with
the weld metal.
8.3.3 The thickness of the plate used and the The direction of deposition of each layer is to
length of the assembly are to be appropriate to alternate from each end of the plate.
the welding process. The plate thickness is to be
not less than 12 [mm]. 8.3.7 The deposited weld metal in each test
assembly is to be analysed and reported
8.3.4 For the approval of filler wire/gas and including the contents of all significant elements.
electrode wire/gas combinations for manual or
semi-automatic welding by GTAW or GMAW, The elements reported will be dependent on the
one test assembly is to be welded using any type of aluminium alloy for which approval of the
size of wire within the range for which approval consumables is requested. The results of the
is sought. analysis are to be within the tolerances specified
in the standards and by the manufacturer.
8.3.5 For automatic multi-run approval, one test
assembly is to be welded by the respective 8.4 Butt weld test assemblies
process using the recommended diameter of
wire. 8.4.1 Plate of the corresponding type of
aluminium alloy and of an appropriate thickness
8.3.6 The weld metal is to be deposited in multi- is to be used for the preparation of the test
run layers in accordance with normal practice. assemblies.
Table 8.4.1 : Requirements for the transverse tensile and bend tests
1)
Grade Base material Tensile Former Bending angle
used for the test strength Rm diameter [°] min.
2
[N/mm ]
min.
RA/WA 5754 190 3t
RB/WB 5086 240 6t
RC/WC 5083 275
5383 or 5456 290 6t 180
5059 330
RD/WD 6061, 6005A or 6082 170 6t
1) During testing, the test specimen shall not reveal any one single flaw greater than 3 [mm] in any
direction. Flaws appearing at the corners of a test specimen shall be ignored in the evaluation, unless
there is evidence that they result from lack fusion.
8.4.2 In order to ensure sound and 8.4.3 One additional assembly, as shown in
representative welds, it is essential that test Fig.8.4.3, is to be prepared for welding in the
assemblies are cleaned and degreased prior to downhand position. The assembly is to be
welding. Assemblies as shown in Fig.8.4.2 are welded using, for the first run, wire of the
to be prepared for each welding position smallest diameter recommended by the
(downhand, horizontal-vertical, vertical-upward, manufacturer and for the remaining runs, wire of
vertical-downward and overhead) for which the the largest diameter to be approved.
consumable is recommended by the
manufacturer; except that consumables 8.4.4 The manufacturer's recommended
satisfying the requirements for downhand and procedures are to be used in making the welds
vertical-upward positions will be considered as and are to be reported.
also complying with the requirements for the
horizontal-vertical position. 8.4.5 The welded assemblies should be
subjected to both radiographic and visual
Back sealing runs are allowed in single V weld examination, aided where necessary by dye
assemblies. In case of double V assembly both penetrant testing, to ensure that the welds are
sides shall be welded with the same welding free from cracks and porosity.
position.
8.4.6 The test specimens are to be taken from 8.4.7 All tensile test specimens should have a
the welded assemblies as shown in Fig.8.4.2 tensile strength not less than the respective
and Fig.8.4.3. For each assembly they are to value shown in Table 8.4.1. The position of each
comprise: fracture is to be reported.
2 transverse tensile specimens; 8.4.8 The bend test specimens are to be bent
1 macro specimen; around a former having a diameter not more
2 face bend specimens; and than the number of times the thickness (t) of the
2 root bend specimens. test specimen as shown in Table 8.4.1.
8.5 Fillet weld test assemblies 8.6 Initial approval tests for two-run
technique
8.5.1 Assemblies are to be prepared and tested
in accordance with the appropriate requirements 8.6.1 Two butt weld test assemblies are to be
of 2.4 except that the plates are to be of the prepared using the following plate thicknesses
aluminium alloy for which approval is required, as shown in Fig.8.7.1:
that no hardness tests are required and that for
automatic multi-run approval only one fillet weld a) one with the maximum thickness for which
bead is to be made using the recommended approval is requested;
wire diameter. In this case, the bead size should
be as large as the maximum single bead size b) one with a thickness approximately one half
recommended by the manufacturer for fillet to two thirds that of the maximum thickness.
welding.
8.7 Annual tests
8.5.2 The results of examination of the macro
specimens and the fractured fillet welds are to 8.7.1 Annual repeat tests are to consist of
be reported in accordance with 2.4.3 and 2.4.5. preparation and testing of the deposited weld
Particular attention is to be given to the metal test assembly as prescribed in 8.3
presence of any porosity. (Fig.8.3.1) and of the downhand buttweld
assembly according to 8.4 (Fig.8.4.2).
End of Chapter
Part 3
General Hull Requirements
January 2014
Indian Register of Shipping
Part 3
Contents
Chapter 10 Bulkheads
Chapter 14 Rudders
Chapter 17 Welding
Contents
1.4 Stability
Section 3 : Documentation
1.5 Damage control plan and booklet for dry
cargo and passenger ships 3.1 General
1.6 Protective location of fuel oil tanks 3.2 Plans for information
2.2 Ships in normal world wide service 3.6 Corrosion protection coatings for salt water
ballast spaces and double side skin spaces
2.3 Structures exposed to low air temperatures
3.7 Corrosion protection for cargo oil tanks of
2.4 Refrigerated spaces crude oil tankers
4.1 General
Section 1 : General
Section 3 : Design Pressures and Forces
1.1 Scope
3.1 General
1.2 Symbols
3.2 External sea pressures
Section 2 : Ship Motions and Accelerations 3.3 Internal pressures on tank structures
2.1 Roll and pitch angles 3.4 Pressures due to dry cargoes, stores,
equipment and accommodation
2.2 Acceleration components
3.5 Forces due to heavy units of cargo and
2.3 Combined accelerations equipment
Section 1 : General
Section 4 : Shear Strength
1.1 Application
4.1 General
1.2 Symbols
4.2 Side shell and longitudinal bulkheads
1.3 Terms thickness requirement
2.1 Still water bending moment and shear force 5.1 Locations
2.2 Wave bending moment and shear force 5.2 Deductions for openings
5.3 Reinforcements
Section 3 : Hull Section Modulus and
Moment of Inertia 5.4 Hatchway corners
Section 1 : General
Section 4 : Side Shell Plating and Stiffeners
1.1 Scope
4.1 Side shell plating
1.2 Symbols
4.2 Side shell longitudinals
Chapter 10 : Bulkheads
4.3 Wash bulkheads loads 5.4 Vertical and transverse stiffeners on ordinary
watertight bulkheads
1.4 Corrosion addition for hatch covers and 4.3 Securing devices
hatch coamings
4.4 Hatch cover supports, stoppers and
supporting structures
Section 2 : Hatch Coamings
2.6 Further requirements for hatch coamings 5.6 Securing and locking arrangement
7.4 Hatchways within enclosed super-structure 7.6 Openings on engine and boiler casing
and tween decks
7.7 Windows and side scuttles
Section 1 : General
Section 3 : Air and Sounding Pipes
1.1 Scope
3.1 General
1.2 Definitions
3.2 Height of air pipes
1.3 Protection
3.3 Closing appliances
1.4 Strength of attachments of fore deck fittings
2.3 Closing appliances 4.3 Materials for valves, fittings and pipes
Chapter 14 : Rudders
Section 1 : General
4.3 Single plated rudders
1.1 Scope
Section 5 : Rudder Stock and Pintles
1.2 Material
5.1 Rudder stock
1.3 Testing
5.2 Pintles
Section 2 : Arrangement and Details
5.3 Bearings of rudder stock / rudder shaft /
2.1 General pintle
Section 1 : General
Section 5 : Anchor Chain Cables
1.1 Introduction
5.1 General
1.2 Design of the anchoring equipment
5.2 Manufacture and testing
1.3 Documentation
4.2 High Holding Power (HHP) anchors 7.2 Strength of windlass securing arrangements
to resist the green sea loads
4.3 Super High Holding Power (SHHP) anchors
7.3 Testing
4.4 Manufacture and testing
1.3 Materials
Section 3 : Rigging
3.1 General
Chapter 17 : Welding
1.2 Documentation
Section 3 : Welded Connections
End of Chapter
Chapter 1
Contents
Section
1 General
2 Definitions
3 Documentation
Section 1
General
1.1.1 The Rules in this part apply to all-welded, 1.3.1 While the Rules cover requirements for the
single hull sea going steel ships of normal form, classification of ships, the attention of all
proportions and speed. concerned is drawn to requirements of various
local, national or international Regulations,
1.1.2 For additional class notations relating to Codes and Recommendations which the vessel
various ship types, requirements as per Pt.5 are may also have to comply with.
to be complied with.
1.4 Stability
1.1.3 Ships of unconventional forms and
proportions or intended for carriage of cargoes 1.4.1 All ships with a length of 24 [m] and above
not covered by the Rules or to be engaged in will be assigned class only after it has been
special service will receive individual demonstrated that their intact stability and
consideration based on the general principles of damage stability (where applicable) are in
the Rules. In these cases, however, additional compliance with the standards laid down by the
calculations and/or model testing may be National statutory authority. The level of intact
required to be carried out and submitted for stability and damage stability in any case should
approval. not be less than that required by IMO
instruments given in 1.4.2 and 1.4.3 respectively
1.1.4 Proposals for use of alternative materials as appropriate.
e.g. aluminium, wood, etc. for some parts of the
ship shall receive special consideration. 1.4.2 Intact stability is to be as per the
requirements of Chapters 1, 2 and 3 of Part A of
1.2 Equivalence the International Code on Intact Stability, 2008
(Resolution MSC 267(85)).
1.2.1 Alternative arrangements, scantlings and
equipment may be accepted provided they can For the following types of ships, in case the
be shown to be equivalent to the overall safety Administration concerned has not laid down
and strength standard of the Rules. Direct criteria for intact stability, it is recommended that
calculations for the derivation of the scantlings the criteria indicated below or their equivalents
as an alternative to those derived by the Rule are satisfied:
formulae, may be accepted on special
consideration. The calculation procedure and - For pontoons of all sizes : Ch.2, Sec 2.2 of
the assumptions made are to be submitted for Part B of the International Code on Intact
approval. Stability, 2008 (Resolution MSC 267(85)).
1.4.3 All ships are required to comply with the 1.4.4 An approved stability information manual
applicable damage stability requirements in is to be available on board for guidance to the
accordance with the following: master as to the stability of the ship under
varying conditions of service. This is to be
a) Part B and Part B-1 through B-4 of Chapter prepared on the basis of MSC Circular 920
II-1 of SOLAS 1974 as adopted by IMO “Model Loading and Stability Manual”.
Resolution MSC 216(82) for passenger
ships regardless of length and cargo ships Additionally, full details of the stability criteria
having load line length “LL” of 80 [m] and appropriate to the ship under all anticipated
above. conditions of service are to be clearly stated in
text supplemented by diagrams using the
Cargo ships which are shown to comply with nomenclature adopted in the manual. Full
any other damage stability regulations details of any requirements for wind and/or wave
indicated in the following (1.4.3 b) to g)) are forces and ice accretion specified by the
excluded from the applicability of the above. Administration are also to be provided.
b) Regulation 27 of ILLC 1966 as applied to 1.5 Damage control plan and booklet for dry
tankers and dry cargo vessels in compliance cargo and passenger ships
with Resolutions A.320(IX) and A.514(13)
provided that in the case of ships to which 1.5.1 Plan : The damage control plan is to
regulation 27(9) applies, main transverse include inboard profile, plan views of each deck
watertight bulkheads, to be considered and transverse sections to the extent necessary
effective, are spaced according to to show the following:
paragraph 12(f) of resolution A.320(IX).
Compliance with Reg.27 of ILLC Protocol - the watertight boundaries of the ship;
1988 is accepted as equivalent to the
above. - the locations and arrangements of cross-
flooding systems and any other system for
In case ships for which Reg.27 of ILLC correction of list;
applies are intended to carry deck cargo
also, then a limiting GM or KG curve is to be - the locations of all internal watertight closing
provided to the master in the stability appliances including on ro-ro ships, internal
manual based on compliance with the ramps or doors and their controls, position
probabilistic damage stability analysis of indicators, alarms and special precautions
SOLAS Chapter II-1 Part B-1. In such cases required, if any, for the closing appliances
the KG used for demonstrating compliance during voyage;
with the deterministic damage stability
requirements of ILLC Reg.27 should be - the locations of all doors in the shell of the
same as that used for the probabilistic ship, position indicators, leakage detection
damage stability calculations required by and surveillance devices;
SOLAS Ch.II-1 Part B-1 at the deepest
subdivision loadline. - the locations of all weathertight closing
appliances in local subdivision boundaries
c) Annex I (Regulation 28) of MARPOL above the bulkhead deck and on the lowest
1973/78, for Oil Tankers except that exposed weather decks, together with
combination carriers with Type B freeboard locations of controls and position indicators,
are not excluded. if applicable;
d) IBC Code, as amended for Chemical - the locations, arrangement and control
Tankers in general. positions of the entire bilge and ballast
system.
e) IGC Code, as amended for Liquefied Gas
Carriers. 1.5.2 Booklet : The damage control booklet is to
contain aforementioned information as in the
f) Resolution MSC 235(82) for Offshore plan and in addition general instructions for
Supply Vessels. controlling the consequential effects of damage
as follows:
g) Resolution MSC 266(84) for Special
Purpose Ships. - shutting off the closing appliances;
- ensuring the safety of personnel onboard; 1.5.4 For cargo ships the plan is to be
permanently exhibited or readily available on the
- ascertaining extent of damage and rates of navigating bridge and in the cargo control room,
flooding by sounding; where applicable.
- cautionary advise regarding causes of any 1.6 Protective location of fuel oil tanks
list; required liquid transfer operations to
lessen list or trim and the resulting effects of 1.6.1 All ships with an aggregate oil fuel
3
additional free surfaces; capacity of 600 [m ] and above are to satisfy the
requirements for oil fuel tank protection as given
- initiating pumping operations to control the in MARPOL Reg.I/12A. For this purpose, the
ingress of water; distances of the oil fuel tanks above the bottom
shell and inboard of the side shell are to be not
The booklet should provide: less than the values specified in the above
MARPOL Regulation.
- details of sounding devices, tank vents and
overflows; Alternatively, such ships may comply with the
accidental oil outflow performance standard
- pump capacities and piping diagrams; specified in paragraph 11 of MARPOL Reg.
I/12A.
- operating procedure of cross-flooding
system; 1.6.2 Small oil fuel tanks of capacity not greater
3
than 30 [m ] are exempted from the
- locations of non-watertight openings with requirements for protective location of the above
non-automatic closing devices through MARPOL Regulation provided the aggregate
which progressive flooding can occur; capacity of such exempted tanks is not greater
3
than 600 [m ].
- details of access and means of escape for
personnel to and from compartments; 1.7 Assumptions
- procedure for alerting ship management and 1.7.1 It is assumed that significant dynamic
other organisations for obtaining and co- excitation of major orders from propellers and
ordinating assistance; machinery do not fall close to any natural
frequency of the hull.
1.5.3 For passenger ships, the plan is to be
permanently exhibited on the navigating bridge, 1.7.2 It is assumed that the ships will be
as well as in the ship's control station, or competently handled and loaded as per the
equivalent. approved loading manuals.
Section 2
Definitions
2.1 Principal particulars rudder post or the centreline of the rudder stock
if there is no rudder post.
2.1.1 The forward perpendicular, F.P., is the
perpendicular drawn at the intersection of the In ships with unusual stern arrangement the
summer load water line with the fore side of the position of the A.P. will be specially considered.
stem.
2.1.3 Rule length, L, is the distance, [m],
In ships with unusual bow arrangement the between the forward and after perpendiculars.
position of the F.P. will be specially considered. However L is to be not less than 96 per cent,
and need not be greater than 97 per cent of the
2.1.2 The after perpendicular, A.P., is the extreme length on the summer load waterline.
perpendicular drawn at the intersection of the
summer load waterline with the after side of the
In ships with unusual bow and/or stern openings on the sides of the ship are fitted
arrangement the Rule length, L, will be specially with means for watertight closing.
considered.
- Superstructure : A decked structure on
2.1.4 "Amidship" is at 0.5L aft of the F.P. freeboard deck extending from side to side
of the ship or with the side plating not
2.1.5 Breadth, B, is the greatest moulded inboard of shell plating by more than 4 per
breadth [m]. cent of the breadth B.
2.1.6 Depth, D, is the moulded depth [m], - Deckhouse : A decked structure above the
measured amidships from top of the keel to the freeboard deck with the side plating being
moulded deck line of the uppermost continuous inboard of the shell plating by more than 4
deck at side. When a rounded gunwale is per cent of the breadth B.
arranged the depth is to be measured to the
continuation of the moulded deck line. - Bottom Structure : Shell plating with
stiffeners and girders below the upper turn
2.1.7 Draught, T, is the moulded draught of bilge and all other elements below and
amidships corresponding to the summer load including the inner bottom plating in case of
waterline, [m]. the double bottom. Sloping hopper tank top
is to be regarded as a bulkhead.
2.1.8 The block co-efficient, Cb, is the moulded
block co-efficient calculated as follows :- - Side Structure : Shell plating with stiffeners
and girders between the upper turn of bilge
and the uppermost continuous deck at side.
moulded displacement [m 3 ] at draught T
Cb = A rounded gunwale is included in the side
LBT structure.
2.1.9 Load line length, LL , is to be taken as 96
per cent of the total length [m], on a waterline at - Deck Structure : Deck plating with stiffeners,
85 per cent of the least moulded depth girders, and supporting pillars.
measured from the top of the keel, or as the
length from the fore side of the stem to the axis - Girder : A collective term for the primary
of the rudder stock on that waterline, if that is supporting members, other terms include :
greater. In ships designed with a rake of keel,
the waterline on which this length is measured is - Transverses - transverse girders under
to be parallel to the designed waterline. the deck.
2.1.10 Speed, V, is the maximum service speed - Web frames - side vertical girders.
in knots on draught T.
- Hatch end beams - transverse deck
2.2 Structural terms girders at the ends of the hatch.
2.2.1 The general terms used in the Rules for - Stringers - horizontal girders.
various structural parts of the ships are defined
as under: - Cross-ties - girders connecting two
vertical girders in a deep tank.
- Strength Deck : In general the uppermost
continuous deck. Where a superstructure - Floor - bottom transverse girders.
deck has within 0.4L amidships, a
continuous length equal to or greater than - Stiffener : A collective term for secondary
(1.5B + 3H), it is to be regarded as the supporting members; other terms being :
strength deck instead of the covered part of
the uppermost continuous deck. (H is the - Frames.
height of the superstructure, [m]).
- Bottom, inner bottom, side or deck
- Freeboard Deck : The freeboard deck is longitudinals.
normally the uppermost complete deck
exposed to weather and sea, which has - Reverse frame - transverse stiffener on
permanent means of closing all openings in the inner bottom.
the weather part and below which all
Section 3
Documentation
3.1.1 Documentation is to be submitted as per 3.4.1 Plans as relevant are to be submitted for
the following paragraphs. In case of certain ship approval as indicated in Table 3.4.1. These
types additional documentation may be required should as far as practicable be complete in all
as per Pt.5. necessary details.
- Stowage factor and angle of repose of bulk 3.5.2 To facilitate the ordering of materials for
cargoes to be carried. repairs, the above plans are to show the
disposition and extent of high strength steel and
- Masses and unbalanced moments of heavy steel of grades other than Grade A, along with
machinery components e.g. engines, the information relating to their physical and
cranes, winches etc. mechanical properties, recommended working,
treatment and welding procedures etc.
3.5.3 A ship construction file is required to be e) Tank testing plan including details of the
maintained on board the ship to facilitate test requirements;
inspection (survey) and repair and maintenance
in future. f) Corrosion protection specifications;
The ship construction file to contain : g) Details for the in-water survey, if
applicable, information for divers,
a) Plans as mentioned at 3.5.1; clearances measurements instructions
etc. tank and compartment boundaries;
b) Essential certificates and records;
h) Docking plan and details of all
c) Manuals required for classification and penetrations normally examined at
statutory requirements; drydocking;
d) Details of equipment forming part of the i) Coating technical file, for ships subject
watertight and weathertight integrity of to compliance with the IMO Coating
the ship; Performance Standard (PSPC). (See
Part 3, Chapter 2, Section 3.6).
Welding details
Note:
End of Chapter
Chapter 2
Materials of Construction
Contents
Section
1 General
2 Use of Steel Grades
3 Corrosion Protection
4 Deck Covering
Section 1
General
1.1 Scope
k = 0.72 for steel with minimum yield stress of
2
1.1.1 The Rules relate, in general, to the 355 [N/mm ]
construction of steel ships. Consideration will
however be given to the use of other materials k = 0.68 for steel with minimum yield stress of
2
also. 390 [N/mm ].
1.1.2 The materials used in the construction of 1.2.3 Where steel castings or forgings are used
the ship are to be manufactured and tested in for sternframes, rudderframes, rudder stocks,
accordance with the requirements of Pt.2. propeller shaft brackets and other major
Materials for which provision is not made in Pt.2 structural items, they are to comply with Pt.2 as
may be accepted, provided that they comply appropriate.
with an approved specification and such tests as
may be considered necessary. 1.3 Aluminium
1.2.2 Steels having a yield stress of 265 section modulus of stiffeners, Za = Zs.ka
2
[N/mm ] and higher, are regarded as higher
tensile steels. Where higher tensile steel is where,
used, the hull girder section modulus and the
local scantlings may be reduced in accordance ta, ts = plating thickness of aluminium and mild
with the relevant requirement of the Rules. For steel respectively.
this purpose, a material factor 'k', is to be taken
as follows: Za, Zs = section modulus of aluminium and mild
steel stiffeners respectively.
k = 0.78 for steel with a minimum yield stress of
2
315 [N/mm ]
235
k =
a σa 1.3.2 The smaller modulus of elasticity of
aluminium is to be taken into account, when
σa = 0.2% proof stress of the aluminium alloy in determining the buckling strength of structural
the welded condition or 70% of the ultimate elements subjected to compression and the
strength in the welded condition, whichever is deflections, where relevant.
2
lesser [N/mm ].
Section 2
Table 2.2.1b) : Minimum material grades for ships with length exceeding 150 m and
single strength deck
Table 2.2.1c) : Minimum material grades for ships with length exceeding 250 m
Table 2.2.1d) : Minimum material grades for single-side skin bulk carriers subjected to
SOLAS Regulation XII/6.5.3 (3)
Table 2.2.1e) : Minimum material grades for ships with ice strengthening
Class I II III
Thickness MS HT MS HT MS HT
[mm]
t ≤ 15 A AH A AH A AH
15 < t ≤ 20 A AH A AH B AH
20 < t ≤ 25 A AH B AH D DH
25 < t ≤ 30 A AH D DH D DH
30 < t ≤ 35 B AH D DH E EH
35 < t ≤ 40 B AH D DH E EH
40 < t ≤ 50 D DH E EH E EH
Notes:
1. For strength members not mentioned in Table 2.2.1a) to Table 2.2.1e), grade A/AH may generally be
used.
2. The steel grade is to correspond to the as-built plate thickness when this is greater than the rule
requirement.
3. Plating materials for sternframes, rudders, rudder horns and shaft brackets are in general not to be of
lower grades than corresponding to class II. For rudder and rudder body plates subjected to stress
concentrations (e.g. in way of lower support of semi-spade rudders or at upper part of spade rudders)
class III is to be applied.
2.3 Structures exposed to low air tempera- MDAT = Mean Daily Average Temperature
tures
MDLT = Mean Daily Low (or minimum)
2.3.1 For ships intended to operate in areas with Temperature.
low air temperatures (below and including -
20°C), e.g. regular service during winter For seasonally restricted service the lowest
seasons to Arctic or Antarctic waters, the value within the period of operation would be
materials in exposed structures are to be applicable.
selected based on the design temperature tD as
defined in 2.3.2. 2.3.3 Materials in the various strength members
above the lowest ballast water line (BWL)
2.3.2 The design temperature tD is to be taken exposed to air are not to be of lower grades than
as the lowest mean daily average air those corresponding to classes I, II and III as
temperature in the area of operation as given in Table 2.3.3, depending on the
illustrated in Fig.2.3.2. categories of structural members
(SECONDARY, PRIMARY and SPECIAL). For
Mean : Statistical mean over observation non-exposed structures and structures below
period (at least 20 years). the lowest ballast water line, See 2.2.
Average : Average during one day and night. 2.3.4 The material grade requirements for hull
members of each class depending on thickness
Lowest : Lowest during year. and design temperature are defined in Table
2.3.5. For design temperatures tD < -55°C,
MDHT = Mean Daily High (or maximum) materials will be specially considered.
Temperature
Material class/grade
Structural member category Within 0.4L amidships Outside 0.4L amidships
SECONDARY:
• Deck plating exposed to weather, in
general I I
• Side plating above BWL
• Transverse bulkheads above BWL
PRIMARY:
• Strength deck plating (see Note 1)
• Continuous longitudinal members
above strength deck, excluding II I
longitudinal hatch coamings
• Longitudinal bulkhead above BWL
• Top wing tank bulkhead above NWL
SPECIAL:
• Sheer strake at strength deck (see
Note 2)
• Stringer plate in strength deck (see
Note 2) III II
• Deck strake at longitudinal bulkhead
(see Note 3)
• Continuous longitudinal hatch
coamings (see Note 4)
Notes:
1. Plating at corners of large hatch openings to be specially considered. Class III or grade E/EH to be
applied in positions where high local stresses may occur.
2. Not to be less than grade E/EH within 0.4L amidships in ships with length exceeding 250 [m].
3. In ships with breadth exceeding 70 [m] at least three deck strakes to be class III.
4. Not to be less than grade D/DH.
Table 2.3.4 : Material grade requirements for classes I, II and III at low temperatures
Class I
Plate
thickness -20/-25°C -26/-35°C -36/-45°C -46/-55°C
[mm]
MS HT MS HT MS HT MS HT
t ≤ 10 A AH B AH D DH D DH
10 < t ≤ 15 B AH D DH D DH D DH
15 < t ≤ 20 B AH D DH D DH E EH
20 < t ≤ 25 D DH D DH D DH E EH
25 < t ≤ 30 D DH D DH E EH E EH
30 < t ≤ 35 D DH D DH E EH E EH
35 < t ≤ 45 D DH E EH E EH X FH
45 < t ≤ 50 E EH E EH X EH X FH
Class II
Plate
thickness -20/-25°C -26/-35°C -36/-45°C -46/-55°C
[mm]
MS HT MS HT MS HT MS HT
t ≤ 10 B AH D DH D DH E EH
10 < t ≤ 20 D DH D DH E EH E EH
20 < t ≤ 30 D DH E EH E EH X FH
30 < t ≤ 40 E EH E EH X FH X FH
40 < t ≤ 45 E EH X FH X FH X X
45 < t ≤ 50 E EH X FH X FH X X
Class III
Plate
thickness -20/-25°C -26/-35°C -36/-45°C -46/-55°C
[mm]
MS HT MS HT MS HT MS HT
t ≤ 10 D DH D DH E EH E EH
10 < t ≤ 20 D DH E EH E EH X FH
20 < t ≤ 25 E EH E EH X FH X FH
25 < t ≤ 30 E EH E EH X FH X FH
30 < t ≤ 35 E EH X FH X FH X X
35 < t ≤ 40 E EH X FH X FH X X
40 < t ≤ 50 X FH X FH X X X X
Notes:
1. X = Not applicable.
2. Single strakes required to be of class III or of grade E/EH of FH are to have breadths not less than
800 + 5.L [mm] maximum 1800 [mm].
3. Plating materials for sternframes rudder horns, rudders and shaft brackets are not to be of lower
grades than those corresponding to the material classes given in Sec.2.2.
Table 2.4.1 : Grades of steel for minimum design temperatures below 0°C
Where one of the internal spaces concerned is not refrigerated, the temperature of the space is to be
taken as 5°C.
Section 3
Corrosion Protection
3.1 General
3.2.5 Tests as follows are to be taken from each
3.1.1 All steelwork, except inside tanks intended test assembly:-
for the carriage of oil or bitumen, is to be
protected against corrosion by application of a) Radiographs - These are to have a
suitable coating. sensitivity of better than 2 per cent of the
plate thickness under examination, as
For protection required in salt water ballast shown by an image quality indicator.
spaces, See 3.6.
b) Photo-macrographs - These may be of
For protection required in holds of dry bulk cargo actual size and are to be taken from near
carriers, see Pt.5, Ch.1, Sec. 2.11. each end and from the centre of the weld.
For the protection required in tanks carrying c) Face and reverse bend test - The test
chemicals or other special cargoes, See Pt. 5, specimens are to be bent by pressure or
Ch.3. hammer blows round a former of diameter
equal to 3 times the plate thickness.
3.1.2 Where bimetallic connections are made,
measures are to be incorporated to preclude d) Impact tests - These are to be carried out at
galvanic corrosion. ambient temperature, on three Charpy V-
notch test specimens prepared in
3.2 Surface preparation, prefabrication accordance with Pt.2. The specimens are to
primers and paints or coatings be notched at the centreline of the weld,
perpendicular to the plate surface.
3.2.1 Steelwork is to be cleared of millscale and
suitably cleaned before the application of 3.2.6 The tests are to be carried out in the
surface paints and coatings. It is recommended presence of a Surveyor of IRS or by an
that blast cleaning or other equally effective independent laboratory specializing in such
means be employed for this purpose. work. A copy of the test report is to be
submitted, together with radiographs and
3.2.2 Where a primer is used to coat steel after macrographs.
surface preparation and prior to fabrication, the
composition of the coating is to be such that it 3.2.7 Paints or other coatings are to be suitable
will have no significant deleterious effect on for the intended purpose in the locations where
subsequent welding work and that it is they are to be used. Unless previously agreed,
compatible with the paints or other coatings at least two coats are to be applied.
subsequently applied.
3.2.8 The paint or coating is to be compatible
3.2.3 To determine the influence of the primer with any previously applied primer, See 3.2.2.
coating on the characteristics of welds, tests are
to be made as detailed in 3.2.4 to 3.2.6. 3.2.9 Paints, varnishes and similar preparations
having a nitrocellulose or other highly flammable
3.2.4 Three butt weld assemblies are to be base, are not to be used in accommodation or
tested using plate material 20 to 25 [mm] thick. machinery spaces.
A 'V' preparation is to be used and, prior to
welding, the surfaces and edges are to be 3.2.10 In ships intended for the carriage of oil
treated as follows:- cargoes having a flash point below 60°C (closed
cup test), paint containing aluminium should not
a) Assembly 1 - Coated in accordance with the in general be used in cargo tanks, adjacent
manufacturer's instructions. ballast tanks, cofferdams, pump rooms as well
as on deck above the mentioned spaces, nor in
b) Assembly 2 - Coated to a thickness any other areas where cargo vapours may
approximately twice the manufacturer's accumulate, unless it has been shown by
instructions. appropriate tests that the paint to be used does
not increase the incentive sparking hazard.
c) Assembly 3 - Uncoated.
b) Steel core bolted to separate supports, 3.5.1 Suitable protection for the underwater
provided that a minimum of two bolts with portion of the hull is to be provided.
lock nuts are used at each support. The
separate supports are to be connected to 3.5.2 Where an impressed current cathodic
the structure by continuous welding of protection system is fitted, plans showing the
adequate section. proposed layout of anodes, reference cells,
wiring diagram and the means of bonding-in of
c) Approved means of mechanical clamping. the rudder and propeller, are to be submitted.
3.3.5 Anodes are to be attached to stiffeners, or 3.5.3 The arrangements for glands, where
may be aligned in way of stiffeners on plane cables pass through the shell, are to include a
bulkhead plating, but they are not to be attached small cofferdam. Cables to anodes are not to be
to the shell. The two ends are not to be attached led through tanks intended for the carriage of
to separate members which are capable of low flash point oils. Where cables are led
relative movement. through cofferdams or clean ballast tanks of
tankers, they are to be enclosed in a substantial
3.3.6 Where cores or supports are welded to the steel tube of about 10 [mm] thickness.
main structure, they are to be kept clear of the
toes of brackets and similar stress raisers. 3.6 Corrosion protection coatings for salt
Where they are welded to asymmetrical water ballast spaces and double side skin
stiffeners, they are to be connected to the web spaces
with the welding kept at least 25 [mm] away
from the edge of the web. In the case of 3.6.1 The following spaces are to be coated
stiffeners or girders with symmetrical face during construction in accordance with the
plates, the connection may be made to the web Performance Standards for Protective Coatings
or to the centreline of the face plate but well (PSPC) adopted by the IMO by Resolution
clear of the free edges. However, it is MSC.215(82), as per applicability indicated in
recommended that anodes are not fitted to face 3.6.2.
plates of high strength steel longitudinals.
a) Dedicated salt water ballast tanks in all follow the requirements of IMO Resolution
ships of 500 GT and above. A.798(19) and contain, as a minimum the
following documentation:
b) Double side skin spaces in bulk carriers
of LL ≥ 150 m. - Owner’s, coating manufacturer’s and
shipyard’s explicit agreement to the
The following tanks are not considered to be scheme for coating selection,
dedicated salt water ballast tanks and therefore application and maintenance.
need not comply with the requirement of IMO
PSPC: - List of seawater ballast tanks identifying
the coating system for each tank,
i) Salt water ballast tanks identified as “Spaces including coating color and whether
included in Net Tonnage” in the 1969 coating system is a hard coating.
International Tonnage Convention Certificate;
- Details of anodes, if used.
ii) Salt water ballast tanks in passenger vessels
also designated for the carriage of grey water. - Manufacturer’s technical product data
sheet for each product.
3.6.2 The IMO Performance Standards for
Protective Coatings (PSPC) are to be applied to - Manufacturer’s evidence of product
ships as follows: quality and ability to meet owner’s
requirements.
i) In case of bulk carriers and tankers that are
subject to the IACS common structural rules: - Evidence of shipyard’s and/or its
subcontractor’s experience in coating
- which are contracted for construction on application.
or after 8 December, 2006.
- Surface preparation procedures and
ii) In case of all ships other than those standards, including inspection points
mentioned in i) above: and methods.
ii) Protected by alternative means of 3.7.3 The Administration may exempt a crude oil
corrosion protection or utilization of tanker from the requirements of 3.7.1 to allow
corrosion resistance material to the use of prototype alternatives to the coating
maintain required structural integrity for system specified in 3.7.1 i), for testing, provided
25 years in accordance with the they are subject to suitable controls, regular
performance standard for alternative assessment and acknowledgement of the need
means of corrosion protection for cargo of immediate remedial action if the system fails
oil tanks of crude oil tankers, adopted by or is shown to be failing. Such exemption is to
the IMO by Resolution MSC. 289(87). be recorded on an exemption certificate.
3.7.2 The requirements given in 3.7.1 are to be 3.7.4 The Administration may exempt a crude oil
applied for crude oil tanker greater than 5000 tanker from the requirement of 3.7.1 if the ship is
tonnes deadweight where : built to be engaged solely in the carriage of
cargoes and cargo handling operations not
st
i) Building contract is placed on or after 1 causing corrosion. Such exemption and
January 2013; conditions for which it is granted is to be
recorded on an exemption certificate. (See
ii) In absence of building contract, the MSC.1/Circ.1421 “Guidelines on exemption for
keels of which are laid or which are at a crude oil tankers solely engaged in the carriage
similar stage of construction on or after of cargoes and cargo handling operations not
st
1 July 2013; causing corrosion”).
st
iii) Or the delivery of which is on or after 1
January 2016.
Section 4
Deck Covering
End of Chapter
Chapter 3
Contents
Section
1 General
2 Corrosion Additions
3 Plating
4 Stiffeners and Girders
5 End Attachments
6 Buckling
Section 1
General
1.3.2 Elsewhere, the frame spacing is generally 700 [mm] or as in 1.3.1, whichever is lesser.
not to exceed the following:
1.3.3 Where the actual frame spacing is higher
- In peaks and cruiser sterns: than that mentioned above, the minimum
thicknesses of various structural members as
600 [mm] or as in 1.3.1, whichever is lesser. given in the Rules may require to be increased.
Corrosion Additions
Section 3
Plating
3.1 General
= 1.10 − 0.5(s/1000 l ) 2 ;
3.1.1 Minimum requirements of thickness of
various platings are given in relevant chapters. however, not to be taken more than 1.0.
3.1.2 The thickness 't' of plating subjected to fr = correction factor for curvature perpendicular
lateral pressure is not to be less than to the stiffeners
s p = (1 - 0.5 s/r)
t=f f + t [mm]
a r 2 σ c 3.1.3 Any tapering of thickness of platings
contributing to the longitudinal strength is to be
where, based upon linear variation of stress σ allowed
at specified regions.
fa = correction factor for aspect ratio of plate
field;
Section 4
4.2.5 The effective cross sectional area of the be taken as 12 for continuous longitudinal
attached plating is not to be less than that of the girders and 10 for all other girders.
face plate.
4.4.3 The effective cross sectional area of the
4.3 Scantlings of stiffeners girder web is to be taken as :
2
4.3.1 The section modulus 'Z' of stiffeners Aw = 0.01 hn tw [cm ]
subjected to lateral pressure is not to be less
than: where,
4.3.2 Where stiffeners are not perpendicular to Fig.4.4.3 : Effective web area of girders
the plating, the section modulus as obtained
from 4.3.1 is to be increased by the factor (1/cos
α), α being the angle between the stiffener web Where the girder flange is at angle θ to the
and the plane perpendicular to the plating. length of the girder, Aw may be taken as:
4.4 Scantlings of girders
Aw = 0.01 hn tw + 1.3 a Sin 2θ Sin θ [cm ]
2
deep girders, value of Sw may be taken as 90% asymmetrical section or at every fourth stiffener
of the actual spacing. in case of symmetrical section. Tripping
brackets are also to be fitted at the toes of end
The web stiffeners may be flat bars of same brackets and in way of concentrated loads such
thickness as that of the web and 1/10 of the as heels of pillars or cross ties.
height of girder, in depth.
Where the width of face plate on one side of the
4.4.5 Where openings are cut in the girder web, web exceeds 15 tf, the tripping brackets are to
they are to be away from the girder ends and be connected to the face plate.
scallops for stiffeners; with their centre located
as near to the neutral axis of the girder as The tripping brackets are to be adequately
practicable. Openings of depth exceeding 25% dimensioned at base and are to have a smooth
of the girder depth or 300 [mm] and, of length transition to the adjoining stiffeners. The free
exceeding the depth of the girder or 60% of the edge of the tripping bracket is to be stiffened if
secondary stiffener spacing, are to be reinforced it's length exceeds 60t [mm]. Additional
all around at the edge; or alternatively by stiffeners are to be fitted parallel to the free edge
providing horizontal and vertical stiffeners. to ensure that the arm length of an unstiffened
triangular end panel does not exceed 100t [mm].
4.4.6 Girders are to be provided with adequate
lateral stability by tripping brackets fitted
generally at every alternate stiffener in case of
Section 5
End Attachments
5.1.2 Scantlings of brackets fitted on stiffeners - Width of flange, w ≥ 40 + Z/25 [mm], but not
not participating in the longitudinal strength are to be less than 50 [mm].
not to be less than the following:
where,
- The arm lengths, 'a and b' (See Fig.4.1.1) 3
are to be such that: Z is the section modulus [cm ], of the
smaller stiffener, being connected.
i) a, b ≥ 0.8 lb
kb, ks are the material factors for the
and bracket and the stiffener, respectively.
Section 6
Buckling
6.1 General
= 0.9 for torsional and web buckling mode of
6.1.1 The critical buckling stress 'σcr' of plate longitudinals
panels and stiffeners and other members to
compressive loads is to be such that: 0.7
= (need not be taken smaller than 0.3);
1 + l m /i
σc
σ cr ≥
η - for axially loaded members such as pillars,
cross-ties, panting beams etc., in general. -
where, to be reduced by 15 per cent where the
loads are primarily dynamic in nature.
σc = compressive stress to be considered as per
Sec.6.3 - for 'lm' and 'i' See 6.2.6.
η = 1.0 for deck, longitudinally stiffened side 6.1.2 The critical compressive buckling stress
shell and single bottom plating 'σcr' may be determined as follows :
τ cr = τ E when τ E ≤ 0.5 τ y
C = 1.30 when plating is stiffened by floors or
deep girders
τy
= τ y (1 − ) when τ E > 0.5 τ y = 1.21 when stiffeners are angles or T sections
4τ E
= 1.10 when stiffeners are bulb flats
where,
= 1.05 when stiffeners are flat bars
τE = ideal elastic shear buckling stress [N/mm ],
2
2
A = cross sectional area [cm ], of the
longitudinal ( )
b 3f h 2w [t f b f2 + 2b f h w + 4h 2w + 3t w b f h w ]10 −6
=
In the calculation of Ia and A, attached plating 12 (b f + h w ) 2
6.2.4 The σE value for the torsional mode of C = spring stiffness exerted by supporting plate
longitudinals may be taken as: panel
k p E t 3p t 3w
π E Iw
2
K =
(3 s t )
It
σE = m + 2 + 0.385 E [N/mm ]
2 2 3
+ 4k p h w t 3p
10 I p l
4 2
m Ip w
2
- for flanged profiles t
σ E = 3.8E w [N/mm 2 ]
4
Ip =polar moment of inertia, [cm ], of profile hw
about connection of stiffener to plate
Buckling of flanges on angles and T-sections of
3
h t w −4 longitudinals is taken care of if the as built flange
= w
10 for flat bars (slabs) thickness is not less than 1/15 of the flange
3 width on one side of the web.
6
Iw = sectorial moment of inertia, [cm ], of profile
about connection of stiffener to plate C = 1.0 for both ends hinged
3
t b h2
= f f w 10 − 6 for ' Tee' profiles
12
Table 6.2.4
(m-1) m < K ≤ m (m+1)
2 2 2 2
0<K<4 4 < K < 36 36 < K < 144
m 1 2 3 m
i = radius of gyration of the member, [cm] For ships with high speed and large flare in the
forebody, σc as obtained from above is to be
= (I/a) increased by σca in the region forward of 0.3L
abaft of F.P. The value of σca is to be taken as :
4
I = moment of inertia of the member, [cm ],
σca = 0 for Caf < 0.4
about the axis perpendicular to the direction of
buckling being considered
50 x
2 = 1 − [ N/mm ] for C af > 0.5
2
a = cross sectional area of the member, [cm ] k 0.3L
lm = length of the member, [m].
where,
Where end connections of a member are
x = distance [m], from F.P., however need not
different with respect to the two principal axes,
be taken as smaller than 0.1L
σE is to be found out for both cases using
appropriate values of 'C' and 'I'. Caf = factor as defined in Pt.3, Ch.5, 2.2.2.
6.3 Compressive stress, σc For intermediate values of Caf, σca is to be
obtained by interpolation.
6.3.1 The σc value for plate panels and stiffeners
taking part in the longitudinal strength is to be 6.3.2 The σc value for axially loaded members is
taken as : to be taken as :
z
σ c = (M s + M w ) 10 5 [N/mm 2 ]; σc =
10.F
[N/mm 2 ]
In a
2
but not to be taken less than 30/k [N/mm ] where,
2
where, a = cross - sectional area of the member, [cm ].
Ms = still water bending moment [kN-m] as per F = Nominal axial force in the member;
Pt.3, Ch.5
3
= AL . p . 10 [kN]
Mw = wave bending moment [kN-m] as per Pt.3,
2
Ch.5 AL = Load area, [m ], being supported by the
member
Values of sagging moments (Ms and Mw) are to
be considered for members above the neutral In the calculation of axial force F for deck pillars,
axis and the hogging values for members below contributions, if any, from the decks above are
the neutral axis. also to be considered.
In = moment of inertia of the hull girder about the In the calculation of axial force F for cross ties or
4
neutral axis, [cm ] panting beams, the larger of the design pressure
'p' at the either ends of the member is to be
z = vertical distance [m], from the neutral axis of considered.
the hull girder to the member under
consideration.
End of Chapter
Chapter 4
Design Loads
Contents
Section
1 General
2 Ship Motions and Accelerations
3 Design Pressures and Forces
Section 1
General
3/2
1.1 Scope = 10.75 - [(L-350)/150] for L > 350 [m]
Section 2
50 c = ( 2kr / √GM )
- The roll angle, Φ= [radians]
B + 75 kr = roll radius of gyration, [m].
where, GM = metacentric height, [m].
c = (1.25 - 0.025 Tr) d Minimum value of Tr resulting from various
possible combinations of kr and GM is to be
d = 1.2 for ships without bilge keel used.
= 1.0 for ships with bilge keel having area In case detailed calculations for kr and GM have
equal to 2.5% of LxB not been carried out, the following values may
be used.
For other percentages of bilge keel areas 'd' is
to be interpolated. kr = 0.39B for ships with even transverse
distribution of mass
Tr is not to be taken greater than 30 [s]
= 0.35B for tanker in ballast
ao
- the pitch angle, θ = 0.25 [radians] = 0.25B for ships loaded with ore between
Cb
longitudinal bulkheads.
2.2 Acceleration components GM = 0.07B
2.2.1 The design values of various acceleration Rr = distance from the centre of the mass under
components are normally to be taken as : consideration to the axis of rotation, [m].
- the surge acceleration, The axis of rotation for roll may be taken on the
centre line of the ship and at a height 'z' above
ax = 0.2 goao √Cb [m/s ]
2
base line
0.7g o a o D
az = [m/s 2 ] = [m]
Cb 2
2
2π
a p = θ R p [m/s 2 ]
Tp
where,
It may be noted that the components arz and apz at = [ a + (g Sinϕ + a ) ] [m/s ]
2
y o ry
2 2
al = [a + (g Sinθ + a ) ] [m/s
2
x o px
2 2
]
Section 3
- for load point above summer load waterline 3.3.1 In case of tanks for crude oil or bunkers
the liquid cargo density 'ρ is not to be taken less
-3 2 3
p = Rs . ks (Cw - 0.8 ho) . 10 [N/mm ] than that of sea water (ρ=1.025 [t/m ]).
2
where, 3.3.2 The pressure 'p', [N/mm ] , in full tanks is
to be taken as the greater of:
ho = vertical distance [m] ,from the summer load
p = ρ (go+0.5av)hs . 10
-3
waterline to the loadpoint. (1)
p = ρ [3 - 0.01B] bt 10 [N/mm ]
-3 2
where,
For L between 20 [m] and 90 [m] the value of 'po'
is to be obtained by linear interpolation. bt = distance [m], between tank side bulkheads
or effective wash bulkhead at the height at
However, in mechanically propelled cargo ships which the strength member is located.
of 500 GT and above and passenger ships, for
tanks forming part of the watertight subdivision, - for tanks with lt > 0.13L and/or bt > 0.56B, p
(See Ch.10, Cl.4.2.1) p0 is to be taken as not will be specially considered.
2
less than 0.024 [N/mm ].
3.3.4 The pressure 'p' acting on girder web
Where automatic pressure valves are fitted, po is panels in cargo tanks or ballast tanks is not to
2
not to be taken as less than valve setting be taken as less than 0.02 [N/mm ].
pressure.
3.4 Pressures due to dry cargoes, stores,
The formulae which normally give the greatest equipment and accommodation
internal pressure p are indicated in Fig.3.3.2a,
Fig.3.3.2b and Fig.3.3.2c for various tank types. 3.4.1 The pressure 'p' on inner bottom, decks or
hatchcovers is to be taken as:
The external sea pressure at ballast draught for
-3 2
open sea conditions as per 3.2.4 may be p = q(go + 0.5 av) x 10 [N/mm ]
deducted from that given by formulae (1),(2) and
(3) above. where,
2
The external sea pressure at ballast draught for q = deck cargo load [t/m ].
harbour conditions as per 3.2.4 may be
deducted from that given by formulae (4) and (5) The standard values of `q' are given in Table
above. 3.4.1. Where approval is sought for loadings
higher than the standard loading, the same is to
3.3.3 The pressure 'p' in tanks which may be be indicated on the plans.
filled between 20 per cent and 90 per cent of the
tank heights is to be taken as the greater of that 3.4.2 Weather deck and weather deck hatch
according to 3.3.2 and the relevant values given covers intended to carry deck cargo are to be
below: designed for external sea pressure as given in
3.2.2 or pressure due to deck cargo as given in
- for strength members located within 0.25 lt 3.4.1, whichever is greater.
from the end bulkheads 'p' is not to be taken
as less than: When the design stowage height of weather
deck cargo is smaller than 2.3 [m], an
p = ρ [4 - 0.005L] lt 10 [N/mm ]
-3 2
appropriate combination of the two loads is to be
considered.
where,
3.4.3 The pressure 'p' from bulk cargoes on
lt = distance [m], between transverse tank sloping and vertical sides or bulkheads is to be
bulkheads or effective transverse wash taken as:
bulkheads at the height at which the strength
-3 2
member is located. Transverse webframes p = C.ρ.hc(go + 0.5 av) . 10 [N/mm ]
covering part of the tank cross-section (e.g. wing
tank structures in tankers) may be regarded as where,
wash bulkheads for this purpose.
C = Sin α Tan (45 - δ/2)+Cos α
2 2 2
In case of ships where due to large volumetric capacity of cargo spaces the stowage rate is less than
3
0.7 [t/m ], a reduction in the value of 'ρ' may be considered, if requested for.
End of Chapter
Chapter 5
Longitudinal Strength
Contents
Section
1 General
2 Vertical Bending Moments and Shear Forces
3 Hull Section Modulus and Moment of Inertia
4 Shear Strength
5 Openings in Longitudinal Strength Members
6 Loading Guidance Information
Section 1
General
Qw = rule wave shear force [kN] as given in quickly ascertained that, at specified read-out
2.2.3. points, the still water bending moments, shear
forces, and the still water torsional and lateral
1.3 Terms loads, where applicable, in any loaded or ballast
condition will not exceed the specified
1.3.1 Effective longitudinal bulkhead : permissible values.
Section 2
2.1 Still water bending moment and shear as specified in 2.1.2. For these calculations,
force downward loads are assumed to be taken as
positive values, and are to be integrated in the
2.1.1 Still water bending moments, Ms [kN-m], forward direction from the aft end of L. The sign
and still water shear forces, Qs [kN], are to be conventions of Ms and Qs are as shown in
calculated at each section along the ship length Fig.2.1.1.
for design cargo and ballast loading conditions
2.1.2 In general the following conditions (based - Any specified non-uniform distribution of
on the amounts of bunker, fresh water, stores loading.
etc. at departure and arrival), are to be
considered for the calculations of Ms and Qs. - Mid-voyage conditions relating to tank
Where the amount and disposition of cleaning or other operations where these
consumables at any intermediate stage of the differ significantly from the ballast
voyage are considered more severe, conditions.
calculations for such intermediate conditions are
to be submitted in addition to those for departure - Docking condition afloat
and arrival conditions. Also, where any
ballasting and/or deballasting is intended during - Loading and unloading transitory conditions.
voyage, calculations of the intermediate
condition just before and just after ballasting c) Chemical tankers:
and/or deballasting any ballast tank are to be
submitted and where approved, included in the - Conditions as specified for oil tankers.
loading manual for guidance.
- Conditions for high density or heated cargo
a) General cargo ships, container ships, roll- and segregated cargo, where these are
on/roll-off and refrigerated cargo carriers, included in the approved cargo list.
bulk carriers, ore carriers:
d) Liquefied gas carriers:
- Homogeneous loading conditions at
maximum draught - Homogeneous loading conditions for all
approved cargoes.
- Ballast conditions
- Ballast conditions.
- Special loading conditions e.g. container or
light load conditions at less than maximum - Cargo conditions where one or more tanks
draught, heavy cargo, empty holds or non- are empty or partially filled or where more
homogeneous cargo conditions, deck cargo than one type of cargo having significantly
conditions etc., where applicable different densities are carried.
- Short voyage or harbour conditions, where - Harbour condition for which an increased
applicable vapour pressure has been approved.
- Homogeneous loading conditions (excluding In addition to the above, any other loading
dry and clean ballast tanks) and ballast or condition likely to result in high bending
part loaded conditions. moments or shear forces may require to be
investigated.
For permissible use of partially filled ballast However, for conventional ore carriers with large
tanks in design loading conditions, See 2.1.3 wing water ballast tanks in the cargo area,
and 2.1.4. where empty or full ballast water filling levels of
one or maximum two pairs of these tanks lead to
2.1.3 Ballast loading conditions involving the ship’s trim exceeding one of the following
partially filled peaks and/or other ballast tanks at conditions, it is sufficient to demonstrate
departure, arrival or during intermediate compliance with maximum, minimum and
conditions are not to be used as design intended partial filling levels of these one or
conditions unless: maximum two pairs of ballast tanks such that
the ship’s condition does not exceed any of
- permissible bending and shear stresses are these trim limits. Filling levels of all other wing
not exceeded for all filling levels between ballast tanks are to be considered between
empty and full; and empty and full. The trim conditions mentioned
above are:
- for bulk carriers, the requirement for
longitudinal strength of hull girder in flooded - trim by stern of 3% of the ship’s length, or
conditions as per Pt.5, Ch.1, Sec.2.2 are - trim by bow of 1.5% of ship’s length, or
complied with for all filling levels between - any trim that cannot maintain propeller
empty and full. immersion (I/D) not less than 25%, where:
To demonstrate compliance with all filling levels - I = the distance from propeller centerline
between empty and full, it will be acceptable if, to the waterline
in each condition at departure, arrival and where - D = propeller diameter
required by 2.1.2 any intermediate condition, the - (see Fig. 2.1.3).
tanks intended to be partially filled are assumed
to be:
- empty
- full
- partially filled at intended level.
2.1.4 In cargo loading conditions involving 2.1.6 The design still water bending moment at
partially filled ballast tanks, the requirements amidships Mso (sagging and hogging), is to be
given in 2.1.3 above need be applied in respect taken equal to the maximum of sagging or
of peak tanks only. hogging still water bending moments obtained
for the loading conditions specified in Sec.2.1.2.
2.1.5 Sequential ballast water exchange :
Requirements of 2.1.3 and 2.1.4 above are not At locations other than amidships, 0.4L, the
applicable to ballast water exchange using the design still water bending moment Ms (sagging
sequential method. However, bending moment and hogging) is normally to be taken as:
and shear force calculations for each de-
ballasting or ballasting stage in the ballast water Ms = Ksm.Mso [kN-m]
exchange sequence are to be included in the
loading manual or ballast water management where,
plan of any vessel that intends to employ the
sequential ballast water exchange method. Ksm = 0.0 at A.P. and F.P.
= 0.15 at 0.1L from A.P. and F.P.
= 1.0 within 0.4L amidships.
Cb is not to be taken as less than 0.6 zfp = vertical distance, [m], measured at F.P.,
from summer load water line to the deckline.
2.2.2 At locations other than amidships, the rule
wave bending moment Mw (sagging and
hogging) is to be taken as: Table 2.2.2 : Modification to Kwm and Kwq
values for high speed/flare
Table 2.2.3
Location Positive Shear Negative
from A.P. Force Kwq (+) Shear Force
Kwq (-)
A.P. 0.0 0.0
0.2L to 0.3L 1.589 C b -0.92
(C b + 0.7)
0.4L to 0.6L 0.70 -0.70
0.7L to 0.85L 1.0 − 1.727 C b
(C b + 0.7)
F.P. 0.0 0.0
Section 3
In case of ships with multi-hatchways zn = the vertical distance from the horizontal
athwartships, the effective sectional area of neutral axis to top of continuous strength
strength members between the hatch openings member.
is normally to be taken as 0.6 times the net area
of the members. y = athwartship distance from the centreline of
the ship to the side of the strength member.
In case of ships with continuous trunks or
longitudinal hatch coamings, their net sectional zn and y are to be measured to the point giving
area may be included in the calculations the largest value of z.
provided they are effectively supported by
longitudinal bulkheads or deep girders. The 3.2 Extent of high strength steel
section modulus at deck however, is then to be
calculated as given in 3.1.3. 3.2.1 Where high strength steels are used in the
main hull structure in order to reduce the section
3.1.2 The main strength members included in modulus requirement, the vertical and
the calculation of hull moment of inertia and longitudinal extent of its use is to be such that
section modulus are to extend continuously adjacent structure made of ordinary hull
through the cargo region and sufficiently far structural steel is not stressed beyond the stress
towards the ends of the ship. Longitudinal level permissible for ordinary steel.
bulkheads are to terminate at effective
transverse bulkheads and large transition 3.2.2 The vertical extent of the high strength
brackets are to be fitted in line with the steel used in deck or bottom structure is to be as
longitudinal bulkheads. Where significant shown in the Fig.3.2.2, the distance zo is not to
changes in structural arrangement occur be more than
adequate transitional structure is to be provided.
zo = In / (100.ZRo) [m]
3.1.3 The midship section modulus 'Z' at deck or
bottom about the transverse neutral axis is to be where,
obtained as follows:
ZRo = Rule midship section modulus required for
3
Z = In / (100.z) [cm ] ordinary steel (k=1.0) as given in 3.3.1 and
3.3.2.
where,
For narrow beam ships the vertical extent of
z = the vertical distance [m] from the horizontal high strength steel may have to be increased
neutral axis upto the strength deck at side or the after special consideration.
base line, as relevant.
3/2
= 10.75 - [(L-350)/150] for L > 350 [m]
Between the specified regions σL is to be For intermediate locations the value of Mwh is to
obtained by linear interpolation. be obtained by linear interpolation.
3.3.2 The minimum requirement of hull section The above requirement is normally satisfied
modulus Z about the transverse neutral axis, at when Zh is not less than
midship, is given by:
2.25 3
Zh = 5 k L ( T + 0.3 B) Cb Rs [cm ]
2 3
Z = k C1 L B (Cb+0.7) (0.5 + Rs/2) [cm ]
3.4 Moment of inertia requirement
where,
3.4.1 The moment of inertia In of the hull section
C1 = 4 + 0.0412 L for L < 90 [m] about the transverse neutral axis, at midship, is
not to be less than:
for 90 [m] ≤ L < 300
3/2
C1 = 10.75 - [(300-L)/100]
3 4
[m] In = 3 C1 L B (Cb+0.7) Rs [cm ].
Section 4
Shear Strength
4.1 General
- For bulk carriers of conventional design:
4.1.1 The shear stress 'τ’ in ship's sides and B . l h . B h . Pc
longitudinal bulkheads based on the total shear ∆Q s = [kN]
2
force (Qs+Qw) is not to exceed 110/k [N/mm ]. 2.2 (B + l h )
= 0.5 for ships without effective longitudinal Ft, Fp = as given in Table 4.2.1 for the item
bulkheads under consideration, [kN/m]
= as given in Table 4.2.1, for the item under lb = length between tank bulkheads [m]
consideration, for ships with effective
longitudinal bulkheads Transverse wash bulkheads with openings more
than 20% are to be considered ineffective for the
∆Qs = shear correction due to uneven load purpose of determining lb.
distribution and shear carrying longitudinal
bottom members and may be taken as: le = lb - S
∆Qs = 0 for nearly uniform loading conditions S = spacing of bottom transverses, [m]
AS = sectional area of the side shell plating (or The net loading is to be arrived at considering
combined area of the inner and outer shell the downward loading of solid or liquid cargo
2
plating), [cm ]. above inner bottom together with that of ballast,
if any, in double bottom tanks below and the
AL, AC = Sectional area of the longitudinal wing upward buoyancy loading corresponding to the
bulkhead plating and centre line bulkhead draught at midpoint of the part concerned in the
2
plating respectively, [cm ]. In case of corrugated loading condition under consideration.
bulkheads the area is to be taken as the product
of mean thickness and the depth. β = 0.7 where a substantially deep girder has
been provided on centre line of the ship.
c, w, d = breadths of the centre tank (or flat
portion of hold between hopper tanks), wing = 1.0 in other cases.
tank and double side tank respectively, [m].
Section 5
5.1.2 Openings in the strength deck within 0.6L The shadow area representing the imaginary
amidships (within the cargo hold region for ships longitudinal extension of an opening is obtained
with large hatch openings) are as far as by drawing two tangent lines with an opening
practicable to be located inside the line of large angle of 30° as shown in Fig.5.2.2.
hatch openings. Necessary openings outside
this line are to be kept well clear of the ship's
side and hatch corners.
5.3.2 Circular openings with diameter equal to or l = longitudinal distance between adjacent
greater than 0.325 m are to have edge hatchways [m]
reinforcement. The sectional area A of the edge
reinforcement is not to be less than b = breadth of the hatchway [m]
2
A = 2.5 b.t. [cm ] In the above formulae l/b need not be taken as
greater than 1.0 and (B - b) is not to be taken as
where, less than 7.5 [m] nor need be taken as greater
than 15 [m].
b = diameter of the opening [m]
5.4.2 Where corners are of streamlined shape,
t = thickness of the plating [mm]. as given by Fig.5.4.2, the transverse extension
of the curvature, a, is not to be less than:
The reinforcement is normally to be of a vertical
ring welded to the plate edge. Alternative a = 0.025 (1.5 + l / b) (B - b) [m]
arrangements may be accepted provided the
reinforcement is within a distance of 0.05b from where,
the plate edge.
l,b are as defined in 5.4.1.
5.3.3 Elliptical openings are to have their major
axis in the fore and aft direction. Where the ratio
of the major axis to minor axis is less than 2 the
openings are to be reinforced as given in 5.3.2
taking b as the breadth of the opening (minor
axis).
where,
Section 6
6.1.2 In addition to the Loading Manual all ships - Verification of type approval, if any
of Category I of 100 [m] in length and above are
to be provided with an approved loading - Verification that the final data of the ship
instrument. has been used
For additional requirements for bulk carriers, ore - Acceptance of number and position of
carriers and combination carriers of L ≥ 150 [m], read-out points
see Pt.5, Ch.1.
- Acceptance of relevant limits for all
For chemical carriers and gas carriers existing read-out points
analog computer may be retained.
- Checking of proper installation and
6.2 Conditions of approval of loading operation of the instrument on board in
manuals accordance with the agreed test
conditions; and that a copy of the
6.2.1 The approved Loading Manual is to be approved operation manual is available.
based on the final data of the ship. The Manual
is to include the design loading and ballast 6.3.2 In case of modifications implying changes
conditions, sub divided into departure and arrival in the main data of the ship, the loading
conditions, upon which the approval of the hull instrument is to be modified accordingly and
scantlings is based. approved.
6.2.2 In case of modifications implying changes 6.3.3 The operation manual and the instrument
in the main data of the ship, a new Loading output must be prepared in a language
Manual is to be issued duly approved. understood by the users. If this language is not
English, a translation into English is to be
6.2.3 The Loading Manual must be prepared in included.
a language understood by the users. If this
End of Chapter
Chapter 6
Contents
Section
1 General
2 Bar Keel
3 Stem
4 Stem Frames and Rudder Horns
5 Propeller Nozzles
Section 1
General
1.1 Scope sections are to be selected as defined in Pt.3,
Ch.2.
1.1.1 For ships with various Ice Class notations,
additional requirements given in Pt.5, Ch.2 are 1.2.2 Bar keels and stems may either be steel
to be complied with. castings or steel forgings.
Section 2
Bar Keel
2.1.1 The scantlings of bar keel are not to be Minor deviations from the above values may be
less than : accepted provided the required sectional area is
maintained.
Depth = 100 + 1.5 L [mm]
Section 3
Stem
2
3.1 Bar stem [N/mm ], the design value of which is to be
taken as :
3.1.1 The cross sectional area 'A' of a bar stem,
2 -3
below the summer load waterline, is not to be pi = (2.2 + 1.5tanα) x (0.4VSinβ + 0.6√L) .10
2
less than [N/mm ]
t = ( 0.08 L + 5.5 ) √k [mm] 3.3.2 The scantlings of plates and stiffeners are
not to be less than the following :
However 't' need not exceed 25.0 [mm].
Plate thickness
3.2.2 The thickness of the plate stem may be
gradually reduced to that of the side shell at the t = 0.028 fa fr s √(pi k) + tc [mm.]
stem head.
Section modulus of stiffeners
3.2.3 The plate stems are to be supported by
2 3
horizontal diaphragms spaced not more than 1.0 Z = 0.15 s pi l k + Zc [cm ]
[m] apart. Where the stem plate radius is large,
a centreline stiffener or web is to be provided. where,
3.3.1 The region forward of 0.1L abaft of F.P. l = span of stiffeners [m].
and above the summer load waterline, is to be
strengthened for bow impact pressure 'pi'
fa,fr are correction factors for aspect ratio and b = mean breadth, [m], of the load area
curvature, respectively, as defined in Pt.3, Ch.3. supported by the girder.
tc,Zc are corrosion additions to thickness and S = Span of the girder, [m].
section modulus of stiffeners as defined in Pt.3,
Ch.3. h = girder height, [mm].
3.3.3 Outside the region specified above, the 3.4 Bulbous bow
scantlings of side plating and stiffeners may be
gradually reduced to the general requirements. 3.4.1 Where a bulbous bow is fitted, the
structural arrangements are to be such that the
3.3.4 Stiffeners are to be connected at ends. bulb is adequately supported and integrated into
Where stiffener webs are not perpendicular to the fore peak structure.
the shell plating adequate tripping brackets are
to be fitted. 3.4.2 At the fore end of the bulb the structure is
generally to be supported by horizontal
3.3.5 Thickness 't' of primary members is not to diaphragms spaced not more than 1.0 [m] apart
be less than: in conjunction with a deep centreline web.
Section 4
4.1.3 Fabricated and cast steel sternframes are For single screw ships:
to be strengthened at intervals by webs. In way
of the upper part of the sternframe arch, these a ≥ 0.2 R [m]
webs are to line up with the floors.
b ≥ (0.7 - 0.04 Nb) R [m]
2
= 40 T k [cm ] for L > 60 [m]
w = 40 T [mm]
Fabricated propeller posts (see Fig.4.2.1 (b))
l = 200 T [mm]
w = 140 T [mm]
r = 18 T [mm]
t1 = 12 (Tk ) [mm]
c ≥ (0.48 - 0.02 Nb) R [m] tw = 6 (Tk ) [mm], however need not exceed
30 [mm].
d ≥ 0.07 R [m]
Cast steel propeller posts - (See Fig.4.2.1 (c))
For twin screw ships:
l = 165 T [mm]
b ≥ (0.5 - 0.03 Nb) R [m]
where, r = 20 T [mm]
R = Propeller radius [m]
t1 = 12 (Tk ) , [mm] however not less than 19
Nb = Number of propeller blades. [mm].
longitudinal axis is to be equivalent to that with Fr = Rudder force [N] as defined in Pt.3, Ch.14,
the Rule scantlings. However the thickness t1 is Sec.3
neither to be less than (minimum of 19 [mm] for
cast steel propeller posts) nor less than
8 (Tk ) the increased thickness of shell plating
adjacent to sternframe.
where,
Fr l
ZT = [cm 3 ]
1000
where,
small ships the use of single arm brackets will the shell connection is not to be less than (150 +
be considered. 0.8L) [mm].
4.4.2 Fabricated brackets are to be designed to 4.5.3 The section modulus of the rudder horn
avoid or reduce the effect of hard spots and 'ZT' about the longitudinal axis is not to be less
ensure a satisfactory connection to the hull than :
structure. The connection of the arms to the
bearing boss is to be by full penetration welding. A
Z T = 0.015 Fr l h k 1 + 0.58 h [cm 3 ]
4.4.3 Generally bracket arms are to be carried A
through the shell plating and attached to floors
or girders of increased thickness. The shell where,
plating in way of shaft brackets is to be
increased in thickness to a minimum of 1.5 Fr = rudder force [N] as defined in Ch.14
times the Rule bottom shell plating thickness
amidships. In way of struts, an insert plate is to lh = vertical distance, [m] from the centre of the
be provided of thickness not less than: horn pintle bearing to the section under
consideration.
t = 1.9 √dts where dts is the tailshaft diameter.
2
The connection of the struts to the shell plating Ah = area of the horn, [m ]
is to be by full penetration welding.
2
A = total area of the rudder, [m ].
4.4.4 The scantlings of solid or built-up shaft
brackets are to comply with the following: 4.5.4 The rudder horn thickness 't' is not to be
less than :
t = 0.4 dts [mm]
0.11 Fr e h k
2 -3
A = 4.5 dts . 10 [cm ]
2
t= [mm]
As
3 -6 3
ZT = 30 dts . 10 [cm ]
where,
where,
2
As = area, [cm ], enclosed by the horn in
t = thickness of the strut horizontal section
A = cross sectional area of the strut eh = horizontal distance, [m], from the centre line
of the horn pintle to the centroid of area As.
ZT = Section modulus of the strut against
transverse bending. 4.5.5 The total sectional area 'Aw' of vertical
parts of the rudder horn contributing to strength
4.5 Rudder horns against the transverse shear is not to be less
than :
4.5.1 Rudder horns supporting semi-spade type
rudders are to be efficiently integrated into the
A
main hull structure, and additional web frames A w = 0.24 Fr k 1 + 1.16 h .10 −3 [cm 2 ]
or side transverses may be required in the A
'tween deck above.
4.5.6 The equivalent stress at any section over
4.5.2 The shell plating is to be increased in the length of the rudder horn is not to exceed
thickness in way of the horn, and the radius at 2
120/k [N/mm ].
Section 5
Propeller Nozzles
Item Requirement
1) Shroud plating in - For NN ≤ 63
way of propeller ts = (11 + 0.1 NN)
blade tips [mm]
- For NN > 63
ts = (14 + 0.052 NN)
[mm]
2) Shroud plating tp = (ts - 7) [mm] but
clear of blade tips, not less than 8
flare and cone [mm]
plating, wall
thickness of leading
and trailing edge
members
5.2.4 The transverse strength of the nozzle is to r = the horizontal distance from centre line of
be maintained by fitting adequate number of ring stock to centre of pressure of nozzle, but not to
webs. At least two ring webs are to be fitted in be taken less than 10% of the chord length of
way of shroud plating, spaced approximately the nozzle.
400 [mm]. Fore and aft of these webs the
spacing of ring webs is generally not to exceed 5.3.2 Effective means are to be provided for
600 [mm]. Ring webs are to be increased in supporting the weight of the nozzle. Where the
thickness in way of the headbox and pintle support is provided by a carrier bearing attached
support structure in accordance with Table 5.2.1 to the nozzle head, the structure in way of the
and the increased thickness is to be maintained bearing is to be adequately strengthened. The
to the adjacent fore and aft web. shell plating in way of nozzle head is to be
increased in thickness by 50%.
5.2.5 Local stiffening is to be fitted in way of the
top and bottom supports which are to be 5.3.3 All nozzle bearings are to be accessible for
integrated with the webs and ring webs. measuring wear without lifting or unshipping the
Continuity of bending strength is to be nozzle.
maintained in these regions.
5.3.4 Satisfactory arrangement is to be provided
5.2.6 Weld details of nozzle plating, webs, to prevent water from entering the steering gear
coupling flanges etc. are to be as given in Sec.4 compartment and lubricant from being washed
of Ch.14 'Rudders' and also as per Ch.17 away from the nozzle carrier. A seal or stuffing
'Welding'. box is to be fitted above the deepest load water
line for this purpose, however, two separate
5.2.7 Leak testing of the nozzle is to be as seals or stuffing boxes are to be provided when
required for rudders as per Ch.18. the nozzle carrier is below the deepest load
water line.
5.2.8 Arrangement is to be provided to drain the
nozzle completely. Drain plugs are to be 5.4 Fixed nozzles
provided with efficient packing.
5.4.1 The nozzle is to be adequately supported
5.2.9 Internal surfaces of nozzles are to be preferably by closed box structures of necessary
efficiently coated for corrosion protection after enclosed area to withstand the lateral force Fr
completion of fabrication and testing. Where it is and Torque Qr given in 5.3.1 and its own weight.
intended to fill the nozzle with plastic foam, The resultant stresses are not to exceed the
details of the foam material is to be submitted. following:
σb = 75/k [N/mm ]
2
5.3 Steerable nozzles Bending stress
Qr = Fr . r [N-m]
σ e 2 = σ + 3τ τ 2 = 90/k [N/mm 2 ]
where,
2
5.4.2 The nozzle support box structure is to be
A = projected area of nozzle [M ] well integrated to the webs and ring webs in the
nozzle and to the hull structure. Structural
V = Maximum service speed [knots] with the continuity is to be maintained between the webs
ship on summer load waterline. When the speed in the nozzle, the top box structure and local
is less than 10 knots. V is to be replaced by the girders/floors inside the hull.
expression Vmin = (V + 20)/3.
End of Chapter
Chapter 7
Bottom Structure
Contents
Section
1 General
2 Structural Arrangement and Details
3 Design Loads
4 Bottom and Inner Bottom Plating
5 Single Bottom
6 Double Bottom
7 Additional Strengthening against Slamming
8 Engine Seatings
Section 1
General
1.1 Scope
b = spacing of girders, [m]
1.1.1 The scantlings and arrangement of bottom
structure as defined in Ch.1, Sec.2 are to S = span of girders, [m]
comply with the requirements given in this
Chapter. ZR
fB =
1.2 Symbols ZB
Section 2
2.1 General (a) Cargo ships of less than 500 tons gross
tonnage.
2.1.1 Except as specified in 2.1.6, passenger
ships and cargo ships other than tankers, are to (b) Ships not propelled by mechanical means.
be fitted with a double bottom extending from
the collision bulkhead to the after peak bulkhead (c) Fishing vessels.
as far as this is practical and compatible with the
design and proper working of the ship. 2.1.7 The engine room of all ships having L > 90
[m] is to have a double bottom.
Note: For the purpose of this requirement, a
“tanker” is a cargo ship constructed or adapted 2.1.8 For ships of L > 90 [m], single bottoms
for the carriage in bulk of liquid cargoes of an within the cargo region, where permitted, are
inflammable nature. normally to be longitudinally stiffened.
For oil tankers, chemical carriers and liquefied 2.1.9 For ships of L > 150 [m] and for ships
gas carriers, the requirements indicated in Pt.5, strengthened for heavy cargoes, double bottoms
Ch.2, Ch.3 and Ch.4 respectively regarding within the cargo region are normally to be
double bottom and location of wells above longitudinally stiffened.
bottom shell are to be complied with.
2.1.10 The continuity of the bottom, bilge and
2.1.2 Where a double bottom is required to be inner bottom longitudinals is to be maintained in
fitted, its depth is to be as per 6.1.1 and the accordance with Ch.3, Sec.5.1.1.
inner bottom is to be continued to the ships side
in such a manner as to protect the bottom to the 2.1.11 The bilge keel and the ground bar to
turn of the bilge. which it is attached, are to be gradually tapered
at ends and arranged to finish in way of suitable
2.1.3 Small wells constructed in the double internal stiffening. Butt welds in the bilge keel
bottom, in connection with the drainage and the ground bar are to be well clear of each
arrangement of holds, are not to extend in depth other and those in the shell plating.
more than necessary. A well extending to the
outer bottom, may be permitted at the after end 2.1.12 The weld connections are to comply with
of the shaft tunnel of the ship. Other wells may the requirements of Ch.17.
be considered provided the arrangements give
protection equivalent to that offered by a double 2.2 Access ventilation and drainage
bottom. In no case the vertical distance from the
bottom of such a well to the plane coinciding 2.2.1 Adequate access is to be provided to all
with the keel line be less than 500 [mm]. parts of the double bottom. The vertical
dimension of lightening holes is not to exceed
2.1.4 A double bottom need not be fitted in way 50 per cent of the girder height. The diameter of
of watertight compartments used exclusively for lightening holes in the bracket floors is not to
the carriage of liquids, provided the safety of the exceed 1/3 of the breadth of the brackets.
ship is not impaired in the event of bottom Lightening holes or manholes are normally not
damage. to be cut in floors or girders towards their ends
and under large pillars or supporting structures.
2.1.5 Any part of a passenger ship or a cargo Manholes in inner bottom are to have
ship other than tanker that is not fitted with a reinforcement rings, and the man hole covers in
double bottom in accordance with 2.1.1 or 2.1.4 the inner bottom plating in cargo holds are to be
is to be capable of withstanding bottom effectively protected. The edges of all holes are
damages as specified in para 8 of SOLAS II-1 to be smooth.
Reg.9.
2.2.2 To ensure the free passage of air and
2.1.6 A double bottom need not be fitted on the water from all parts of the tanks to air pipes and
following ships: suctions, air and drain holes are to be provided
in all non-watertight members. The air holes are
to be placed as near to the inner bottom as
possible and their total area is to be greater than with a rigid watertight closing device. A notice
the area of the filling pipes. The drain holes are board stating that the access opening to the
to be placed as near to the bottom as possible. pipe tunnel is to be kept closed, is to be fitted
near the opening. The opening is to be regarded
2.2.3 The access opening to pipe tunnel is to be as an opening in watertight bulkhead.
visible above the floor plates and is to be fitted
Section 3
Design Loads
Section 4
4.2 Bottom, bilge and inner bottom plating s = stiffener spacing, [mm].
s p
t = fa .f r . + t c [mm]
2 σ
Table 4.2.1 : σ values for bottom, bilge and inner bottom plating [N/mm ]
2
Note : 1) In way of hold tanks amidships intended for ballast or cargo oil the value of σ is to be reduced
2
by 10/k [N/mm ]
4.2.2 The minimum thickness requirement of the = 6.0 [mm], for inner bottom plating elsewhere
bottom and inner bottom plating is given by where ceiling is not fitted.
t = (to+0.04L) √k + tc [mm] for bottom plating 4.2.3 The bottom bilge and inner bottom plating
is also to comply with the requirements of
= (to+0.03L) √k + tc [mm] for inner bottom plating. buckling strength given in Ch.3, Sec.6.
L need not be taken as more than 250 [m]. For ships of L > 90 [m], the thickness of these
platings within 0.4L amidships, corresponding to
to = 5.0 [mm], in general. the buckling strength requirement may be
approximated as :
= 7.0 [mm], for inner bottom plating below dry
cargo hatchway openings where ceiling is not - For longitudinally stiffened plating
fitted.
Section 5
Single Bottom
5.1.1 Plate floors of following scantlings are to web thickness, t = (5.5+0.06L) √k [mm]
be fitted at every frame
2
face plate area, a = (5+0.65L)k. [cm ]
depth at centre line, d = 40(B+T) [mm]
Side girders -
thickness of web, t = (d/100+3) √k [mm]
web thickness, t = (5+0.04L) √k [mm].
2
face plate area, a = 3.5 T.√k [cm ]
2
face plate area, a = (5+0.35L)k [cm ].
The thickness of face plate is not to be less than
1/15 of the face width. The thickness of face plates is not to be less
than 1/15 of the face width.
The top of floors, in general, is to be level from
side to side. However, in ships having Towards the fore and after ends, the scantlings
considerable rise of floor, the depth of web at 10 of the bottom girders may be reduced by 10 per
per cent of the span from ends, is not to be less cent.
than 1/2 d [mm].
5.1.3 In the engine room, the thickness of floors
5.1.2 On all ships one centre girder is to be fitted webs and the face plate area as given in 5.1.1
and in addition side girders are to be fitted such are to be increased by 1 [mm] and 50 per cent
that the spacing of girders does not exceed 2.5 respectively. The floors are not to be flanged.
[m]. The girders are to extend as far forward and
aft as practicable and where they are cut at If the height of floors is reduced in way of
transverse bulkheads the longitudinal strength is crankcase, the face plate area is to be suitably
to be maintained. Where the bottom structure increased, however the reduced height is
changes into a double bottom structure, the normally not to be less than 2/3 of 'd' as given in
bottom girders are to extend at least 3 frame 5.1.1.
spaces into double bottom structures.
5.1.4 In the after peak of single screw ships, the
The scantlings of the bottom girders, within 0.5L height of the floors is to be increased such that
amidships, are not to be less than the following: their upper edge is well above the stern tube.
Section 6
Double Bottom
t = (0.008d + 1) √k [mm], for side girders and longitudinal stiffeners within 0.4L amidships
plate floors.
2
= 160/k [N/mm ] for longitudinal stiffeners within
6.1.3 The thickness 't' of girders and floors 0.1L from ends and for transverse or vertical
forming boundaries of double bottom tanks is stiffeners in general.
not to be less than that obtained from 6.1.2 and
that given below: Between the regions specified above σ for
longitudinal stiffeners may be obtained by linear
interpolation.
s p
t= + t c [mm]
2 σ Longitudinal stiffeners are to have end
connections, other stiffeners may be sniped at
where, ends provided the section modulus Z is
increased by 25 per cent.
p = design pressure as given in 3.2.1.
6.1.5 The longitudinal girders are to be
σ = (200 - 100 fB)/k, max. 160/k [N/mm ], for
2 satisfactorily stiffened against buckling in
longitudinally stiffened longitudinal girders within accordance with the requirements given in Ch.3,
0.4L amidships Sec.6.
Draught T [m] Under deep tanks (See Note 1) Clear of deep tanks (maximum 3.0 [m])
T≤2 Every 4th frame Every 6th frame
2 < T ≤ 5.4 Every 3rd frame Every 5th frame
5.4 < T ≤ 8.1 Every 3rd frame Every 4th frame
T > 8.1 Every 2nd frame Every 3rd frame
Note 1 : Under tanks with height greater than 0.7 times the distance between
inner bottom and main deck
6.2.3 Where bracket floors are fitted the section bearers. In engine room, plate floors are to be
modulus 'Z' of the bottom frames and reverse fitted at every second side frames. Additionally,
frames is not to be less than: under the main engine seatings, floors
extending to the first side girder outside the
spl 2 k engine seating, are to be fitted at intermediate
Z= + Z c [cm 3 ] frames. Under deep tanks with height greater
1.6 than 0.7 times the distance between inner
bottom and main deck, the spacing of floors is
where, normally not to exceed 2.5 [m]. Elsewhere, the
spacing is normally not to exceed 3.6 [m].
p = applicable design pressure as given in 3.1.1
and 3.3.1 for bottom frames and reverse frames 6.3.3 The plate floors are to be stiffened at every
respectively. longitudinal by a vertical stiffener of depth same
as that of the inner bottom longitudinal and
l = span of frames [m] measured between girder thickness as that of the floor. Between plate
or brackets. floors, transverse brackets are to be fitted at
every frame at the margin plate and at a spacing
Where vertical struts according to 6.2.4 are not exceeding 1.25 [m] on either side of the
fitted, the section modulus of bottom and centre girder. The thickness of brackets is to be
reverse frames may be reduced by 35 per cent. same as that of the plate floors. The brackets
are to extend upto the adjacent longitudinal and
6.2.4 The cross sectional area 'A' of the struts is are to be flanged 75 [mm] at their free edges.
not to be less than
2
6.3.4 The section modulus 'Z' of the bottom and
A = c . k . l . s . T . [cm ] inner bottom longitudinals is not to be less than
where,
spl 2 .10 3
Z= + Z c [cm 3 ]
-4
c = 7x10 in way of ballast tanks 12σ
-4
= 6x10 elsewhere where,
l = actual span [m], without considering the strut. p = applicable design pressure as given in 3.1.1
and 3.3.1 for bottom longitudinals and inner
The moment of inertia I of the struts is not to be bottom longitudinals respectively;
less than
l = span of longitudinals [m], measured between
2 -6 4
I = 2.5 A . d x 10 [cm ] the plate floors
Section 7
7.1 General
0.2
7.1.1 Where the minimum design ballast draught
Tbf
c1 = 3.6 - 6.5 L
at F.P. is less than 0.04L [m] (maximum 8.5
[m]), the bottom forward is to be additionally
strengthened as given in Sec.7.2 and Sec.7.3. c1 need not be taken more than 1.0
7.1.2 Where the shape of the after sections is Tbf = minimum design ballast draft [m] at F.P.
such that there are large flat areas of bottom
shell, additional stiffening and/or increased shell c2 = distribution factor (see also Fig.7.3.1)
plate thickness may be required. c2 = 0 for x/L ≤ 0.5
7.1.3 Where a ship is classed for 'Restricted
x x
Service' or 'Sheltered water service', compliance c 2 = − 0.5 / c 3 for 0.5 < ≤ (0.5 + c 3 )
with the requirements of this section may be L L
modified or waived altogether.
x
7.2 Spacing of floors and girders c 2 = 1.0 for (0.5 + c 3 ) < ≤ (0.65 + c 3 )
L
7.2.1 The floors and girders in the region
forward of 0.25L abaft of F.P. are to be spaced 1 − x/L x
as given in 7.2.2 and 7.2.3. c 2 = 0.5 1 + for > (0.65 + c 3 )
0.35 − c 3 L
7.2.2 Where transverse framing is adopted,
floors are to be fitted at every frame. The where,
spacing of longitudinal girders is not to exceed 3
times the transverse frame spacing. In addition,
L
intermediate half height girders or equivalent c 3 = 0.33 . C b + ;
longitudinals are to be fitted. 2500
7.2.3 Where longitudinal framing system is c3 need not be taken greater than 0.35
adopted, the plate floors are to be fitted at
alternate frames. The spacing of longitudinal x = distance of the load point from A.P. [m].
girders is not to exceed 3 times the longitudinal
frame spacing. In case of longitudinally stiffened For self propelled vessels:
single bottoms, the arrangements and scantlings
will be specially considered. cs= 1.0 for V/√L ≥ 1.2
7.3.1 The scantlings of bottom plating, stiffeners For intermediate values to be obtained by linear
and girders upto (0.05 Tbf) above base line (upto interpolation
bilge curvature in case of ships with rise of floor)
are to be based on the design slamming For non-self propelled vessels:
pressure PSL given below:
cs = 0.4.
PSL = 0.162 √L . c1 . c2 . cs [N/mm ]
2
(1.7 Af + Aw) ≥ 2 As
where,
2
Af = net weld area at flange, [cm ].
2
Aw = net weld area at web, [cm ].
7.3.2 The thickness 't' of the bottom plating is
7.3.4 Near the shell plating, the spacing of
not to be less than:
stiffeners on the girder webs or bulkheads is not
to exceed 90 times the thickness of the web or
t = 0.028 fa.fr.s. √PSL.√k + tc [mm] bulkhead plating.
Above the region mentioned in 7.3.1 the 7.3.5 The sum 'As' of the shear areas at the
thickness may be gradually reduced to the ends of the girder or girder system supporting
general requirement. any specified area of the bottom is not to be less
than
7.3.3 The section modulus 'Z' of bottom
longitudinals or frames is not to be less than 2
As = C4 S.b.PSL .k [cm ]
2 3
Z = 0.15 s. PSL . l . k + Zc [cm ] where,
The shear area, 'As' of the stiffeners is not to be
10 S b
less than C 4 = 501 − ,
s 2
LB
As = 0.028(l- 1000 ).s.PSL.k + 0.01h tc [cm ] - but not to be taken less than 25.
Section 8
Engine Seatings
End of Chapter
Chapter 8
Side Structure
Contents
Section
1 General
2 Structural Arrangement and Details
3 Design Loads
4 Side Shell Plating and Stiffeners
5 Girders
Section 1
General
1.1 Scope ZR
fD =
1.1.1 The scantlings and arrangement of side ZD
structure as defined in Ch.1, Sec.2 and also
those of sides of the superstructures are to ZR
comply with the requirements of this Chapter. fB =
ZB
1.2 Symbols
fS = fD for side shell area above neutral axis
L, B, T, Cb, k as defined in Ch.1, Sec.2.
= fB for side shell area below neutral axis
tc, Zc are corrosion additions to thickness and
section modulus respectively, as given in Ch.3, where,
Sec.2.1
3
ZR = Rule midship section modulus [cm ] as
fa,fr are correction factors for aspect ratio and required by Ch.5, Sec.3.3.1.
curvature respectively, as defined in Ch.3,
3
Sec.3.1. ZD, ZB = Actual midship section moduli [cm ]
provided at deck and bottom respectively;
Cw, ao, ks as defined in Ch.4, Sec.1.2 and calculated as per Ch.5,Sec.3.1.
Sec.3.2.
z
Tb = lowest design ballast draught [m]. For fz =
preliminary purposes, Tb may be taken as 0.35T zn
[m] for cargo vessels and (2 + 0.02 L) [m] for
tankers. where,
s = spacing of stiffeners, [mm]. zn = vertical distance [m], from the neutral axis
of the hull girder to the strength deck or bottom,
l = span of stiffeners, [m]. as relevant.
b = spacing of girders, [m]. z = vertical distance [m], from the neutral axis of
the hull girder to the stiffener or girder.
S = span of girders, [m].
φ= roll angle [radian], as given in Ch.4, Sec.2.
Section 2
2.1.2 Where the side shell is stiffened 2.2.1 The thickness of sheer strake as obtained
longitudinally, the continuity of the side from 4.1.5 is to be increased by 30 per cent on
longitudinals within a distance of 0.15D from each side of a superstructure end bulkhead
bottom or from strength deck is to be maintained located within 0.5L amidships if the
in accordance with Ch.3, Sec.5.1.1. The web superstructure deck is a partial strength deck.
frames are to be fitted in line with the bottom
transverses or plate floors. 2.2.2 Where a rounded sheer strake is adopted
the radius in general, is not to be less than 15
2.1.3 The position, shape and reinforcement of times the plate thickness.
sea inlets or other openings in side shell are to
be in accordance with the requirements of Ch.5, 2.2.3 Bulwarks are generally not to be welded to
Sec.5. the top of the sheer strake within 0.6L
amidships.
2.1.4 In the case of superstructures exceeding
0.15L in length and ending within 0.5L 2.2.4 Where the sheer strake extends above the
amidships, the side plating of the deck stringer plate, the top edge of the sheer
superstructures is to be increased by 25 per strake is to be kept free from notches and
cent in way of the break. Also see Ch.11, isolated welded fittings, and is to be ground
Sec.4.1.5. smooth with rounded edges. Drainage openings
with smooth transition in the longitudinal
2.1.5 The thickness of the shell plating is to be direction may be allowed on special
increased locally by 50 per cent in way of consideration.
sternframe, propeller brackets and rudder horn.
For reinforcements in way of anchor pockets, 2.2.5 The welding of deck fittings to rounded
hawse pipes etc. refer to Ch.15, Sec.2.1. sheer strake within 0.6L amidships is not
permitted, unless approved in each case.
Section 3
Design Loads
3.1 External sea pressure - for load points above the summer load
waterline
3.1.1 The design pressure 'p' on side shell is to
-3 2
be taken as: p = Rs ks (Cw - 0.8 ho) . 10 [N/mm ]
3.2.1 Where the side shell forms a boundary of = 0.024 for L ≥ 90 [m]
a tank, the design pressure 'p' is to be taken as
the greater of external sea pressure given by For L between 20 [m] and 90 [m] 'po' to be
Sec.3.1 and the net internal tank pressure 'pi' obtained by linear interpolation.
given by 3.2.2.
However, in mechanically propelled cargo ships
3.2.2 The net internal tank pressure 'pi' is to be of 500 GT and above and passenger ships, for
taken as: tanks forming part of the watertight subdivision,
(See Ch.10, Cl.4.2.1) p0 is to be taken as not
2
pi = Internal pressure due to liquid cargo in tanks less than 0.024 [N/mm ].
as given in Ch.4, Sec.3.3.2 less the applicable
external sea pressure at lowest design ballast In case of tanks with stepped upper contour, the
draught 'Tb' as given in Ch.4, Sec.3.2.4. largest value of 'pi' resulting from hs, b
measurements to various tank top corners is to
- For side shell above draught Tb, pi may be be considered (See Fig.3.2.2).
taken as the greater of:
2
- For vessels of L<90 [m], for side shell below
pi = 0.01 hs + po [N/mm ], or draught Tb, pi, may be, approximated as the
greater of :
= 6.7 (hs + φb) .10 [N/mm ], or
-3 2
2
pi = 0.01 (hs - hb) + po [N/mm ], or
-3 2
= 6.7 hp . 10 [N/mm ]
-3 2
= (6.7hp - 10hb) x 10 [N/mm ]
where,
where,
hs, b = The vertical and athwartship distance
[m], respectively, from the load point to the tank hs, hp, po = as given above
corner at the top of tank which is furthermost
away. hb = vertical distance [m], from the load point to
the waterline corresponding to draught Tb.
hp = vertical distance [m], from the load point to
the top of air pipe.
Section 4
s p Table 4.1.1.
t = fafr + t c [mm]
2 σ
Between neutral
Framing At strength deck or
Region At neutral axis axis and strength
system bottom
deck or bottom
(175 - 120 fS)/k To be obtained by
Vertical 120/k
max. 120/k linear interpolation
0.4L amidships between values at
(185 - 100 fS)/k
Longitudinal 140/k neutral axis and at
max. 120/k
deck or bottom
Within 0.05L from
F.P. and 0.1L from 160/k
A.P.
To be obtained by linear interpolation between allowable values at regions
Elsewhere specified above
L need not be taken as more than 250 [m]. σ = (215 - 135 fS . fz) /k, maximum 160/k
2
[N/mm ] for side longitudinals up to depth 'D'
and within 0.4L amidships.
where,
spl2 k
Z= + Z c [cm 3 ] and
2.4 p = applicable design pressure as given in
Sec.3.
= 6.5 √(L.k) [cm ]
3
4.3.3 The section modulus of a main frame 4.5.1 Vertical peak frames forward of the
however, is not to be less than that required for collision bulkhead and aft of the after peak
the tween deck frame above. bulkhead are to have section modulus 'Z' not
less than
4.3.4 Main frame brackets are to be as follows:
spl2 k
length of the bracket : for upper bracket : Z= + Z c [cm 3 ] and
70 l [mm] 1.6
Where the free edge of the bracket exceeds 40 4.6 Tripping brackets
times the bracket thickness, the brackets are to
4.6.1 Where the span of frames exceeds 5 [m]
and/or the flange width is less than 1/20 of the
Section 5
Girders
5.1.1 Web frames are to be fitted in way of hatch The panting beams are to comply with buckling
end beams and deck transverses. strength requirement given in Ch.3, Sec.6 and
are to be bracketed to the frames. Intermediate
5.1.2 In the engine and boiler room, web frames frames are to be bracketed to the stringers.
are to be fitted at the forward and aft end of the
engine and every 5th frame in general. In 5.1.4 The scantlings of simple girders and web
addition, where the engine room is situated aft frames supporting frames and longitudinals are
and the span of the frames up to the lowest to be in accordance with 5.1.5. The scantlings of
deck exceeds 6.5 [m], a side stringer is to be webs supporting fully effective side stringers are
provided. The section modulus `Z' of the web to based on point loadings and 'σ' values given
frames and side stringers is to be obtained as in 5.1.5. The scantlings of the complex girder
per 5.1.5 taking 'b' as the mean of the web system are to be based on a direct stress
frame or stringer spacings respectively, on analysis. The buckling strength of the cross ties,
either side. The depth of the webs and stringers where fitted, is to comply with the requirements
are not to be less than 2.5 times the depth of the given in Ch.3, Sec.6.
ordinary frames.
5.1.5 The section modulus 'Z' of simple girders
Adequate deep beams are to be provided in line and web frames is not to be less than :
with the web frames.
b p S 2 .10 6
5.1.3 In peak spaces, side stringers supporting Z= + Z c [cm 3 ]
vertical peak frames are normally to be fitted at mσ
every 2.6 [m]. The section modulus `Z' of the
stringers is to be obtained as per 5.1.5. The where,
stringers are to be supported by web frames.
2
p = applicable design pressure [N/mm ], as
Alternatively in fore peak spaces, unflanged given in Sec 3.
stringers supported by panting beams at
alternate frames may be provided. The m = 12 for continuous longitudinal girders with
scantlings of these stringers is not to be less end attachments in accordance with Ch.3,
than the following : Sec.5.
2
A = 60 Sbpk + 0.01 h tc [cm ] for stringers and
σ = (190 - 135 fS . fz)/k, max 160/k [N/mm ], for
2
upper ends of the web frames.
continuous longitudinal girders within 0.4L
2
amidships. = 80 Sbpk + 0.01 h tc [cm ] for lower ends of the
web frames.
2
= 160/k [N/mm ] for longitudinal girders within
0.1L from ends and for web frames in general. where,
End of Chapter
Chapter 9
Deck Structure
Contents
Section
1 General
2 Structural Arrangement and Details
3 Design Loads
4 Deck Platings and Stiffeners
5 Deck Girders and Pillars
6 Decks for Wheel Loading
Section 1
General
1.1 Scope ZR
fD =
1.1.1 The scantlings and arrangement of deck ZD
structure as defined in Ch.1, Sec.2 are to
comply with the requirements given in this where,
Chapter.
ZR = Rule midship section modulus [cm3], as
1.2 Symbols required by Ch.5, Sec.3.3.1.
Section 2
2.1.5 In ships with large hatch openings, the - cross section of stool at top of transverse
effective cross-sectional area of the deck bulkhead
between the hatchways is to be sufficient to
withstand the transverse load acting on the - cross section of transverse bulkhead (if
ship's sides. Bending and shear stresses arising plane or horizontally corrugated) down to
as a result of loading on the transverse base of top wing tank or to 0.15 D from
bulkhead supported by the deck area and also deck.
as a result of displacements caused by torsion
of the hull girder, are to be considered and the The compressive stress in the above mentioned
2
necessary reinforcements are to be provided. items is not to be greater than 120/k [N/mm ],
nor 80 per cent of the critical buckling stress
The following items may be included in the found in accordance with Ch.3, Sec.6.
effective cross-sectional area of the decks;
corrosion additions, if any, are to be deducted: 2.1.6 Hatchway corners are to be of
streamlined, elliptical or circular shape as given
- deck plating in Ch.5, Sec.5.4. Where shapes other than the
streamlined shape or equivalent are adopted,
- transverse beams and deck transverses insert plates are to be fitted at the hatch corners
in strength deck. The insert plates are to be 25
- hatch end beams (upon special conside- per cent thicker than the deck plating outside the
ration) line of hatchways and are to extend as shown in
Fig.2.1.6. The butts of insert plates are to be 2.1.7 The weld connections are to comply with
well clear of those in coaming. the requirements of Ch.17.
Section 3
Design Loads
2
- 0.015 [N/mm ] for weather decks forward of = ρ.H [t/m ] for tween decks
2
0.15L from F.P. or forward of deckhouse
front whichever is the foremost position 2
= 1.6 [t/m ] for platform decks in machinery
2 spaces
- 0.005 [N/mm ] for weather decks elsewhere.
2
= 0.35 [t/m ] for accommodation decks.
3.1.2 For weather decks except those forming
crowns of tanks in dry cargo ships, the design H = tween deck height or height measured upto
pressure 'p' is to be taken as the greater of that the top of hatchway coaming, [m].
given by 3.1.1 and 3.2.1, taking deck load `q' as
not less than:
ρ = cargo density [t/m ], not to be taken as less
3
3
than 0.7 [t/m ] except as specified in Ch.4,
q = 1.0 [t/m ] for L ≤ 100 [m]
2
Sec.3.4.1.
= 1.3 [t/m ] on superstructure deck for L ≥ 150
2
3.2.2 For decks forming crowns of tanks the
[m] design pressure 'p' is to be taken as the greater
of that given by 3.2.1 and 3.3.2.
= 1.75 [t/m ] on freeboard deck for L ≥ 150 [m]
2
considered.
2
= 0.01 hs+po [N/mm ]
3.1.3 For weather decks forming crowns of
tanks, the design pressure 'p' is to be taken as where,
the greater of that given by 3.1.1 and 3.3.2.
hp = vertical distance [m], from the deck to the
top of air pipe
2
= 0.024 [N/mm ] for L ≥ 90 [m]
2
= 0.01 hs + po [N/mm ]
For L between 20 [m] and 90 [m], 'po' is to be where, hp and po are as given in 3.3.1.
obtained by linear interpolation.
hs, b = the vertical and athwartship distance, [m]
However, in mechanically propelled cargo ships respectively, from the point of deck under
of 500 GT and above and passenger ships, for consideration to the tank corner at the top of the
tanks forming part of the watertight subdivision, tank which is furthermost away.
(See Ch.10, Cl.4.2.1) p0 is to be taken as not
2
less than 0.024 [N/mm ]. In case of tanks with stepped upper contour, the
largest value of 'p' resulting from the hs, b,
3.3.2 The design pressure 'p' for decks forming measurements to various tank top corners is to
the crown of a tank may be taken as the greater be considered.
of the following:
Section 4
4.1.2 The thickness 't' of deck platings is not to L need not be taken as more than 250 [m].
be less than the minimum requirement given in
4.1.3 nor less than: where,
Section 5
5.1.4 The effective cross sectional area 'A' of the 5.3.4 Where the heels of hold pillars are not
girder web at ends obtained as per Ch.3, directly above the intersection of plate floors and
Sec.4.4 is not to be less than: girders, partial floors and intercostal girders are
to be fitted as necessary to support the pillars.
2
A = 70.S.b.p k + 0.01h tc [cm ] Lightening holes or manholes are not to be cut
in the floors and girders below the heels of
where, pillars.
h = girder height [mm]. 5.3.5 Inside tanks, hollow pillars are not to be
used and strengthening at the heads and heels
of pillars is not to be obtained by means of
Section 6
conditions
however, need not be taken as greater than 1.0
2
= 180/k [N/mm ] in general, for harbour
38 conditions
m= for b ≤ s.
(b/s) − 4.7 (b/s) + 6.5
2
= As per Table 6.4.1 for deck longitudinals
within 0.4L amidships, but not exceeding the
above general values.
6.4 Deck stiffeners
For deck longitudinals between 0.4L amidships
6.4.1 The section modulus 'Z' of deck beams and 0.1L from ends is to be varied linearly.
and longitudinals subjected to wheel loadings is
not to be less than:
Table 6.4.1 : σ Values for longitudinals
c . a . b . l . p −3 within 0.4L amidships
Z= 3 10 + Z c [cm 3 ]
mσ
σ [N/mm ]
2
Condition
End of Chapter
Chapter 10
Bulkheads
Contents
Section
1 General
2 Subdivision and Arrangement
3 Structural Arrangement and Details
4 Design Loads
5 Plating and Stiffeners
6 Girders
Section 1
General
1.1.1 The requirements of this chapter cover the tc, Zc are corrosion additions to thickness and
arrangement and scantlings of watertight and section modulus respectively as given in Ch.3,
deep tank bulkheads. Sec.2.1
1.1.2 The requirements also cover the non- ao, kv are as defined in Ch.4.
watertight bulkheads and shaft tunnels.
s = spacing of stiffeners [mm]
1.2 Statutory requirements
l = span of stiffeners [m]
1.2.1 Where applicable, the number and
disposition of bulkheads are to be arranged to b = spacing of girders [m]
meet the requirements for subdivision,
floodability and damage stability in accordance S = span of girders [m]
with the requirements of the National Authority
of the country in which the ship is registered. ZR
fD =
1.3 Definitions and Symbols ZD
where,
Section 2
For ships without longitudinal bulkheads in the Xc,min = 0.05LL - XR [m] for L < 200 [m].
cargo region, additional transverse watertight
bulkheads are to be fitted so that the total = 10 - XR [m] for L ≥ 200 [m].
number of bulkheads is not less than that given
in Table 2.1.1. Xc,max = 0.05 LL - XR + 3 [m] for L < 100 [m].
2.3 After peak bulkhead and shaft tunnel 2.5 Openings in watertight bulkheads and
closing appliances - General
2.3.1 All ships are to have an after peak
bulkhead generally enclosing the sterntube and 2.5.1 Openings may be accepted in watertight
rudder trunk in a watertight compartment. In twin bulkheads except in that part of collision
screw ships where the bossing ends forward of bulkhead which is situated below the bulkhead
the after peak bulkhead, the sterntubes are to deck / freeboard deck. The number of openings
be enclosed in suitable watertight spaces inside in watertight subdivisions is to be kept to a
or aft of the shaft tunnels. minimum compatible with the design and proper
working of the ship. Where penetrations of
2.3.2 In passenger ships, the stern gland is to watertight bulkheads are necessary for access,
be situated in a watertight shaft tunnel or other piping, ventilation, electrical cables, etc.,
watertight space separate from the stern tube arrangements are to be made to maintain the
compartment and of such volume that if flooded watertight integrity. Relaxation in the
by leakage through the stern gland, the watertightness of openings above the bulkhead
bulkhead deck will not be immersed. deck / freeboard deck may be considered
In cargo ships, where the inboard end of the provided it is demonstrated that any progressive
stern tube extends into the engine room, flooding can be easily controlled and that the
provision of an approved watertight/ oil tight safety of the ship is not impaired.
gland system for sealing of the inboard end of
the stern tube at the aft peak/engine room 2.5.2 Openings in the collision bulkhead above
watertight bulkhead is considered sufficient to the bulkhead deck / freeboard deck are to have
minimize danger of water penetrating into the weathertight doors or an equivalent
ship in case of damage to stern tube arrangement.
arrangements.
(See also Pt.4, Ch.4, Sec. 6.16). 2.5.3 Doors, manholes, permanent access
openings or ventilation ducts are not to be cut in
2.3.3 In ships with engines situated amidships, a the collision bulkhead below the freeboard deck.
watertight shaft tunnel is to be arranged.
Openings in the forward end of shaft tunnels are 2.5.4 Where watertight bulkhead stiffeners are
to be fitted with watertight sliding doors capable cut in way of watertight doors in the lower part of
of being operated from a position above the load the bulkhead, the opening is to be suitably
water line. framed and reinforced. Where stiffeners are not
cut but the spacing between the stiffeners is
2.4 Height of bulkheads increased on account of watertight doors, the
stiffeners at the sides of the doorways are to be
2.4.1 The watertight bulkheads are in general to increased in depth and strength so that the
extend to the bulkhead deck / freeboard deck. efficiency is at least equal to that of the
Indian Register of Shipping
Chapter 10 Part 3
Page 4 of 13 Bulkheads
unpierced bulkhead, without taking the stiffeners e) Hinged Door : A door having a pivoting
of the door-frame into consideration. motion about one vertical or horizontal
edge.
2.6 Doors in watertight bulkheads for ships
where subdivision / damage stability require- 2.6.3 Structural design
ments are applicable
Doors are to be of approved design and are to
2.6.1 The requirements in 2.6.1 to 2.6.16 apply be of a strength equivalent to that of the
to doors located in way of the internal watertight subdivision bulkheads in which they are fitted.
subdivision boundaries and the external
watertight boundaries necessary to ensure 2.6.4 Operation mode, location and outfitting
compliance with the relevant subdivision and
damage stability regulations. Doors are to be fitted in accordance with all
requirements regarding their operation mode,
These requirements do not apply to doors location and outfitting, i.e. provision of controls,
located in external boundaries above equilibrium means of indication etc. as shown in Table
or intermediate waterplanes. 2.6.4. For passenger ships, in addition to the
requirements given in the Table 2.6.4 the
2.6.2 Definitions watertight doors and their controls are to be
located in compliance with the following:
For the purpose of the requirements in this
subsection (2.6) the following definitions apply: a) The door is to be located inboard of the
damage zone B/5 on P&S as per SOLAS II-
a) Watertight : Capable of preventing the 1 Reg.13.7.
passage of water in any direction under a
design head. The design head for any part b) The door controls including hydraulic piping
of a structure shall be determined by and electric cables are to be kept as close
reference to its location relative to the as practicable to the bulkhead in which the
bulkhead deck or freeboard deck, as doors are fitted in order to minimize the
applicable, or to the most unfavourable likelihood of them being involved in any
equilibrium / intermediate waterplane, in damage to the ship. The positioning of
accordance with the applicable subdivision doors and controls is to be such that if the
and damage stability regulations, whichever ship sustains damage within damage zone
is the greater. A watertight door is thus one B/5 as mentioned above, the operation of
that will maintain the watertight integrity of the doors clear of the damaged portion of
the subdivision bulkhead in which it is the ship is not impaired.
located.
2.6.5 Frequency of use whilst at sea
b) Equilibrium Waterplane : The waterplane in
still water when, taking account of flooding a) Normally closed
due to an assumed damage, the weight and Kept closed at sea but may be used if
buoyancy forces acting on a vessel are in authorised. To be closed again after use.
balance. This relates to the final condition
when no further flooding takes place or after b) Permanently closed
cross flooding is completed.
The time of opening such doors in port and
c) Intermediate Waterplane : The waterplane of closing them before the ship leaves port
in still water, which represents the shall be entered in the log-book. Should
instantaneous floating position of a vessel at such doors be accessible during the
some intermediate stage between voyage, they shall be fitted with a device to
commencement and completion of flooding prevent unauthorised opening.
when, taking account of the assumed
instantaneous state of flooding, the weight c) Normally open
and buoyancy forces acting on a vessel are May be left open provided it is always ready
in balance. to be immediately closed.
Table 2.6.4 : Internal doors in watertight bulkheads in cargo ships and passenger ships
Position 1. 2. 3. 4. 5. 6. 7. 8.
relative to Frequency Type Remote Indication Audible Notice Comments Regulation
equilibrium of use control6 locally and alarm6
or whilst at on bridge6
intermediate sea
waterplane
I. Passenger Ships
Certain doors
may be left SOLAS II-1/ 13;
Norm.
POS Yes Yes Yes No open, see SOLAS II-1/22.1, 2,
A. At or Closed
SOLAS II- 3 and 4
below 1/22.4
Perm. SOLAS II-1/13.9 &
S, H No No No Yes See Notes 1+4
Closed 2
Norm. POS, SOLAS II-1/22.4
Yes Yes Yes No
Open POH SOLAS II-1/ 17.1
S, H No Yes No Yes See Note 2 MSC/Circ.541
B. Above
Norm. Doors giving
Closed SOLAS II-1/17.1
S, H No Yes No Yes access to Ro-
SOLAS II-1/23
Ro Deck
II. Cargo Ships
Used POS Yes Yes Yes No SOLAS II-1/13.2
Notes:
2.6.6 Types of doors in Table 2.6.4 the ship listed to either side. In the case of
passenger ships, it is to be possible to close
Power operated, sliding or rolling POS the door from a position above the bulkhead
Power operated, hinged POH deck with an all round crank motion or some
Sliding or rolling S other movement providing the same degree
Hinged H of safety.
Where shown in Table 2.6.4, position indicators Where a watertight door is located adjacent to a
are to be provided at all remote operating fire door, both doors are to be capable of
positions as well as locally, on both sides of the independent operation, remotely if required and
doors, to show whether the doors are open or from both sides of the each door.
closed and if applicable, with all dogs/cleats fully
and properly engaged. 2.6.12 Testing
An indication (i.e. red light) should be placed b) For large doors intended for use in the
locally showing that the door is in remote control watertight subdivision boundaries of cargo
mode ("doors closed mode"). Special care spaces, structural analysis may be accepted
should be taken in order to avoid potential in lieu of pressure testing. Where such
danger when passing through the door. doors utilise gasket seals, a prototype
Signboard/instructions should be placed in way pressure test to confirm that the
of the door advising how to act when the door is compression of the gasket material is
in "doors closed" mode. capable of accommodating any deflection,
revealed by the structural analysis, is to be
2.6.9 Alarms carried out.
Doors which are to be capable of being remotely c) Doors which are not immersed by an
closed are to be provided with an audible alarm, equilibrium or intermediate waterplane but
distinct from any other alarm in the area, which become intermittently immersed at angles of
will sound whenever such a door is remotely heel in the required range of positive
closed. For passenger ships the alarm shall stability beyond the equilibrium position are
sound for at lest 5 s but not more than 10 s to be hose tested.
before the door begins to move and shall
continue sounding until the door is completely 2.6.13 Pressure testing
closed. In the case of remote closure by hand
operation, an alarm is required to sound only The head of water used for the pressure test
while the door is actually moving. shall correspond to at least the head measured
from the lower edge of the door opening, at the
In passenger areas and areas of high ambient location in which the door is to be fitted in the
noise, the audible alarms are to be vessel, to the bulkhead deck or freeboard deck,
supplemented by visual signals at both sides of as applicable, or to the most unfavourable
the doors. damage waterplane, if that be greater. Testing
may be carried out at the factory or other shore
2.6.10 Notices based testing facility prior to installation in the
ship.
As shown in Table 2.6.4, doors which are
normally closed at sea but not provided with 2.6.14 For doors on passenger ships which are
means of remote closure, are to have notices normally open and used at sea or which become
fixed to both sides of the doors stating, 'To be submerged by the equilibrium or intermediate
kept closed at sea'. Doors which are to be waterplane, a prototype test shall be conducted,
Indian Register of Shipping
Rules and Regulations for the Construction and Classification of Steel Ships - 2014
Page 7 of 13
___________________________________________________________________________________
on each side of the door, to check the - tanks for fuel oil or lubricating oil
satisfactory closing of the door against a force
equivalent to a water head of at least 1 [m] - tanks for edible oil
above the sill on the centre line of the door.
- tanks for fresh water and feed water.
2.6.15 Hose testing
2.7.2 Tanks for lubricating oil are also to be
After installation in a ship if pressure test is not separated by cofferdams from those carrying
carried out, all watertight doors are to be subject fuel oil. However, these cofferdams need not be
to a hose test in accordance with Pt.3, Ch.18. fitted provided that the common boundaries
Hose testing is to be carried out from each side have full penetration welds and the head of
of the door unless, for a specific application, lubricating oil is not less than that in the adjacent
exposure to floodwater is anticipated only from fuel oil tanks. In this case, a permanent notice is
one side. Where a hose test is not practicable to be displayed near the lubricating oil tank that
because of possible damage to machinery, the oil level is not to be less than that in the
electrical equipment, insulation or outfitting adjacent fuel oil tank at any time.
items, it may be replaced by means such as an
ultrasonic leak test or an equivalent test. 2.8 Fore peak spaces
Section 3
Section 4
Design Loads
For the definition of 'loadpoint' see Ch.4, Sec.3. Where automatic pressure valves are fitted, po is
not to be taken as less than the valve release
4.1.2 Watertight bulkheads enclosing hold pressure.
spaces to carry water ballast are to be treated
as tank bulkheads. 4.2.2 For longitudinal bulkheads (and transverse
bulkheads at sides) in way of wide tanks, the
4.1.3 The design pressure for the end bulkheads design pressure is normally given by the greater
of bulk cargo spaces are to be obtained as per of 'p' according to 4.2.1 and
Ch.4, Sec.3.4.3.
p = 6.7 (hs + φ b) x 10 [N/mm ]
-3 2
p = [4 - 0.005L] l t x 10 −3 [ N/mm 2 ]
lt = distance [m] between transverse tank
bulkheads or effective transverse wash
bulkheads at the height at which the strength - for transverse bulkheads, and
member is located. Transverse web frames
covering part of the tank cross-section (e.g. wing p = [3 - 0.01B] b t x 10 −3 [ N/mm 2 ]
tank structures in tankers) may be regarded as
wash bulkheads for this purpose. - for longitudinal bulkheads.
- for strength members located within 0.25 bt where,
from the tank side bulkheads the pressure
'p' is not to be less than
lt = the greater of the distances between the
adjacent transverse bulkheads.
p = ρ [3 - 0.01B] b t x 10 −3 [ N/mm 2 ]
bt = the greater of the distances between the
where, adjacent longitudinal bulkheads.
Section 5
Between neutral
At strength deck or
Region Framing system At neutral axis axis and strength
at bottom
deck or bottom
(175 - 120 fs)/k To be obtained by
Vertical 140/k
max. 120/k linear interpolation
0.4L amidships
(185 - 100 fs)/k To be obtained by
Longitudinal 160/k
max. 120/k linear interpolation
Within 0.1L from
160/k
ends
To be obtained by linear interpolation between allowable values at regions specified
Elsewhere
above.
where,
where, σ s
2
σ c = σ F 1 − F
ta = thickness of adjacent plating [mm] not to be c 1000 t f
taken greater than t.
p = applicable design pressure given in Sec.4. = 20 for non-fixed upper end of vertical
corrugation
m = 12
= ms for vertical corrugation, lower end to stool
σ = (215 - 135 fs fz)/k, max. 160/k [N/mm ] for
2
5.3.3 Actual section modulus of corrugations is m = 16 for stiffeners fixed at both ends
to be obtained as per 5.2.4.
= 12 for stiffeners fixed at one end (lower end in
5.3.4 Brackets are normally to be fitted at the case of vertical stiffeners) and simply supported
ends of non-continuous stiffeners. Where at the other end.
stiffeners are sniped at the ends, the thickness
of the plating supported by the stiffeners is not = 8 for stiffeners simply supported at both ends.
to be less than: σ = 220/k.
t = 1.25 √[( l - 0.0005s) s.p.k] + tc [mm]. 5.4.2 The thickness of web and flange is to be
as required in 5.1.2. For sniped ends, the
5.4 Vertical and transverse stiffeners on thickness of bulkhead plating is to be as per
ordinary watertight bulkheads 5.3.4.
5.4.1 The section modulus of bulkhead stiffeners 5.4.3 Actual section modulus of corrugations is
is not to be less than to be obtained as per 5.2.4.
Section 6
Girders
2
6.1 General = 160/k [N/mm ] for continuous longitudinal
girders within 0.1L from ends and for vertical or
6.1.1 Bulkhead stringers and deep transverses transverse girders on tank and collision
are to be arranged in line with other primary bulkheads.
supporting structure to the adjoining deck, side
shell and bottom so as to facilitate the formation = 220/k for vertical and transverse girders in
of continuous ring structures. Otherwise ordinary watertight bulkheads.
equivalent scarphing arrangement is to be
provided. = 210/k for vertical and transverse girders in dry
bulk cargo bulkheads.
6.1.2 The section modulus requirement 'Z' of
simple girders is not to be less than: For continuous longitudinal girders between the
regions specified above, 'σ' may be obtained by
b.p.S 2 x10 6 linear interpolation.
Z= + Z c [cm 3 ]
mσ 6.1.3 The depth of the girders should not be less
than 2.5 times the depth of the cutout (if any) for
where, the passage of continuous stiffeners. The web
area requirement (after deduction of the cutouts)
m = 12 for continuous longitudinal girders with at the girder ends is given by:
end attachments in accordance with Ch.3,
Sec.5. 2
Aw = CkSbP + 0.01 dw tc [cm ]
The web area at middle of span to be not less In addition to satisfying the local requirements
than 0.5 Aw. specified in 6.1, the scantlings of bulkhead
girders, which are a part of a complex girder
6.1.4 The girders are to be satisfactorily system in holds for heavy cargo or tanks may
stiffened against buckling in accordance with the have to be based on direct stress analysis.
requirements given in Ch.3, Sec.6. Tripping
End of Chapter
Chapter 11
Contents
Section
1 General
2 Design Loads
3 Scantlings
4 Structural Arrangement and Details
5 Bulwarks and Guard Rails
6 Means of Embarkation and Disembarkation
Section 1
General
B' = actual max. breadth of the ship, [m] on the l = span of stiffener [m].
exposed weather deck at the position
considered.
Section 2
Design Loads
L f L f
20 .89 25 1.33
30 1.75 35 2.17
40 2.57 45 2.96
50 3.34 55 3.71
60 4.07 65 4.42
70 4.76 75 5.09
80 5.41 85 5.72
90 6.03 95 6.32
100 6.61 105 6.89
110 7.16 115 7.43
120 7.68 125 7.93
130 8.18 135 8.42
140 8.65 145 8.8
150 9.10 155 9.25
160 9.39 165 9.52
170 9.65 175 9.77
180 9.80 190 10.09
200 10.27 210 10.43
220 10.57 230 10.68
240 10.70 250 10.86
260 10.93 270 10.98
280 11.01 290 11.03
300 11.03
Section 3
Scantlings
3.1 End bulkheads of superstructures and t =(4 + 0.01 L1) √k [mm] for upper tiers.
deckhouses and exposed sides in
deckhouses 3.1.3 The section modulus Z of stiffeners on
fronts, sides and end bulkheads of all erections
3.1.1 The thickness 't' of steel plating of the other than sides of superstructures is not to be
fronts, sides and aft ends of the deckhouses and less than
the front and aft ends of the superstructures
2 3
corresponding to the design pressure is given by Z = 0.35 sl p [cm ] in general
t = (5 + 0.01 L1) √k [mm] for the lowest tier; The modulus may be linearly decreased to the
general value at the first deck above the
t = 0.0085 s √k [mm]
Section 4
4.1 Structural continuity poop and bridge, the side plating is to extend
beyond the ends of the superstructure, and is to
4.1.1 Adequate transverse strength is to be be gradually reduced in height down to the
provided to the deckhouses and superstructures sheer strake. The transition should be smooth
by means of transverse bulkheads, girders and and without any discontinuity. The extended
web frames. plating is to be adequately stiffened, particularly
at its upper edge.
4.1.2 The front and the after end bulkheads of
the superstructures and deckhouses should be 4.1.6 Deck girders are to be fitted below the
effectively supported below by a transverse sides of long deckhouses and are to extend at
bulkhead or by a combination of partial least three frame spaces beyond the deckhouse
bulkheads, girders and pillars. Similarly, the ends. The depth of the girders is to be at least
exposed sides and internal bulkheads of various 100 [mm] greater than the depth of the beams
tiers of erections are to be located, as far as and the girders are to be adequately stiffened at
practicable, above bulkheads or above deep the lower edge.
girders below, or equivalent.
4.1.7 The connection area between the corners
4.1.3 Adequate web frames are to be provided of long deckhouses and deck plating should be
in way of large openings, boat davits and other increased locally. Deck beams under the
points of high loading. corners of deck houses are not to be scalloped
for a distance of 0.5 [m] on either side of the
4.1.4 All openings cut on the sides are to be corners.
substantially framed and have well rounded
corners. Continuous coamings or girders are to 4.2 Navigation bridge visibility
be fitted below and above doors and similar
openings. The size and number of openings on 4.2.1 Attention is drawn to Chapter V,
the sides are to be avoided or minimized at the Regulation 22 of SOLAS 1994 Amendments
ends of erections situated within 0.4L amidships. regarding Navigation Bridge Visibility
requirements, applicable to ships of loadline
4.1.5 At the ends of superstructures, which have length equal to or greater than 45 [m].
no set-in from the ships' side, and at the ends of
Section 5
5.1.1 Bulwarks or guard rails are to be provided 5.3.1 The thickness of the bulwark plating is not
on the exposed parts of the freeboard and to be less than that required for the
superstructure decks and also on the first tier of superstructure side plating in the same location
the deckhouse decks. The height of the if the height of the bulwark is equal to or greater
bulwarks or guard rails measured above the than 1.8 [m]. Where the height of the bulwark is
sheathing, if any, is not to be less than 1.0 [m]. 1.0 [m], the thickness need not exceed 6.0
Consideration will be given to cases where this [mm]. For intermediate bulwark heights the
height would interfere with the normal operation thickness may be obtained by interpolation.
of the ship.
5.3.2 The section modulus 'Z' at the bottom of
5.2 Bulwark construction the bulwark stay is not to be less than:
2 3
5.2.1 Bulwarks are to be stiffened at the upper Z = (33 + 0.44 L) h s [cm ]
edge by a strong rail section and supported by
stays from the deck. The spacing of stays where,
forward of 0.07L from F.P. is to be not more
than 1.2 [m] on Type 'A', Type 'B-60' and Type h = height of the bulwark [m].
'B-100' ships as defined in the ILLC, and not
more than 1.8 [m]. on other types. Elsewhere, s = spacing of bulwark stays [m].
the bulwark stays are to be not more than 1.8
[m] apart. Where bulwarks are cut in way of a In the calculation of section modulus 'Z', only the
gangway or other openings, stays of increased material connected to the deck is to be included.
strength are to be fitted at the ends of the The contribution from bulwark plating and/or
openings. stay flange may be considered depending upon
the construction details.
Bulwark stays are to be supported by, or are to
be in line with, suitable underdeck stiffening, 5.3.3 When the bulwark is subjected to loads
which is to be connected by double continuous from any deck cargo, the scantlings will be
fillet welds in way of the bulwark stay specially considered.
connection.
5.4 Freeing arrangements
Bulwarks are to be adequately strengthened in
way of the eyeplates for cargo gear, and in way 5.4.1 Where bulwarks on the weather portion on
of the mooring pipes the plating is to be freeboard or superstructure decks form wells,
increased in thickness and also adequately provision is to be made for rapidly freeing the
stiffened. decks of water. In general the minimum freeing
area "A" on each side of the ship for each well
5.2.2 Bulwarks are generally not to be welded to on the freeboard deck is to be given by the
the top of the sheerstrake within 0.6L amidships. following in cases where the sheer in way of the
well is standard or greater than standard.
5.2.3 Bulwarks should not be cut in way of the
breaks of the superstructures, and are also to be Where, length of the bulwark (l) in the well is
arranged to ensure their freedom from main less than or equal to 20 [m] -
structural stresses. At the ends of the
2
superstructures where the side plating is A = 0.7 + 0.035 l [m ];
extended and tapered to align with the bulwark
plating, the transition plating is to be suitably and where l exceeds 20 [m] -
stiffened and supported. Where freeing ports or
2
other openings are essential in this plate, they A = 0.07 l [m ];
are to be suitably framed and kept well clear of
the free edge. l not to be taken as greater than 0.7 LL, where LL
is the loadline length of the vessel (See Ch.1)
5.4.3 On a flush deck ship with a substantial (i) If the freeflow area is not less than the
deckhouse amidships, it is considered that the freeing area calculated from 5.4.5 above
deckhouse provides sufficient break to form two as if the hatchway coamings were
wells and that each could be given the required continuous, then the minimum freeing
freeing port area based upon the length of the port area calculated from 5.4.1 & 5.4.2
'well'. It would not then be allowed to base the should be deemed sufficient.
area upon 0.7 LL.
(ii) If the freeflow area is equal to or less
For a 'substantial' deckhouse, the breadth of the than the freeing area calculated from
deckhouse should be at least 80% of the beam 5.4.1 & 5.4.2, the minimum freeing area
of the vessel and the passageways along the in the bulwarks should be determined
sides of the ship should not exceed 1.5 [m] in from 5.4.5.
width.
(iii) If the freeflow area is smaller than
Where a screen bulkhead is fitted completely calculated from 5.4.5 but greater than
across the vessel, at the forward end of a calculated from 5.4.1 and 5.4.2, the
midship deck house, this would effectively divide minimum freeing port area should be
the exposed deck into wells and no limitation on determined from the following formula.
the breadth of the deckhouse is considered
necessary in this case. 2
F = F1 + F2 - fp [m ]
5.4.5 The effectiveness of the freeing port area fp = the total net area of passages and gaps
in bulwarks required in 5.4.1 above depends on between hatch ends and superstructures or
the free flow across the deck of a ship. Where deckhouses up to the actual height of bulwark
there is no free flow due to the presence of a 2
[m ].
continuous trunk or hatchway coaming the
freeing area in bulwarks is to be calculated as 5.4.7 All such openings in the bulwark are to be
per Table 5.4.5. The area of freeing ports at protected by rails or bars spaced not more than
intermediate breadths shall be obtained by 230 [mm] apart. If shutters are fitted to freeing
linear interpolation. ports ample clearance is to be provided to
prevent jamming. Hinges are to have pins or
bearings of non-corrodible materials. If shutters
Stanchions with increased breadth to be aligned 5.7 Protection of crew requirements for
with member below deck which is to be min. 100 specific types
x 12 flatbar welded to deck by double
continuous fillet weld. The stanchions with Note : Some Administrations may have more
increased breadth need not be aligned with stringent requirements for protection of crew
under deck structure for deck plating exceeding than those given below.
20 [mm].
c) Wire ropes may only be accepted in lieu of 5.7.1 Protection of crew shall be provided by at
guardrails in special circumstances and then least one of the means denoted in Table 5.7.1.
only in limited lengths.
Acceptable arrangements referred to in the table
d) Lengths of chain may be accepted in lieu of are defined as follows:
guard rails if they are fitted between two
fixed stanchions and/or bulwarks. a) A well lighted and ventilated underdeck
passage (clear opening 0.8 [m] wide, 2 [m]
e) The clear opening below the lowest course high) as close as practicable to the
of the guard rails is not to exceed 230 [mm]. freeboard deck, connecting and providing
Where this course is not measured from the access to the locations in question.
deck, but from the sheerstrake or a b) On or near the centreline of a ship a
waterway bar, which is not in the same permanent and efficiently constructed
vertical plane as the rails, the length of gangway fitted at the level of the
opening is the diagonal distance between superstructure deck, providing a continuous
the lowest of the rails and the top of the platform at least 0.6 [m] in width and a non-
sheerstrake or waterway bar. The other slip surface, with guard rails extending on
courses are not to be more than 380 [mm] each side throughout its length. Guard rails
apart. Where rounded gunwales are fitted shall be at least 1 [m] high with courses as
the guard rail supports are to be placed on required in 5.6.e) above and supported by
the flat of the deck, as close as possible to stanchions spaced not more than 1.5 [m]; a
the beginning of the curvature of the foot stop shall be provided.
gunwale.
Acceptable arrangements
Assigned according to type of freeboard
Type of
Location of access in ships summer assigned:
Ship
freeboard Type Type Type
Type A
B-100 B-60 B&B+
All ships 1.1 Access to Midship Quarters ≤ 3000 mm a a a a
other than b b b b
Oil 1.1.1 Between poop and bridge, or e e c(1) c(1)
Tankers, e c(2)
Chemical f(1) c(4)
Tankers
and Gas 1.1.2 Between poop and deckhouse > 3000 mm a a a d(1)
Carriers containing living b b b d(2)
accommodation or navigating e e c(1) d(3)
equipment, or both c(2) e
e f(1)
f(1) f(2)
f(2) f(4)
1.2 Access to Ends ≤ 3000 mm a a a
1.2.1 Between poop and bow (if b b b
there is no bridge) c(1) c(1) c(1)
1.2.2 Between bridge and bow, or e c(2) c(2)
f(1) e e
f(1) f(1)
f(2) f(2)
1.2.3 Between a deckhouse > 3000 mm a a a
containing living b b b
accommodation or navigating c(1) c(1) c(1)
equipment, or both, and bow, d(1) c(2) c(2)
or e d(1) c(4)
1.2.4 In the case of a flush deck f(1) d(2) d(1)
vessel, between crew e d(2)
accommodation and the f(1) d(3)
forward and after ends of ships f(2) e
f(1)
f(2)
f(4)
Oil 2.1 Access to Bow ≤ (Af + Hs)*
Tankers, 2.1.1 Between poop and bow or a
Chemical 2.1.2 Between a deckhouse e
Tankers containing living f(1)
and Gas accommodation or navigating f(5)
Carriers equipment, or both, and bow,
or
2.1.3 In the case of a flush deck > (Af+ Hs)* a
vessel, between crew e
accommodation and the f(1)
forward end of ship f(2)
2.2 Access to After End As required in 1.2.4 for other types of
2.2.1 In the case of a flush deck ships
vessel, between crew
accommodation and the after
end of ship
* Af : the minimum summer freeboard calculated as type A ship regardless of the type of freeboard actually
assigned.
Hs : the standard height of superstructure as defined in Pt.3, Ch.12, 7.4.1.
Note : Deviations from some or all of these requirements or alternative arrangements for such cases as ships with
very high gangways (i.e. certain gas carriers) may be allowed subject to agreement case-by-case with the relevant
flag Administration.
c) A permanent walkway at least 0.6 [m] in accommodating at least one person and be
width fitted at freeboard deck level so constructed as to afford weather
consisting of two rows of guardrails with protection on the forward, port and
stanchions spaced not more than 3 [m]. The starboard sides.
number of courses of rails and their spacing
to be as required by 5.6.e above. On Type B f) A permanent and efficiently constructed
ships hatchway coamings not less than 0.6 walkway fitted at freeboard deck level on or
[m] in height may be regarded as forming as near as practicable to the center line of
one side of the walkway, provided that the ship having the same specifications as
between the hatchways two rows of guard those for a permanent gangway listed in (e)
rails are fitted. except for foot-stops. On Type B ships
(certified for the carriage of liquids in bulk),
d) A 10 [mm] minimum diameter wire rope with a combined height of hatch coaming
lifeline supported by stanchions about 10 and fitted hatch cover of together not less
[m] apart, or A single handrail or wire rope than 1 [m] in height the hatchway coamings
attached to hatchcoamings, continued and may be regarded as forming one side of the
adequately supported between hatchways. walkway, provided that between the
hatchways two rows of guard rails are fitted.
e) A permanent and efficiently constructed
gangway fitted at or above the level of the Alternative transverse locations to 'c', 'd' and 'f'
superstructure deck on or as near as above: (indicated as (1) to (5) in Table 5.7.1).
practicable to the center line of the ship:
(1) At or near center line of ship; or fitted on
- located so as not to hinder easy access hatchways at or near center line of ship.
across the working areas of the deck;
(2) Fitted one each side of the ship
- providing a continuous platform at least 1.0
[m] in width; (3) Fitted on one side, provision being made for
fitting on either side
- constructed of fire resistant and non-slip
material; (4) Fitted on one side only.
Note : FRP gratings used in lieu of steel gratings (5) Fitted on each side of the hatchways as
for safe access to tanker bows are to possess: near to the center line as practicable.
• low flame spread characteristics and are not The following requirements also to be met:
to generate excessive quantities of smoke
and toxic products, as per the FTP Code; i. In all cases where wire ropes are fitted,
and adequate devices are to be provided to
ensure their tautness
• adequate structural fire integrity as per
national / international standards. ii. Wire ropes may only be accepted in lieu
of guard rails in special circumstances
- fitted with guard rails extending on each and then only in limited lengths.
side throughout its length; guard rails should
be at least 1.0 [m] high with courses as iii. Lengths of chain may only be accepted
required by 5.6.e above and supported by in lieu of guard rails if fitted between two
stanchions spaced not more than 1.5 [m]; fixed stanchions.
- provided with a foot stop on each side; iv. Where stanchions are fitted, every 3rd
stanchion is to be supported by a
- having openings, with ladders where bracket or stay.
appropriate, to and from the deck. Openings
should not be more than 40 [m] apart; v. Removable or hinged stanchions shall
be capable of being locked in the
- having shelters of substantial construction upright position.
set in way of the gangway at intervals not
exceeding 45 [m] if the length of the vi. A means of passage over obstructions,
exposed deck to be traversed exceeds 70 if any, such as pipes or other fittings of a
[m]. Every such shelter should be capable of permanent nature, should be provided.
vii. Generally, the width of the gangway or platform or deck level walkway fitted in
deck level walkway should not exceed accordance with arrangement (e) or (f),
1.5 [m]. respectively, may be reduced to 0.6 [m].
viii. For tankers less than 100 [m] in length,
the minimum width of the gangway
Section 6
number of passengers and crew and their horizontal, unless designed and constructed for
luggage. use at angles greater than these and marked as
such, as required by 6.3.5.1.
6.3.4.2 The arrangement at the head of the
accommodation ladder is to provide direct 6.3.7.2 Gangways are not to be secured to
access between the ladder and the ship’s deck ship’s guardrails unless they have been
by a platform securely guarded by handrails and designed for that purpose. If positioned through
adequate handholds. The ladder should be an open section of bulwark or railings, any
securely attached to the ship to prevent remaining gaps are to be adequately fenced.
overturning.
6.3.7.3 Adequate lighting for means of
6.3.4.3 For ships on which the height of the embarkation and disembarkation and for the
embarkation / disembarkation deck exceeds 20 immediate approaches are to be ensured from
[m] above the waterline specified in 6.3.4.1 and the ship and/or the shore in hours of darkness.
on other ships where compliance with the
provisions of 6.3.4.1 is considered impractical, 6.3.8 Safety net
an alternative means of providing safe access to
the ship or supplementary means of safe access 6.3.8.1 A safety net is to be mounted in way of
to the bottom platform of the accommodation the accommodation ladders and gangways
ladder may be accepted. where it is possible that a person may fall from
them or between the ship and quayside.
6.3.5 Marking
6.3.9 Verification
6.3.5.1 Each accommodation ladder or gangway
is to be clearly marked at each end with a plate 6.3.9.1 Upon installation the entire arrangement
showing the restrictions on the safe operation of the means of embarkation and
and loading, including the maximum and disembarkation will be verified for compliance
minimum permitted design angles of inclination, with the requirements of this section.
design load, maximum load on bottom end
plate, etc. Where the maximum operational load 6.4 Inspection and maintenance
is less than the design load, it should also be
shown on the marking plate. 6.4.1 The maintenance and inspection
requirements for means of embarkation and
6.3.6 Test disembarkation are to be addressed by the
ship’s safety management system.
6.3.6.1 After installation, the winch and the
accommodation ladder are to be operationally 6.4.2 The wires used to support the means of
tested to confirm proper operation and condition embarkation and disembarkation are to be
of the winch and the ladder after the test. renewed when necessary due to deterioration or
at intervals of not more than 5 years, whichever
6.3.6.2 The winch is to be tested as a part of the is earlier.
complete accommodation ladder unit through a
minimum of two times hoisting and lowering of 6.4.3 Arrangements should also be made to
the accommodation ladder in accordance with examine the underside of gangways and
the onboard test requirement specified in accommodation ladders at regular intervals.
applicable international standards such as ISO
7364:1983. 6.4.4 All inspections, maintenance work and
repairs of accommodation ladders and
6.3.6.3 Every new accommodation ladder is to gangways should be recorded in order to
be subjected to a static load test of the specified provide an accurate history for each appliance.
maximum working load upon installation. The information to be recorded appropriately on
board should include the date of the most recent
6.3.7 Positioning inspection, the name of the person or body who
carried out that inspection, the due date for the
6.3.7.1 Gangways are not to be used at an next inspection and the dates of renewal of
angle of inclination greater than 30° from the wires used to support the embarkation and
horizontal and accommodation ladders are not disembarkation arrangement.
to be used at an angle greater than 55° from the
End of Chapter
Chapter 12
Contents
Section
1 General
2 Hatch Coamings
3 Hatch Covers
4 Hatch Cover Securing Arrangement
5 Side Shell Doors and Stern Doors
6 Bow Doors and Inner Doors
7 Miscellaneous Openings
Section 1
General
1.1.1 This Chapter applies to all ship types in - Upon exposed freeboard and raised quarter
general. Additional requirements pertaining to decks for their entire length and
special ship types are given in Pt.5.
- Upon exposed superstructure decks
1.1.2 The requirements conform, where situated forward of the 0.25L from the F.P.
applicable, to those of the International
Convention on Load Lines, 1966 (ILLC, 1966) Position 2
as amended by the 1988 protocol, as amended
in 2003. Reference should also be made to the - Upon exposed superstructure decks
additional requirements of the National Authority situated abaft the 0.25L from the F.P and
of the country in which the ship is to be located at least one standard height of
registered. superstructure above the freeboard deck,
and.
Requirements for hatch covers and coamings of
bulk carriers, ore carriers and combination - Upon exposed superstructure decks located
carriers are given in Pt.5, Ch.1. forward of 0.25L from the F.P. and at least
two standard heights of superstructure
1.2 Definitions above the freeboard deck.
1.2.1 Where the freeboard is increased in Note : The upper limit of the vertical extent of
accordance with Ch.11, Sec.1.2.2 the actual Position 2 need not be considered to exceed
freeboard deck may be treated as the two standard superstructure heights at locations
superstructure deck, while considering the abaft the 0.25L from the F.P. and three standard
requirements given in this chapter. The superstructure heights forward of 0.25L from the
requirements of hatches and doors on the F.P.
weather decks are given with respect to two
basic positions as follows: 1.2.2 σy = the minimum upper yield strength of
2
the material [N/mm ].
1.3 Hatch cover and coaming load model 1.3.1 Vertical design weather load
Structural assessment of hatch covers and The pressure p H , [N/mm²], on the hatch cover
hatch coamings is to be carried out using the panels is given in Table 1.3.1. The vertical
design loads, defined in this section: design weather load need not be combined with
cargo loads given in 1.3.3 and 1.3.4.
Definitions:
In Fig.1.3.1.1 the positions 1 and 2 for the
purpose of design weather loads are illustrated
L = Rule length of ship [m] as defined in for an example ship.
Ch1. Sec.2
LL = Loadline length of ship [m] as Where an increased freeboard is assigned, the
defined in Ch1. Sec.2 design load for hatch covers according to Table
1.3.1 on the actual freeboard deck may be as
x = Longitudinal co-ordinate of mid required for a superstructure deck, provided the
point of assessed structural summer freeboard is such that the resulting
member measured from aft end of draught will not be greater than that
length L or LL, as applicable corresponding to the minimum freeboard
Tfb = Draught, [m], corresponding to the calculated from an assumed freeboard deck
assigned summer load line situated at a distance at least equal to the
hN = Standard superstructure height [m] standard superstructure height hN below the
actual freeboard deck. (See Fig.1.3.1.2).
= 1.05 + 0.01 LL, 1.8 ≤ hN ≤ 2.3
(Also see Table 7.5.1)
9.81x10 −3
⋅ (4.28 x L L + 28) ⋅
x
− 1.71 x L L + 95
−3
76 LL
9.81x10
(
⋅ 1.5 ⋅ L L + 116 ) upon exposed superstructure decks located at least one
76
superstructure standard height above the freeboard deck
9.81x10 −3
⋅ (1.5 x L L + 116 )
76
for LLL > 100 m
on freeboard deck for type B ships according to ICLL
1
9.81x10 −3 (0.0296 ⋅ L1 + 3.04 ) ⋅
x
− 0.0222 ⋅ L1 + 1.22
LL
on freeboard deck for ships with less freeboard than type B
according to ICLL
9.81 ⋅ 3.5.10 −3
9.81x10 −3 (0.1452 ⋅ L1 + 8.52 ) ⋅
x
− 0.1089 ⋅ L1 + 9.89
LL
L1 = LL but not more than 340 [m]
9.81 x 3.5.10 −3
for 24 m ≤ LL ≤ 100 m
9.81 x 10 −3
⋅ (1.1 x L L + 87.6 )
76
for LL > 100 m
2
9.81x2.6.10 −3
upon exposed superstructure decks located at least one superstructure standard height
above the lowest Position 2 deck
9.81x 2.1
2**
2**
2** 2
2 1* 1*
Freeboard Deck 1 1 1
0.25 LL
Length LL
* reduced load upon exposed superstructure decks located at least one superstructure standard
height above the freeboard deck
** reduced load upon exposed superstructure decks of vessels with LL > 100 m located at least
one superstructure standard height above the lowest Position 2 deck
2**
2**
2** 2**
2** 2 2
Actual Freeboard Deck 2 2 1*
Assumed Freeboard Deck ≥ hN
0.25 LL
Length LLL
* reduced load upon exposed superstructure decks located at least one superstructure standard
height above the freeboard deck
** reduced load upon exposed superstructure decks of vessels with LL > 100 m located at least
one superstructure standard height above the lowest Position 2 deck
Fig. 1.3.1.2 : Positions 1 and 2 for design weather loads for an increased freeboard
= 10.75 − for
150 0.6 ≤ C B ≤ 0.8 , when determining scantlings of
350 [m] ≤ L ≤ 500 [m] aft ends of coamings and aft
hatch cover skirt plates
forward of amidships, CB need
L
cL = 90
for L < 90 [m] not be taken less than 0,8.
Table 1.4 : Corrosion additions tc for hatch covers and hatch coamings
Section 2
Hatch Coamings
2.2.6 Hatch coamings and supporting structures For sniped stiffeners at coaming corners section
are to be adequately stiffened to resist the modulus and shear area at the fixed support
loading from hatch covers, in longitudinal, have to be increased by 35%. The gross
transverse and vertical directions. thickness of the coaming plate at the sniped
stiffener end shall not be less than:
2.2.7 The stresses in the under deck structures
induced by the load transmitted by the stays are
p A . 10 -3.s.(1000l − 0.5 s)
not to be greater than the allowable stresses for t = 19.6. [mm]
coaming stays indicated in 2.5.2. σF
2.2.8 The coamings are to be satisfactorily Horizontal stiffeners on hatch coamings, which
stiffened against buckling. are part of the longitudinal hull structure, are to
be designed according to Ch.10, Sec.5.2.
2.3 Hatch coaming strength criteria
2.5 Coaming stays
2.3.1 Local net plate thickness of coamings
Coaming stays are to be designed for the loads
The net thickness of weather deck hatch transmitted through them and permissible
coamings shall not be less than the larger of the stresses according to 3.3.1
following values:
2.5.1 Coaming stay section modulus
p A .10 3
t = 0.0142 . s [mm] The net section modulus ‘Z’ of coaming stays
0.95. σ F with a height less than 1.6 [m] and which are to
be designed for the load pA, is not be less than:
L1
t min = 6 + [mm] 526
100 Z= . e . h s2 . p A .10 3 [cm 3 ]
σF
s = stiffener spacing [mm]
e = spacing of coaming stays [m]
L1 = L, need not be taken greater than 300 [m]
hs = height of coaming stay [m]
σ F = minimum yield stress [N/mm2]
Coaming stays of coamings having a height of
Longitudinal strength aspects are to be verified 1.6 [m] or more are to be designed using direct
according to Ch.5. calculations under consideration of the
permissible stresses according to 3.3.1. The
2.4 Net scantling of secondary stiffeners of effective breadth of the coaming plate shall not
coamings be larger than the effective plate breadth
according to 3.7.1.
The stiffeners must be continuous at the
coaming stays. For stiffeners with both ends Coaming stays are to be supported by
constraint, the elastic net section modulus Z appropriate substructures. Face plates may only
3 2
[cm ] and net shear area As, [cm ], calculated on be included in the calculation if an appropriate
the basis of net thickness, is not be less than:
hw = web height of coaming stay at its lower end Structures under deck are to be checked against
[m] the load transmitted by the stays.
tc = corrosion addition [mm] according to 1.4. Unless otherwise stated, weld connections and
materials are to be dimensioned and selected in
Webs are to be connected to the deck by fillet accordance with the requirements of Ch.17 and
welds on both sides with throat thickness of 0.44 Ch.2 respectively.
tw.
2.6.3 Stays
2.5.3 Coaming stays under friction load
On ships carrying cargo on deck such as timber,
For coaming stays, which transfer friction forces coal or coke, the stays are to be spaced not
at hatch cover supports, sufficient fatigue more than 1.5 [m] apart.
strength is to be verified. (Also see 4.4.2).
2.6.4 Drainage arrangement at the coaming
2.6 Further requirements for hatch coamings
If drain channels are provided inside the line of
2.6.1 Longitudinal strength gasket by means of a gutter bar or vertical
extension of the hatch side and end coaming,
Hatch coamings which are part of the drain openings are to be provided at appropriate
longitudinal hull structure are to be designed positions of the drain channels.
according to the requirements of Ch.5.
Drain openings in hatch coamings are to be
For structural members welded to coamings and arranged with sufficient distance to areas of
for cutouts in the top of coamings sufficient stress concentration (e.g. hatch corners,
fatigue strength is to be verified. transitions to crane posts).
Longitudinal hatch coamings with a length Drain openings are to be arranged at the ends
exceeding 0.1L [m] are to be provided with of drain channels and are to be provided with
tapered brackets or equivalent transitions and a non-return valves to prevent ingress of water
corresponding substructure at both ends. At the from outside. It is unacceptable to connect fire
end of the brackets they are to be connected to hoses to the drain openings for this purpose.
the deck by full penetration welds of minimum
300 [mm] in length. If a continuous outer steel contact between
cover and ship structure is arranged, drainage
from the space between the steel contact and
the gasket is also to be provided for.
Section 3
Hatch Covers
'd' : Access hatch covers for cargo oil tanks and 3.2.1 The scantlings of the hatch cover plating,
adjacent spaces. The hatch covers are to be of secondary stiffeners and primary supporting
steel and gasketed. members are to be determined as per 3.4, 3.5
and 3.6 respectively using the design loads
'e' : Access hatch covers other than 'd'. For given in 1.3.
Types 'A', 'B-100' and 'B-60' ships, the covers
are to be of steel, and weathertightness is to be 3.2.2 Hatchcovers of special construction and
ensured by means of gaskets. arrangement e.g. covers designed and
constructed as a grillage, covers supported
Note : Modern hatch cover designs of lift-away- along more than two opposite edges and covers
covers are in many cases called pontoon supporting other covers, may require
covers. This definition does not fit to the submission of direct strength calculation taking
definition above. Modern lift-away hatch cover into account the arrangement of stiffeners and
designs should belong to one of the two the supporting members.
categories single skin covers or double skin
cover. When a beam or a grillage analysis is used, the
secondary stiffeners are not to be included in
the attached flange area of the primary load according to 1.3.1 is to be not more than
members. 0.0056 ⋅ l g [m] where lg [m] is the greatest span
of primary supporting members.
3.3 Permissible stresses and deflections
Note: Where hatch covers are arranged for
3.3.1 Stresses
carrying containers and mixed stowage is
allowed, i.e., a 40'-container stowed on top of
The equivalent stress σv in steel hatch cover two 20'-containers, particular attention is to be
structures related to the net thickness shall not paid to the deflections of hatch covers. Further
exceed 0.8 σF, where σF is the minimum yield the possible contact of deflected hatch covers
2
stress, [N/mm ], of the material. For design with in hold cargo has to be observed.
loads according to 1.3.2 to 1.3.5, the equivalent
stress σv related to the net thickness shall not 3.4 Local net plate thickness
exceed 0.9 σF when the stresses are assessed
by means of FEM using plane stress or shell The local net plate thickness t, [mm], of the
elements. hatch cover top plating is not to be less than:
σ V = σ x 2 − σ x ⋅ σ y + σ y 2 + 3τ 2 [N/mm ]
2 s = stiffener spacing [m]
2
p = pressure pH and pL, [N/mm ], as
defined in 1.3.
σx = normal stress, [N/mm2], in x-direction
σ
2
= normal stress, [N/mm ], of hatch cover
σy = normal stress, [N/mm2], in y-direction top plating
τ
2
= shear stress, [N/mm ], in the x-y plane
σa = 0,8 ⋅ σ F [N/mm2]
Indices x and y are coordinates of a two- For flange plates under compression sufficient
dimensional Cartesian system in the plane of buckling strength according to 3.8 is to be
the considered structural element. demonstrated.
In case of FEM calculations using shell or plane Note:
strain elements, the stresses are to be read from The normal stress ‘σ’ of the hatch cover plating
the centre of the individual element. Where shell may be determined at a distance s from webs of
elements are used, the stresses are to be adjacent primary supporting members
evaluated at the mid plane of the element. perpendicular to secondary stiffeners and at a
distance ‘s/2’ from the web of an adjacent
Stress concentrations are to be assessed to the primary supporting member parallel to
satisfaction of IRS. secondary stiffeners, refer to Fig. 3.2. The
greater of both stresses is to be taken. For the
3.3.2 Deflection
distribution of normal stress σ between two
The vertical deflection of primary supporting parallel girders, refer to 3.8.3.2.
members due to the vertical design weather
The net thickness of webs of primary supporting Cross-sectional properties are to be determined
members is not to be less than: considering the effective breadth. Cross
sectional areas of secondary stiffeners parallel
t = 6.5 ⋅ s [mm] to the primary supporting member under
consideration within the effective breadth can be
included, refer Fig. 3.8.3.2.1.
t min = 5 [mm]
The effective breadth of plating em of primary
s = stiffener spacing [m].
supporting members is to be determined
according to Table 3.7.1, considering the type of
3.6.2 Edge girders (Skirt plates)
loading. Special calculations may be required for
Scantlings of edge girders are obtained from the determining the effective breadth of one-sided or
calculations according to 3.7 under non-symmetrical flanges.
consideration of permissible stresses as per
3.3.1. The effective cross sectional area of plates is
not to be less than the cross sectional area of
The net thickness of the outer edge girders the face plate.
exposed to wash of sea is not to be less than
the largest of the following values: For flange plates under compression with
secondary stiffeners perpendicular to the web of
the primary supporting member, the effective
width is to be determined according to 3.8.3.2.
l/e 0 1 2 3 4 5 6 7 ≥8
em1 is to be applied where primary supporting members are loaded by uniformly distributed loads or
else by not less than 6 equally spaced single loads
em2 is to be applied where primary supporting members are loaded by 3 or less single loads
Intermediate values may be obtained by direct interpolation.
l length of zero-points of bending moment curve:
l = l0 for simply supported primary supporting members
l = 0,6 · l0 for primary supporting members with both ends constraint,
where l0 is the unsupported length of the primary supporting member
e width of plating supported, measured from centre to centre of the adjacent unsupported fields
Definitions
3.7.2 General requirements for FEM
calculations a = length of the longer side of a single plate
field [mm] (x-direction)
For strength calculations of hatch covers by
means of finite elements, the cover geometry is b = breadth of the shorter side of a single
to be idealized as realistically as possible. plate field [mm] (y-direction)
Element size is to be appropriate to account for α = aspect ratio of single plate field
effective breadth. In no case element width is to
= a/b
be larger than stiffener spacing. In way of force
transfer points and cutouts the mesh has to be n = number of single plate field breadths
refined where applicable. The ratio of element within the partial or total plate field
length to width is not exceed 4. t = net plate thickness [mm]
σ x = (σ x* − 0.3 ⋅ σ *y ) 0.91
F1= correction factor for boundary condition at
the longitudinal stiffeners according to
Table 3.8.
σ y = (σ *y − 0.3 ⋅ σ x* ) 0.91
1
Guidance values where both ends are 1.05 for flat bars
effectively connected to adjacent
structures 1.10 for bulb sections
1
Exact values may be determined by direct calculations
2
Higher value may be taken if it is verified by a buckling strength check of the
partial plate field using non-linear FEA and deemed appropriate by IRS, but
not greater than 2.0
2
σe = reference stress, [N/mm ], taken equal = 1.10 for hatch covers when subjected
to to loads according to 1.3.2 to 1.3.5
2
t λ
0.9 ⋅ E = reference degree of slenderness,
= b taken equal to:
σF
=
Ψ = edge stress ratio taken equal to K ⋅σ e
= σ 2 / σ 1 where
K = buckling factor according to Table
σ1 = maximum compressive stress 3.8.2.
e2
σ ⋅S
e3
σx ⋅S σ x ⋅σ y ⋅ S 2 τ ⋅S ⋅ 3
e1
+ y − B + ≤ 1.0
κ ⋅σ κ y ⋅σ F σ F2 κτ ⋅ σ F
x F
The first two terms and the last term of the Where σy ≤ 0 (tensile stress), κy = 1.0.
above condition shall not exceed 1,0.
The exponents e1, e2 and e3 as well as the
The reduction factors kx, ky and kτ are given in factor B are to be taken as given by Table 3.8.1.
Table 3.8.2.
Exponents e1 - e3 and
Plate panel
factor B
e1 1 + κ x4
e2 1 + κ y4
e3 1 + κ x ⋅ κ y ⋅ κ τ2
B
σx and σy positive (κ x ⋅ κ y )5
(compressive stress)
B
σx or σy negative 1
(tensive stress)
Table 3.8.2 : Buckling and reduction factors for plane elementary plate panels
Buckling- Edge Aspect
Load Case stress ratio Buckling factor K Reduction factor κ
ratio ψ α =a b
1 8.4 κx =1 for
1 ≥ψ ≥ 0 K=
ψ + 1.1 λ ≤ λc
1 0.22
κ x = c − 2 for
0 > ψ > −1 K = 7.63 − ψ (6.26 − 10ψ ) λ λ
α ≥1 λ > λc
c = (1.25 − 0.12ψ ) ≤ 1.25
ψ ≤ −1 K = (1 − ψ ) ⋅ 5.975
2
c 0.88
λc = 1 + 1 −
2 c
2 1 R + F 2 (H − R )
1 2.1
2
κ y = c −
1 ≥ψ ≥ 0
α ≥1 K = F1 1 + 2 ⋅ λ λ2
α (ψ + 1.1)
c = (1.25 − 0.12ψ ) ≤ 1.25
1 2,1(1 + ψ )
2
K = F1 1 + 2 ⋅
1 ≤ α ≤ 1,5 α 1.1 λ
R = λ 1 − for λ < λc
ψ c
− (13.9 − 10ψ ) R = 0.22 for λ ≥ λc
α2
c 0.88
λc = 1 + 1 −
0 > ψ > −1 1 2.1(1 + ψ )
2
2 c
K = F1 1 + 2 ⋅
α 1.1 K
−1
α > 1,5 ψ F = 1 − 0.912 ⋅ c1 ≥ 0
− ⋅ (5.87 + 1.87α 2 λp
α 2
8.6
+ − 10ψ )
α 2
λ p 2 = λ2 − 0.5 for
1≤α ≤ 1 ≤ λp2 ≤ 3
1 −ψ
2
3(1 −ψ ) K = F1 ⋅ 5.975 F
4 α c1 = 1 − 1 ≥ 0
α
1 −ψ 2 2λ
H =λ− ≥R
K = F1 ⋅ 3.9675
ψ ≤ −1 c T + T 2 − 4
α> α
3(1 −ψ )
1 −ψ
4
4 + 0.5375 T =λ+
14 1
+
α 15λ 3
+ 1.87]
3 1
4 0.425 + 2
1 ≥ψ ≥ 0 α
K=
3ψ + 1
α >0
1
K = 4 0.425 + 2 (1 + ψ ) κx =1 for λ ≤ 0.7
0 > ψ ≥ −1 α
− 5ψ (1 − 3.42ψ ) κx =
1
for λ > 0.7
4
λ + 0,51
2
1 3 −ψ
1 ≥ ψ ≥ −1 α >0 K = 0.425 + 2
α 2
5
K = Kτ ⋅ 3
α ≥1 4 κτ = 1 for λ ≤ 0.84
Kτ = 5.34 + 2
=== α κτ =
0,84
for λ > 0.84
0 <α <1 λ
5.34
Kτ = 4 + 2
α
Explanations for boundary conditions - - - - - plate edge free
──── plate edge simply supported
3.8.2 Webs and flanges of primary 3.8.3.2 Effective width of top and lower
supporting members hatch cover plating
For non-stiffened webs and flanges of primary For demonstration of buckling strength
supporting members sufficient buckling strength according to 3.8.3.3 through 3.8.3.4 the effective
as for the hatch cover top and lower plating is to width of plating may be determined by the
be demonstrated according to 3.8.1. following formulae:
It is to be demonstrated that the continuous The effective width of plating is not to be taken
longitudinal and transverse stiffeners of partial greater than the value em obtained from 3.7.1.
and total plate fields comply with the conditions
set out in 3.8.3.3 through 3.8.3.4. The effective width e'm of stiffened flange plates
of primary supporting members may be
determined as follows:
Note:
σ x2
a ≥ em c1 = 0 ≤ c1 ≤ 1
σ x1
e'm = n ⋅ am < em
n = 2,7 ⋅
em
≤ 1
c2 =
1.5 "
e
( )
. e ml + e "m2 − 0.5
a
stiffener
p zy = 2 ⋅ c x ⋅ σ xl + σ y 1 + y + 2τ 1
n⋅b a ⋅t
M0 = bending moment, [Nmm], due to the
a
deformation “w” of stiffener, taken equal to:
M 0 = FKi
pz ⋅ w ( )
with c f − p z > 0 Ax
c f − pz σ xl = σ x 1 +
b⋅t
M1 = bending moment, [Nmm], due to the
lateral load “p” equal to:
cx , c y = factor taking into account the
stresses perpendicular to the
3 2 stiffener's axis and distributed
p .10 . b . a
M1 = for longitudinal stiffeners variable along the stiffener's length
24 x10 3
= 0.5. (1 + Ψ ) for 0 ≤ Ψ ≤ 1
2
Ax , A y = net sectional area, [mm ] of the p . b . a 4 .10 3
longitudinal or transverse stiffener,
w 1= for longitudinal stifeners
384 .10 7 . E . I x
respectively, without attached plating
m1 m2
τ 1 = τ − t σ F ⋅ E + 2 ≥ 0 5 . a . p . (n . b) 4 .10 3
a
2
b w 1= for transverse
384 .10 7 . E . I y . c 2x
for longitudinal stiffeners: stiffeners
cf = elastic support provided by the stiffener,
2
a [N/mm ]
≥ 2.0 : m1 = 1.47 m2 = 0.49
b i) For longitudinal stiffeners:
π2
c fx = FKix ⋅ ⋅ (1 + c px )
a2
a
< 2.0 : m1 = 1.96 m2 = 0.37
b 1
c px =
for transverse stiffeners: 12.10 4 . I x
0.91. − 1
t 3 .b
1 +
a 1.96 c xa
≥ 0.5 : m1 = 0.37 m2 =
n.b n2
a 1.47
≥ 0.5 : m1 = 0.49 m2 =
n.b n2
2
a 2b
c xa = + for a ≥ 2b
2b a
w = w0 + w1 a 2
2
c xa = 1 + for a < 2b
wo = assumed imperfection [mm]
2b
a b
w0 x ≤ min( , ,10)
250 250 ii) For transverse stiffeners:
- for longitudinal stiffeners
π2
a n ⋅b c fy = c S ⋅ FKiy ⋅ ⋅ (1 + c py )
w0 y ≤ min( ,
250 250
,10) (n ⋅ b )2
- for transverse stiffeners
1
c py =
Note: 12.10 4 . I y
0.91. 3
− 1
For stiffeners sniped at both ends wo must not t . a
be taken less than the distance from the 1 +
midpoint of plating to the neutral axis of the c ya
profile including effective width of plating.
σF
λT =
σ KiT
n ⋅ b 2a
2
c ya = + for
2a n ⋅ b E π 2 ⋅ I ω ⋅ 10 2
n ⋅ b ≥ 2a
σ KiT = 2
ε + 0.385 ⋅ I T ,
IP a
2 2
n ⋅ b 2 [N/mm ]
c ya = 1 + for
2a For I P , IT , Iω
see Fig. 3.8.3.4.1 and Table
n ⋅ b < 2a 3.8.3.4.1.
κT =
1
for λT > 0.2 Af = net flange area equal to: A f = b f ⋅ t f
Φ+ Φ −λ 2 2
T tf
e f = hw + , [mm]
Φ = 0.5(1 + 0.21(λT − 0.2)+ λ )
2 2
T
Section IP IT Iω
hw3 ⋅ t w hw ⋅ t w3 t hw3 ⋅ t w3
Flat bar 1 − 0.63 w
4
3 ⋅ 10 4 3 ⋅10 hw 36 ⋅ 10 6
τa = allowable shear stress 3.11.2 The ends of the web plates are to be
doubled, or inserts fitted for at least 180 [mm]
= 0.46 σF [N/mm ]
2
along the length of the web.
x is the distance [m] from the end of the span to 3.11.3 The beams which carry the ends of wood
the section considered. The value of x is not to or steel hatch covers, a 50 [mm] vertical flat is to
be taken more than 0.25l. be arranged on the upper face plate. The width
of bearing surface for hatch covers is to be not
3.10 Wooden hatch covers less than 65 [mm].
3.10.1 Wooden hatch covers are to have a 3.11.4 Carriers or sockets, or other suitable
finished thickness of not less than 60[mm] in arrangements are to be provided as means of
association with an unsupported span of 1.5 [m] the efficient fitting and securing of portable hatch
and of not less than 82 [mm] with 2 [m] beams. The arrangements are to be of suitable
unsupported span. The thickness for the construction and the width of the bearing
intermediate span may be obtained by linear surface is not to be less than 75 [mm].
interpolation. Where the tween deck height
exceeds 2.6 [m], the thickness of the wood 3.11.5 Sliding hatch beams are to be provided
hatch cover is to be increased at the rate of 16.5 with an efficient device for locking them in their
per cent per metre of excess tween deck height. correct fore and aft positions when the hatchway
is closed.
3.10.2 The ends of all wooden hatch covers are
to be protected by encircling with galvanized 3.12 Direct calculations
steel bands, about 65 [mm] wide and 3 [mm]
thick, efficiently secured. 3.12.1 Hatchcovers of special construction and
arrangement e.g. covers designed and
3.11 Portable hatch beams constructed as a grillage, covers supported
along more than two opposite edges and covers
3.11.1 The section modulus and the moment of supporting other covers, may require
inertia of the portable hatch beams stiffened at submission of direct strength calculation taking
their upper and lower edges by continuous flat into account the arrangement of stiffeners and
the supporting members.
Section 4
- The exposed deck on which the hatch 4.1.6 A metallic contact is to be kept between
covers are located is situated above a depth the hatchcover and the hull to effect electrical
H(x) . H(x) is to be shown to comply with the earthing.
following criteria:
4.1.7 Where rod cleats are fitted, resilient
H(x) ≥ Tfb + fb + h [m] washers or cushions are to be incorporated.
Tfb = draught [m] corresponding to the 4.1.8 In case where hydraulic arrangement is
assigned summer load line provided for securing the cleats, the system is to
remain mechanically locked in closed position in
fb = minimum required freeboard [m], the event of a failure of the hydraulic system.
determined in accordance with ICLL Reg.28
as modified by further regulations as 4.1.9 Materials used in the manufacturer of
applicable. stoppers or securing devices including welding
electrodes are to be in accordance with relevant
x requirements given in Part 2.
h = 4.6 m for ≤ 0.75
LL 4.2 Portable steel covers - tarpaulins and
battening devices
x
= 6.9 m for ≥ 0.75 4.2.1 At least two layers of tarpaulins in good
LL condition are to be provided for each hatchway
in position 1 and 2. The tarpaulins are to be free
- Labyrinths, gutter bars or equivalents are to from jute, and are to be waterproof and of ample
be fitted proximate to the edges of each strength. The minimum mass of the material
panel in way of the coamings. The clear 2
before treatment is to be 0.65 [kg/m ] if the
profile of these opening is to be kept as 2
material is to be tarred, 0.60 [kg/m ] if it is to be
small as possible. 2
chemically dressed and 0.55 [kg/m ] if to be
dressed with black oil. A certificate to this effect
- Where a hatch is covered by several hatch is to be supplied by the makers of the tarpaulins.
cover panels the clear openings of the gap Special consideration will be given to the
in between the panels is not to be wider synthetic materials for the tarpaulins.
than 50 [mm].
4.2.2 Cleats are to be of an approved pattern, at
- The labyrinths and gaps between hatch least 65 [mm] wide, with edges so rounded as to
cover panels is to be considered as minimize damage to the wedges, and are to be
unprotected openings with respect to the spaced not more than 600 [mm] from centre to
requirements of intact and damage stability centre; the first and last cleats along each side
calculations. or end being not more than 150 [mm] from the
hatch corners. Cleats are to be so set as to fit
- With regard to drainage of cargo holds and the taper of the wedges.
the necessary fire-fighting system reference
is made to the sections Piping Systems, 4.2.3 Battens and wedges are to be efficient and
Valves and Pumps and Fire Protection and in good condition. Wedges are to be of tough
Fire Extinguishing Equipment of Pt.4, Ch.3, wood, generally not more than 200 [mm] in
Pt.6 and Pt. 5, Ch.5, Sec. 2.2 of the Rules. length and 50 [mm] in width. They should have a
taper of not more than 1 in 6 and should not be
- Bilge alarms is be provided in each hold less than 13 [mm] thick at the point.
fitted with non-weathertight covers.
4.2.4 For all hatchways in positions 1 and 2,
- Furthermore, Chapter 3 of IMO MSC/Circ. steel bars or other equivalent means are to be
1087 is to be referred to concerning the provided in order to efficiently and independently
stowage and segregation of containers secure each section of hatch covers after the
containing dangerous goods.
tarpaulins are battened down. Hatch covers of mechanically locked in the closed position in the
more than 1.5 [m] in length are to be secured by event of failure of the hydraulic system.
at least two such securing devices. Where
hatchway covers extend over intermediate 4.3.4 Cross-sectional area of the securing
supports, steel bars or their equivalent are to be devices
fitted at each end of each section of the covers.
2
At all other hatchways in exposed position on The gross cross-sectional area [cm ] of the
weather decks, ring bolts or other fittings securing devices is not to be less than:
suitable for lashings are to be provided.
A = 0.28 ⋅ q ⋅ s SD ⋅ k l
Acceptable equivalent means to steel bars are
to consist of devices and materials which will
q = packing line pressure [N/mm],
provide strength and stiffness equivalent to that
of steel. Steel wire ropes cannot be regarded as minimum 5 [N/mm]
satisfactory equivalent means. Care is to be
taken that tarpaulins are adequately protected sSD = spacing between securing devices
[m], not to be taken less than 2 [m]
from the possibility of damage arising from the
usage of securing devices which do not provide e
a flat bearing surface. 235
k l = , σF is the minimum yield strength
4.3 Securing devices σF
2
of the material [N/mm ], but is not to be taken
4.3.1 General greater than 0,7 σm where σm is the tensile
2
strength of the material [N/mm ].
Securing devices between cover and coaming
and at cross-joints are to be installed to provide
weathertightness. Sufficient packing line e = 0.75 for σ F > 235 2
[N/mm ]
= 1.00 for σ F ≤ 235
pressure is to be maintained. 2
[N/mm ]
If necessary, sufficient abrasive strength may be Supports as well as the adjacent structures and
shown by tests demonstrating an abrasion of substructures are to be designed such that the
support surfaces of not more than 0.3 [mm] per permissible stresses according to 3.3.1 are not
year in service at a total distance of shifting of exceeded.
15000 [m/year].
For substructures and adjacent structures of
The substructures of the supports must be of supports subjected to horizontal forces Ph, a
such a design, that a uniform pressure fatigue strength analysis is to be carried out.
distribution is achieved.
4.4.3 Hatch cover stoppers
Irrespective of the arrangement of stoppers, the
supports must be able to transmit the following Hatch covers shall be sufficiently secured
force Ph in the longitudinal and transverse against horizontal shifting. Stoppers are to be
direction: provided for hatch covers on which cargo is
carried.
PV
Ph = µ ⋅ The greater of the loads resulting from 1.3.2 and
d 4.4.1 is to be applied for the dimensioning of the
Pv = vertical supporting force stoppers and their substructures.
µ = frictional coefficient The permissible stress in stoppers and their
= 0.5 in general substructures, in the cover, and of the coamings
is to be determined according to 3.3.1. In
For non-metallic, low-friction support materials addition, the provisions in 4.4.2 are to be
on steel, the friction coefficient may be reduced observed.
but not to be less than 0.35 and to the
satisfaction of IRS.
Section 5
5.1.3 Side shell doors and stern doors are to be Securing device : a device used to keep the
so fitted as to ensure tightness and structural door closed by preventing it from rotating about
integrity commensurate with their location and its hinges or about pivotted attachments to the
the surrounding structure. ship.
The sill of any side shell door is, in general, not Supporting devices : a device used to transmit
to be below a line drawn parallel to the external or internal loads from the door to a
freeboard deck at side, with its lowest point 230 securing device and from the securing device to
[mm] above the uppermost loadline. the ship's structure, or a device other than a
securing device, such as a hinge, stopper or
5.1.4 Where the sill of any side shell door is other fixed device, that transmits loads from the
below the line specified in 5.1.3 satisfactory door to the ship's structure.
additional features are to be fitted to maintain
5.2.1 The design forces, [N] considered for the ho = vertical distance [m] from the summer load
scantlings of primary members, securing and waterline to the load point under consideration.
supporting devices of side shell doors and stern
2
doors are to be not less than: b) Pe = 0.01 (T1-ZG) + 0.025 [N/mm ] for ZG <
T1, and
i) Design forces for securing or supporting
2
devices of doors opening inwards: 0.025 [N/mm ] for ZG > T1
6
- external force : Fe = APe 10 + Fp where,
150
σ c= σ 2 + 3τ 2 = [N/mm 2 ] 5.4.6 The section modulus of secondary
k horizontal or vertical stiffeners is not to be less
than that required for side framing as per Ch.8,
where k, the material factor, is not to be taken Sec.4.3.2 and 4.3.5.
less than 0.72 unless a direct strength analysis
with regard to relevant modes of failures is Where doors serve as vehicle ramps, the
carried out. stiffener scantlings are not to be less than
required for vehicle decks.
5.3.2 The buckling strength of primary members
is to be verified as being adequate. 5.4.7 The secondary stiffeners are to be
supported by primary members constituting the
5.3.3 For steel to steel bearings in securing and main stiffening of the door.
supporting devices, the nominal bearing
pressure calculated by dividing the design force 5.4.8 The primary members and the hull
by the projected bearing area is not to exceed structure in way are to have sufficient stiffness
0.8, where is the yield stress of the bearing to ensure structural integrity of the boundary of
material. For other bearing materials, the the door.
permissible bearing pressure is to be
determined according to the manufacturer's 5.4.9 Scantlings of the primary members are to
specification. be based on direct strength calculations in
association with the design forces given in 5.2
5.3.4 The arrangement of securing and and permissible stresses given in 5.3.1.
supporting devices is to be such that threaded
bolts do not carry support forces. The maximum 5.5 Securing and supporting of doors
tension in way of threads of bolts not carrying
2
support forces is not to exceed 125/k [N/mm ]. 5.5.1 Side shell doors and stern doors are to be
fitted with adequate means of securing and
5.4 Scantlings supporting so as to be commensurate with the
strength and stiffness of the surrounding
5.4.1 The strength of side shell doors and stern structure. The hull supporting structure in way of
doors is to be commensurate with that of the the doors is to be suitable for the same design
surrounding structure. loads and design stresses as the securing and
supporting devices.
5.4.2 Side shell doors and stern doors are to be
adequately stiffened and means are to be Where packing is required, the packing material
provided to prevent any lateral or vertical is to be of a comparatively soft type and the
movement of the doors when closed. Adequate supporting forces are to be carried by the steel
strength is to be provided in the connections of structure only. Other types of packing may be
the lifting/manoeuvring arms and hinges to the specially considered.
door structure and to the ship's structure.
Maximum design clearance between securing
5.4.3 Where doors also serve as vehicle ramps, and supporting devices is not generally to
the design of the hinges should take into exceed 3 [mm].
account the ship's angle of trim and heel which
may result in uneven loading on the hinges. A means is to be provided for mechanically
fixing the door in the open position.
5.4.4 Shell door openings are to have well-
rounded corners and adequate compensation is 5.5.2 Only the active supporting and securing
to be arranged with web frames at sides and devices having an effective stiffness in the
stringers or equivalent above and below. relevant direction are to be included and
considered to calculate the reaction forces
5.4.5 The thickness of the door plating is not to acting on the devices. Small and/or flexible
be less than the required thickness for the side devices such as cleats intended to provide local
shell plating, using the door stiffener spacing, compression of the packing material are not
and not less than the minimum required generally to be included in the calculations in
thickness of shell plating as per Ch.8, Sec.4.1. 5.5.4. The number of securing and supporting
devices are generally to be the minimum
Where doors serve as vehicle ramps, the plating practical whilst taking into account the
thickness is to be not less than required for requirement for redundant provision given in
vehicle decks.
5.5.5 and the available space for adequate inaccessible to unauthorized persons. A notice
support in the hull structure. plate, giving instructions to the effect that all
securing devices are to be closed and locked
5.5.3 Securing and supporting devices are to be before leaving harbour, is to be placed at each
adequately designed so that they can withstand operating panel and is to be supplemented by
the reaction forces within the permissible warning indicator lights.
stresses given in 5.3.1.
Alternative means of securing are to be provided
5.5.4 The distribution of the reaction forces for emergency use in case of failure of the
acting on the securing devices and supporting power systems.
devices may require direct calculations taking
into account the flexibility of the hull structure 5.6.3 Where hydraulic securing devices are
and the actual position of the supports. applied, the system is to be mechanically
lockable in closed position. This means that in
5.5.5 The arrangement of securing devices and the event of loss of the hydraulic fluid, the
supporting devices in way of these securing securing devices remain locked.
devices is to be designed with redundancy so
that in the event of failure of any single securing The hydraulic system for securing and locking
or supporting device the remaining devices are devices is to be isolated from other hydraulic
capable to withstand the reaction forces without circuits, when in closed position.
exceeding by more than 20 per cent the
permissible stresses as given in 5.3.1. 5.6.4 The requirements in 5.6.5 to 5.6.8 apply to
doors in the boundary of special category
5.5.6 All load transmitting elements in the design spaces or ro-ro spaces, as defined in Pt.6, Ch.1,
load path, from the door through securing and Sec.3, through which such spaces may be
supporting devices into the ship's structure, flooded.
including pins, support brackets, back-up
brackets and welded connections, are to be to For cargo ships, where no part of the door is
the same strength standard as required for the below the uppermost waterline and the area of
2
securing and supporting devices. the door opening is not greater than 6 [m ], the
requirements of this section need not be
5.6 Securing and locking arrangement applied.
5.6.1 Securing devices are to be simple to 5.6.5 Separate indicator lights and audible
operate and easily accessible. alarms are to be provided on the navigation
bridge and on each operating panel to indicate
Securing devices are to be equipped with that the doors are closed and that their securing
mechanical locking arrangement (self locking or and locking devices are properly positioned.
separate arrangement), or are to be of the
gravity type. The opening and closing systems The indication panel is to be provided with a
as well as securing and locking devices are to lamp test function. It shall not be possible to turn
be interlocked in such a way that they can only off the indicator light.
operate in the proper sequence.
5.6.6 The indicator system is to be designed on
5.6.2 Doors which are located partly or totally the fail safe principle and is to indicate by visual
below the freeboard deck with a clear opening alarms if the door is not fully closed and not fully
2
area greater than 6 [m ] are to be provided with locked and by audible alarms if securing devices
an arrangement for remote control, from a become open or locking devices become
position above the freeboard deck of: unsecured. The power supply for the indicator
system is to be independent of the power supply
- the closing and opening of the doors, for operating the doors and is to be provided
- associated securing and locking with a backup power supply from the emergency
devices. source of power or other secure power supply
such as a UPS.
For doors which are required to be equipped
with a remote control arrangement, indication of The sensors of the indicator system are to be
the open/closed position of the door and the protected from water, ice formation and
securing and locking device is to be provided at mechanical damages.
the remote control stations. The operating
panels for operation of doors are to be
The requirements for fail safe design principle 5.6.9 For ro-ro passenger ships, on international
are to be similar to those for bow doors as voyages, the special category spaces and ro-ro
indicated in 6.7.4. spaces are to be continuously patrolled or
monitored by effective means, such as CCTV
5.6.7 The indication panel on the navigation surveillance, so that any movement of vehicles
bridge is to be equipped with a mode selection in adverse weather conditions and unauthorized
function "harbour/sea voyage", so arranged that access by passengers thereto, can be detected
audible alarm is given if the vessel leaves whilst the ship is underway.
harbour with side shell or stern doors not closed
or with any of the securing devices not in the 5.7 Operating and maintenance manual
correct position.
5.7.1 An Operating and Maintenance Manual for
5.6.8 For passenger ships, a water leakage the side shell and stern doors is to be provided
detection system with audible alarm and CCTV onboard and contain necessary information
surveillance is to be arranged to provide an indicated in 6.8.1, as applicable.
indication to the navigation bridge and to the
engine control room of any leakage through the This Manual has to be submitted for approval.
doors.
5.7.2 Documented operating procedures for
For cargo ships, a water leakage detection closing and securing side shell and stern doors
system with audible alarm is to be arranged to are to be kept on board and posted at the
provide an indication to the navigation bridge. appropriate places.
Section 6
h = height, [m], of the door between the levels of W = mass of the visor door, [ t ];
the bottom of the door and the upper deck or
between the bottom of the door and the top of a = vertical distance, [m], from visor pivot to the
the door, whichever is the lesser; centroid of the transverse vertical projected area
of the visor door, as shown in Fig.6.2.3;
l = length, [m], of the door at a height h/2 above
the bottom of the door; b = horizontal distance, [m], from visor pivot to
the centroid of the horizontal projected area of
w = breadth, [m], of the door at a height h/2 the visor door, as shown in Fig.6.2.3;
above the bottom of the door;
c = horizontal distance, [m], from visor pivot to
Pe = external pressure, as given in 6.2.1 with the centre of gravity of visor mass, as shown in
flare angle and entry angle β measured at a Fig.6.2.3.
location on the shell h/2 above the bottom of the
6.2.4 The design of lifting arms of a visor door withstand the design loads defined in 6.2, using
and its supports is to take into account the static the following permissible stresses:
and dynamic forces applied during the lifting and
lowering operations, and a minimum wind bending stress:
2
pressure of 0.0015 [N/mm ].
120
6.2.5 The design external pressure, considered σ= [N/mm 2 ]
for the scantlings of primary members, securing k
and supporting devices and surrounding
structure of inner doors is to be taken as the shear stress:
greater of the following:
80
a) Pe = 0.45 L x 10
-3 2
[N/mm ]
τ= [N/mm 2 ]
k
2
b) Ph = 0.01h [N/mm ] equivalent stress:
where,
150
σ c = σ 2 + 3τ 2 = [N/mm 2 ]
h = the distance, [m], from the load point to the k
top of the cargo space.
where, k, the material factor, is not to be taken
L = ship's length [m], but need not be taken less than 0.72, unless a direct fatigue analysis is
greater than 200 [m]. carried out.
6.2.6 The design internal pressure Pb, 6.3.2 The buckling strength of primary members
considered for the scantlings of securing is to be in accordance with Ch.3, Sec.6.
devices of inner doors is not to be less than:
6.3.3 For steel to steel bearings in securing and
2
Pb = 0.025 [N/mm ] supporting devices, the nominal bearing
pressure calculated by dividing the design force
6.3 Strength criteria by the projected bearing area is not to exceed
0.8 times the yield stress of the bearing material.
6.3.1 Scantlings of the primary members, For other bearing materials, the bearing
securing and supporting devices of bow doors pressure is not to exceed the manufacturer's
and inner doors are to be determined to recommended value.
requirements for redundancy given in 6.6.7 and Ax. For visor doors, longitudinal reaction forces
6.6.8 and the space available for adequate of pin and/or wedge supports at the door base
support in the hull structure. contributing to this moment are not to be in the
forward direction.
6.6.3 For visor doors opening outwards, the
pivot arrangement is generally to be such that The arrangement of securing and supporting
the visor is self closing under external loads, devices is to be designed with redundancy so
that is My > 0. Moreover, the closing moment My that in the event of failure of any single securing
as given in 6.2.3 is to be not less than: or supporting device the remaining devices are
capable to withstand the reaction forces without
2 2 0.5 2 2 0.5
Myo = 10 c W+0.1 (a + b ) (Fx + Fz ) [kN-m] exceeding the permissible stresses given in
6.3.1, by more than 20 per cent .
6.6.4 Securing and supporting devices are to be
adequately designed so that they can withstand 6.6.8 For visor doors, two securing devices are
the reaction forces within the permissible to be provided at the lower part of the door,
stresses given in 6.3.1. each capable of providing the full reaction force
required to prevent opening of the door within
6.6.5 For visor doors, the reaction forces applied the permissible stresses given in 6.3.1. The
on the effective securing and supporting devices opening moment Mo, in kN-m, to be balanced by
assuming the door as a rigid body, are to be this reaction force, is not to be taken less than:
determined for the following combinations of
external loads acting simultaneously together Mo = 10 W d + 5Ax a
with the self weight of the door;
where,
i) case 1 : Fx and Fz
ii) case 2 : 0.7Fy acting on each side separately d = vertical distance, [m], from the hinge axis to
together with 0.7Fx and 0.7Fz the centre of gravity of the door,
a = as defined in 6.2.3.
where Fx, Fy and Fz are determined as indicated
in 6.2.2 and applied at the centroid of projected For visor doors, the securing and supporting
areas. devices excluding the hinges should be capable
of resisting the vertical design force (Fz - 10W),
6.6.6 For side-opening doors, the reaction in kN, within the permissible stresses given in
forces applied on the effective securing and 6.3.1.
supporting devices assuming the door as a rigid
body, are to be determined for the following 6.6.9 For side-opening doors, thrust bearing has
combination of external loads acting to be provided in way of girder ends at the
simultaneously together with the self weight of closing of the two leaves to prevent one leaf to
the door: shift towards the other one under effect of
unsymmetrical pressure (See Fig.6.6.9). Each
i) case 1 : Fx, Fy and Fz acting on both doors part of the thrust bearing has to be kept secured
ii) case 2 : 0.7Fx and 0.7Fz acting on both doors on the other part by means of securing devices.
and 0.7Fy acting on each door separately, Any other arrangement serving the same
purpose may be proposed.
where Fx, Fy and Fz are determined as indicated
in 6.2.2 and applied at the centroid of projected 6.6.10 All load transmitting elements in the
areas. design load path, from door through securing
and supporting devices into the ship structure,
6.6.7 The support forces as determined including pins, supporting brackets, back-up
according to 6.2.2, 6.6.5 i) and 6.6.6 i) shall brackets and welded connections, are to be to
generally give rise to a zero moment about the the same strength standard as required for the
transverse axis through the centroid of the area securing end supporting devices.
Alternative means of securing are to be provided 2) Limit switches electrically closed when the
for emergency use in case of failure of the door is closed (when more than one limit switch
power systems. is provided they may be connected in series).
6.7.3 Where hydraulic securing devices are 3) Limit switches electrically closed when
applied, the system is to be mechanically securing arrangements are in place (when more
lockable in closed position (i.e. in the event of
than one limit switch is provided they may be 6.8 Operating and maintenance manual
connected in series).
6.8.1 An Operating and Maintenance Manual for
4) Two electrical circuits (may be provided in the bow door and inner door has to be provided
one multicore cable), one for the indication of on board and contain necessary information on:
door closed/not closed and the other for door
locked / not locked. - main particulars and design drawings
special safety precautions;
5) In case of dislocation of limit switches, details of vessel;
indication to show : not closed / not locked / equipment and design loading (for ramps);
securing arrangement not in place – as key plan of equipment (doors and ramps);
appropriate. manufacturer’s recommended testing for
equipment;
6.7.5 A water leakage detection system with description of equipment:
audible alarm and CCTV surveillance is to be
arranged to provide an indication to the bow doors
navigation bridge and to the engine control room inner bow doors
of leakage through the inner door. bow ramp/doors
side doors
Between the bow door and the inner door a stern doors
CCTV surveillance system is to be fitted with a central power pack
monitor on the navigation bridge and in the bridge panel
engine control room. The system is to monitor engine control room panel.
the position of doors and a sufficient number of
their securing devices. Special consideration is - service conditions: limiting heel and trim of
to be given for lighting and contrasting colour of ship for loading/unloading;
objects under surveillance. limiting heel and trim for door operations;
doors/ramps operating instructions;
6.7.6 A drainage system is to be arranged in the doors/ramps emergency operating instruc-
area between bow door and ramp, or where no tions.
ramp is fitted, between the bow door and inner
door. The system is to be equipped with an - Maintenance schedule and extent of
audible alarm function to the navigation bridge maintenance;
for water level in these areas exceeding 0.5 [m] trouble shooting and acceptable clearances;
above the car deck level. manufacturer’s maintenance procedures.
6.7.7 For ro-ro passenger ships on international - register of inspections, including inspection
voyages, the special category spaces and ro-ro of locking, securing and supporting devices,
spaces are to be continuously patrolled or repairs and renewals.
monitored by effective means, such as CCTV
surveillance, so that any movement of vehicles This manual is to be submitted for approval.
in adverse weather conditions or unauthorized
access by passengers thereto, can be detected 6.8.2 Documented operating procedures for
whilst the ship is underway. closing and securing the bow door and inner
door are to be kept on board and posted at
appropriate place.
Section 7
Miscellaneous Openings
The hatch covers are to be adequately stiffened. 7.2.3 Primary securing devices
7.1.6 Escape hatches are to be capable of being 7.2.3.1 Small hatches located on exposed fore
operated from either side. deck are to be fitted with primary securing
devices such that their hatch covers can be
7.1.7 For hatch covers constructed of materials secured in place and weathertight by means of a
other than steel, the scantlings are to provide mechanism employing any one of the following
equivalent strength. methods:
7.1.8 In addition to the requirements, in 7.1.1 to i) Butterfly nuts tightening onto forks
7.1.6, small hatches on the exposed foredeck of (clamps),
vessels with L ≥ 80 [m] are to meet the ii) Quick acting cleats, or
requirements of 7.2. iii) Central locking device.
Table 7.2.2 : Scantlings for small steel hatch covers on the fore deck
Small hatches on the fore deck except those 7.3.1 Manholes and flush scuttles on the decks
designed for emergency escapes are to be fitted fitted in Positions 1 and 2 or within
with an independent secondary securing device superstructures other than enclosed
e.g. by means of a sliding bolt, a hasp or a superstructures, are to be closed by substantial
backing bar of slack fit, which is capable of covers capable of closing them weathertight.
keeping the hatch cover in place, even in the Unless secured by closely spaced bolts, the
event that the primary securing device became covers are to be permanently attached.
loosened or dislodged. It is to be fitted on the
side opposite to the hatch cover hinges. 7.4 Hatchways within enclosed super-
structure and tween decks
Table 7.5.1
Standard height [m]
Freeboard Length LL [m]
Raised quarter deck Other super-structure
≤ 30 0.9 1.8
75 1.2 1.8
≥ 125 1.80 2.3
At intermediate length of the ship, standard height to be obtained by linear interpolation
are to be capable of being operated and
7.5.2 Steel doors or doors of other equivalent secured from both sides.
material are to be fitted to the following access
openings in: 7.5.3 Portable sills to be avoided. However in
order to facilitate the loading/ unloading of heavy
a) bulkheads at ends of enclosed spare parts or similar items portable sills may be
superstructures. fitted on the following conditions:
7.5.8 The height of door sills may be required to 'Deadlights', in accordance with recognised
be increased on ships of Type 'A', Type 'B-100' standards, are fitted to the inside of windows
or Type 'B-60' where this is shown to be and side scuttles while 'storm covers', of
necessary by the floatability calculations comparable specifications to deadlights, are
required by the ILLC 1966. The engine casing in fitted to the outside of windows, where
such ships, when not protected by an outer accessible, and may be hinged or portable.
structure will require two weathertight doors in
series, with the sill height of the outer and inner 7.7.2 Side scuttles are defined as being round or
door being not less than 600 [mm] and 230 [mm] oval in shape and where the area of openings
2
respectively. does not exceed 0.16 M .
7.5.9 When the closing appliances of openings Windows are defined as being rectangular in
in superstructures and deckhouses do not shape generally having a radius at each corner
comply with the requirements of 7.5.2, the (depending on the window size in accordance
openings on the interior deck are to be treated with recognised national or international
as if exposed to the weather deck. standards) and also those associated with round
or oval shapes where the area of openings
2
7.6 Openings on engine and boiler casing exceeds 0.16 M .
7.6.1 Machinery space openings in Position 1 or 7.7.3 Side scuttles to the following spaces shall
2 are to have efficient closing appliances. The be fitted with efficient hinged inside deadlights:
openings and coamings for fiddley, funnel and
machinery space ventilators in the casing in a) spaces below the freeboard deck
those positions are to be provided with strong b) spaces within the first tier of enclosed
covers of steel or other equivalent material superstructures
permanently attached in their proper positions c) first tier deckhouses on the freeboard deck
and capable of being secured weathertight. protecting openings leading below
d) first tier deckhouses on the freeboard deck
7.6.2 Doorways in the engine and boiler casings considered buoyant in stability calculations.
are to be arranged to provide the maximum
protection of the space below. The deadlights shall be capable of being
effectively closed and secured watertight if fitted
7.6.3 Skylights are to be of substantial below the freeboard deck and weathertight if
construction and secured firmly to the deck. For fitted above.
skylights in position 1 or 2 the coaming height is
not to be less than that of the hatch coaming. 7.7.4 Side scuttles shall not be fitted in such a
Efficient means are to be provided for closing position that their sills are below a line drawn
and securing the hinged scuttles, if any. The parallel to the freeboard deck at side and having
thickness of glasses in fixed or opening skylights its lowest point 0.025B or 500 [mm], whichever
is to be appropriate to their position and size as is the greater distance, above the summer load
required for side scuttles. Glasses in any line (or timber summer load line, if assigned).
position are to be protected against mechanical
damage, and where fitted in Positions 1 and 2
7.7.5 Side scuttles shall be of the non-opening permanently attached external storm covers of
type in ships subject to damage stability approved design and of substantial construction
regulations, if the calculations indicate that they and capable of being effectively closed and
would become immersed by any intermediate secured weathertight.
stage of flooding or the final equilibrium
waterplane in any required damage case. 7.7.8 Cabin bulkheads and doors in the second
tier separating side scuttles and windows from a
7.7.6 Windows shall not be fitted below the direct access leading below may be accepted
freeboard deck, in the first tier end bulkheads or in place of deadlights or storm covers fitted to
sides of enclosed superstructures and in first tier the side scuttles and windows.
deckhouses considered buoyant in the stability
calculations or protecting openings leading Deckhouses situated on a raised quarter deck or
below. on the deck of a superstructure of less than
standard height may be regarded as being in the
7.7.7 Side scuttles and windows at the side shell second tier as far as the provision of deadlights
in the second tier, protecting direct access is concerned, provided the height of the raised
below or considered buoyant in the stability quarter deck or superstructure is equal to, or
calculations, shall be provided with efficient greater than, the standard quarter deck height.
hinged inside deadlights capable of being
effectively closed and secured weathertight. 7.7.9 Side scuttles and windows facing open or
enclosed lifeboat and liferaft embarkation areas
Side scuttles and windows set inboard from the and below such areas in such a position that
side shell in the second tier, protecting direct their failure during a fire would impede the
access below to spaces listed in 7.6.3, shall be launching of or embarkation into lifeboats or
provided with either efficient hinged inside liferafts are to have adequate fire integrity.
deadlights or, where they are accessible,
End of Chapter
Chapter 13
Contents
Section
1 General
2 Ventilators
3 Air and Sounding Pipes
4 Scuppers and Sanitary Discharges
Section 1
General
1.1 Scope less than 0.1L or 22 [m] above the summer load
waterline, whichever is the lesser:
1.1.1 This Chapter applies to all ships and
provides requirements for ventilators, air and However, these requirements need not be
sounding pipes and overboard discharges. applied to cargo tank venting systems and inert
gas systems of oil tankers, chemical carriers
1.1.2 The requirements conform, where and liquefied gas carriers.
relevant, to those of the International
Convention on Load Lines, 1966. Reference 1.4.2 Design load
should also be made to any additional
requirements of the National Authority of the The green sea pressure ‘p’ acting on air pipes,
country in which the ship is to be registered. ventilators and their closing appliances is to be
taken as:
1.2 Definitions
p = 0.5 ρ V Cd Cs Cp [kN/m ]
2 2
1.4 Strength of attachments of fore deck = 0.8 for an air pipe or ventilator head of
fittings cylindrical form with its axis in the
vertical direction.
1.4.1 The airpipes, ventilators and their closing
devices fitted on ships of L ≥ 80 [m] on exposed Cs = slamming coefficient = 3.2
decks in the forward 0.25L are to satisfy the
requirements given in 1.4.2 and 1.4.3 if the Cp = protection coefficient:
height of the exposed deck in way of the item is
Indian Register of Shipping
Chapter 13 Part 3
Page 2 of 8 Ventilators, Air Pipes and Discharges
(a)
Table 1.4.3a) : 900 mm ventilator pipe thickness and bracket standards
Notes :
a) For other ventilator heights, the relevant requirements of 1.4.2 and 1.4.3 are to be applied.
b) Brackets need not extend over the joint flange for the head.
(a)
Table 1.4.3b) : 760 mm air pipe thickness and bracket standard
Notes :
a) For other air pipe heights, the relevant requirements of 1.4.2 and 1.4.3 are to be applied.
b) Brackets need not extend over the joint flange for the head.
c) Brackets need not be provided if the as fitted gross thickness of air pipes is not less than 10.5 [mm].
Section 2
Ventilators
2.1 General
- 760 [mm] in position 2
2.1.1 Special care is to be taken in the design
and positioning of ventilator openings and these heights being measured above deck
coamings, particularly in the region of the sheathing where fitted. Particularly in exposed
forward end of superstructures and other points positions, the height of coamings may be
of high stress. The deck plating in way of the required to be increased.
coamings is to be efficiently stiffened.
2.2.2 The height of ventilator coamings may be
2.1.2 Ventilators from deep tanks and tunnels required to be increased on ships of Type 'A',
passing through 'tween decks are to have Type 'B-100' and Type 'B-60' where this is
scantlings suitable for withstanding the shown to be necessary by the floatability
pressures to which they may be subjected, and criterion required by the International
are to be made watertight. Convention on Load Lines, 1966.
2.1.3 For the requirements of fire precautions on 2.2.3 The thickness of ventilator coamings is not
cargo and passenger ships, see Pt.6, Ch.2, to be less than 6.0 [mm] for ventilators upto 80
Sec.2. [mm] external diameter and 8.5 [mm] for
ventilators of external diameters 165 [mm] and
2.2 Coamings above; the thickness for intermediate diameters
may be obtained by interpolation.
2.2.1 The height of ventilator coamings exposed
to the weather is to be not less than : 2.2.4 Where the height of the ventilator exceeds
that required by 2.2.1 the thickness given in
- 900 [mm] in position 1 2.2.3 may be gradually reduced, above the
required minimum height, to a minimum of 6.0 heights for machinery space and emergency
[mm]. The ventilator is to be adequately stayed. generator room ventilator coamings may be
considered with provision of weathertight closing
2.3 Closing appliances appliances in combination with other suitable
arrangements to ensure an uninterrupted,
2.3.1 All ventilator openings are to be provided adequate supply of ventilation to these spaces.
with efficient weathertight closing appliances
except where:- 2.3.3 In ships where the load line length, LL, is
not more than 100 [m], the closing appliances
(a) the height of the coaming is greater than 4.5 are to be permanently attached to the ventilator
[m] in position 1, or coaming. Whereas in other ships, they may be
conveniently stowed near the ventilator to which
(b) the height of the coaming is greater than 2.3 they are to be fitted.
[m] in position 2
2.3.4 Where, in ferries, ventilators are proposed
in which case closing appliances need not be to be led overboard in an enclosed 'tween deck'
provided unless unusual features of design the closing arrangements are to be submitted for
make it necessary. approval. If such ventilators are led overboard
more than 4.5 [m] above the main vehicle deck,
The weathertight closing appliance for all closing appliances may be omitted, provided
ventilators in positions 1 and 2 are to be of steel that satisfactory baffles and drainage
or other equivalent materials. Wood plugs and arrangements are provided, as in the case of air
canvas covers are not acceptable in these intakes or exhaust openings for machinery
positions. spaces, which may be arranged in the sides of
the ship.
2.3.2 In general, ventilators which are necessary
to continuously supply the machinery space and 2.3.5 On offshore supply ships, to ensure
on demand, immediately supply the emergency satisfactory operation in all weather conditions,
generator room, should have coamings with machinery space ventilation inlets and outlets
sufficient heights specified in 2.3.1, without are to be located in such positions that closing
having to fit weathertight closing appliances. appliances will not be necessary.
Section 3
3.1 General
- 450 [mm] on superstructure decks
3.1.1 Air and sounding pipes are to comply with
the requirements of Pt.4, Ch.2. these heights being measured above deck
sheathing, where fitted. Air pipes with height
3.1.2 Striking plates of suitable thickness, or exceeding 900 [mm] are to be additionally
their equivalent, are to be fitted under all supported.
sounding pipes.
3.2.2 Lower heights may be approved in cases
3.1.3 On offshore supply ships air pipes are to where these are essential for the working of the
be situated clear of the cargo containment ship, provided that the design and arrangements
areas. are otherwise satisfactory. In such cases,
efficient, permanently attached closing
3.2 Height of air pipes appliances of an approved automatic type will
generally be required.
3.2.1 The height of air pipes from the upper
surface of decks exposed to the weather, to the 3.2.3 The height of air pipes may be required to
point where water may have access below is not be increased on ships of Type 'A', Type 'B-100'
normally to be less than : and Type 'B-60' where this is shown to be
necessary by the floatability calculations
- 760 [mm] on freeboard deck
3.2.4 Air pipes are generally to be led to an 3.3.6 The clear area through an air pipe closing
exposed deck, but alternative arrangements will device is to be at least equal to the area of the
be considered in the case of ferries where such inlet. Air pipe closing devices are to be self
an arrangement is not practicable. draining.
3.2.5 The thickness of the portion of the air pipe 3.3.7 In the case of air pipe closing devices of
exposed to weather is not to be less than 6.0 the float type, suitable guides are to be provided
[mm] upto 80 [mm] external diameter and 8.5 to ensure unobstructed operation. The
[mm] for 165 [mm] and above; the thickness for maximum allowable tolerances for wall
intermediate external diameters may be thickness of ball floats is not to exceed 10% of
obtained by interpolation. the nominal thickness.
3.3 Closing appliances 3.3.8 Casings of air pipe closing devices are to
be of approved metallic materials adequately
3.3.1 All openings of air and sounding pipes are protected against corrosion. The inner and the
to be provided with permanently attached, outer chambers of an automatic air pipe head is
satisfactory means of closing to prevent the free to be of a minimum thickness of 6 [mm].
entry of water.
3.3.9 For galvanized steel air pipe heads, the
3.3.2 Air pipe closing devices are to be of an zinc coating is to be applied by the hot method
approved type and so designed that they and the coating thickness is to be 70 to 100
withstand both ambient and working conditions microns.
and be suitable for use at inclinations upto and
o
including 40 . For areas of the head susceptible to erosion
(e.g. those parts directly subjected to ballast
3.3.3 Closing devices are to be of automatic water impact when the tank is being pressed up,
type. Pressure-vacuum valves (P-V valves) may for example the inner chamber area above the
however, be accepted on tankers. air pipe, plus an overlap of 10° or more on either
side) an additional harder coating such as
3.3.4 Air pipe closing devices are to be so aluminium bearing epoxy coating or equivalent,
constructed as to allow inspection of the closure is to be applied over the zinc coating.
and the inside of the casing as well as changing
of the seals. 3.3.10 Closures and seats made of non-metallic
materials are to be compatible with the media
3.3.5 Efficient ball or float seating arrangements intended to be carried in the tank at
o o
are to be provided for the closures. Bars, cage temperatures between -25 C and 85 C and sea
or other devices are to be provided to prevent water.
the ball or float from contacting the inner
chamber in its normal state and made in such a
way that the ball or float is not damaged when
Section 4
4.2.6 If, in association with 4.1.8, a valve is 4.2.12 Alternatively, the upper gate valve may
required by 4.1.3, this valve should preferably be replaced by a hinged weathertight cover at
be fitted as close as possible to the point of the inboard end of the chute together with a
entry of the pipe into the tank. If fitted below the discharge flap which replaces the lower gate
freeboard deck, the valve is to be capable of valve.
being controlled from an easily accessible The cover and the flap are to be arranged with
position above the freeboard deck. Local control an interlock so that the discharge flap cannot be
is also to be arranged, unless the valve is operated until the cover is closed.
inaccessible. An indicator is to be fitted at the
control position showing whether the valve is The chute is to be constructed of material of
open or closed. substantial thickness (See Part 4, Chapter 3,
Section 3.5) upto and including the cover.
4.2.7 In a ship to which timber freeboards are
assigned, the summer load waterline is to be 4.2.13 The gate valve controls and/or hinged
regarded as that corresponding to the timber cover are to be clearly marked: “Keep closed
summer freeboard. when not in use”.
4.2.8 It is considered that requirements for non- 4.3 Materials for valves, fittings and pipes
return valves are applicable only to those
discharges which remain open during the 4.3.1 All shell fittings and valves required by 4.2
normal operation of a vessel. For discharges are to be of steel, bronze or other approved
which must necessarily be closed at sea, such ductile material; ordinary cast iron or similar
as gravity drains from topside ballast tanks, a material is not acceptable. Materials are to
single screw down valve operated from the deck satisfy the requirements of Pt.2.
is sufficient.
4.3.2 All these items, if made of steel or other
The inboard end of a gravity discharge which approved material with low corrosion resistance,
leads overboard from an enclosed are to be suitably protected against wastage.
superstructure or space is to be located above
the waterline formed by a 5 degree heel, to port 4.3.3 The lengths of pipe attached to the shell
or starboard, at a draft corresponding to be fittings, elbow pieces or valves are to be of
assigned summer freeboard. galvanized steel or other equivalent approved
material.
4.2.9 For garbage chutes an acceptable
equivalent to the non-return valve with a positive 4.3.4 Where plastic pipes are used for sanitary
means of closing from a position above the discharges and scuppers, they are also subject
freeboard deck would be two gate valves to the requirement of Fig.4.2.1, and the valve at
controlled from the working deck of the chute. the shell is to be operated from outside the
The lowest gate valve should, in addition, be space in which the valve is located.
controlled from a position above the freeboard
deck. An interlock system is to be arranged Where such plastic pipes are located below the
between the two valves. The distance between summer waterline, the valve is to be operated
the two gate valves is to be adequate to allow from a position above freeboard deck.
the smooth operation of the interlock system.
The portion of discharge line from the shell to
4.2.10 It is recommended that the inboard end the first valve as well as shell fittings and valves
of the garbage chute be located above the shall be of steel; bronze or other approved
waterline formed by an 8.5 deg heel, to port or ductile material.
starboard, at a draft corresponding to the
assigned summer freeboard, but not less than The approval of plastic piping in any location will
1000[mm] above the summer waterline. be subject to the consideration of strength and
fire hazards involved with special reference to
4.2.11 Where the inboard end of the garbage penetrations through bulkheads, decks or other
chute exceeds 0.01LL above the summer significant compartment boundaries. Attention
waterline, valve control from the freeboard deck must be paid to valid fire technical regulations.
is not required, provided the inboard gate valve
is always accessible under service conditions.
End of Chapter
Chapter 10
Bulkheads
Contents
Section
1 General
2 Subdivision and Arrangement
3 Structural Arrangement and Details
4 Design Loads
5 Plating and Stiffeners
6 Girders
Section 1
General
1.1.1 The requirements of this chapter cover the tc, Zc are corrosion additions to thickness and
arrangement and scantlings of watertight and section modulus respectively as given in Ch.3,
deep tank bulkheads. Sec.2.1
1.1.2 The requirements also cover the non- ao, kv are as defined in Ch.4.
watertight bulkheads and shaft tunnels.
s = spacing of stiffeners [mm]
1.2 Statutory requirements
l = span of stiffeners [m]
1.2.1 Where applicable, the number and
disposition of bulkheads are to be arranged to b = spacing of girders [m]
meet the requirements for subdivision,
floodability and damage stability in accordance S = span of girders [m]
with the requirements of the National Authority
of the country in which the ship is registered. ZR
fD =
1.3 Definitions and Symbols ZD
where,
Section 2
For ships without longitudinal bulkheads in the Xc,min = 0.05LL - XR [m] for L < 200 [m].
cargo region, additional transverse watertight
bulkheads are to be fitted so that the total = 10 - XR [m] for L ≥ 200 [m].
number of bulkheads is not less than that given
in Table 2.1.1. Xc,max = 0.05 LL - XR + 3 [m] for L < 100 [m].
2.3 After peak bulkhead and shaft tunnel 2.5 Openings in watertight bulkheads and
closing appliances - General
2.3.1 All ships are to have an after peak
bulkhead generally enclosing the sterntube and 2.5.1 Openings may be accepted in watertight
rudder trunk in a watertight compartment. In twin bulkheads except in that part of collision
screw ships where the bossing ends forward of bulkhead which is situated below the bulkhead
the after peak bulkhead, the sterntubes are to deck / freeboard deck. The number of openings
be enclosed in suitable watertight spaces inside in watertight subdivisions is to be kept to a
or aft of the shaft tunnels. minimum compatible with the design and proper
working of the ship. Where penetrations of
2.3.2 In passenger ships, the stern gland is to watertight bulkheads are necessary for access,
be situated in a watertight shaft tunnel or other piping, ventilation, electrical cables, etc.,
watertight space separate from the stern tube arrangements are to be made to maintain the
compartment and of such volume that if flooded watertight integrity. Relaxation in the
by leakage through the stern gland, the watertightness of openings above the bulkhead
bulkhead deck will not be immersed. deck / freeboard deck may be considered
In cargo ships, where the inboard end of the provided it is demonstrated that any progressive
stern tube extends into the engine room, flooding can be easily controlled and that the
provision of an approved watertight/ oil tight safety of the ship is not impaired.
gland system for sealing of the inboard end of
the stern tube at the aft peak/engine room 2.5.2 Openings in the collision bulkhead above
watertight bulkhead is considered sufficient to the bulkhead deck / freeboard deck are to have
minimize danger of water penetrating into the weathertight doors or an equivalent
ship in case of damage to stern tube arrangement.
arrangements.
(See also Pt.4, Ch.4, Sec. 6.16). 2.5.3 Doors, manholes, permanent access
openings or ventilation ducts are not to be cut in
2.3.3 In ships with engines situated amidships, a the collision bulkhead below the freeboard deck.
watertight shaft tunnel is to be arranged.
Openings in the forward end of shaft tunnels are 2.5.4 Where watertight bulkhead stiffeners are
to be fitted with watertight sliding doors capable cut in way of watertight doors in the lower part of
of being operated from a position above the load the bulkhead, the opening is to be suitably
water line. framed and reinforced. Where stiffeners are not
cut but the spacing between the stiffeners is
2.4 Height of bulkheads increased on account of watertight doors, the
stiffeners at the sides of the doorways are to be
2.4.1 The watertight bulkheads are in general to increased in depth and strength so that the
extend to the bulkhead deck / freeboard deck. efficiency is at least equal to that of the
Indian Register of Shipping
Chapter 10 Part 3
Page 4 of 13 Bulkheads
unpierced bulkhead, without taking the stiffeners e) Hinged Door : A door having a pivoting
of the door-frame into consideration. motion about one vertical or horizontal
edge.
2.6 Doors in watertight bulkheads for ships
where subdivision / damage stability require- 2.6.3 Structural design
ments are applicable
Doors are to be of approved design and are to
2.6.1 The requirements in 2.6.1 to 2.6.16 apply be of a strength equivalent to that of the
to doors located in way of the internal watertight subdivision bulkheads in which they are fitted.
subdivision boundaries and the external
watertight boundaries necessary to ensure 2.6.4 Operation mode, location and outfitting
compliance with the relevant subdivision and
damage stability regulations. Doors are to be fitted in accordance with all
requirements regarding their operation mode,
These requirements do not apply to doors location and outfitting, i.e. provision of controls,
located in external boundaries above equilibrium means of indication etc. as shown in Table
or intermediate waterplanes. 2.6.4. For passenger ships, in addition to the
requirements given in the Table 2.6.4 the
2.6.2 Definitions watertight doors and their controls are to be
located in compliance with the following:
For the purpose of the requirements in this
subsection (2.6) the following definitions apply: a) The door is to be located inboard of the
damage zone B/5 on P&S as per SOLAS II-
a) Watertight : Capable of preventing the 1 Reg.13.7.
passage of water in any direction under a
design head. The design head for any part b) The door controls including hydraulic piping
of a structure shall be determined by and electric cables are to be kept as close
reference to its location relative to the as practicable to the bulkhead in which the
bulkhead deck or freeboard deck, as doors are fitted in order to minimize the
applicable, or to the most unfavourable likelihood of them being involved in any
equilibrium / intermediate waterplane, in damage to the ship. The positioning of
accordance with the applicable subdivision doors and controls is to be such that if the
and damage stability regulations, whichever ship sustains damage within damage zone
is the greater. A watertight door is thus one B/5 as mentioned above, the operation of
that will maintain the watertight integrity of the doors clear of the damaged portion of
the subdivision bulkhead in which it is the ship is not impaired.
located.
2.6.5 Frequency of use whilst at sea
b) Equilibrium Waterplane : The waterplane in
still water when, taking account of flooding a) Normally closed
due to an assumed damage, the weight and Kept closed at sea but may be used if
buoyancy forces acting on a vessel are in authorised. To be closed again after use.
balance. This relates to the final condition
when no further flooding takes place or after b) Permanently closed
cross flooding is completed.
The time of opening such doors in port and
c) Intermediate Waterplane : The waterplane of closing them before the ship leaves port
in still water, which represents the shall be entered in the log-book. Should
instantaneous floating position of a vessel at such doors be accessible during the
some intermediate stage between voyage, they shall be fitted with a device to
commencement and completion of flooding prevent unauthorised opening.
when, taking account of the assumed
instantaneous state of flooding, the weight c) Normally open
and buoyancy forces acting on a vessel are May be left open provided it is always ready
in balance. to be immediately closed.
Table 2.6.4 : Internal doors in watertight bulkheads in cargo ships and passenger ships
Position 1. 2. 3. 4. 5. 6. 7. 8.
relative to Frequency Type Remote Indication Audible Notice Comments Regulation
equilibrium of use control6 locally and alarm6
or whilst at on bridge6
intermediate sea
waterplane
I. Passenger Ships
Certain doors
may be left SOLAS II-1/ 13;
Norm.
POS Yes Yes Yes No open, see SOLAS II-1/22.1, 2,
A. At or Closed
SOLAS II- 3 and 4
below 1/22.4
Perm. SOLAS II-1/13.9 &
S, H No No No Yes See Notes 1+4
Closed 2
Norm. POS, SOLAS II-1/22.4
Yes Yes Yes No
Open POH SOLAS II-1/ 17.1
S, H No Yes No Yes See Note 2 MSC/Circ.541
B. Above
Norm. Doors giving
Closed SOLAS II-1/17.1
S, H No Yes No Yes access to Ro-
SOLAS II-1/23
Ro Deck
II. Cargo Ships
Used POS Yes Yes Yes No SOLAS II-1/13.2
Notes:
2.6.6 Types of doors in Table 2.6.4 the ship listed to either side. In the case of
passenger ships, it is to be possible to close
Power operated, sliding or rolling POS the door from a position above the bulkhead
Power operated, hinged POH deck with an all round crank motion or some
Sliding or rolling S other movement providing the same degree
Hinged H of safety.
Where shown in Table 2.6.4, position indicators Where a watertight door is located adjacent to a
are to be provided at all remote operating fire door, both doors are to be capable of
positions as well as locally, on both sides of the independent operation, remotely if required and
doors, to show whether the doors are open or from both sides of the each door.
closed and if applicable, with all dogs/cleats fully
and properly engaged. 2.6.12 Testing
An indication (i.e. red light) should be placed b) For large doors intended for use in the
locally showing that the door is in remote control watertight subdivision boundaries of cargo
mode ("doors closed mode"). Special care spaces, structural analysis may be accepted
should be taken in order to avoid potential in lieu of pressure testing. Where such
danger when passing through the door. doors utilise gasket seals, a prototype
Signboard/instructions should be placed in way pressure test to confirm that the
of the door advising how to act when the door is compression of the gasket material is
in "doors closed" mode. capable of accommodating any deflection,
revealed by the structural analysis, is to be
2.6.9 Alarms carried out.
Doors which are to be capable of being remotely c) Doors which are not immersed by an
closed are to be provided with an audible alarm, equilibrium or intermediate waterplane but
distinct from any other alarm in the area, which become intermittently immersed at angles of
will sound whenever such a door is remotely heel in the required range of positive
closed. For passenger ships the alarm shall stability beyond the equilibrium position are
sound for at lest 5 s but not more than 10 s to be hose tested.
before the door begins to move and shall
continue sounding until the door is completely 2.6.13 Pressure testing
closed. In the case of remote closure by hand
operation, an alarm is required to sound only The head of water used for the pressure test
while the door is actually moving. shall correspond to at least the head measured
from the lower edge of the door opening, at the
In passenger areas and areas of high ambient location in which the door is to be fitted in the
noise, the audible alarms are to be vessel, to the bulkhead deck or freeboard deck,
supplemented by visual signals at both sides of as applicable, or to the most unfavourable
the doors. damage waterplane, if that be greater. Testing
may be carried out at the factory or other shore
2.6.10 Notices based testing facility prior to installation in the
ship.
As shown in Table 2.6.4, doors which are
normally closed at sea but not provided with 2.6.14 For doors on passenger ships which are
means of remote closure, are to have notices normally open and used at sea or which become
fixed to both sides of the doors stating, 'To be submerged by the equilibrium or intermediate
kept closed at sea'. Doors which are to be waterplane, a prototype test shall be conducted,
Indian Register of Shipping
Rules and Regulations for the Construction and Classification of Steel Ships - 2014
Page 7 of 13
___________________________________________________________________________________
on each side of the door, to check the - tanks for fuel oil or lubricating oil
satisfactory closing of the door against a force
equivalent to a water head of at least 1 [m] - tanks for edible oil
above the sill on the centre line of the door.
- tanks for fresh water and feed water.
2.6.15 Hose testing
2.7.2 Tanks for lubricating oil are also to be
After installation in a ship if pressure test is not separated by cofferdams from those carrying
carried out, all watertight doors are to be subject fuel oil. However, these cofferdams need not be
to a hose test in accordance with Pt.3, Ch.18. fitted provided that the common boundaries
Hose testing is to be carried out from each side have full penetration welds and the head of
of the door unless, for a specific application, lubricating oil is not less than that in the adjacent
exposure to floodwater is anticipated only from fuel oil tanks. In this case, a permanent notice is
one side. Where a hose test is not practicable to be displayed near the lubricating oil tank that
because of possible damage to machinery, the oil level is not to be less than that in the
electrical equipment, insulation or outfitting adjacent fuel oil tank at any time.
items, it may be replaced by means such as an
ultrasonic leak test or an equivalent test. 2.8 Fore peak spaces
Section 3
Section 4
Design Loads
For the definition of 'loadpoint' see Ch.4, Sec.3. Where automatic pressure valves are fitted, po is
not to be taken as less than the valve release
4.1.2 Watertight bulkheads enclosing hold pressure.
spaces to carry water ballast are to be treated
as tank bulkheads. 4.2.2 For longitudinal bulkheads (and transverse
bulkheads at sides) in way of wide tanks, the
4.1.3 The design pressure for the end bulkheads design pressure is normally given by the greater
of bulk cargo spaces are to be obtained as per of 'p' according to 4.2.1 and
Ch.4, Sec.3.4.3.
p = 6.7 (hs + φ b) x 10 [N/mm ]
-3 2
p = [4 - 0.005L] l t x 10 −3 [ N/mm 2 ]
lt = distance [m] between transverse tank
bulkheads or effective transverse wash
bulkheads at the height at which the strength - for transverse bulkheads, and
member is located. Transverse web frames
covering part of the tank cross-section (e.g. wing p = [3 - 0.01B] b t x 10 −3 [ N/mm 2 ]
tank structures in tankers) may be regarded as
wash bulkheads for this purpose. - for longitudinal bulkheads.
- for strength members located within 0.25 bt where,
from the tank side bulkheads the pressure
'p' is not to be less than
lt = the greater of the distances between the
adjacent transverse bulkheads.
p = ρ [3 - 0.01B] b t x 10 −3 [ N/mm 2 ]
bt = the greater of the distances between the
where, adjacent longitudinal bulkheads.
Section 5
Between neutral
At strength deck or
Region Framing system At neutral axis axis and strength
at bottom
deck or bottom
(175 - 120 fs)/k To be obtained by
Vertical 140/k
max. 120/k linear interpolation
0.4L amidships
(185 - 100 fs)/k To be obtained by
Longitudinal 160/k
max. 120/k linear interpolation
Within 0.1L from
160/k
ends
To be obtained by linear interpolation between allowable values at regions specified
Elsewhere
above.
where,
where, σ s
2
σ c = σ F 1 − F
ta = thickness of adjacent plating [mm] not to be c 1000 t f
taken greater than t.
Chapter 15
Contents
Section
1 General
2 Structural Arrangement for Anchoring Equipment
3 Equipment Specification
4 Anchors
5 Anchors Chain Cables
6 Towlines, Mooring Lines and associated Shipboard Fittings
7 Windlass and Chain Stoppers
Section 1
General
For vessels of 500 GT and above, towing 2) Length, diameter, grade and type of chain
arrangement plan is to be submitted for cables.
approval.
1.3.2 Following details of the proposed 3) Type and breaking load of steel and fibre
equipment are to be submitted for approval:- ropes.
Section 2
2.1 General
The chain lockers boundaries and chain pipes
2.1.1 The anchors are normally to be housed in are to be watertight upto the weather deck.
hawse pipes and anchor pockets of adequate Bulkheads which form common boundary of
size, scantlings and suitable form to prevent chain lockers need not be watertight. Where a
movement of anchor and chain due to wave means of access to spurling pipes or cable
action. lockers is located below the weather deck, the
access cover and its securing arrangements are
The arrangements are to provide an easy lead to be in accordance with recognized standards
of chain cable from windlass to the anchors. or equivalent for watertight manhole covers.
Upon release of the brake, the anchors are to
immediately start falling by their own weight. Provisions are to be made to minimize the
Substantial chafing lips are to be provided at ingress of water to the chain locker in bad
shell and deck. These are to have sufficiently weather. The chain pipes are to be provided
large, radiused faces to minimise the probability with permanently attached closing appliances
of cable links being subjected to large bending such as steel plates with cutouts for chain links
stresses. Alternatively, roller fairleads of suitable or canvas hoods with lashing arrangements. For
design may be fitted. requirements regarding drainage of chain
lockers, See Pt.4.
Alternative arrangements for housing of anchors
will be specially considered. Provisions are to be made for securing the
inboard ends of the chains to the structure. The
2.1.2 The shell plating and framing in way of the strength of this attachment should be between
hawse pipes are to be reinforced as necessary. 15 per cent to 30 per cent of the breaking
strength of the chain cable. It is recommended
2.1.3 On ships provided with a bulbous bow, that suitable arrangements be provided so that
and where it is not possible to obtain ample in an emergency the inboard end of the chain
clearance between shell plating and anchors (bitter end) can be readily made to slip from an
during anchor handling, adequate local accessible position outside the chain locker.
reinforcements on bulbous bow are to be
provided. 2.1.5 The windlass and chain stoppers are to be
efficiently bedded and secured to deck. The
2.1.4 The chain locker is to have adequate thickness of deck plating is to be increased in
capacity and depth to provide an easy direct way of the windlass and chain stoppers and
lead for the cable into the chain pipes, when the adequate stiffening underneath is to be
cable is fully stowed. The chain pipes are to be provided.
of suitable size and provided with chafing lips.
The port and starboard cables are to have
separate spaces.
Section 3
Equipment Specification
3.1.1 The equipment number, EN, on which the K = 1.00 for vessels of Unrestricted Service.
requirements of equipment are based is to be K = 0.85 for vessels of Coastal Service
calculated as follows :- K = 0.775 for vessels of Restricted Water
Service.
EN = K.ENc K = 0.50 for vessels of Sheltered Water Service.
∆ = moulded displacement, [t], to the summer 3.1.3 For tugs, while determining the equipment
load water line number EN, the term '2BH' in Sec.3.1.1 may be
substituted by 2(aB + Σ hibi) where bi is the
H = effective height, [m], from the summer load breadth, [m], of the widest superstructure or
waterline to the top of the uppermost deckhouse of each tier having a breadth greater
deckhouse, to be measured as follows: than B/4.
a = distance [m] from summer load waterline 3.2.1 For fishing vessels the equipment is to be
amidships to the upper deck at side in accordance with the requirements given in
Table 3.2.1 using EN as calculated in 3.1.
hi = height [m] on the centreline of each tier of
houses having a breadth greater than B/4. For 3.2.2 For other vessels the equipment is to be in
lowest tier, hi is to be measured at centre line accordance with the requirements given in Table
from upper deck, or from a notional deck line 3.2.2 using EN as calculated in 3.1.
where there is a local discontinuity in the upper
deck. 3.2.3 The two bower anchors in Table 3.2.1 and
Table 3.2.2 are to be connected to their cables
2
A = area [m ] in profile view of the hull, and positioned onboard ready for use. The total
superstructures and houses above the summer length of chain is to be divided in approximately
load waterline, which is within the Rule length of equal parts between the two bower anchors.
the vessel. Houses of breadth less than B/4 are
to be disregarded. 3.2.4 For tugs the particulars of towlines are to
be based upon the maximum bollard pull and
In the calculation of H and A, sheer and trim are the intended duty of the vessel. However, in no
to be ignored. case the breaking strength of the towline is to be
less than twice the maximum bollard pull.
Parts of windscreens or bulwarks which are
more than 1.5[m] in height are to be regarded as 3.2.5 For offshore supply vessels the length and
parts of houses when determining H and A. The the diameter of chain cable is to be based on an
height of the hatch coamings and that of any equipment letter two steps higher than that
deck cargo, such as containers, may be corresponding to the EN of the vessel. Towline
disregarded. is to be as per 1.1.2
'K' is a factor depending upon the type of vessel 3.2.6 For unmanned barges and pontoons of
and service notation as given below: length "L" less than 30 [m] no anchor need be
provided.
For fishing vessels,
Where length "L" is greater than or equal to 30
K = 1.00 [m] only one anchor of the tabular weight need
be provided. The attached chain cable is to be
of the tabular diameter and 2 L [m] in length.
Stockless Bower
Stud-Link Chain Cables Mooring Lines (Recommendation)
Anchors
Equip Diameter and chain
Steel or natural fibre ropes
EN ment Mass per Total grade
letter Number anchor length Breaking
CC1 CC2 Length
[kg] [m] Number strength
[mm] [mm] [m]
[kN]
30 & ≤ 40 Aof1 2 80 165 11 2 50 29
Stockless Bower
Stud-Link Chain Cables Mooring Lines (Recommendation)
Anchors
Equip Diameter and chain
Steel or natural fibre ropes
EN ment Mass per Total grade
letter Number anchor length Breaking
CC1 CC2 Length
[kg] [m] Number strength
[mm] [mm] [m]
[kN]
> 450 & ≤ 500 Nf 2 1440 412.5 38 34 3 140 108
Towline
Stud-link chain cables for bower 1)
Stockless (Recommendati Mooring lines
anchors
bower anchors on)
Equi Diameter and grade Steel or natural fibre ropes
pme Min.
EN
nt Total Min.
Mass break-
letter length Min. Length
Num per CC1 CC2 CC3 breaking Num ing
[m] length of each
ber anchor [mm] [mm] [mm] strength ber stren-
[m] [m]
[kg] [kN] gth
[kN]
50 & ≤ 70 A 2 180 220 14 12.5 180 98 3 80 34
> 70 & ≤ 90 B 2 240 220 16 14 180 98 3 100 37
> 90 & ≤ 110 C 2 300 247.5 17.5 16 180 98 3 110 39
> 110 & ≤ 130 D 2 360 247.5 19 17.5 180 98 3 110 44
> 130 & ≤ 150 E 2 420 275 20.5 17.5 180 98 3 120 49
> 150 & ≤ 175 F 2 480 275 22 19 180 98 3 120 54
> 175 & ≤ 205 G 2 570 302.5 24 20.5 180 112 3 120 59
> 205 & ≤ 240 H 2 660 302.5 26 22 20.5 180 129 4 120 64
> 240 & ≤ 280 I 2 780 330 28 24 22 180 150 4 120 69
> 280 & ≤ 320 J 2 900 357.5 30 26 24 180 174 4 140 74
> 320 & ≤ 360 K 2 1020 357.5 32 28 24 180 207 4 140 78
> 360 & ≤ 400 L 2 1140 385 34 30 26 180 224 4 140 88
> 400 & ≤ 450 M 2 1290 385 36 32 28 180 250 4 140 98
> 450 & ≤ 500 N 2 1440 412.5 38 34 30 180 277 4 140 108
> 500 & ≤ 550 O 2 1590 412.5 40 34 30 190 306 4 160 123
> 550 & ≤ 600 P 2 1740 440 42 36 32 190 338 4 160 132
> 600 & ≤ 660 Q 2 1920 440 44 38 34 190 371 4 160 147
> 660 & ≤ 720 R 2 2100 440 46 40 36 190 406 4 160 157
> 720 & ≤ 780 S 2 2280 467.5 48 42 36 190 441 4 170 172
> 780 & ≤ 840 T 2 2460 467.5 50 44 38 190 480 4 170 186
> 840 & ≤ 910 U 2 2640 467.5 52 46 40 190 518 4 170 201
> 910 & ≤ 980 V 2 2850 495 54 48 42 190 559 4 170 216
> 980 & ≤ 1060 W 2 3060 495 56 50 44 200 603 4 180 230
> 1060 & ≤ 1140 X 2 3300 495 58 50 46 200 647 4 180 250
Towline
Stud-link chain cables for bower 1)
Stockless (Recommendati Mooring lines
anchors
bower anchors on)
Equi Diameter and grade Steel or natural fibre ropes
pme
EN Min.
nt Total
Mass Min. break-
letter length Min. Length
Num per CC1 CC2 CC3 breaking Num ing
[m] length of each
ber anchor [mm] [mm] [mm] strength ber stren-
[m] [m]
[kg] [kN] gth
[kN]
> 1140 & ≤ 1220 Y 2 3540 522.5 60 52 46 200 691 4 180 270
> 1220 & ≤ 1300 Z 2 3780 522.5 62 54 48 200 738 4 180 284
> 1300 & ≤ 1390 A+ 2 4050 522.5 64 56 50 200 786 4 180 309
> 1390 & ≤ 1480 B+ 2 4320 550 66 58 50 200 836 4 180 324
> 1480 & ≤ 1570 C+ 2 4590 550 68 60 52 220 888 5 190 324
> 1570 & ≤ 1670 D+ 2 4890 550 70 62 54 220 941 5 190 333
> 1670 & ≤ 1790 E+ 2 5250 577.5 73 64 56 220 1024 5 190 353
> 1790 & ≤ 1930 F+ 2 5610 577.5 76 66 58 220 1109 5 190 378
> 1930 & ≤ 2080 G+ 2 6000 577.5 78 68 60 220 1168 5 190 402
> 2080 & ≤ 2230 H+ 2 6450 605 81 70 62 240 1259 5 200 422
> 2230 & ≤ 2380 I+ 2 6900 605 84 73 64 240 1356 5 200 451
> 2380 & ≤ 2530 J+ 2 7350 605 87 76 66 240 1453 5 200 480
> 2530 & ≤ 2700 K+ 2 7800 632.5 90 78 68 260 1471 6 200 480
> 2700 & ≤ 2870 L+ 2 8300 632.5 92 81 70 260 1471 6 200 490
> 2870 & ≤ 3040 M+ 2 8700 632.5 95 84 73 260 1471 6 200 500
> 3040 & ≤ 3210 N+ 2 9300 660 97 84 76 280 1471 6 200 520
> 3210 & ≤ 3400 O+ 2 9900 660 100 87 78 280 1471 6 200 554
> 3400 & ≤ 3600 P+ 2 10500 660 102 90 78 280 1471 6 200 588
> 3600 & ≤ 3800 Q+ 2 11100 687.5 105 92 81 300 1471 6 200 618
> 3800 & ≤ 4000 R+ 2 11700 687.5 107 95 84 300 1471 6 200 647
> 4000 & ≤ 4200 S+ 2 12300 687.5 111 97 87 300 1471 7 200 647
> 4200 & ≤ 4400 T+ 2 12900 715 114 100 87 300 1471 7 200 657
> 4400 & ≤ 4600 U+ 2 13500 715 117 102 90 300 1471 7 200 667
> 4600 & ≤ 4800 V+ 2 14100 715 120 105 92 300 1471 7 200 677
> 4800 & ≤ 5000 W+ 2 14700 742.5 122 107 95 300 1471 7 200 686
> 5000 & ≤ 5200 X+ 2 15400 742.5 124 111 97 300 1471 8 200 686
> 5200 & ≤ 5500 Y+ 2 16100 742.5 127 111 97 300 1471 8 200 696
> 5500 & ≤ 5800 Z+ 2 16900 742.5 130 114 100 300 1471 8 200 706
> 5800 & ≤ 6100 A* 2 17800 742.5 132 117 102 300 1471 8 200 706
> 6100 & ≤ 6500 B* 2 18800 742.5 137 120 107 300 1471 9 200 716
> 6500 & ≤ 6900 C* 2 20000 770 124 111 300 1471 9 200 726
> 6900 & ≤ 7400 D* 2 21500 770 127 114 300 1471 10 200 726
> 7400 & ≤ 7900 E* 2 23000 770 132 117 300 1471 11 200 726
> 7900 & ≤ 8400 F* 2 24500 770 137 122 300 1471 11 200 735
> 8400 & ≤ 8900 G* 2 26000 770 142 127 300 1471 12 200 735
> 8900 & ≤ 9400 H* 2 27500 770 147 132 300 1471 13 200 735
> 9400 & ≤ 10000 I* 2 29000 770 152 132 300 1471 14 200 735
> 10000 & ≤ 10700 J* 2 31000 770 137 15 200 735
> 10700 & ≤ 11500 K* 2 33000 770 142 16 200 735
Towline
Stud-link chain cables for bower 1)
Stockless (Recommendati Mooring lines
anchors
bower anchors on)
Equi Diameter and grade Steel or natural fibre ropes
pme
EN Min.
nt Total
Mass Min. break-
letter length Min. Length
Num per CC1 CC2 CC3 breaking Num ing
[m] length of each
ber anchor [mm] [mm] [mm] strength ber stren-
[m] [m]
[kg] [kN] gth
[kN]
> 11500 & ≤ 12400 L* 2 35500 770 147 17 200 735
> 12400 & ≤ 13400 M* 2 38500 770 152 18 200 735
> 13400 & ≤ 14600 N* 2 42000 770 157 19 200 735
> 14600 & ≤ 16000 O* 2 46000 770 162 21 200 735
1) For individual mooring lines with required breaking force above 490 [kN] according to the table, the required strength may be
reduced by the corresponding increase of the number of mooring lines and vice versa, provided that the total of all mooring lines
on board is not less than the Rule value. However, the number of mooring lines is not to be less than 6, and no line is to have a
breaking force less than 490 [kN].
Section 4
Anchors
4.1.3 The mass of the head, including pins and H.H.P. anchors are to be designed for effective
fittings, of an ordinary stockless anchor is not to hold of the sea bed irrespective of the angle or
be less than 60 per cent of the total mass of the position at which they first settle on the sea bed
anchor. after dropping from a normal type of hawse pipe.
In case of doubt a demonstration of these
4.1.4 The mass 'ex stock' of stocked bower or abilities may be required. The designs are to be
stream anchors is not to be less than 80 per tested on sea bed to show that they have a
cent of the tabular mass of ordinary stockless holding down power per unit of mass at least
bower anchors. The mass of the stock is to be twice that of approved ordinary stockless
25 per cent of the total mass of the anchor anchor.
including the shackle etc. but excluding the
stock. 4.2.2 If approval is sought for a range of anchor
sizes, at least two sizes are to be tested. The
4.1.5 When anchors of a design approved for mass of the larger anchor to be tested is not to
the designation 'High Holding Power' or 'Super be less than one-tenth of that of the largest
High Holding Power' are used as bower anchor of which approval is sought. The smaller
anchors, the mass of each such anchor may be of the two anchors to be tested is to have a
75 percent or 50 percent respectively of the mass not less than one-tenth of that of the
larger.
4.3 Super High Holding Power (SHHP) Tests in comparison with a previously approved
anchors SHHP anchor may be also accepted as a basis
for approval.
4.3.1 A super high holding power anchor is an
anchor with a holding power of at least four If approval is sought for a range of anchor sizes
times that of an ordinary stockless anchor of the then at least three anchor sizes are to be tested,
same mass. The use of SHHP anchors is to be indicative of the bottom middle and top of the
limited to vessels with service restrictions given mass range.
in Pt.1, Ch.1, Sec. 2.7.3. These anchors are not
to require prior adjustment or special placement 4.3.4 The holding power test load is not to
on the sea bed. exceed the proof load of the anchor.
The SHHP anchor mass should generally not 4.4 Manufacture and testing
exceed 1500 [kg].
4.4.1 Anchors and anchor shackles are to be
4.3.2 For approval and/or acceptance as a manufactured and tested in accordance with the
SHHP anchor satisfactory full scale tests are to requirements of Pt.2, Ch.10.
be made confirming that the anchor has a
Section 5
5.1 General 5.1.4 When the vessel may anchor where the
current exceeds 2.5 m/s, a length of heavier
5.1.1 Anchor chain cables and steel wire ropes chain cable locally between the anchor and the
(where proposed in lieu of chain cables) are to rest of the chain to enhance anchor bedding is
be as required by Sec.3. recommended.
5.1.2 Grade CC3 chain cable is to be used only 5.2 Manufacture and testing
when diameter is 20.5 [mm] or more.
5.2.1 Chain cables, steel wire ropes and
5.1.3 Grade CC1 chain cable having material shackles are to be manufactured and tested in
2
tensile strength of less than 400 [N/mm ] is not accordance with the requirements of Pt.2,
to be used in association with high holding Ch.10.
power or super high holding power anchors.
Section 6
6.1.4 The diameter of a fibre rope is not to be 6.3.3 Mooring winches should be fitted with
less than 20 [mm]. drum brakes, the strength of which is sufficient
to prevent unreeling of the mooring line when
6.2 Manufacture and testing the rope tension is equal to 80 per cent of the
breaking strength of the rope as fitted on the first
6.2.1 Steel wire ropes are to be manufactured layer on the winch drum.
and tested in accordance with the requirements
of Pt.2, Ch.10. 6.4 Design loads
6.2.2 Fibre ropes will be specially considered in 6.4.1 Where required, the minimum design
each case. loads to be considered for shipboard fittings and
supporting hull structures are to be as follows:
6.3 Towing and Mooring arrangements
a) For normal towing operations (e.g.
6.3.1 Means are to be provided to enable towing harbour / manoeuvring), 1.25 times the
lines and mooring lines to be adequately intended maximum towing load (e.g.
secured on board a ship. Bollards and bitts,
static bollard pull) as indicated on the arrangement of tug boats and selection
towing and mooring arrangement plan. of mooring lines.
b) For other towing operations (e.g. 6.4.2 The design load is to be applied through
escort), the nominal breaking strength the tow line / mooring line according to the
of the tow-line as required in Table arrangement shown on the towing and mooring
3.2.2 corresponding to the equipment arrangements plan
number of the vessel as per 3.1.1.
While calculating equipment number for 6.4.3 When a specific SWL (Safe Working Load)
this purpose, the side projected areas is applied for a shipboard fitting by which the
including maximum stacks of deck design load will be greater than the above
cargoes are to be taken into account in minimum values, the strength of the fitting is to
the estimation of area ‘A’. be designed using this specific design load.
c) For mooring operations, 1.25 times the 6.4.4 The method of application of the design
breaking strength of the mooring line as load to the fittings and supporting hull structures
required in Table 3.2.2 corresponding is to be taken into account such that the total
to the equipment number of the vessel load need not be more than twice the design
as per 3.1.1. However, side projected load, i.e. no more than one turn of one line (see
area including maximum stacks of deck Fig.6.4.4).
cargoes is to be taken into account for
assessment of lateral wind forces,
Fig.6.4.4
Allowable stresses given below are not to be Where the arrangements and details of deck
exceeded: fittings and their supporting hull structures are
designed based on a variation of mooring
Normal stress = σy arrangement (number of mooring lines and their
individual strength) that is permitted as per Note
Shear stress, τ = 0.6 σy 1 of Table 3.2.2, the following information is to
be clearly indicated on the plan:
Where σy = specified minimum upper yield
2 a) the arrangement of mooring lines showing
stress [N/mm ];
number of lines (N), together with
Normal stress is the sum of the bending stress
and axial stress with the corresponding shearing b) the breaking strength of each mooring line
stress acting perpendicular to the normal stress. (BS).
Stress concentration factors are not to be taken 6.6 Emergency towing procedure
into account in the above allowable stresses.
6.6.1 A ship specific emergency towing
The required gross thickness is obtained by procedure is to be provided according to SOLAS
adding a corrosion addition of 2.0 [mm] to the Ch.II-1/Reg.3-4 on ships as indicated in the
net scantling except for oil tankers and bulk following:
carriers covered by the common structural rules,
where the corrosion additions specified in those a) all passenger ships, not later than 01
rules would be applicable. January 2010
6.5.4 The safeworking load SWL for normal b) cargo ships constructed on or after 01
towing operations (e.g. harbour / manoeuvring) January 2010
is not to exceed 80% of the design load as per
6.4.1a) and that for other towing operations (e.g. c) Cargo ships constructed before 01 January
escort) is not to exceed the design load as per 2010, not later than 01 January 2012.
6.4.1b).
In the case of oil tankers, chemical carriers and
For mooring operations, the SWL is not to liquefied gas carriers, the requirement for
exceed 80% of the design load as per 6.4.1c). emergency towing arrangements given in Pt.5,
Ch.2, Sec.2.8, Pt.5, Ch.3, IR2.8 and Pt.5, Ch.4,
The above requirements on SWL apply for a IR3.9 respectively are also to be complied with.
single post basis (no more than one turn of
cable). 6.6.2 The emergency towing procedure is to be
based on existing arrangements and equipment
The safe working load SWL of each shipboard available on board the ship
fitting is to be marked (by weld bead or
equivalent). 6.6.3 The emergency towing procedure is to
include:
6.5.5 Towing and mooring arrangement plan
a) drawings of fore and aft deck showing
The SWL for the intended use for each possible emergency towing arrangements;
shipboard fitting is to be noted in the towing and
mooring arrangement plan available on board b) inventory of equipment on board that can be
for the guidance of the Master. used for emergency towing;
Information provided on the plan is to include in c) means and methods of communication; and
respect of each shipboard fitting:
d) sample procedures to facilitate the
a) location on the ship; preparation for and conducting of
b) fitting type; emergency towing operations.
c) SWL;
d) Purpose (mooring / harbour towing / (Refer to the IMO guidelines for owners /
escort towing); and operators on preparing emergency towing
e) Manner of applying towing or mooring procedures (MSC.1/Circ.1255)).
line load including limiting fleet angles.
Section 7
The windlass is to be also capable of exerting, The following green sea pressures are to be
for a period of not less than 2 minutes, a pull of considered:
not less than 1.5 times the continuous duty pull.
2
The speed in this period can be lower. - Pressure ‘px’ equal to 200 [kN/m ], normal to
the shaft axis as shown in Fig.7.2.2 and
The above criteria do not require both anchors acting over the projected area in this
to be raised or lowered simultaneously on direction.
windlass fitted with two cable lifters.
2
- Pressure ‘py’ equal to 150 [kN/m ], parallel
7.1.6 The capacity of the windlass brake is to be to the shaft axis as shown in Fig.7.2.2 acting
sufficient for safe stopping of anchor and chain both inboard and outboard separately, over
cable when paying out. the multiple of ‘f’ times the projected area in
this direction.
The windlass with brakes engaged and release
coupling disengaged is to be able to withstand where ‘f’ is defined as:
static pull of 45 per cent of the tabular breaking
strength of the chain without any permanent
f = 1+B/H, but need not be taken greater than Fxi = (Px - αgM) / N
2.5 Fyi = (Py - αgM) / N
where, and
xi, yi = x and y coordinates of bolt group ‘i’ from The safety factor against bolt proof strength is to
the centroid of all N bolt groups, positive in the be not less than 2.0.
direction opposite to that of the applied force
[cm] 7.3 Testing
Ai = cross sectional area of all bolts in group ‘i’ 7.3.1 After installation on board, anchoring tests
2
[cm ] are to be carried out to demonstrate satisfactory
working.
Ix = Σ Ai xi for N bolt groups
2
Py Px
h
W
Fore
Py
B
Centre Line of
Windlass
Px
Px
Coordinates x i and y i are shown as either
positive (+ve) or negative (-ve).
Centre Line of
Windlass
Py
x (-ve)
3
y (+ve)
2
y (+ve)
1
End of Chapter
Chapter 16
Contents
Section
1 General
2 Masts
3 Rigging
Section 1
General
ii) Plan showing proposed scantlings of i) All horizontal, vertical and torsional
mast, derrick post and standing rigging. forces,
ii) Deflection of the structure,
iii) Plan showing supporting structures and iii) Variations in the moment of inertia of
strengthening of hull in way of mast, post the parts of the structure,
and standing rigging fastenings, iv) The effects of outriggers and similar
structures,
iv) Specification of the steel wire ropes v) Elasticity and sag in stays, where fitted.
intended to be used for standing rigging,
indicating rope construction, scantlings 1.3 Materials
and minimum breaking strength.
1.3.1 Steel for masts, derrick posts, crane
pedestals and associated items are to be tested
and approved in accordance with the
requirements of Pt.2, Ch.3. Material grades of
steel are to be as follows:
Section 2
Masts
where,
For the above Table, SWL corresponding to the
l = length of the mast [m] measured above largest derrick operating on the mast is to be
upper supporting deck to hounds. taken.
The diameter is to be maintained upto the level The thickness of the mast plating is to be
of the gooseneck fitting where this is entirely adequate to prevent buckling and in no case is
supported by the mast. In case of masts without to be less than 7.5 [mm].
derricks, the diameter may be reduced to 0.75 d
at top. 2.2 Construction details
2.1.2 For masts without derricks, the thickness 't' 2.2.1 Masts are to be adequately supported by
of the mast plating is not to be less than atleast two decks and are to be efficiently
scarphed into the main hull structure. The hull
t = 0.01d + 2.5 [mm] or 5 [mm] whichever is structure is to be suitably reinforced. A
greater. deckhouse may be considered as a support
provided adequate strength is ensured by
2.1.3 The scantlings of masts with derricks are additional stiffening and increased plate
to be based on calculations mentioned in 1.2.2 thickness.
and 1.2.3. The total stress σt at any location, is
not to exceed the allowable stress values given 2.2.2 In general, mast scantlings are not to be
below:- reduced inside the deckhouse and are to be
maintained upto the level of the gooseneck
Allowable stresses in masts fitting where it is entirely supported by the mast.
SWL Stayed Unstayed mast
mast 2.2.3 Cross trees, outriggers, brackets on bridge
SWL ≤ 10t 0.50 σy 0.55 σ y fronts and similar structures are to be of such
SWL ≥ 60t 0.625 σ y 0.675 σ y design that the stresses on them resulting from
10 < SWL < the cargo gear and any other significant forces
By linear interpolation do not exceed the values given in 2.1.3 for
60
unstayed masts. The design is also to be such
where, as to minimize the moments acting on the mast.
Attachment to the mast is to be such as to avoid
σt = [(σ b ]
+ σ c ) + 3τ 2 [ N/mm 2 ]
2
distortion of the mast under the load.
2.2.5 Care should be taken in the design of 2.2.8 Where a mast supports a derrick with a
masts and fittings to reduce the likelihood of SWL > 25 [t], all welded joints of the masts
water collecting in inaccessible parts of the below a level 3.0 [m] above the uppermost
structure. Adequate means of drainage should supporting deck or that of the derrick head,
be provided to remove any water which might whichever is higher, are to be examined by non-
otherwise accumulate. destructive crack or flaw detection method.
2.2.6 Masts are to be strengthened either by 2.2.9 Where higher tensile steel is used,
addition of doubling plates or equivalent preheating or other heat treatments may be
strengthening, or by an increase of the thickness required at the Surveyors discretion. Such
of the plating at the following locations: treatments will normally be required for all ring
seams on masts supporting derricks of SWL >
i) In way of the fastening of the derrick heels, 60 [t]. Non-destructive examination may be
required in areas of high stresses.
ii) In way of the fastening of the derrick spans,
2.2.10 Lightning conductors are to be fitted to
iii) In way of the fastening of all metal fittings. masts having wood, aluminium or plastic top
masts or where a break in electrical conductivity
Suitable arrangements are to be made to avoid occurs in other arrangements.
notch effects.
Section 3
Rigging
3.1.1 The positioning of the rigging (shrouds, 3.2.1 The scantlings of the stay are to be such
stays etc.) is to be so designed as to ensure as to provide the necessary tensile force and
proper working of the cargo gear and that they elongation for the stayed mast. The breaking
do not foul with the running rigging or derrick load of the stay is to be not less than 3.5 times
booms under the expected service conditions. the maximum calculated force on that stay.
3.1.2 Wire rope stays are to be in one length 3.2.2 The connection of the stay to a deck,
and are to be set up with an initial tension of 30 bulwark, house or mast is to be such as to allow
2
[N/mm ]. rotation at the point of attachment and is to be
designed so that the stay cannot become
disconnected while the derrick system is in use.
End of Chapter
Chapter 17
Welding
Contents
Section
1 General
2 Welding
3 Welded Connections
Section 1
General
Section 2
Welding
2.1 Welders and supervision 2.2.2 For the connection of two different grades
of steel of the same tensile strength properties,
2.1.1 Welders are to be proficient in the type of electrodes suitable for the lower grade will be
work on which they are to be engaged. The generally acceptable except at structural
records of their tests and qualifications are to be discontinuities or other points of stress
kept by the builders and made available to the concentration.
Surveyors. A sufficient number of skilled
supervisors are to be employed to ensure 2.2.3 For the connection of steel of different
effective control at all stages of assembly and tensile strengths, the electrodes are to be
welding operations. suitable for the tensile strength of the
component, on the basis of which the weld fillet
2.2 Welding electrodes size has been determined in Sec.3.
2.3.3 Tack welding is to be kept to a minimum, 2.6.1 Effective arrangements are to be provided
and where used, should be equal in quality to for the inspection of finished welds to ensure
that of the finished welds. Any defective tack that all welding has been satisfactorily
weld is to be cut out before completing the completed.
finished welds. Care is to be taken in removing
the tack welds to ensure that the structure is not 2.6.2 All finished welds are to be visually
damaged in doing so. inspected and are to be sound, uniform and
substantially free from slag inclusions, porosity,
2.4 Welding procedure undercutting or other defects. Welds and
adjacent base metal are to be free from injurious
2.4.1 Only approved welding procedures are to arc strikes.
be used, See 2.5.
2.6.3 For the examination of important structural
2.4.2 Structural arrangements are to be such as welds, visual inspection is to be supplemented
to allow adequate access for satisfactory by radiography or other acceptable non-
completion of all welding operations. Welded destructive crack or flaw detection methods. The
joints are to be so arranged so as to facilitate extent of such examination is to be to the
downhand welding wherever possible. Surveyors' satisfaction, but particular attention is
to be given to the following locations:
2.4.3 The sequence of welding is to be so
planned that any restraint during welding a) Junction and crossings of seams and butts
operations is reduced to a minimum. The ends in strength deck, sheer strake, side and
of the frames and stiffeners should be left bottom shell within 0.4L amidships.
unattached to the plating at the subassembly
stage until connecting welds are made, in the b) Butts of keel plating and rounded
intersecting systems of plating, framing and sheerstrake within 0.4L amidships.
stiffeners, at the erection stage.
c) Insert plates in way of hatch openings on
Where a butt meets a seam, the welding of the the strength deck.
seam should be interrupted well clear of the
junction and not be continued until the butt is d) Butts of longitudinal framing and longitudinal
completed. Welding of the butt should continue bulkhead stiffeners within 0.4L amidships.
past the open seam and the weld be chipped
out for the seam to be welded straight through. 2.6.4 Defective sections of welds as found by
visual or non- destructive examination or
2.4.4 Adequate precautions are to be taken to leakages under hydrostatic tests, are to be
ensure that the welding site is protected from gouged out as necessary and carefully
the deleterious effects of high moisture, severe rewelded.
wind and extreme cold.
Section 3
Welded Connections
3.1 Butt welds The weld factors for various connections are
generally to be as given in Table 3.2.1.
3.1.1 Plates of equal thickness may be manually
butt welded as per Fig.3.1.1. For automatic Where an approved automatic deep penetration
welding procedures and special welding procedure is used, the weld factors may be
techniques, the welding procedure will be reduced by 15 per cent.
specially considered.
3.2.2 The throat thickness is not to be less than
3.1.2 For joints of plates with difference in 3.0 [mm] for tp upto 8.0 [mm] and 0.21 tp or 3.25
thickness of more than 4 [mm], the thicker plate [mm], whichever is greater, for tp over 8 [mm].
is to be tapered. The taper is not to exceed 1:3. The throat thickness is also generally not to be
Edge preparation after the tapering is to be as greater than 0.44 tp for double continuous welds
indicated in 3.1.1 above. and the greater of 0.44 tp or 4.5 [mm] for
intermittent welds.
3.1.3 All manual butt welds are normally to be
welded from both sides. Where a back ceiling 3.2.3 The leg length is not to be less than √2
run is not practicable or in certain cases when times the specified throat thickness.
the stress level in the members is very low,
welding on one side may be permitted provided 3.2.4 Where the connection is highly stressed,
the welding process is found satisfactory. deep penetration or full penetration welding may
be required. Where full penetration welding is
3.1.4 Where stiffening members, attached by required, the abutting plate may require to be
continuous fillet welds, cross the finished butt or beveled. (See Fig.3.2.4).
seam welds, these welds are to be made flush
in way of the faying surface. Similarly for butt 3.2.5 Continuous welding is to be adopted in the
welds in webs of stiffening members, the butt following locations and may be used elsewhere
weld is to be first completed and made flush with if desired.
the stiffening member before the stiffener is
connected to the plating by fillet weld. The ends a) Boundaries of weathertight decks and
of the flush portion are to run out smoothly erections, including hatch coamings,
without notches or any sudden change of companionways and other openings.
section. Where such conditions can not be
complied with, a scallop is to be arranged in the b) Boundaries of tanks and watertight
web of the stiffening member. Scallops are to be compartments.
of such size and in such a position, that a
satisfactory weld can be made. c) All structures in the afterpeak and the
afterpeak bulkhead stiffeners.
3.2 'T' connections
d) All welding inside tanks intended for
3.2.1 The throat thickness (See Fig.3.2.1) of the chemicals or edible liquid cargoes.
fillet welds is given by:
e) All lap welds in tanks.
throat thickness = tp . weld factor . d/s
f) Floors and girders to bottom shell in the
where, 0.25L forward.
tp = thickness [mm], of the thinner of the two g) Primary and secondary members to plating
parts being connected. in way of end connection and end brackets
to plating in the case of lap connection.
d = distance [mm], between the successive weld
fillets. h) Where the thickness of the abutting member
(i.e. stiffener web) is greater than 15 [mm]
s = length [mm], of the correctly proportioned and also exceeds the thickness of the table
weld fillets, clear of end craters is not to be less member (e.g. plating).
than 75 [mm].
Permitted type of
weld
Structural Items Weld Factors Remarks
Double Intermi-
cont. ttent
Single Bottom
Centre girder To keel plate or bar keel 0.3 *
To face plate 0.15 *
Side girder To bottom shell 0.15 *
To face plate 0.13 *
To floors 0.20 *
Floors To keel plate 0.15 *
To shell plating 0.15 *
To centre girder 0.35 *
To longitudinal bulkheads 0.35 *
To face plate 0.15 *
Stern-tube covering 0.15 *
Bottom longitudinal To shell plating 0.13 *
Permitted type of
weld
Structural Items Weld Factors Remarks
Double Intermi-
cont. ttent
Structure in Machinery Space
Floors and girders To shell and inner bottom 0.3 *
To face plate 0.2 *
Transverse and longitudinal To shell plating 0.15 *
frames
Floors To centre girder in way of
engine, thrust blocks and
boiler seatings
- in single bottom 0.50 *
- in double bottom 0.30 *
Main engine foundation To top plate 0.5 * See Note 2
girders
To hull structure 0.4 *
Floors To engine girder 0.4 *
Brackets etc. To engine girders 0.3 *
Side Structure
Transverse frames To side shell
- in tanks 0.13 *
- elsewhere 0.11 * For bulk carriers see
Pt.5, Ch.1, Sec.2.5
Side longitudinals To shell plating 0.13 *
Web frames and side To shell plating
stringers
- within 0.2 x span from 0.35 *
ends
- elsewhere 0.20 *
To face plate and tripping 0.15 *
bracket
Web frames To side stringers 0.3 *
Deck Structure
Strength deck To shell F.P. See Note 3
Other decks To shell and bulkheads 0.3 *
Generally
Deck beams To deck plating
- in tanks 0.13 *
- elsewhere 0.11 *
Deck longitudinals To decks 0.13 *
Deck girders To deck plating
- within 0.2 x span from 0.35 *
ends
- elsewhere 0.20 *
To face plating and 0.15 *
tripping brackets
Cantilever webs To shell, decks, face 0.35 *
plates and longitudinal
girders at ends
Pillars To deck, inner bottom and 0.40 *
pillar brackets
Permitted type of
weld
Structural Items Weld Factors Remarks
Double Intermi-
cont. ttent
Construction in 0.25L from F.P.
Floors and girders To shell 0.25 *
To inner bottom 0.25 *
Bottom longitudinals To shell 0.15 *
Shell To transverse and 0.15 *
longitudinal
Panting stringers To shell and frames 0.30 *
All internal structure In fore peak (unless a 0.13 *
higher factor is specified)
Aft Peak Construction
All internal structure On bottom, side shell and 0.3 *
See 3.2.5
aft peak bulkhead
Bulkheads and Partitions
Boundaries of Watertight, oiltight and 0.4 * To be specially
wash bulkheads and shaft considered for chemical
tunnels cargo tanks
Stiffeners On tank and wash 0.13 *
bulkheads
On pillar bulkheads 0.13 *
On ordinary bulkheads 0.11 *
Vertical and horizontal To bulkhead plating
girders in tanks and wash
- within 0.2 x span from 0.40 *
bulkheads
ends
- elsewhere 0.30 *
- to faceplace 0.30 *
- to tripping brackets 0.15 *
Vertical and horizontal To bulkhead plating
girders elsewhere
- within 0.2 x span from 0.35 *
ends
- elsewhere 0.20 *
To faceplate and tripping 0.15 *
brackets
Primary Structures in Cargo Tanks
Webs To shell, deck and
bulkheads
- within 0.2 x span from 0.4 *
ends
- elsewhere 0.3 * * See 3.2.6
Permitted type of
weld
Structural Items Weld Factors Remarks
Double Intermi-
cont. ttent
Hatchways and Closing Appliances
Hatch coaming To deck at corners 0.5 *
To deck elsewhere 0.4 *
To face plate 0.4 *
To hatch cover rest bar 0.16 *
Hatch cover To stiffeners 0.12 *
Intermittent welding means chain intermittent, staggered intermittent or scalloped welding with rounded ends.
For permitted use see 3.2.6.
Note 1 For tank boundaries see 3.2.5. Where intermittent fillet welding of internals is proposed, see 3.2.6.
Note 2 Preferably to be deep penetration or full penetration weld depending on the thickness of the engine girders.
Note 3 Generally full penetration, but alternative proposals may be considered depending on tp.
End of Chapter
Chapter 18
Contents
Section
1 Hull Inspection
2 Workmanship
3 Testing of Tanks and Tight Boundaries
Section 1
Hull Inspection
Section 2
Workmanship
2.1.1 All workmanship is to be of good quality 2.3.1 Flanging and bending of plates while cold
and in accordance with good shipbuilding forming are not to have an average bending
practice. Any defect is to be rectified to the radius less than three times the plating
satisfaction of the Surveyor before being thickness. The minimum radius is not to be less
covered with paint, cement or other composition. than twice the plating thickness.
2.1.2 The assembly sequence and welding 2.3.2 During joggling of plates and profiles, the
sequence are to be agreed prior to construction depth of joggle is not to be less than four times
and are to be to the satisfaction of the Surveyor. and the bending radius not less than twice the
web thickness.
2.2 Plate edges and cut-outs
2.4 Hammering, bending and straightening
2.2.1 Openings, holes and other cut-outs in the
main structural components are to be rounded 2.4.1 Steel being worked on when hot, is not to
off by adequately large radii. The free edges of be overheated, and it is to be hammered and
cut-outs, hatch corners etc. are to be properly bent in the appropriate heat condition. Steel
prepared and are to be free from notches. All which is burnt, is not to be used.
edges should be faired.
2.4.2 Flame heating may be employed to
straighten buckled plating when the buckling is
not severe.
Indian Register of Shipping
Chapter 18 Part 3
Page 2 of 8 Hull Inspection, Workmanship and Testing
Section 3
- New ships prior to delivery, and 3.2.2 The testing of the cargo containment
- Structures involved in, or affected by, major systems of liquefied gas carriers is to be in
conversions or repairs’ affecting structural accordance with Pt.5, Ch.4, Sec.4.10 and Table
integrity are to be confirmed by these test 3.4.2.
procedures.
3.2.3 Testing of structures not listed in Table
3.2 Application 3.4.1 or 3.4.2 is to be specially considered.
3.2.1 All gravity tanks and other boundaries 3.3 Types of tests and definitions
required to be watertight or weathertight are to
be tested in accordance with this section and 3.3.1 The following two types of tests are
proven tight and structurally adequate as specified in this requirement:
follows:
.1) Structural test : A test to verify the structural
- Gravity tanks for their tightness and adequacy of the construction of the tanks. This
structural adequacy. may be a hydrostatic test or, where the situation
- Watertight boundaries other than tank warrants, a hydropneumatic test.
boundaries for their watertightness,
and .2) Leak test : A test to verify the tightness of
- Weathertight boundaries for their the boundary. Unless a specific test is indicated,
weathertightness. this may be a hydrostatic / hydropneumatic test
or air test. Leak test with note 3 in Table 3.4.1
Note : Gravity tank means a tank that is subject includes hose test as an acceptable method of
to vapour pressure not greater than 0.07 [MPa]. the test.
“Watertight means having scantlings and 3.3.2 Definition of each type of test is as follows:
arrangements capable of preventing the
passage of water in any direction under the
Hydrostatic Test: A test by filling the space with a liquid to a specified head
(Leak and Structural)
Hydropneumatic Test: A test wherein the space is partially filled with liquid and air pressure
(Leak and Structural) applied on top of the liquid surface
Hose Test (Leak) A test to verify the tightness of the joint by a jet of water
Air Tests: (Leak) A test to verify the tightness by means of air pressure differential and
leak detection solution. It includes tank air tests and joint air tests,
such as compressed air test and vacuum box test.
Compressed Air Fillet Weld An air test of a filet welded tee joint with a leak indicating solution
Test: (Leak) applied on the fillet welds
Vacuum Box Test: (Leak) A box over a joint with leak indicating solution applied on the fillet or
butt welds. A vacuum is created inside the box to detect any leaks
Ultrasonic Test: (Leak) A test to verify the tightness of a sealing by means of ultrasound
Penetration Test: (Leak) A test to verify that no continuous leakages exist in the boundaries of
a compartment by the application of low surface tension liquids.
3.4 Test procedures after the last ship of the series, such exemption
may be reconsidered. In any case, structural
3.4.1 General testing is to be carried out for at least one tank
for each vessel in order to verify structural
Tests are to be carried out in the presence of fabrication adequacy. However, the
the Surveyor at a stage sufficiently close to the requirements in this paragraph for sister vessels
completion of the work with all hatches, doors, do not apply to cargo space boundaries in
windows, etc., installed and all penetrations tankers and combination carriers and tanks for
including pipe connections fitted and before any segregated cargoes or pollutants.
ceiling and cement work is applied over the
joints. Specific test requirements are given in .2 These subsequent tanks may require
3.4.4 and Table 3.4.1. For the timing of structural testing if found necessary after the
application of coating and the provision of safe structural testing of the first tank.
access to joints, see 3.4.5, 3.4.6 and Table
3.4.3. .3 Tanks for structural test are to be selected so
that all representative structural members are
3.4.2 Structural test procedures tested for the expected tension and
compression.
3.4.2.1 Type and time of test
.4 For watertight boundaries of spaces other
Where a structural test is specified in Table than tanks (excluding chain lockers), structural
3.4.1 or Table 3.4.2, a hydrostatic test in testing is not compulsory. However, the
accordance with 3.4.4.1 will be acceptable. watertightness in all boundaries of such spaces
Where practical limitations, (strength of building are to be verified by leak tests and thorough
berth, density of liquid, etc.) prevent the inspection.
performance of a hydrostatic test, a
hydropneumatic test in accordance with 3.4.4.2 3.4.3 Leak test procedures
may be accepted as an equivalent method.
For the leak test specified in Table 3.4.1, a tank
Provided the results of a leak test are confirmed air test, compressed air fillet weld test, vacuum
satisfactory, a hydrostatic test for confirmation of box test in accordance with 3.4.4.4 to 3.4.4.6, or
structural adequacy may be carried out while the their combination will be acceptable. A
vessel is afloat. hydrostatic or hydropneumatic test may also be
accepted as the leak test provided 3.4.5 and
3.4.2.2 Number of structural tests 3.4.6 are complied with. A hose test will also be
acceptable for the locations as specified in
(Note : Concurrence of the Flag Administration Table 3.4.1 with Note 3.
is to be obtained prior to allowing relaxation for
structural tests for tanks of same structural A joint air test may be carried out in the block
configuration and for tanks in sister vessels). stage provided all work on the block that may
affect the tightness of the joint is completed
.1 A structural test is to be carried out for at least before the test. See also 3.4.5.1 for the
one tank of the same construction (i.e. tanks of application of final coating and 3.4.6 for safe
the same structural design and configuration access to the joint and their summary in Table
and same general workmanship as determined 3.4.3.
by the attending Surveyor) on each vessel
provided all subsequent tanks are tested for 3.4.4 Details of tests
leaks by an air test.
3.4.4.1 Hydrostatic test
However, where structural adequacy of a tank
was verified by structural testing required in Unless other liquid is approved, the hydrostatic
Table 3.4.1, the subsequent vessels in the test is to consist of filling the space by fresh
series (i.e. sister ships built in the same water or sea water, whichever is appropriate for
shipyard) may be exempted from such testing testing of the space, to the level specified in
for other tanks which have structural similarity to Table 3.4.1 or Table 3.4.2
the tested tank, provided that the water-
tightness in all boundaries of exempted tanks In case a tank for cargoes with higher density is
are verified by leak tests and thorough to be tested with fresh water or sea water, the
inspection. For sister ships built several years
A hydropneumatic test where approved is to be Note : Where a leak test of partial penetration
such that the test condition in conjunction with welding is required and the root face is
the approved liquid level and air pressure will sufficiently large (i.e. 6-8 mm), the compressed
simulate the actual loading as far as practicable. air test is to be applied in the same manner as
The requirements and recommendations for for a fillet weld.
tank air tests in 3.4.4.4 will also apply to the
hydropneumatic test. 3.4.4.6 Vacuum box test
A U-tube with a height sufficient to hold a head For butt joints by automatic process, final
of water corresponding to the required test coating may be applied anytime before
pressure is to be arranged. The cross sectional completion of the leak test of the space bounded
area of the U-tube is not to be less than that of by the joint.
the pipe supplying air to the tank. In addition to
U-tube, a master gauge or other approved However, the Surveyor reserves the right to
means to verify the pressure is to be provided. require a leak test prior to the application of the
final coating over automatic erection butt welds.
3.4.4.5 Compressed air fillet weld test
For all other joints, final coating is to be applied
In this air test, compressed air is injected from after the completion of the leak test of the joint.
one end of a fillet welded joint and the pressure See also Table 3.4.3.
verified at the other end of the joint by a
pressure gauge on the opposite side. Pressure
Any temporary coating which may conceal For leak tests, a safe access to all joints under
defects or leaks is to be applied at a time as examination is to be provided. See also Table
specified for final coating. This requirement does 3.4.3.
not apply to shop primer.
1. Structural test is to be carried out for at least one tank of the same construction (i.e. same
design and same workmanship) on each vessel provided all subsequent tanks are tested for
leaks by an air test.
Where structural adequacy of a tank was verified by structural testing, the subsequent vessels
in the series (i.e. sister ships built in the same shipyard) may be exempted from such testing
for other tanks which have the structural similarity to the tested tank, provided that the water-
tightness in all boundaries of exempted tanks are verified by leak tests and thorough
inspection is carried out. In any case, structural testing is to be carried out for at least one tank
for each vessel in order to verify structural fabrication adequacy. However, the requirements in
this paragraph for sister vessels do not apply to cargo space boundaries in tankers and
combination carriers and tanks for segregated cargoes or pollutants. (See 3.4.2.2(1)).
2. Top of tank is deck forming the top of the tank excluding any hatchways.
3. Hose Test may also be considered as a method of the test, see 3.3.2.
4. Including tanks arranged in accordance with the provisions of SOLAS regulation II-1/9.4.
5. Including duct keels and dry compartments arranged in accordance with the provisions of
SOLAS regulation II-1/9.4.
6. Where water tightness of watertight door has not been confirmed by prototype test, testing by
filling watertight spaces with water is to be carried out. See SOLAS regulation II-1/16.2 and
MSC/Circ.1176.
7. Where a hose test is not practicable, other testing methods listed in 3.4.4.7 through 3.4.4.9 may
be applicable subject to adequacy of such testing methods being verified. See SOLAS
regulation II-1/11.1.
8. An alternative to the hose testing, other testing methods listed in 3.4.4.7 through 3.4.4.9 may be
applicable subject to the adequacy of such testing methods being verified. See SOLAS
regulation II-1/11.1.
9. For vessels of L < 90 [m], the head of water above highest point of tank may be (0.02L + 0.6)
[m], but not less than 1.0 [m]. However, in mechanically propelled cargo ships of 500 GT and
above and passenger ships, for tanks forming part of the watertight subdivision (See Pt.3,
Ch.10, 4.2.1), head of water above the highest point of tank is to be 2.4 [m].
10. Watertight shell doors are to be prototype tested prior to installation on board.
Table 3.4.2 : Additional Test requirements for Special Service Ships / Tanks
Sr. Type of Ship / Structures to Type of Test Test Head of Pressure Remarks
No. Tank be tested
1 Liquefied gas Cargo See 3.4.4.1 See 3.4.4.1 See also
carrier containment Table 3.4.1
systems (See for other
remarks) tanks and
boundaries
2 Edible liquid Independent Leak and The greater of
tanks tanks structural - top of the
overflow, or
- to 0,9 [m]
above top
1
of tank
3 Chemical carrier Integral or Leak and The greater of
independent structural - to 2,4 [m]
cargo tanks above top
1
of tank , or
1
- to top of tank
plus setting
of any
pressure
relief valve
Note : 1. Top of tank is deck forming the top of the tank excluding any hatchways
Table 3.4.3 : Application of leak test, coating and provision of safe access for
type of welded joints
1 2
Type of welded joints Leak Test Coating Safe Access
Before leak After leak Leak test Structural
test test and test
before
structural
test
Butt Automatic Not required Allowed N/A Not required Not required
Manual or Required Not allowed Allowed Required Not required
semi-
automatic
Fillet Boundary Required Not allowed Allowed Required Not required
including
penetrations
Notes :
1. Coating refers to internal (tank / hold coating), where applied and external (shell/deck) painting.
It does not refer to shop primer.
End of Chapter
Part 4
Main and Auxiliary Machinery
January 2014
Indian Register of Shipping
Part 4
Contents
Chapter 9 Deleted
Contents
Section 1 : General
2.3 Fire protection
1.1 Scope
2.4 Ventilation
1.2 Machinery to be constructed under survey
2.5 Communications
1.3 Extent of survey
2.6 Machinery controls
1.4 Departures from the rules
2.2 Accessibility
Section 1 : General
1.8 Flanges
1.1 Scope
1.9 Materials
1.2 Classes of pipes
1.3 Design pressure Section 2 : Carbon and Low Alloy Steel Pipes
and Fittings
1.4 Design temperature
2.1 Materials
1.5 Design symbols
2.2 Minimum thickness of steel pipes and bends
1.6 Heat treatment
2.3 Types of connection
1.7 Minimum thickness of pipes and bends
2.6 Welding, non-destructive examination and 5.7 Requirements for pipes/piping systems
post-weld heat treatment of welded pipes depending on service and/or locations
2.7 Mechanical joints 5.8 Material approval and quality control during
manufacture
6.2 Scope
Section 4 : Cast Iron Pipes and Fittings
6.3 Design and construction
4.1 Spheroidal or nodular graphite cast iron
6.4 Installation
4.2 Grey cast iron
6.5 Tests
5.1 General
Section 7 : Hydraulic Tests on Pipes and
5.2 Terms and definitions Fittings
1.4 Valves and cocks 2.4 Drainage from fore and aft peaks
1.5 Shipside fittings (other than sanitary 2.5 Drainage from tanks, cofferdams and void
discharges and scuppers) spaces
1.6 Piping installation 2.6 Drainage from spaces above fore and after
peaks, chain lockers and above machinery
spaces
2.11 Pump types 5.2 Steam pipes in way of holds, shaft and pipe
tunnels
2.12 Bilge piping arrangements and fittings
5.3 Relief valves
2.13 Additional requirements for passenger
ships 5.4 Steam supply to auxiliaries
2.14 Drainage arrangements on vessels not 5.5 Steam for fire extinguishing in cargo holds
fitted with propelling machinery
5.6 Condensate pumps
2.15 Ballast system
3.6 Water level detectors on single hold cargo Section 7 : Engine Cooling Water Systems
ships other than bulk carriers
7.1 General
Section 4 : Fuel Oil Systems
7.2 Cooling water main supply
4.1 General
7.3 Cooling water standby supply
4.2 Oil fuel tanks
7.4 Relief valves on cooling water pumps
4.3 Oil fuel piping
7.5 Sea inlets for cooling water pumps
4.4 Arrangement of valves, cocks, pumps and
fittings
Section 8 : Lubricating Oil Piping Systems
4.5 Heating arrangements
8.1 General
4.6 Temperature indication
8.2 Pumps
4.7 Filling arrangements
8.3 Control of pumps and alarms
4.8 Alternate carriage of oil fuel and water
ballast 8.4 Emergency supply for propulsion turbines
and propulsion turbogenerators
4.9 Deep tanks for the alternative carriage of oil,
water ballast or dry cargo 8.5 Filters
4.10 Oil fuel burning arrangements 8.6 Valves and cocks on lubricating oil tanks
4.11 Engine starting arrangements 6.15 Keys and keyways for propeller
connections
4.12 Type testing of oil engines
6.16 Stern tube and bearings
4.13 Work's trials (acceptance test)
6.17 Roller element bearings
4.14 Shipboard trials
6.18 Shaft bearing materials
4.15 Dual fuel diesel engines
6.19 Glass Reinforced Plastic coating
Section 5 : Gearing
Section 7 : Propellers
5.1 Scope
7.1 Scope
5.2 Plans and particulars
7.2 Plans and particulars
5.3 Materials
7.3 Materials
5.4 Design and construction
7.4 Design
5.5 Accuracy of gear cutting and alignment
7.5 Fitting of propellers
5.6 Balancing of gear pinions and wheels
Section 8 : Vibrations and Alignment
5.7 Gearcases
8.1 Scope
5.8 Type tests and sea trials
8.2 Basic system requirements
5.9 Alignment and weardown gauges
8.3 Resilient mountings
5.10 Trials
8.4 Torsional vibration
Section 6 : Main Propulsion Shafting
8.5 Axial vibrations
6.1 Scope
8.6 Lateral vibrations
6.2 Alternative calculation methods
8.7 Shaft alignment
6.3 Plans and particulars
Section 9 : Thrusters
6.4 Materials for shafting
9.1 Scope
6.5 Intermediate and thrust shafts
9.2 Plans and particulars
6.6 Tailshafts and stern tube shafts
9.3 Materials
6.7 Hollow shafts
9.4 Design and construction
6.8 Integral couplings
9.5 Piping systems
6.9 Demountable couplings
9.6 Control and monitoring
6.10 Tooth couplings
Indian Register of Shipping
Part 4
Page 6 of 12 Contents
Section 1 : General
2.6 Standpipe and branches
1.4 Plans and particulars 2.9 Shell type exhaust gas heated economizers
that may be isolated from the steam plant
1.5 Classification of pressure vessels system
2.4 Conical ends subject to internal pressure 4.2 Other pressure vessels
7.2 Trials
Section 2 : Performance
2.3 Other requirements 8.2 For tankers, chemical tankers or gas carriers
of 10,000 tons gross and upwards
Section 3 : Construction and Design 8.3 For tankers, chemical tankers or gas carriers
of 10,000 tons gross and upwards but of less
3.1 General than 100,000 tonnes deadweight
3.2 Components
Section 9 : Guidelines for the Acceptance of
3.3 Valve and relief valve arrangement Non-duplicated Rudder Actuators for Tanker,
Chemical Tankers or Gas Carriers of 10,000
3.4 Flexible hoses tons gross and upwards but of less than
100,000 tonnes Deadweight
9.2 Design
4.1 General
9.3 Construction details
IR4.2 Mechanical, hydraulic and electrical
independency and failure detection and 9.4 Non-destructive testing
response of steering control systems
9.5 Testing
2.2 Electrical and electronic devices 6.3 Additional requirements for programmable
electronic systems used for essential services
2.3 Hydraulic controls and safety critical systems
2.6 Bridge control for main propulsion machinery 6.6 Additional requirements for wireless data
links
2.7 Valve control system
6.7 Protection against modification
1.10 Design and construction 2.16 Fire detection and extinguishing systems
1.12 Electrical equipment for use in explosive 2.18 Heating and cooking equipment
gas atmospheres
2.19 Temporary external supply / shore
1.13 Enclosures connection
3.2 Conductors
Section 2 : System Design
3.3 Insulating materials
2.1 General
3.4 Construction
2.2 Supply and distribution systems
3.5 Testing
2.3 Voltage and frequency variations
3.6 Voltage rating
2.4 Earth indication
3.7 Choice of insulating material
2.5 Number, arrangement and capacity of
generators 3.8 Choice of protective covering
2.7 Number and capacity of transformers or 3.10 Correction factors for current rating
power convertors
3.15 Penetration of bulkheads and decks by 7.4 Heating and cooking equipment
cables
7.5 Lightning conductors
3.16 Installation of cables in pipes and conduits
8.4 Cables
Section 4 : Switchgear and Control Gear
Assemblies 8.5 Overload and short circuit protection
8.11 Identification
Section 5 : Rotating Machines - Construction
and Testing
Section 9 : Crew and Passenger Emergency
5.1 General Safety Systems
5.5 Overloads
Section 10 : Ship Safety Systems
5.6 Brushgear
10.1 Watertight doors
5.7 Inspection and testing
10.2 Shell doors, loading doors and other
closing appliances
Section 6 : Converting Equipment
11.1 General
11.9 Requirements for tankers intended for the 12.9 Power Transformers
carriage in bulk of oil cargoes having a flash
point not exceeding 60°C (closed cup test) 12.10 Cables
11.10 Requirements for ships for the carriage of 12.11 Switchgear and controlgear assemblies
liquefied gases in bulk
12.12 Auxiliary systems
11.11 Requirements for ships intended for the
carriage in bulk of other flammable liquid 12.13 Installation
cargoes
13.4 Performance
Section 12 : High Voltage Systems
13.5 Voltage drop
12.1 Scope
Chapter 9 : Deleted
Section 2 : Fusion Welded Pressure Vessels 2.9 Repairs to welded seams on fusion welded
pressure vessels
2.1 Manufacture of Class 1 and Class 2 fusion
welded pressure vessels 2.10 Post-weld heat treatment of pressure
vessels
2.2 Manufacture of Class 3 fusion welded
pressure vessels
Section 3 : Welded Pressure Pipes
2.3 Preliminary tests for Class 1 and Class 2
fusion welded pressure vessels 3.1 General
2.4 Preliminary tests for Class 3 fusion welded 3.2 Non-destructive examination of welded
pressure vessels pipes
2.5 Routine tests for Class 1 and Class 2 fusion 3.3 Post-weld heat treatment
welded pressure vessels
3.4 Heat treatment after forming of pipes
End of Chapter
Chapter 1
Contents
Section
1 General
2 Machinery Room Arrangements
3 Trials
4 Certification of Machinery and Components Based upon
Quality Management Systems
Section 1
General
- Main propulsion engines, including their - Air compressors, air receivers and other
associated gearing, flexible couplings, pressure vessels necessary for the
scavenge blowers and superchargers; operation of main propulsion and essential
machinery. Any other unfired pressure
- Boilers supplying steam for propulsion or for vessels for which plans are required to be
services essential for the safety or the submitted for approval in accordance with
operation of the ship at sea, including the requirements of Ch.5;
superheaters, economisers, desuper-
heaters, steam receivers. All other boilers - Alarm and control equipment as detailed in
having working pressures exceeding 0.34 Ch.7;
2
[N/mm ], and having heating surfaces
2
greater than 4.65 [m ]; - Electrical equipment and electrical
propelling machinery as detailed in Ch.8.
- All pumps essential for safety of the ship, in operation and in restoring the propulsion, no
e.g. fire, bilge and ballast pumps; and stored energy for starting and operating the
propulsion plant, the main source of electrical
- Valves and other components detailed in power and other essential auxiliaries is assumed
Ch.2. to be available. In order to restore operation
from the "dead ship" condition, an emergency
1.3 Extent of survey generator complying with the requirements of
Pt.4, Ch.8, Cl.2.8 may be used provided that the
1.3.1 The Surveyors are to examine and test the emergency power supply from it is available at
materials and workmanship from the all times. It is assumed that means are available
commencement of work until the final test of the to start the emergency generator at all times.
machinery under full power working conditions.
Any defects, etc., are to be indicated as early as 1.6.2 "Blackout" is a sudden loss of electric
possible. power in the main distribution system. All means
of starting by stored energy are available.
1.3.2 Where items of machinery are
manufactured as individual or series produced 1.7 Environmental conditions
units, IRS would be prepared to give
consideration to the adoption of a survey 1.7.1 All components and systems covered by
procedure based upon quality assurance the Rules are to be designed to operate under
concepts as detailed in Sec.4. the following environmental conditions if not
otherwise specified in the detailed requirements
1.4 Departures from the rules for the component or system:
1.4.1 Where it is proposed to depart from the - ambient air temperature in the machinery
requirements of the Rules, IRS will be prepared space between 0°C and 55°C;
to give due consideration to the circumstances
of any special case. - relative humidity of air in the machinery
space up to 96 per cent;
1.4.2 Any novelty in the construction of the
machinery, boilers or pressure vessels is to be - sea water temperature up to 32°C; and
reported to IRS.
- list, rolling, trim and pitch in accordance with
1.5 Plans and particulars Table 1.7.1.
1.5.1 Before the work is commenced, plans in 1.7.2 Where the Rules have requirements for
triplicate of all machinery items, as detailed in capacity or effect of machinery, these are to be
relevant Chapters of this Part giving the based on a total barometric pressure of 1 bar,
requirements for individual systems, are to be an engine room ambient temperature or suction
submitted for approval. The particulars of the air temperature of 45°C, a relative humidity of 60
machinery, including power ratings and design per cent and a sea water temperature or where
calculations, where applicable, necessary to applicable the temperature of the charge air
verify the design, are also to be submitted. Any coolant at inlet of 32°C. The engine
subsequent modifications are subject to manufacturer is not expected to provide
approval before being put in to operation. simulated ambient reference conditions at test
bed.
1.5.2 The strength requirements for rotating
parts of the machinery, as specified in relevant 1.7.3 In the case of ships to be classed for
Chapters of this Part, are based upon strength restricted service, the rating is to be suitable for
consideration only and their application does not the temperature conditions associated with the
relieve the manufacturer from the responsibility geographical limits of the restricted service.
for the presence of dangerous vibrations in the
installation at speeds within the operating range. 1.7.4 Where electrical equipment is installed
within environmentally controlled spaces the
1.6 Availability of machinery for operation ambient temperature for which the equipment is
suitable may be reduced from 45°C to a value
1.6.1 Ship's machinery is to be so arranged that not less than 35°C provided:
it can be brought in to operation from the "dead
ship" condition using only the facilities available - The equipment is not for use for emergency
on board. "Dead ship" condition is understood to services.
mean a condition under which the main
propulsion plant, boilers and auxiliaries are not
Indian Register of Shipping
Rules and Regulations for the Construction and Classification of Steel Ships - 2014
Page 3 of 8
___________________________________________________________________________________
1
Angle of inclination
Installations/Components Athwartships Fore and aft
Static Dynamic Static Dynamic
4
Main and auxiliary machinery 15° 22.5° 5° 7.5°
Safety equipment
e.g. emergency power installations,
3 3
emergency fire pumps and their devices 22.5° 22.5° 10° 10°
Switch gear, electric and electronic
2
appliances and remote control systems
Notes
2 Switches and controls are to remain in their last set position. Upto an angle of inclination of 45° no
undesired switching operations or operational changes may occur.
3 In ships for the carriage of liquefied gases and of chemicals the emergency power supply must also
remain operable with the ship flooded to a final athwartships inclination upto maximum of 30°.
4 For ships where Rule length (L) exceeds 100 [m], the fore and aft static angle of inclination can be
taken as 500/L degrees.
5 Any deviations from these angles of inclination taking into consideration the size and service
conditions of the ship will be specially considered.
- Audible and visual alarms are provided, at a - For auxiliary machinery, the maximum
continually manned control station, to continuous shaft power and corresponding
indicate any malfunction of the cooling units. revolutions per minute which will be used in
service.
- It is to be ensured that electrical cables for
their entire length are adequately rated for 1.9 Units
the maximum ambient temperature to which
they are exposed along their length. 1.9.1 Units and formulae included in the Rules
are shown in SI units.
- The equipment used for cooling and
maintaining the lesser ambient temperature 1.9.2 Where the metric version of shaft power,
is to be classified as a secondary essential i.e. (shp), appears in the Rules, 1 shp is
service, as defined in Ch.8, sec.1. equivalent to 75 [kgf] [m/sec] or 0.735 [kW].
1.9.3 Pressure gauges may be calibrated in bar 1.11.2 For emergency generator engines, fuel
having a flash point (closed cup test) of not less
where, than 43°C may be used.
2 2
1 bar = 0.1 [N/mm ] = 1.02 [kgf/cm ]. 1.11.3 Fuels with flash points lower than 60°C,
but not less than 43°C unless specially
1.10 Astern power approved, may be used in ships intended for
service restricted to geographical limits where it
1.10.1 In order to maintain sufficient can be ensured that the temperature of the
maneuverability and secure control of the ship in machinery and boiler spaces will always be
all normal conditions, the main propulsion 10°C below the flash point of fuel. In such
machinery is to be capable of reversing the cases, safety precautions and the arrangements
direction of thrust so as to bring the ship to rest for storage and pumping will be specially
from the maximum service speed. The main considered. (Also refer Pt.6, Ch.2, 1.2.1).
propulsion machinery is to be capable of
maintaining in free route astern at least 70% of 1.11.4 The use of fuels having a lower flash
the ahead revolutions. point than specified in 1.11.1 to 1.11.3 as
applicable may be permitted provided that such
1.10.2 Where steam turbines are used for main fuel is not stored in any machinery space and
propulsion, they are to be capable of arrangements for the complete installation are
maintaining in free route astern at least 70% of specially approved.
the ahead revolutions for a period of at least 15
minutes. The astern trial is to be limited to 30 1.11.5 For engines operating on "boil-off"
minutes or in accordance with manufacturer’s vapours from the cargo, the arrangements will
recommendation to avoid overheating of the be specially considered.
turbine due to the effects of “windage” and
friction. 1.12 Materials
1.10.3 For main propulsion systems with 1.12.1 The materials used in the construction
reversing gears, controllable pitch propeller or are to be manufactured and tested in
electric propeller drive, running astern is not to accordance with the requirements of Pt.2 of the
lead to overload of the propulsion machinery. Rules. Materials for which provision is not made
therein may be accepted, provided that they
1.10.4 The ahead revolutions as mentioned comply with an approved specification and such
above are understood as those corresponding to tests as may be considered necessary.
the maximum continuous ahead power for which
the vessel is classed. 1.12.2 Installation of material which contain
asbestos is prohibited.
1.10.5 The reversing characteristics of the
propulsion plant are to be demonstrated and 1.13 Alternative design and arrangements
recorded during trials.
1.13.1 The Rules generally cover the
1.11 Fuel requirements of SOLAS Ch.II-1, Parts C, D and
E. Design and arrangements alternative to these
1.11.1 The flash point (closed cup test) of oil fuel requirements may be accepted based on
for use in ships classed for unrestricted service, SOLAS Reg. II-1/55 and MSC.1/Circ. 1212.
in general, is not to be less than 60°C.
Section 2
2.1.2 The design and arrangement of machinery c) Oil filters fitted in parallel for the purpose of
foundations, shaft connections, piping and enabling cleaning without disturbing oil
ducting is to take into account the effects of supply to engines (e.g. duplex filters) are to
thermal expansion, vibrations, mis-alignment be provided with arrangements that will
and hull interaction to ensure operation within minimise the possibility of a filter under
safe limits. pressure being opened by mistake.
Filter/filter chambers are to be provided with
Bolts and nuts exposed to dynamic forces and suitable means for :
vibrations are to be properly secured.
- venting when put in to operation; and
2.2 Accessibility
- depressurizing before being opened.
2.2.1 Accessibility, for attendance and
maintenance purposes, is to be provided for Valves or cocks with drain pipes led to a
machinery plants. safe location are to be used for this
purpose.
2.3 Fire protection
d) Hydraulic units with working pressure above
2.3.1 All surfaces of machinery where the 15 bar are preferably to be placed in
surface temperature may exceed 220°C, e.g., separate spaces. If it is impracticable to
steam and exhaust gas lines, silencers, boilers, locate such units in separate space,
exhaust gas boilers, turbo blowers, etc. are to adequate shielding is to be provided.
be effectively shielded to prevent ignition of
combustible materials coming in to contact with 2.3.4 Flammable or oil absorbing materials are
them. Where insulation covering these surfaces not to be used in floors, gratings, etc. in boiler
is oil absorbing or may permit penetration of oil, and engine rooms, shaft tunnels or in
the insulation is to be encased in steel or its compartments where settling tanks are installed.
equivalent.
2.3.5 Segregation of oil fuel purifiers
2.3.2 The insulation is to be of a type and so
supported that it will not crack or deteriorate a) Oil fuel purifiers for heated oil are to be in
when subjected to vibration. separate room enclosed by steel bulkheads
extending from deck to deck and provided
2.3.3 Oil spillages coming into contact with hot with self-closing steel doors.
surfaces, electrical installations or other sources
of ignition. b) The room is to be provided with :
Section 3
Trials
3.1.1 Tests of components and trials of 3.2.1 For all types of installations, the sea trials
machinery, as detailed in the Chapters giving are to be of sufficient duration, and carried out
the requirements for individual systems are to under normal maneuvering conditions, to prove
be carried out to the satisfaction of the the machinery under rated power. The trials are
Surveyors. also to demonstrate that any vibration which
may occur within the operating speed range is
acceptable.
3.2.3 Where controllable pitch propellers are 3.2.6 Where the ship is provided with
fitted, the free route astern trial is to be carried supplementary means for maneuvering or
out with the propeller blades set in full pitch stopping, the effectiveness of such means is to
astern position. Where emergency manual pitch be demonstrated and recorded as referred to in
setting facilities are provided, their operation is 3.2.5.
to be demonstrated to the satisfaction of the
Surveyors. 3.2.7 All trials are to be to Surveyor's
satisfaction.
Section 4
products have been of a consistently high management systems is satisfactory, IRS will
standard. issue to the manufacturer a Quality Assurance
Approval Certificate which will include details of
4.2.3 The manufacturer should have the products for which approval has been given.
implemented quality management systems
generally in accordance with the ISO 9000 4.4.3 An extension of approval in respect of
series of standards. product type may be given at the discretion of
IRS without any additional assessment.
4.2.4 The manufacturer shall establish and
maintain procedures and controls to ensure that 4.4.4 The certificate will be valid for 3 years
IRS requirements for certification of materials subject to a satisfactory annual surveillance
and components at sub-contractors's works are assessment.
complied with to the satisfaction of IRS.
4.4.5 When significant faults or deficiencies are
4.3 Information required for approval found during surveillance assessments or
surveillance assessments are not carried out,
4.3.1 Manufacturers applying for approval under the certificate of approval may be
this scheme are to submit the following withdrawn/suspended at the discretion of IRS.
information :
4.5 Certification of products
- Description of the products for which
certification is required including, where 4.5.1 After issue of the Quality Assurance
applicable, model or type number; Approval Certificate, the manufacturer would be
authorized to issue certificate for products on
- Applicable plans and details of materials behalf of IRS subject to the certificates being
used; countersigned by IRS Surveyors. Arrangements
for this will be specially advised by IRS.
- An outline description of all important
manufacturing plant and equipment; 4.6 Certification of diesel engines
End of Chapter
Chapter 2
Contents
Section
1 General
2 Carbon and Low Alloy Steel Pipes and Fittings
3 Copper and Copper Alloy Pipes and Fittings
4 Cast Iron Pipes and Fittings
5 Plastic Pipes and Fittings
6 Flexible Hoses
7 Hydraulic Tests on Pipes and Fittings
Section 1
General
1.1.1 The requirements of this Chapter apply to 1.2.1 For the purpose of testing, type of joints to
the design and construction of piping systems, be adopted, heat treatment and welding
including pipe fittings and valves forming parts procedure, piping systems are divided into three
of such systems for the following services: classes, as given in Table 1.2.1.
Air, vapour, gas (excluding liquefied gas cargo 1.3 Design pressure
and process piping), water, lubricating oil, fuel
oil, hydraulic fluid systems for steering gear, 1.3.1 The design pressure, P, is the maximum
toxic gas and liquids, cargo oil and tank cleaning permissible working pressure and is to be not
piping and open ended lines such as drains, less than the highest set pressure of the safety
overflows, vents and boiler escape pipes. valve or relief valve. For oil fuel pipes the design
pressure is to be taken in accordance with Table
1.1.2 The requirements of this Chapter do not 1.3.1. For gaseous fuel, the design pressure will
cover the following: be specially considered.
Exhaust pipes from internal combustion engines 1.3.2 In water tube boiler installations, the
and gas turbines, and pipes forming integral part design pressure for steam piping between the
of a boiler. boiler and integral superheater outlet is to be
taken as the design pressure of the boiler, i.e.
1.1.3 Hydraulic fluid systems other than those not less than the highest set pressure of any
for steering gear will be specially considered. safety valve on the boiler drum. For piping
leading from the superheater outlet, the design
1.1.4 For requirements pertaining to piping pressure is to be taken as the highest set
systems for liquefied gases (cargo and process) pressure of the superheater safety valves.
and cargo piping systems of ships carrying
chemicals in bulk reference should be made to
applicable Chapters of Pt.5 of the Rules.
1.3.3 The design pressure of feed piping and restrict the pressure to a lower value than the
other piping on the discharge from pumps is to shut valve load, the design pressure is to be the
be taken as the pump pressure at full rated highest set pressure of the protective device.
speed against a shut valve. Where a safety
valve or other protective device is fitted to
3,4
Table 1.2.1 : Classes of piping systems
Steam P > 16 or T > 300 16 ≥ P > 7 and 300 ≥ T > 170 P ≤ 7 and T ≤ 170
Thermal Oil P > 16 or T > 300 16 ≥ P > 7 and 300 ≥ T > 150 P ≤ 7 and T ≤ 150
Fuel oil + Lubricating oil +
P > 16 or T > 150 16 ≥ P > 7 and 150 ≥ T > 60 P ≤ 7 and T ≤ 60
Flammable hydraulic oil
5
Other media including
water, air, gases, non- P > 40 or T > 300 40 ≥ P > 16 and 300 ≥ T > 200 P ≤ 16 and T ≤ 200
flammable hydraulic oil
Notes:
1 Safeguards for reducing leakage possibility and limiting its consequences will be specially
considered e.g. leading pipes in positions where leakage of internal fluids will not cause a potential
hazard or damage to surrounding areas or by the usage of pipe ducts, shielding, screening etc.
2 Cargo oil pipes belong to Class III piping systems.
3 P = Design pressure in bar as defined in 1.3
4 T = Design temperature in °C as defined in 1.4.
5 For open ended pipes (drains, overflow, vents, exhaust gas lines, boiler escape lines, etc.)
irrespective of the temperature, Class III pipes may be used.
Table 1.3.1 : Definition of the design pressure for fuel oil systems
Working
Pressure (WP)
WP ≤ 7 bar 3 bar or max. working pressure, 3 bar or max. working pressure,
whichever is greater whichever is greater
WP > 7 bar Max. working pressure 14 bar or max. working pressure,
whichever is greater
1.5.1 The symbols used in this Chapter are 1.7 Minimum thickness of pipes and bends
defined as follows:
1.7.1 The minimum thickness, t, of straight pipes
a = percentage negative manufacturing is to be determined by the following formula
tolerance on thickness; when ratio of outside-diameter to inside-
diameter does not exceed the value 1.7:-
b = bending allowance [mm];
PD 100
c = corrosion allowance [mm]; t = + c [mm]
20Ke + P 100 − a
D = outside diameter of pipe [mm] (see 1.5.2);
where,
d = inside diameter of pipe [mm] (see 1.5.3);
P, D, e and a are defined in 1.5.1.
e = weld efficiency factor (see 1.5.4);
The maximum permissible design stress, K, is to
P = design pressure, in bar; be taken as the lowest of the following values:-
t = the minimum thickness of a straight pipe 1% creep in 100,000 hrs at the design
[mm], including corrosion allowance and temperature.
negative tolerance, where applicable;
Et = specified minimum lower yield or 0.2 per
tb = the minimum thickness of a straight pipe to cent proof stress at the design temperature
be used for a pipe bend [mm]; including bending
allowance, corrosion allowance and negative R20 = specified minimum tensile strength at
tolerance, where applicable; ambient temperature
1.5.2 The outside diameter, D, is subject to Value of K may be obtained from Sec.2, Table
manufacturing tolerance, but these are not to be 2.1.1 and Table 2.1.2 for carbon and low alloy
used in the evaluation of formulae. steel pipes and fittings or from Sec.3, Table
3.2.1 for copper and copper alloys pipes and
1.5.3 The inside diameter, d, is not to be fittings.
confused with nominal size, which is an
accepted designation associated with outside c is obtained from Sec.2, Table 2.2.1 for carbon
diameters of standard rolling sizes. and low alloy steel pipes and fittings or from
Sec.3, Table 3.2.3 for copper and copper alloys
1.5.4 The weld efficiency factor, e, is to be taken pipes and fittings.
as 1.0 for seamless and electric resistance and
induction welded steel pipes delivered by 1.7.2 Where it is proposed to use, for high
manufacturers approved for making welded temperature service, alloy steels other than
those detailed in Sec.2, particulars of the tube
sizes, design conditions and appropriate flanges and related bolts, will be specially
national or proprietary material specifications considered.
are to be submitted for consideration.
1.8.2 Gaskets are to be suitable for the medium
1.7.3 The minimum thickness, tb, of a straight being conveyed under design pressure and
steel pipe to be used for a pipe bend is to be temperature conditions and their dimensions
determined by the following formula, except and configurations are to be in accordance with
where it can be demonstrated that the use of a a recognized standard and for the intended
thickness less than tb would not reduce the service.
thickness below 't' at any point after bending:-
1.9 Materials
PD 100
tb = + b + c [mm] 1.9.1 Materials for ferrous castings and forgings
20Ke + P 100 − a of Class I and Class II piping systems are to be
produced at Works approved by IRS and are in
where, general to be tested in accordance with the
requirements of Pt.2 of the Rules.
P, D, R, e, b and a are defined in 1.5.1;
1.9.2 The manufacturer's test certificate for
K and c are defined in 1.7.1; materials of valves and fittings will be accepted
in lieu of the IRS certificate provided the
D PD maximum conditions are less than given in
b= [mm] Table 1.9.1.
2.5R 20Ke + P
1.9.3 Pipes and bodies of valves, intended to be
In general, R, is to be not less than 3D. fitted on ship's side and bottom or on collision
bulkhead, are to comply with the requirements
1.7.4 Notwithstanding the requirements of 1.7.1 of Class II piping systems.
and 1.7.3, the minimum thickness of pipes is not
to be less than that indicated in Sec.2 or 3, as 1.9.4 Materials for Class III piping systems may
applicable. For threaded pipes, where permitted, be manufactured and tested in accordance with
the minimum thickness is to be measured at the the requirements of an acceptable national/
bottom of the thread. international standard.
1.8 Flanges 1.9.5 Stainless steel grades 304, 304L, 316 and
316L are generally not considered suitable for
1.8.1 The dimensions of flanges and related use in seawater piping systems due to their
bolts, gaskets are to be chosen in accordance limited corrosion resistance in contact with sea
with recognised national/international standards. water.
For special applications, the dimensions of the
Table 1.9.1 : Maximum conditions for valves and fittings for which manufacturer's test
certificate is acceptable
Section 2
2.1 Materials
2.2 Minimum thickness of steel pipes and
2.1.1 Pipes having forge butt welded longitudinal bends
seams are not to be used for oil fuel systems,
for heating coils in oil tanks, or for pressures 2.2.1 The minimum thickness of steel pipes and
exceeding 4.0 bar. bends is to be higher of that calculated by
Sec.1, Cl.1.7 and that indicated in Table 2.2.2,
2.1.2 Steel pipes, valves and fittings may be Table 2.2.3 or Table 2.2.4 as applicable.
used within the temperature limits indicated in
Table 2.1.1 and Table 2.1.2. Where rimming 2.2.2 The value of 'c' to be used in Sec.1, Cl.1.7
steel is used for pipes manufactured by electric is to be in accordance with Table 2.2.1
resistance or induction welding processes, the
design temperature is limited to 400°C.
Specified 2
Maximum permissible stress [N/mm ]
min.
tensile Maximum design temperature °C
strength
[N/mm2] 50 100 150 200 250 300 350 400 410 420 430 440 450
320 107 105 99 92 78 62 57 55 55 54 54 54 49
360 120 117 110 103 91 76 69 68 68 68 64 56 49
410 136 131 124 117 106 93 86 84 79 71 64 56 49
460 151 146 139 132 122 111 101 99 98 85 73 62 53
490 160 156 148 141 131 121 111 109 98 85 73 62 53
2
Specified Minimum permissible stress [N/mm ]
min. tensile
Type of steel strength Maximum design temperature °C
[N/mm2] 50 100 200 300 350 400 440 450 460 470
1 Cr 1/2 Mo 440 159 150 137 114 106 102 101 101 100 99
2 1/4 Cr 1 Mo
410 76 67 57 50 47 45 44 43 43 42
annealed
2 1/4 Cr 1 Mo
normalised and 490 167 163 153 144 140 136 130 128 127 116
tempered (Note 1)
2 1/4 Cr 1 Mo
normalised and 490 167 163 153 144 140 136 130 122 114 105
tempered (Note 2)
1/2 Cr 1/2 Mo 1/4 V 460 166 162 147 120 115 111 106 105 103 102
Maximum design temperature °C
480 490 500 510 520 530 540 550 560 570
1 Cr 1/2 Mo 440 98 97 91 76 62 51 42 34 27 22
2 1/4 Cr 1 Mo
410 42 42 41 41 41 40 40 40 37 32
annealed
2 1/4 Cr 1 Mo
normalised and 490 106 96 86 76 67 58 49 43 37 32
tempered (Note 1)
2 1/4 Cr 1 Mo
normalised and 490 96 88 79 72 64 56 49 43 37 32
tempered (Note 2)
1/2 Cr 1/2 Mo 1/4 V 460 101 99 97 94 82 72 62 53 45 37
Notes:
1 Maximum permissible stress values applicable when the tempering temperature does not exceed 750°C.
2 Maximum permissible stress values applicable when the tempering temperature exceeds 750°C.
Notes:
1 For pipes passing through tanks an additional corrosion allowance is to be considered according to
the figures given in Table and depending upon the external medium in order to account for the
external corrosion.
2 The corrosion allowance may be reduced where pipes and any integral pipe joints are protected
against corrosion by means of coating, lining etc., however, the reduction is not to be more than 50
percent in any case.
3 In the case of use of special alloy steel with sufficient corrosion resistance, the corrosion allowance
may be reduced to zero.
11
Table 2.2.2 : Minimum wall thickness for steel pipes [All dimension in mm]
Table 2.2.3 : Minimum wall thickness for steel pipes for CO2 fire extinguishing
Notes:
1 Pipes are to be galvanised at least internally, except those fitted in the engine room where
galvanising may be dispensed with.
2 For threaded pipes, where allowed, the minimum wall thickness is to be measured at the bottom of
the thread.
3 The external diameters and thicknesses have been selected from ISO recommendations R 336 for
smooth welded and seamless steel pipes. For pipes covered by other standards, slightly less
thickness may be accepted.
4 For larger diameters, the minimum wall thickness will be specially considered.
5 In general, the minimum thickness is the nominal wall thickness and no allowance need be made for
negative tolerance and reduction in wall thickness due to bending.
Table 2.2.4 : Minimum wall thickness for austenitic stainless steel pipes
2.6 Welding, non-destructive examination 2.7.4 Where the application of mechanical joints
and post-weld heat treatment of welded results in reduction in pipe wall thickness due to
pipes the use of bite type rings or other structural
elements, this is to be taken into account in
2.6.1 Requirements regarding welding determining the minimum wall thickness of the
procedures, non-destructive examination of pipe to withstand the design pressure.
welds and post-weld heat treatment are given in
Ch.10. The materials used in construction of
mechanical joints is to be compatible with the
2.7 Mechanical joints piping material and internal and external media.
In general the mechanical joints are to be of fire
2.7.1 Mechanical joints means devices intended resistant type as required by Table 2.7.1.
for direct connection of pipe lengths other than
by flanges, threaded joints or welding as 2.7.5 The pressure pulsation, piping vibration,
described in 2.4, 2.5 and 2.6. temperature variation and any other similar
adverse effects occurring during operation on
2.7.2 The requirements given here are board is not to result in failure of joint integrity or
applicable to pipe unions, compression its tightness.
couplings, slip-on joints as shown in Fig.2.7.
Similar joints complying with these requirements 2.7.6 Mechanical joints, which in the event of
may be acceptable. damage could cause fire or flooding, are not to
be used in piping sections directly connected to
2.7.3 Mechanical joints including pipe unions, the sea openings or tanks containing flammable
compression couplings, slip-on joints and similar fluids.
joints are to be of approved type for the
pressure ratings, service conditions and the 2.7.7 The mechanical joints are to be designed
intended application. The construction and type to withstand internal and external pressure as
are to conform to the examples shown in Fig.2.7 applicable and where used in suction lines are
and are to be in accordance with Table 2.7.1 to be capable of operating under vacuum.
and Table 2.7.2 for their classification and
application. (For approval refer “Type Approval 2.7.8 The number of mechanical joints in oil
of Mechanical Joints used in Piping”). systems is to be kept to a minimum. In general,
2.7.9 Piping in which a mechanical joint is fitted 2.7.14 Mechanical joints are to be subjected to
is to be adequately adjusted, aligned and the following tests:
supported Supports or hangers are not to be
used to force alignment of piping at the point of .1 leakage test
connection. .2 vacuum test
.3 vibration (fatigue) test
2.7.10 Slip-on joints are normally not to be used .4 fire endurance test
in pipelines in cargo holds, tanks and other .5 burst pressure test at 4 times the design
spaces which are not easily accessible, unless pressure (for design pressures above 200 bar,
approved in each case. the burst pressure will be specially considered
by IRS)
2.7.11 Application of mechanical joints inside .6 pressure pulsation test
tanks may be permitted only for the same media .7 assembly test
that is in the tanks. .8 pull out test.
2.7.12 Unrestrained slip-on joints are to be used NOTE : For details of tests refer classification
only in cases where compensation of lateral notes, “Type Approval of Mechanical Joints
pipe deformation is necessary. Usage of these used in Piping”.
joints as the main means of pipe connection is
not permitted. 2.7.15 The installation of mechanical joints is to
be in accordance with the manufacturer’s
2.7.13 In particular cases, sizes in excess of assembly instructions and using special tools
those mentioned in Table 2.7.2 may be and gauges as required.
Kind of connections
Systems Pipe unions Compression Slip-on joints
couplings 6)
Flammable Fluids (Flash point ≤ 60°)
1 Cargo oil lines + + +5)
2 Crude oil washing lines + + +5)
3 Vent lines + + +3)
Inert Gas
4 Water seal effluent lines + + +
5 Scrubber effluent lines + + +
6 Main lines + + +2) 5)
7 Distributions lines + + +5)
Flammable Fluids (Flash point > 60°)
8 Cargo oil lines + + +5)
9 Fuel oil lines + + +3) 2)
10 Lubricating oil lines + + +2) 3)
11 Hydraulic oil + + +2) 3)
12 Thermal oil + + +2) 3)
Sea Water
13 Bilge lines + + +1)
14 Fire main and water spray + + +3)
15 Foam system + + +3)
16 Sprinkler system + + +3)
17 Ballast system + + +1)
Sea Water (contd.)
18 Cooling water system + + +1)
19 Tank cleaning services + + +
20 Non-essential systems + + +
Fresh Water
21 Cooling water system + + +1)
Kind of connections
Systems Pipe unions Compression Slip-on joints
couplings 6)
Sounding / Vent
Sanitary / Drains / Scuppers
22 Condensate return + + +1)
23 Non-essential system + + +
24 Deck Drains (Internal) + + +4)
25 Sanitary Drains + + +
26 Scuppers and Discharge + + -
(Overboard)
27 Water tanks / Dry spaces + + +
28 Oil tanks (f.p > 60°C) + + +2) 3)
Miscellaneous
29 Starting / Control air 1) + + -
30 Service air (non-essential) + + +
31 Brine + + +
32 CO2 system 1) + + -
33 Steam + + + 7)
Abbreviations
+ Application is allowed
- Application is not allowed
Footnotes:
Table 2.7.2 : Application of mechanical joints depending upon the class of piping
Abbreviations:
+ Application is allowed
- Application is not allowed
Section 3
3.1 Materials
3.2 Minimum thickness of pipes
3.1.1 Pipes are to be seamless and branches
are to be provided by cast or stamped fittings, 3.2.1 The minimum thickness of copper and
pipe pressings or other approved fabrications. copper alloy pipes and bends is to be higher of
Copper pipes for class I and II are to be that calculated by Sec.1, Cl.1.7 and that
seamless. indicated in Table 3.2.2.
3.1.2 Brazing and welding materials are to be 3.2.2 The value of 'c' to be used in Sec.1, Cl.1.7
suitable for the operating temperature and for is to be in accordance with Table 3.2.3.
the medium being carried. All brazing and
welding are to be carried out to the satisfaction 3.3 Heat treatment
of the Surveyors.
3.3.1 Pipes which have been hardened by cold
3.1.3 In general, the maximum permissible bending are to be suitably heat treated on
service temperature of copper and copper alloy completion of fabrication and prior to being
pipes, valves and fittings is not to exceed 200°C tested by hydraulic pressure. Copper pipes are
for copper and aluminium brass, and 300°C for to be annealed and copper alloy pipes are to be
copper nickel. Cast bronze valves and fittings either annealed or stress relief heat treated.
complying with the requirements of Pt.2 Ch.8
may be accepted up to 260°C.
Specified 2
Permissible stress [N/mm ]
min.
Condition of Maximum design temperature °C
Pipe material tensile
supply
strength
2 50 75 100 125 150 175
[N/mm ]
Copper Annealed 220 41.2 41.2 40.2 40.2 34.3 27.5
Aluminium brass Annealed 320 78.5 78.5 78.5 78.5 78.5 78.5
95/5 90/10 copper
Annealed 270 68.6 68.6 67.7 65.7 63.7 61.8
nickel-iron
70/30 copper nickel Annealed 360 81.4 79.4 77.5 75.5 73.5 71.6
Maximum design temperature °C
200 225 250 275 300
Copper Annealed 220 18.6 - - - -
Aluminium brass Annealed 320 24.5 - - - -
95/5 90/10 copper
Annealed 270 58.8 55.9 52.0 48.1 44.1
nickel-iron
70/30 copper nickel Annealed 360 69.6 67.7 65.7 63.7 61.8
Notes :
Table 3.2.2 : Minimum thickness for copper and copper alloy pipes
Table 3.2.3 : Corrosion allowance 'c' for copper and copper alloy pipes
For media without corrosive action in respect of the material employed and in case of special alloys
with sufficient corrosion resistance, the corrosion allowance may be reduced to zero.
Section 4
4.1 Spheroidal or nodular graphite cast iron general, to be subject to the same limitations as
grey cast iron.
4.1.1 Spheroidal or nodular graphite iron
castings for pipes, valves and fittings in Class II 4.2 Grey cast iron
and III piping systems are to be made in a grade
having a specified minimum elongation not less 4.2.1 Grey cast iron pipes, valves and fittings
than 12 per cent on gauge length of 5.65√So, will, in general, be accepted in Class III piping
where So is the actual cross-sectional area of systems except as stated in 4.2.2. Grey cast
the test piece. iron valves and fittings may be accepted in the
Class II steam systems, but the design pressure
4.1.2 Proposals for the use of this material in or temperature is not to exceed 13 bar or 220°C
Class I piping systems will be specially respectively.
considered, but in no case is the material to be
used in systems where the design temperature 4.2.2 Grey cast iron is not to be used for the
exceeds 350°C. following:
4.1.3 Where the elongation is less than the a) Pipes for steam systems and fire
minimum required by 4.1.1, the material is, in extinguishing systems;
Section 5
5.1.3 Plastic pipes and fittings will, in general, be 5.2.5 "Nominal pressure" means the maximum
accepted in Class III piping systems. Proposals permissible working pressure which should be
for the use of plastics in Class I and Class II determined in accordance with the requirements
piping systems will be specially considered. in 5.3.3.
5.1.4 These requirements are not applicable to 5.2.6 "Fire endurance" means the capability of
flexible pipes and hoses and mechanical piping to maintain its strength and integrity (i.e.
couplings used in metallic piping systems. capable of performing its intended function) for
some predetermined period of time while
5.1.5 Piping systems made of thermoplastic exposed to fire.
materials, such as polyethylene (PE),
polypropylene (PP), polybutylene (PB) and 5.3 Strength
intended for non-essential services are to meet
the requirements of recognized standards and 5.3.1 The strength of the pipes is to be
that of 5.8 and 5.9. However the safety aspects determined by hydrostatic pressure tests to
due to fire will require to be considered. failure on representative sizes of the pipe.
5.1.6 The use of plastics may be restricted by 5.3.2 The strength of fittings and joints is to be
statutory requirements of the National Authority not less than that of the pipes.
of the country in which the ship is to be
registered. 5.3.3 The nominal pressure is to be determined
from the following conditions :
5.1.7 The specification of piping is to be in
accordance with a recognized national or a) Internal Pressure
international standard acceptable to IRS. In
addition, requirements given in 5.3 to 5.6 are to For an internal pressure the nominal pressure,
be complied with. Pn, is to be lesser of the following :
or where,
External diameter D Minimum wall thickness External diameter Minimum wall thickness
[mm] [mm] D [mm] [mm]
5.4.1 The sum of the longitudinal stresses due 5.6.1 The permissible working temperature
to pressure, weight and other loads is not to depending on the working pressure is to be in
exceed the allowable stress in the longitudinal accordance with Manufacturer's recommen-
direction. dations, but in each case it is to be at least 20°C
lower than the minimum heat distortion
5.4.2 In the case of fibre reinforced plastic pipes, temperature of the pipe material, determined
the sum of the longitudinal stresses is not to according to ISO 75 method A, or equivalent.
exceed half of the nominal circumferential stress
derived from the nominal internal pressure 5.6.2 The minimum heat distortion temperature
condition (See 5.3.3). is to be not less than 80°C.
Sr.
Piping Systems Location
No.
A B C D E F G H I J K
Accommoda-
Ballast water
pump rooms
Ro/Ro cargo
Cargo pump
Cargo tanks
void spaces
cargo holds
Open decks
Cofferdams
tion service
and control
pipe tunnel
Category A
machinery
Machinery
and ducts
spaces of
Other dry
spaces &
spaces
rooms
holds
Other
tanks
1 2 3 4 5 6 7 8 9 10 11 12 13
CARGO (FLAMMABLE CARGOES f.p. ≤ 60°C
1. Cargo lines NA NA L1 NA NA O NA O10 O NA L12
Crude oil
2. NA NA L1 NA NA O NA O10 O NA L12
washing lines
3. Vent lines NA NA NA NA NA O NA O10 O NA X
INERT GAS
Water seal
4. NA NA O1 NA NA O1 O1 O1 O1 NA O
effluent line
Scrubber
5. O1 O1 NA NA NA NA NA O1 O1 NA O
effluent line
6. Main line O O L1 NA NA NA NA NA O NA L16
7. Distribution lines NA NA L1 NA NA O NA NA O NA L12
FLAMMABLE LIQUIDS (f.p. > 60°C)
8. Cargo lines X X L1 X X NA3 O O10 O NA L1
3
9. Fuel oil X X L1 X X NA O O O L1 L1
10. Lubricating X X L1 X X NA NA NA O L1 L1
11. Hydraulic oil X X L1 X X O O O O L1 L1
1
SEAWATER
Bilge main &
12. L17 L17 L1 X X NA O O O NA L1
branches
Fire main &
13. L1 L1 L1 X NA NA NA O O X L1
water spray
14. Foam system L1 L1 L1 NA NA NA NA NA O L1 L1
15. Sprinkler system L1 L1 L3 X NA NA NA O O L3 L3
10
16. Ballast L3 L1 L3 L3 X O O O O L2 L2
Cooling water,
17. essential L3 L3 NA NA NA NA NA O O NA L2
services
Tank cleaning
18. services fixed NA NA L3 NA NA O NA O O NA L32
machines
Non-essential
19. O O O O O NA O O O O O
systems
FRESH WATER
Cooling water
20. L3 L3 NA NA NA NA O O O L3 L3
essential
Condensate
21. L3 L3 L3 O O NA NA NA O O O
return
Non-essential
22. O O O O O NA O O O O O
systems
Sr.
Piping Systems Location
No.
A B C D E F G H I J K
Accommoda-
Ballast water
pump rooms
Ro/Ro cargo
Cargo pump
Cargo tanks
void spaces
cargo holds
Open decks
Cofferdams
tion service
and control
pipe tunnel
Category A
machinery
Machinery
and ducts
spaces of
Other dry
spaces &
spaces
rooms
holds
Other
tanks
1 2 3 4 5 6 7 8 9 10 11 12 13
SANITARY/DRAINS/SCUPPERS
Deck drains
23. L14 L14 NA L14 O NA O O O O O
(internal)
Sanitary drains
24. O O NA O O NA O O O O O
(internal)
Scuppers and
25. discharges O1,8 O1,8 O1,8 O1,8 O1,8 O O O O O1,8 O
(overboard)
SOUNDING/AIR
Water tanks/dry
26. O O O O O O10 O O O O O
spaces
Oil tanks (f.p. >
27. X X X X X X3 O O10 O X X
60°C)
MISCELLANEOUS
28. Control air L15 L15 L15 L15 L15 NA O O O L15 L15
Service air (non-
29. O O O O O NA O O O O O
essential)
30. Brine O O NA O O NA NA NA O O O
Auxiliary low
31. pressure steam L2 L2 O9 O9 O9 O O O O O9 O9
(≤ 7 bar)
Abbreviations:
Footnotes:
1 Where non-metallic piping is use, remotely controlled valves to be provided at ship's side (valve
is to be controlled from outside space).
3 When cargo tanks contain flammable liquids with f.p. > 60°C, "O" may replace "NA" or "X".
4 For drains serving only the space concerned, "O" may replace "L1".
5 When controlling functions are not required by statutory requirements or guidelines, "O" may
replace "L1".
6 For pipe between machinery space and deck water seal, "O" may replace "L1".
9 For essential services, such as fuel oil tank heating and ship's whistle, "X" is to replace "O".
10 For tankers where compliance with paragraph 3 (f) of Regulation 13F of Annex I of MARPOL
73/78 is required, "NA" is to replace "O".
Location Definitions:
5.8 Material approval and quality control fittings are produced with consistent and uniform
during manufacture mechanical and physical properties.
5.8.1 Prototypes of pipes and fittings are to be 5.8.4 Each pipe and fitting made by hand lay up
tested to determine short-term and long-term technique, is to be tested by the Manufacturer at
design strength, fire endurance and low surface a hydrostatic pressure not less than 1.5 times
flame spread characteristics, electrical the nominal pressure. For other pipes and
resistance (for electrically conductive pipes), fittings, manufactured in accordance with the
impact resistance in accordance with this recognized standards by machined processes
Section. (e.g. ‘Continuous extruding’, ‘Filament wound
and centrifugally cast’) the hydrostatic pressure
5.8.2 For prototype testing representative test may be carried out in accordance with
samples of pipes and fittings are to be selected requirements stipulated in the relevant standard
to the satisfaction of the Classification Society. to which the pipe or fittings are manufactured,
provided that there is an effective quality system
5.8.3 The Manufacturer is to have quality in place at manufacturer’s works.
system that meets ISO 9000 series standards or
equivalent. The quality system is to consist of 5.8.5 Piping and fittings are to be permanently
elements necessary to ensure that pipes and marked with identification. Identification is to
include pressure ratings, the design standards
5.9.1.3 Heavy components in the piping system 5.9.5.1 In piping systems for fluids with
such as valves and expansion joints are to be conductivity less than 1000 pico siemens per
independently supported. metre (pS/m) such as refined products and
distillates use is to be made of conductive pipes.
5.9.2 Expansion
5.9.5.2 Regardless of the fluid being conveyed,
5.9.2.1 Suitable provision is to be made in each plastic piping is to be electrically conductive if
pipeline to allow for relative movement between the piping passes through a hazardous area.
pipes made of plastic and the steel structure, The resistance to earth from any point in the
6
having due regard to: piping system is not to exceed 1 x 10 Ohm. It is
preferred that pipes and fittings be
i) the difference in the coefficients of thermal homogeneously conductive. Pipes and fittings
expansion; having conductive layers are to be protected
against a possibility of spark damage to the pipe
ii) deformations of the ship's hull and its wall. Satisfactory earthing is to be provided.
structure.
5.9.5.3 After completion of the installation, the
5.9.2.2 When calculating the thermal resistance to earth is to be verified. Earthing
expansions, account is to be taken of the wires are to be accessible for inspection.
system working temperature and the
temperature at which assembly is performed.
Indian Register of Shipping
Chapter 2 Part 4
Page 24 of 30 Piping Design Requirements
5.9.7.3 If the bulkhead or deck is also a fire 5.9.9.3 Selection of the pipes used for test
division and destruction by fire of plastic pipes assembly, is to be in accordance with the
may cause the inflow of liquid from tanks, a following:
metallic shut-off valve operable from above the
freeboard deck should be fitted at the bulkhead a) When the largest size to be joined is 200
or deck. mm nominal outside diameter, or smaller,
the test assembly is to be the largest piping
5.9.8 Control during installation size to be joined.
5.9.8.1 Installation is to be in accordance with b) When the largest size to be joined is greater
the Manufacturer's guidelines. than 200 mm nominal outside diameter, the
size of the test assembly is to be either 200
5.9.8.2 Prior to commencing the work, joining mm or 25% of the largest piping size to be
techniques are to be approved by the joined, whichever is greater.
Classification Society.
5.9.9.4 When conducting performance
5.9.8.3 The tests and examinations specified in qualifications, each bonder and each bonding
this Section are to be completed before operator are to make up test assemblies, the
shipboard piping installation commences. size and number of which are to be as required
above.
5.9.8.4 The personnel performing this work are
to be properly qualified and certified to the 5.9.10 Testing after installation on board
satisfaction of the Classification Society.
5.9.10.1 Piping systems for essential services
5.9.8.5 The procedure of making bonds is to are to be subjected to a test pressure not less
include: than 1.5 times the design pressure or 4 bar
whichever is greater.
i) materials used,
5.9.10.2 Piping systems for non-essential
ii) tools and fixtures, services are to be checked for leakage under
operational conditions.
iii) joint preparation requirements,
1) Certificates and reports for relevant tests The standards to be used for testing of pipes,
previously carried out. joints and fittings are given in Table 5.10.1 and
2) Details of relevant standards. Table 5.10.2.
Table 5.10.1 : Typical standards for general requirements for all systems
Notes:
(1) Test to be witnessed by IRS Surveyor.
(2) If applicable.
Notes:
(1) Test to be witnessed by IRS Surveyor.
(2) If applicable.
Tests 1, 2 and 5 of above table are optional. However, if carried out, the range of approved applications
for the pipes will be limited accordingly (See Table 5.7.1).
Section 6
Flexible Hoses
6.2.1 The requirements of 6.3 to 6.6 apply to 6.3.1 Flexible hoses are to be designed and
flexible hoses of metallic or non-metallic material constructed in accordance with recognized
intended for a permanent connection between a National or International Standards. Flexible
fixed piping system and items of machinery hoses constructed of rubber or plastics materials
where necessary to accommodate relative and intended for use in bilge, ballast,
movement between the machinery and the fixed compressed air, oil fuel, lubricating, hydraulic
piping system. The requirements may also be and thermal oil systems are to incorporate a
applied to temporarily connected flexible hoses single double or more closely woven integral
or hoses of portable equipment. wire braid or other suitable material for
reinforcement.
6.2.2 Flexible hose assemblies as defined in
6.1.1 may be accepted for use in oil fuel, Flexible hoses of plastics materials such as
lubricating, hydraulic and thermal oil systems, Teflon or Nylon, (which are used for the
fresh water and sea water cooling systems, purposes mentioned above), where
compressed air systems, bilge and ballast reinforcement is not possible by incorporating
systems and Class III steam systems where closely woven integral wire braid are to have
they comply with 6.3 to 6.6. Flexible hoses are
Section 7
7.1 Hydraulic tests before installation on Pt and P are defined in Sec.1, Cl.1.5.1
board
2
K100 = allowable stress for 100°C [N/mm ]
7.1.1 All Class I and II pipes and their
associated fittings are to be tested by hydraulic Kt = allowable stress for the design temperature
2
pressure to the Surveyor's satisfaction. Further, [N/mm ].
all steam, feed, compressed air and fuel oil
pipes, together with their fittings, are to be 7.1.4 In no case is the membrane stress to
similarly tested where the design pressure is exceed 90 per cent of the yield stress at the
greater than 3.5 bar. The test is to be carried out testing temperature.
after completion of manufacture and before
installation on board and, where applicable, 7.1.5 All valves and fittings are to be tested in
before insulating and coating. accordance with recognized standards, but not
less than 1.5 times the nominal pressure rating
7.1.2 Where the design temperature does not at ambient temperature. Valves, cocks and
exceed 300°C, the test pressure is to be 1.5 distance pieces intended to be fitted on the ship
times the design pressure. side below the load waterline are to be
hydraulically tested to a pressure not less than 5
7.1.3 For steel pipes and integral fittings for use bar.
in systems where the design temperature
exceeds 300°C, the test pressure is to be as 7.1.6 When, for technical reasons, it is not
follows but need not exceed twice the design possible to carry out complete hydrotesting
pressure: before assembly on board for all sections of
piping, proposals for testing the remaining/
K 100 closing lengths of piping, particularly in respect
Pt = 1.5 P bar of the closing seams, are to be submitted for
Kt approval.
End of Chapter
Chapter 3
Contents
Section
1 General
2 Bilge and Ballast Piping Systems
3 Vents, Sounding, Overflow and Scuppers and Discharges Piping Systems
4 Fuel Oil Systems
5 Steam Piping and Condensate Piping Systems
6 Boiler Feed Piping Systems
7 Engine Cooling Water Systems
8 Lubricating Oil Piping Systems
Section 1
General
1.1.1 The requirements of this Chapter are d) Steam piping and condensate piping
applicable to all ships but may be modified for systems;
ships classed for restricted services or for
special services. e) Bilge and ballast piping systems;
a) General arrangement of pumps and piping n) Fire main and fire extinguishing piping
systems; systems.
b) Oil-fuel filling, transfer and service piping 1.2.2 The plans are to include the information
systems; like size, wall thickness, maximum working
pressure, temperature and material of all pipes,
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Chapter 3 Part 4
Page 2 of 24 Pumping and Piping
1.4 Valves and cocks 1.5.4 Valves and cocks are to be attached to the
shell plating by bolts tapped into the plating and
1.4.1 All the valves and cocks are to be so fitted with countersunk heads, or by studs
designed and constructed so that the valve screwed into heavy steel pads fitted to the
covers or glands will not slacken up when the plating. The stud holes are not to penetrate the
valves are operated. pad plating.
1.4.2 All the valves are to be designed to close 1.5.5 Ship side valves and fittings, if made of
with right hand (clockwise when facing the end steel or material with low corrosion resistance,
of the stem) motion of the wheel of the valve. are to be suitably protected against wastage.
1.4.3 All the valves and cocks are to be fitted in 1.5.6 Gratings are to be fitted at all openings in
places where they are easily accessible at all ship's side for inlet of seawater. The net area
times and are to be fitted with legible through the gratings is to be at least twice the
nameplates indicating their function in the area of the valves connected to the opening.
system and their installation is to be such that it Provision is to be made to clear the gratings by
can be readily observed that they are open or low pressure steam or compressed air.
closed.
1.5.7 The scantlings of valves and valve stools
1.4.4 All the valves and cocks fitted with remote fitted with steam, or compressed air clearing
control are to be provided with local manual connections are to be suitable for the maximum
control independent of the remote operating pressure to which the valves and stools may be
mechanism. The operation of the local control is subjected.
not to render the remote control system
inoperable. 1.6 Piping installation
1.4.5 The valves, cocks and other fittings which 1.6.1 Heavy pipes and valves are to be so
are attached directly to plating, which is required supported that their weight is not taken up by
to be of watertight construction, are to be connected pumps and fittings.
secured to the plating by means of studs
screwed into the plating and not by bolts 1.6.2 Support of the pipes is to be such that
passing through clearance holes. Alternatively detrimental vibrations do not arise in the system.
the studs may be welded to the plating.
1.6.3 Where pipes are carried through watertight
1.5 Shipside fittings (other than sanitary bulkheads or tank tops, means are to be made
discharges and scuppers) to ensure the integrity of the watertightness of
the compartment.
1.5.1 All sea inlet and overboard discharge
valves are to be fitted in either of the following 1.6.4 As far as possible, installation of pipes for
ways : water, oil, exhaust gases from oil engines or
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Rules and Regulations for the Construction and Classification of Steel Ships - 2014
Page 3 of 24
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steam, is to be avoided near electric damaged mechanically, are to be suitably
switchboards. If this is impracticable, all the protected.
joints in pipe line and valves are to be at a safe
distance from the switchboards and shielded to 1.6.9 All pipes which pass through chambers
prevent damage to switchboard. intended for the carriage or storage of
refrigerated cargo are to be well insulated. In
1.6.5 Provision is to be made to take care of case the temperature of the chamber is below
expansion or contraction stresses in pipes due 0°C the pipes are to be insulated from the ship's
to temperature stresses or working of the hull. structure also, except at positions where the
temperature of the ship's structure is always
1.6.6 Expansion pieces of approved type, made above 0°C and is controlled by outside
of oil resistant re-inforced rubber or other temperature.
approved material may be used in circulating
water systems in machinery spaces. Air refreshing pipes leading to and from
refrigerated chambers need not be insulated
1.6.7 All piping systems, where a pressure from the ship's structure.
greater than the designed pressure could be
developed, are to be protected by suitable relief 1.6.10 Deck wash pipes and discharge pipes
valves. from the pumps to domestic water tanks are not
to pass through cargo holds.
1.6.8 All pipes, situated in cargo spaces, fish
holds or other spaces, where they can be
Section 2
are to be fitted in suitable positions in the fore means of a self closing cock situated in a well
and after ends of holds over 30 [m] in length. lighted and accessible position, and draining into
engine room or tunnel.
2.3 Drainage from refrigerated cargo spaces
2.4.3 The collision bulkhead is not to be pierced
2.3.1 Provision is to be made for the continuous below the bulkhead deck by more than one pipe
drainage of the inside of all insulated chambers for dealing with the contents inside the fore peak
and cooler trays. tank. Where the forepeak is divided into two
compartments for carrying two different kinds of
2.3.2 Drains which are led from lower holds and liquids, the collision bulkhead may be pierced by
cooler trays situated on the tank top are to be two pipes, i.e. one for each compartment
fitted with liquid sealed traps and non-return provided that there is no practical alternative to
bilge valves. piercing by such a second pipe and that having
regard to the additional subdivision provided in
2.3.3 Drains from 'tween deck chambers and the forepeak, the safety of the ship is
from cooler trays which are situated well above maintained.
the tank top are to be fitted with liquid sealed
traps. 2.4.4 The pipe/pipes piercing the collision
bulkhead is/are to be provided with screwdown
2.3.4 Where drains from separate chambers join valve/s capable of being operated from above
a common main, the branch pipes are each to the bulkhead deck/freeboard deck and the chest
be provided with a liquid sealed trap. of the valve is to be secured to the collision
bulkhead inside the forepeak tank except as
2.3.5 The liquid sealed traps are to be of permitted by 2.4.5. An indicator is to be provided
adequate depth and are to have a pressure to indicate whether the valve is open or shut.
head of at least 100 [mm] when connected to air
ducts and 50 [mm] otherwise and arrangements IR2.4.4 Local hand powered operation is
are to be made for ready access to the traps for required from above the bulkhead
cleaning and refilling with brine. deck/freeboard deck for the valve specified
above.
2.3.6 Sluices, scuppers or drain pipes, which
would permit drainage from compartments 2.4.5 Any valve required by 2.4.4 may be fitted
outside the insulated chambers into the bilges of on the after side of the collision bulkhead,
the latter, are not to be fitted. provided the valve is readily accessible at all
times and the space in which it is located is not
2.3.7 Screwed plugs or other means for blanking a cargo space.
off scuppers draining insulating chambers and
cooler trays are not to be fitted. If, however, it is 2.4.6 In ships other than passenger ships, the
especially desired to provide means for valve required by 2.4.3 may be fitted on the after
temporarily closing these scuppers, they may be side of the collision bulkhead, provided the valve
fitted with shutoff valves controlled from readily is readily accessible at all times and is not
accessible positions on a deck above the load subject to mechanical damage.
waterline. An indicator is to be provided to
indicate whether the valve is open or shut. 2.5 Drainage from tanks, cofferdams and
void spaces
2.4 Drainage from fore and aft peaks
2.5.1 All the tanks except self-draining tanks,
2.4.1 Where the peaks are used as tanks, a whether for water ballast, oil fuel, liquid cargoes
power pump suction is to be led to each tank, etc. are to be provided with suction pipes led to
except in case of small tanks (generally not suitable power pumps. The pumping plant is to
3
exceeding 2 [m ] used for the carriage of be so arranged that any water or liquid within
domestic fresh water where hand pumps may any compartment of the ship can be pumped out
be used. through atleast one suction, when the ship is on
an even keel and/or designed trim and is either
2.4.2 The peaks may be drained by hand pumps upright or has a list of not more than 5 degrees.
provided the peaks are not used as tanks and
they are not connected to bilge main. The 2.5.2 Where the length of the ballast tank
suction lift is to be well within the capacity of the exceeds 30 [m], an additional suction is to be
hand pumps and is not to exceed 7.3 [m]. provided at the forward end of the tank. Where
the width of the tank is unusually large, suctions
In case of vessels of length 24 [m] or less and near the centerline in addition to wing suctions
fishing vessels, after peak may be drained by may be required.
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Rules and Regulations for the Construction and Classification of Steel Ships - 2014
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2.7.2 Machinery spaces without double bottom:
2.5.3 Suction pipes from the cofferdams and
void spaces are to be led to the main bilge line. In ships without inner bottom, where the rise of
floor is 5 degrees or more, one branch and one
2.5.4 In ships where deep tanks may be used direct bilge suctions are to be led to positions as
for either water ballast or dry cargo, provision is near the center-line as possible. Bilge suctions
to be made for blanking the water ballast suction at wings will be required in all ships having rise
and filling when the tank is being used for of floor less than 5 degrees.
carrying cargo and for blanking the bilge line
when the tank is being used for carriage of 2.7.3 General requirements for machinery
water ballast. spaces:
2.6 Drainage from spaces above fore and a) In ships where machinery is situated at the
after peaks, chain lockers and above after end, it will generally be necessary to
machinery spaces provide suctions at the forward wings in
addition to the suctions at the after end of
2.6.1 Provision is to be made for the drainage of the machinery space;
chain locker and watertight compartments above
the fore peak tank by hand or power pump b) Special means are to be provided to prevent
suctions. accumulation of bilge water under main
propulsion generators and motors;
2.6.2 Steering gear compartments or other small
enclosed spaces situated above the after peak c) Where the machinery space is divided into
tank are to be provided with suitable means of watertight compartments, the drainage
drainage, either by hand or power bilge system for all compartments except for main
suctions. engine room is to be same as for cargo
holds except that one direct bilge suction
2.6.3 If the compartments referred to in 2.6.2 are from each watertight compartment would
adequately isolated from the adjacent 'tween also be required;
decks, they may be drained by scuppers of not
less than 38 [mm] bore, discharging into the d) The direct bilge suctions in machinery
tunnel (or machinery spaces in case of ships space(s) are to be led to independent power
with machinery aft) and fitted with self-closing pump(s), and the arrangements are to be
cocks situated in well lighted and visible such that these direct suctions can be used
positions. These arrangements are not independently of the main bilge line
applicable to passenger ships unless they are suctions.
specially approved in relation to subdivision
considerations. 2.7.4 Emergency bilge suction :
c) If the inner bottom has inverse camber or c) In steamships, the main sea water
discontinuity or depressions formed due to circulating pump is to be fitted with an
crankpins or other recesses, additional emergency bilge suction. This suction is to
suctions are to be provided. have diameter of at least two third of the
pump suction;
2.8.1 A bilge suction, connected to the main 2.9.5 The area of each branch pipe connecting
bilge line is to be provided for draining the tunnel the bilge main to a distribution chest is to be not
well. This tunnel well may extend to the outer less than the sum of the areas required by the
bottom. If the shaft tunnel slopes from aft to rules for the two largest branch bilge suction
forward end, an additional bilge suction at pipes connected to that chest, but need not be
forward end is to be provided. greater than that required for the main bilge line.
2.8.2 Internal diameter of the tunnel bilge 2.10 Bilge pumps and ejectors
suction pipe is not to be less than 65 [mm]
except for vessels of length less than 60 [m], 2.10.1 All ships, other than passenger ships, are
where tunnel bilge suction pipes of 50 [mm] bore to be provided with at least two independent
are acceptable. power bilge pumps. For ships of length 91.5 [m]
and below, one of these pumps may be main
2.8.3 Where the length of the tunnel is more engine driven. See 2.13 for requirements
than 30 [m], bilge suctions are to be provided at regarding passenger ships.
both the forward and aft ends.
2.10.2 The capacity of each bilge pump is to be
2.9 Sizes of bilge suctions sufficient enough to give the water a speed of at
least 122 [metres/minute] through the rule size
2.9.1 The internal diameter of the bilge pipes is of the main bilge line under normal working
not to be less than that found by the following conditions.
formula to the nearest 5 [mm] commercial size
available: The capacity of the bilge pump may be found by
the following formula :
dm = 1.68 L (B + D) + 25 [mm] -3 2 3
Q = 5.75 x 10 x d [m /hour]
c) The arrangements are such that at least one b) Where one tank is used for the drainage of
of these pumps is immediately available for several watertight compartments, the
bilge duty, when required, even when the scupper pipes are to be provided with
remaining pumps are in use for other screw-down non- return valves.
essential duties such as fire fighting.
2.12.5 No drain valve or cock is to be fitted to
2.10.7 For bilge pump capacity for ships having the collision bulkhead. Drain valves or cocks are
closed vehicle and ro-ro spaces and special not to be fitted to other watertight bulkheads if
category spaces, refer Pt.6, Ch.7, Cl. 3.6.1.4 alternative means of drainage are practicable.
and 3.6.1.5. These arrangements are not permissible in
passenger ships.
2.11 Pump types
2.12.6 Where drain valves or cocks are fitted to
2.11.1 The bilge pumps required by the rules bulkheads other than collision bulkhead, as
are to be of self-priming type, unless an permitted by 2.12.5, the drain valves or cocks
approved priming system is provided for these are to be at all times readily accessible and are
ships. to be capable of being shut off from positions
above the bulkhead deck. Indicators are to be
2.12 Bilge piping arrangements and fittings provided to show whether the drains are open or
shut.
2.12.1 Bilge pipes are not, as far as possible, to
pass through double bottom tanks. If 2.12.7 Bilge pipes which are required for
unavoidable, such bilge pipes are to be provided draining cargo or machinery spaces are to be
with welded joints or heavy flanged joints and entirely distinct from sea inlet pipes or from
are to be tested after fitting to the same pipes which may be used for filling or emptying
pressure as the tanks through which they pass. spaces where water or oil is carried. This does
not, however, exclude a bilge ejection
2.12.2 The parts of bilge pipes passing through connection, a connecting pipe from a pump to its
deep tanks, intended to carry water ballast, suction valve chest, or a deep tank suction pipe
fresh water, liquid cargo or fuel oil are normally suitably connected through a change-over
to be contained in a pipe tunnel, but where this device to bilge, ballast or oil line.
is not done, the pipes are to be of heavy gauge
with welded or heavy flanged joints. The open 2.12.8 The arrangement of pumps, valves and
ends of such pipes are to be fitted with non- piping is to be such that any pump could be
return valves. The pipes are to be tested, after opened up for overhaul and repairs without
fitting, to a pressure of not less than the affecting the operation of the other pumps.
2.12.9 The arrangement of valves, pumps, 2.12.16 Where relief valves are fitted to pumps
cocks and their pipe connections is to be such having sea connections, these valves are to be
as to prevent the possibility of placing one fitted in readily visible positions above the
watertight compartment in communication with platform. The arrangement is to be such that
another, or of cargo spaces, machinery spaces any discharge from the relief valves will also be
or other dry spaces coming in communication readily visible.
with the sea or the tanks. For this purpose the
bilge suction pipe of any pump also having sea 2.12.17 Where non-return valves are fitted to the
suction is to be fitted with a non-return valve open ends of bilge suction pipes in cargo holds
which cannot permit communication between in order to decrease the risk of flooding, they are
the bilges and the sea or the compartments in to be of an approved type which does not offer
use as tanks. undue obstruction to the flow of water.
2.12.10 Screw-down non-return valves are to be 2.13 Additional requirements for passenger
provided in the following fittings : ships
a) Bilge distribution chest valves; 2.13.1 All passenger ships are to have at least
three power bilge pumps connected to the bilge
b) Direct bilge suction and bilge pump main, one of which may be attached to the
connection to main line; propelling unit. Where the bilge pump numeral is
30 or more, one additional independent power
c) Bilge suction hose connections on the pump is to be provided. Sanitary, ballast and
pumps or on the main line; general service pumps may be accepted as
independent power bilge pumps if fitted with
d) Emergency bilge suctions. necessary connections to the bilge pumping
system.
2.12.11 Bilge suction pipes from machinery
spaces and shaft tunnel, except emergency The bilge pump numeral is to be calculated as
bilge suction, are to be led from easily follows:
accessible mud boxes fitted with straight tail
pipes to the bilges. The open ends of the tail When P1 is greater than P : bilge pump numeral
pipes are not to be fitted with strum boxes. The
mud boxes are to be provided with covers which M + 2P1
can be easily opened and closed for cleaning = 72
purposes. V + P1 − P
2.12.12 Strum boxes are to be fitted to the open in other cases: bilge pump numeral
ends of bilge suction pipes from the cargo holds.
The diameter of holes from these strum boxes is
M + 2P
not to be more than 10 [mm] and the total area = 72
of the holes is not to be less than twice the area V
of the pipes.
where,
2.12.13 Where access manholes to bilge wells
are necessary, they are to be fitted as near to LL = the load line length of the ship (metres), as
the suction strums as practicable. defined in Pt.3, Ch.1, Cl.2.1.9;
2.12.14 Adequate distance is to be provided M = the volume of the machinery space (cubic
between the open ends of suction pipes and metres), as defined in Pt.6, Ch.1, Sec.3 that is
bilge well bottom to permit adequate and easy below the bulkhead deck; with the addition
flow of water and to facilitate cleaning. thereto of the volume of any permanent oil fuel
bunkers which may be situated above the inner
2.12.15 All the valves, cocks and mud boxes are bottom and forward of, or abaft, the machinery
to be located in easily accessible positions space;
above or at the same level as the floor plates.
Where this is unavoidable, they may be fitted P = the whole volume of the passenger and
immediately below the floor plates provided the crew spaces below the bulkhead deck (cubic
floor plates are capable of being opened and metres) which are provided for the
closed easily and suitable name plates are fitted accommodation and use of passengers and
indicating the fittings below. crew, excluding baggage, store, provision and
mail rooms;
the horizontal plane passing through the point of connected to a bilge main having at least one
intersection with the frame line amidships of a branch to each compartment.
transverse diagonal line inclined at 25 degrees
to the base line and cutting it at a point one half 2.15 Ballast system
the ship's moulded breadth from the middle line.
A well extending to the outer bottom is, 2.15.1 Provision is to be made for ballasting and
however, permitted at the after end of the shaft deballasting all the ballast tanks by pipe lines
tunnel. which are entirely separate and distinct from
pipe lines used for bilging.
2.14 Drainage arrangements on vessels not
fitted with propelling machinery 2.15.2 Where the length of the ballast tanks
exceeds 30 [m], an additional suction is to be
2.14.1 Vessels not fitted with propelling provided at the forward end of the tanks. Where
machinery are to be provided effective hand the width of the tank is unusually large, suction
pumps which can be operated from above the near the centerline in addition to wing suctions
bulkhead deck or the highest convenient level may be required.
which is always available. There is to be one
pump for each compartment or two pumps
Section 3
3.2.15 Vent pipes are to be self-draining under 3.3.7 Overflow pipes are to be self-draining
normal conditions of trim. under normal conditions of trim.
3.2.16 The thickness of the exposed portion of 3.3.8 For size of overflow pipes, see 3.2.11.
the vent pipes are to be as required in Pt.3,
Ch.13, 3.2.5. 3.4 Sounding arrangements (Also refer Pt.6,
Ch.2, 1.2.for F.O., L.O. and other flammable
3.3 Overflow pipes oils)
3.3.1 All tanks which can be pumped up are to 3.4.1 All tanks, cofferdams and pipe tunnels are
be fitted with overflow pipes when the pressure to be provided with sounding pipes or other
head corresponding to the height of vent pipe is approved means for ascertaining the level of
greater than that for which the tanks are suitable liquid in the tanks. Means of ascertaining the
or when the sectional area of the vent pipes is level of liquid in oil fuel tanks is to be of safe
less than that required by 3.2.11. type. Level switches may be used provided they
are contained in steel enclosure or other
3.3.2 Oil fuel and lubricating oil tanks which can enclosures not destroyed by fire. Bilges of
be pumped up and which have openings for compartments which are not, at all times, readily
fittings, for example - for a float sounding accessible are to be provided with sounding
system, are to be fitted with overflow pipes. The pipes. The soundings are to be taken as near
tank openings, for such fittings, are to be the suction pipes as practicable.
situated above the highest point of the overflow
piping. 3.4.2 Oil level gauges may be used for tanks
containing lubricating oil, oil fuel or other
3.3.3 In the case of oil fuel and lubricating oil flammable liquid in place of sounding pipes,
tanks, the overflow pipe is to be led to an subject to the following conditions:
overflow tank of adequate capacity or to a
storage tank having space reserved for overflow - In passenger ships such gauges should not
purposes and be in readily visible position. A require penetration below the top of the tank
sight glass is to be provided in the overflow pipe and their failure or overfilling of the tanks will
to indicate when the tanks are overflowing. Such not allow release of their contents; and
sight glasses are to be placed only in the vertical
portion of the pipes and be located in a readily
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Chapter 3 Part 4
Page 12 of 24 Pumping and Piping
- In cargo ships, the failure of level gauges or 3.4.6 Striking plates of adequate thickness and
overfilling of the tank will not allow release size are to be fitted under open ended sounding
of their contents into the space. The use of pipes. Where slotted pipes having closed ends
cylindrical gauge glasses is not acceptable. are employed, the closing plugs are to be of
Flat type glasses may be accepted provided substantial construction.
they are of heat resisting quality, adequately
supported, protected from mechanical 3.4.7 All sounding pipes are to be not less than
damage and fitted with self closing valves 32 [mm] bore. All sounding pipes, whether for
between the gauges and the tanks. compartments or tanks, which pass through
refrigerated spaces or the insulation thereof, in
3.4.3 Except as permitted by 3.4.4 sounding which the temperatures contemplated are 0°C or
pipes are to be led to positions above the below, are to be not less than 65 [mm] bore.
bulkhead deck which are at all times accessible.
In the case of oil fuel tanks, cargo oil tanks and 3.4.8 The upper ends of all sounding pipes are
lubricating oil tanks, the sounding pipes are to to be provided with efficient closing devices. The
be led to safe positions on the open deck. The sounding pipes are to be arranged as straight as
sounding pipes should not terminate in any practicable, and if curved, the curvature is to be
space where the risk of ignition from spillage large enough to permit easy passage of
from sounding pipe exists. Sounding pipes are sounding rod/chain.
not to terminate in passenger or crew spaces.
3.5 Scuppers and discharges (Also refer Pt.3,
3.4.4 Where it is impracticable to comply with Ch.13)
3.4.3 above, short sounding pipes may be fitted
in readily accessible positions as indicated in the 3.5.1 Scupper and discharge pipes which are
following: not required to be of substantial thickness in
accordance with Pt.3 are to be at least 4.5 [mm]
a) Passenger ships: thick for pipes of 155 [mm] external diameter
and less; and 6.0 [mm] for pipes of external
- Only to double bottom tanks and diameter of 230 [mm] and more, intermediate
cofferdams in machinery spaces. sizes are to be determined by linear
- All short sounding pipes are to be interpolation.
provided with self-closing cocks as
described in Pt.6, Ch.2, 1.2.2.3.5.1. 3.5.2 Scupper and discharge pipes which are
required to be of substantial thickness in
b) Cargo ships: accordance with Pt.3 are to be at least of
following thickness:
- Only to tanks and cofferdams in
machinery spaces and shaft tunnels. - 7 [mm] thick for pipes of external diameter
- Short sounding pipes to oil fuel, of equal to or less than 80 [mm];
lubricating oil and other flammable oil - 10 [mm] thick for pipes of external diameter
tanks are to be provided as per Pt.6, equal to 180 [mm];
Ch.2, 1.2.2.3.51 and 1.2.3.1(a) and (b). - 12.5 [mm] thick for pipes of external
Short sounding pipes to other types of diameter equal to or more than 220 [mm];
tanks and cofferdams may be fitted with
screw caps attached by chain to the Intermediate sizes are to be determined by
pipe or with shut-off cocks. linear interpolation.
3.4.5 Elbow sounding pipes are not to be used 3.5.3 Overboard discharges are to be so located
for deep tanks unless the elbows and pipes are as to prevent any discharge of water into the life
situated within closed cofferdams or within tanks boats.
containing similar liquids. They may, however,
be fitted to other tanks and may be used for 3.6 Water level detectors on single hold
sounding bilges, provided that it is not cargo ships other than bulk carriers
practicable to lead them direct to the tanks or
compartments. 3.6.1 Ships of load line length LLL (see Pt.3,
Ch.1 for definition of LLL) less than 80 [m] and
a) The elbows are to be of heavy construction having a single cargo hold below the freeboard
and adequately supported; deck or cargo holds below the freeboard deck
b) In passenger ships, elbow sounding pipes which are not separated by at least one full
are not permissible. watertight bulkhead, are to be fitted with water
level detectors in such cargo hold/s, unless
exempted by 3.6.3.
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3.6.2 The water level detectors are to: 3.6.3 The water level detectors required in 3.6.1
need not be fitted in ships having watertight side
i) give an audible and visual alarm at the compartments each side of the cargo hold
navigation bridge when the water level length extending vertically at least from inner
above the inner bottom in the cargo hold bottom to freeboard deck.
reaches a height of not less than 0.3 [m]
and another when such level reaches Note : The water level detectors are to be of
not more than 15% of the mean depth of approved type. For further details regarding
the cargo hold; and performance tests, sensor locations, installation
and other testing requirements refer
ii) be fitted at the aft end of the hold, or classification notes: “Type approval, installation
above its lowest part where the inner and testing of water level detectors on bulk
bottom is not parallel to the design carriers and Single Hold Cargo Ships other than
waterline. Where webs or partial Bulk Carriers”.
watertight bulkheads are fitted above
the inner bottom, fitting of additional
detectors may be required.
Section 4
Fig.4.2.4 : ‘Equivalent arrangement’ for F.O. service tanks (Refer Clause 4.2.4)
A) Main and auxiliary engines and boilers operating on heavy fuel (one fuel ship)
Rule requirements
Equivalent arrangements
The above arrangement only applies where main and auxiliary engines can operate with heavy fuel oil
under all load conditions and, in the case of main engines, during manoeuvring.
For pilot burners of auxiliary boilers if provided, an additional MDO tank for 8 h operation may be
necessary.
B) Main engines and boilers on HFO and aux. Engines on MDO (two fuel ship)
Rule requirement
HFO Serv Tank HFO Serv Tank MDO Serv MDO Serv Tank
Capacity for at least Capacity for at least Tank Capacity for at least 8.h
8.h each 8.h each Capacity for at each Aux. Eng
Main Eng + Main Eng + least 8.h each
Aux Boiler Aux Boiler Aux. Eng
Equivalent arrangement
Fig.4.2.4 : (Contd.)
Notes:
1. The arrangements in A) and B) above apply, provided the propulsion and vital systems which use two
types of fuel, support rapid fuel change over and are capable of operating in all normal operating
conditions at sea with both types of fuel (MDO and HFO)
2. Service tank is a fuel oil tank which contains only fuel of a quality ready for use, i.e. fuel of a grade and
quality that meets the specification required by the equipment manufacturer. A service tank is to be
declared as such and not to be used for any other purpose.
3. Use of a settling tank with or without purifiers alone and one service tank is not acceptable as an
“equivalent arrangement” to two service tanks.
4. The equivalent arrangements described above are the interpretations followed by IRS, unless the flag
administration has provided a different interpretation.
4.3 Oil fuel piping copper or copper alloy, except those which pass
through storage tanks.
4.3.1 Oil fuel pressure pipes are to be led,
where practicable, remote from heated surfaces 4.3.7 Pipes for tanks storing fresh water are to
and electrical appliances, but where this is be separate and distinct from any pipes which
impracticable the pipes are to have a minimum may be used for oil or oily water, and are not to
number of joints and are to be led in well lighted be led through tanks which contain oil, nor are
and readily visible positions. oil pipes to be led through fresh water tanks.
4.3.2 Pipes conveying oil heated above 60°C 4.3.8 Pipes conveying vegetable oils or similar
are to be of seamless steel or other approved cargo oils are not to be led through oil fuel
material having flanged or welded joints. tanks, nor are oil fuel pipes to be led through
tanks containing such cargoes.
4.3.3 The flanges are to be machined, and the
jointing material, which is to be impervious to oil 4.3.9 In passenger ships, provision is to be
heated to 150°C, is to be the thinnest possible, made for the transfer of oil fuel from any oil fuel
so that the flanges are practically metal to metal. storage or settling tank to any other oil fuel
The scantlings of the pipes and their flanges are storage tank.
to be suitable for a pressure of at least 14 bar or
for the design pressure, whichever is the 4.3.10 Where IRS may permit the conveying of
greater. oil and combustible liquids through accommo-
dation and service spaces, the pipes conveying
4.3.4 The short joining lengths of pipes to the oil or combustible liquids are to be of a material
burners from the control valves at the boiler may approved by IRS having regard to the risk of fire.
have cone unions, provided these are of
specially robust construction. 4.4 Arrangement of valves, cocks, pumps
and fittings
4.3.5 Flexible hoses of approved material and
design may be used for the burner pipes, 4.4.1 The oil fuel pumping arrangements are to
provided that spare length complete with be distinct from other pumping systems as far as
couplings, are carried on board. practicable and the means provided for
preventing dangerous interconnection in service
4.3.6 Transfer, suction and other low pressure are to be thoroughly effective.
oil pipes and all pipes passing through oil
storage tanks are to be made of cast iron or 4.4.2 All valves and cocks forming part of the oil
steel, having flanged joints suitable for a working fuel installation are to be capable of being
pressure of not less than 7 bar. The flanges are controlled from readily accessible positions
to be machined and the jointing material is to be which, in the engine room and boiler spaces are
impervious to oil. Where the pipes are of 25 to be above the working platform.
[mm] bore or less, they may be seamless
4.4.3 Every oil fuel suction pipe from a double cannot exceed that for which the piping is
bottom tank is to be fitted with a valve or a cock. designed.
4.4.4 For oil fuel tanks which are situated above 4.4.10 Valves or cocks are to be interposed
the double bottom tanks, the inlet and outlet, between the pumps on the suction and
pipes which are connected to the tank at a point discharge pipes in order that any pump may be
lower than the outlet of the overflow pipe or shut off for opening up and overhaul.
below the top of the tanks without an overflow
pipe, are to be fitted with shut off valves located 4.4.11 Relief valves are to be fitted on the oil
on the tank itself. side of the heaters and are to be adjusted to
operate at a pressure of 3.5 bar above that of
4.4.5 In the engine and boiler spaces, valves, the supply pump relief valves. The discharge
mentioned in 4.4.4, are to be capable of being from the relief valves is to be led to a safe
closed locally and from positions outside these position.
spaces which will always be accessible in the
event of fire occurring in these spaces. 4.4.12 Drip trays are to be fitted at location
Instructions for closing the valves are to be where frequent leakage is expected, oil burners
indicated at the valves and at the remote control at furnace mouths, drain and valves under daily
positions. The controls for remote operation of service tanks, filter and all other oil fuel
the quick closing valve for the emergency appliances which are required to be opened up
generator fuel tank are to be in a separate frequently for cleaning or adjustment. Where
location from other quick closing valves for tanks drain pipes are provided from collected
in the engine room. leakages, they shall be led to a suitable oil drain
tank not forming part of an overflow system.
4.4.6 Every oil fuel suction pipe which is led into
the engine and boiler spaces, from a tank 4.4.13 Where MARPOL Regulation I/12A for
situated above the double bottom, outside these protective location of fuel oil tanks applies (see
spaces (including shaft tunnel, pipe tunnel or Pt.3, Ch.1, Sec.1.6), the fuel oil lines, suction
similar spaces), is to be fitted in the machinery wells and valves are to satisfy the requirements
space with a valve controlled as in 4.4.5, except of paragraph 9 and 10 of the above MARPOL
where the valve on the tank is already capable Regulation.
of being closed from an accessible position
above the bulkhead deck. Valves for such fuel oil tanks are to be located
above the bottom at distances not less than that
4.4.7 Settling tanks are to be provided with required for suction wells` in paragraph 10 of
means for draining water from the bottom of the MARPOL Regulation I/12A. Plan showing the
tanks. If the settling tanks are not provided, the location of tanks, suction wells and valves,
oil fuel bunkers or daily service tanks are to be indicating the distances are to be submitted for
fitted with water drains. approval.
Open drains for removing water from oil tanks The requirements for locations of oil fuel lines do
are to be fitted with valves or cocks of self- not apply to fuel oil air escapes and overflow
closing type, and suitable provision is to be pipes.
made for collecting the oily discharge.
4.5 Heating arrangements
4.4.8 Where a power driven pump is necessary
for transferring oil fuel, a stand by pump is to be 4.5.1 Steam heating installation
provided and connected ready for use, or,
alternatively, emergency connections may be 4.5.1.1 Where steam is used for heating oil fuel,
made to another suitable power driven pump. cargo oil or lubricating oil, in bunkers, tanks,
heaters or separators, the exhaust drains are to
4.4.9 All pumps which are capable of developing discharge the condensate into an observation
a pressure exceeding the design pressure of the tank in a well lighted and accessible position
system are to be provided with relief valves. where it can be readily seen whether or not it is
Each relief valve is to be in close circuit, i.e. free from oil.
arranged to discharge back to the suction side
of the pump and to effectively limit the pump 4.5.2 Thermal oil installations
discharge pressure to the design pressure of the
system. Pressure relief valves need not be fitted 4.5.2.1 The inlet and outlet valves of oil-fired
when the system is secured only by centrifugal thermal oil heaters and exhaust-fired thermal oil
pumps so designed that the pressure delivered heaters is to be controllable from outside the
compartment where they are situated.
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Alternatively an arrangement for quick gravity collection and drainage, to prevent water
drainage of the thermal oil contained in the flowing into the diesel engine. The drain is
system into a collecting tank is acceptable. to be led to a suitable location.
4.5.2.2 Heating of liquid cargoes with flash 4.5.3 Oil fuel in storage tanks is not to be heated
points below 60°C shall be arranged by means to a temperature within 10°C below the flash
of a separate secondary system, located point of the oil. Where oil fuel in service tanks,
completely within the cargo area. settling tanks and any other tanks in the supply
system is heated following arrangements are to
A single circuit system is acceptable on the be provided:
following conditions:
- The length of the vent pipes from such tanks
- system is so arranged that a positive and/or a cooling device is sufficient for
pressure in the coil shall be at least 3 [m] cooling the vapours to below 60°C;
water column above the static head of the otherwise the outlet of the vent pipes is to
cargo when circulating pump is not in be located at least 3 m away from a source
operation, of ignition;
- the thermal oil system expansion tank shall - There are no openings from the vapour
be fitted with high and low level alarms, space of the fuel tanks in to machinery
spaces (bolted manholes are acceptable);
- means to be provided in the thermal oil
system expansion tank for detection of - Any enclosed spaces are not to be located
flammable cargo vapours. Portable directly above such oil fuel tanks, except for
equipment is accepted, vented cofferdams; and
- valves for the individual heating coils is to - Electrical equipment is not to be fitted in the
be provided with locking arrangement to vapour space of the tanks, unless they are
ensure that the coils are under static certified intrinsically safe.
pressure at all times.
4.6 Temperature indication
4.5.2.3 The thermal oil circulating pumps is to be
arranged for emergency stopping from a 4.6.1 Tanks and heaters in which oil is heated
position outside the space where they are are to be provided with suitable means for
situated. ascertaining the temperature of the oil.
4.5.2.4 Vents from expansion tanks and thermal 4.7 Filling arrangements
oil storage tanks of thermal oil heating plants is
to be led to open deck. 4.7.1 The bunkering of the ship is to be carried
out through a permanently fitted pipeline,
4.5.2.5 Exhaust-fired thermal oil heaters provided with the required fittings and ensuring
fuel delivery to all storage tanks. The open end
− The heater is to be so designed and of the filling pipe is to be led to the tank bottom.
installed that all tubes are easily and readily
be inspected for signs of corrosion and In passenger ships fuel bunkering stations are to
leakage. be isolated from other spaces and are to be
efficiently drained and ventilated.
− Visual inspection and tightness testing of
the heater tubes is to be not less than the 4.7.2 Provision is to be made against over-
working pressure and is to be carried out pressure in the filling pipes, served by pumps on
annually. Hydraulic testing is to be carried board, and any relief valve fitted for this purpose
out bi-annually. is to discharge into an overflow tank or other
safe position.
− The heater is to be fitted with temperature
sensor(s) and an alarm for fire detection. 4.8 Alternate carriage of oil fuel and water
ballast
− A fixed fire extinguishing and cooling system
is to be fitted. A drenching system providing 4.8.1 Where it is intended to carry oil fuel and
copious amounts of water is acceptable. water ballast in the same tanks alternatively, the
The exhaust ducting below the exhaust valves or cocks connecting the suction pipes of
boiler is to be arranged for adequate these tanks with the ballast pump and those
connecting them with the oil fuel transfer pump 4.10.1.3 In systems where oil is fed to the
are to be so arranged that the oil may be burners by gravity, duplex filters are to be fitted
pumped from one tank by the oil fuel pump at in the supply pipeline to the burners and so
the same time as the ballast pump is being used arranged that one filter can be opened up when
on any other tank. the other is in use.
Where settling or service tanks are fitted, each 4.10.1.4 Where steam is required to bring the
having a capacity sufficient to permit 12 hour boiler plant into operation, starting up oil fuel
normal service without replenishment, the above unit, including an auxiliary heater and hand
requirement may be dispensed with. pump, or other suitable starting up device, which
does not require power from shore, is to be
4.8.2 Attention is drawn to the statutory provided.
requirements issued by the National Authorities
in connection with International Convention for 4.10.1.5 Where burners are provided with steam
the Prevention of Pollution of the Sea by Oil, purging and/or atomizing connections, the
1973/78. arrangements are to be such that oil fuel cannot
find its way into steam system in the event of
4.9 Deep tanks for the alternative carriage of valve leakage.
oil, water ballast or dry cargo
4.10.1.6 The burner arrangements are to be
4.9.1 In the case of deep tanks which can be such that a burner cannot be withdrawn unless
used for the carriage of oil fuel, cargo oil, water the oil fuel supply to that burner is shut off and
ballast or dry cargo, provision is to be made for that oil cannot be turned on unless the burner
blank flanging the oil and water ballast filling and has been correctly coupled to the supply line.
suction pipes, also the steam coils if retained in
place, when the tank is used for dry cargo, and 4.10.1.7 A quick-closing master valve is to be
for blank flanging the bilge suction pipes when fitted to the oil supply to each boiler manifold,
the tanks are used for oil or water ballast. suitably located so that the valve can be readily
operated in an emergency, either directly or by
4.9.2 If the deep tanks are connected to an means of remote control, having regard to the
overflow system, the arrangements are to be machinery arrangements and location of
such that liquid or vapour from other tanks controls.
cannot enter the deep tanks when dry cargo is
carried in them. 4.10.1.8 In the case of top-fired boilers, means
are to be provided so that, in the event of flame
4.10 Oil fuel burning arrangements failure, oil fuel supply to the burners is shut off
automatically, and audible and visual warnings
4.10.1 For boilers are given.
4.10.1.1 Where steam is required for the main 4.10.1.9 Provision is to be made, by suitable
propelling engines, for auxiliary machinery for non-return arrangements, to prevent oil from
essential services, or for heating of heavy fuel spill systems being returned to the burners when
oil and is generated by burning oil fuel under oil supply to these burners has been shut off.
pressure, there are to be not less than two oil
burning units, each unit comprising a pressure 4.10.1.10 For alternatively fired furnaces of the
pump, suction and discharge filters and a boilers using exhaust gases and oil fuel, the
heater. For auxiliary boilers, a single oil burning exhaust gas inlet pipe is to be provided with an
unit may be accepted, provided that alternative isolating device and interlocking arrangements
means, such as an exhaust gas boiler or whereby oil fuel can only be supplied to the
composite boiler, are available for supplying burners when the isolating device is closed to
steam for essential services. the boiler.
4.10.1.2 In two unit installations, each unit is to 4.10.2 For internal combustion engines
be capable of supplying fuel for generating all
the steam required for essential services. In 4.10.2.1 Filters are to be fitted in the supply lines
installations of three or more units, the to the main and auxiliary machinery. For non-
capacities and arrangements of the units are to redundant units for essential services, it must be
be such that all the steam required for essential possible to clean the filters without stopping the
services can be maintained with any one unit unit or reducing the supply of filtered oil to the
out of action. unit.
4.10.4.2 In emission control areas one of the 4.11 Remote stop of oil fuel pumps and fans
following configurations are to be provided:
4.11.1 Emergency stop of power supply to the
a) Fuel oil pumps as in 4.10.4.1, provided these following pumps and fans is to be arranged from
are each suitable for marine fuels with a sulphur a central place outside the engine and boiler
content not exceeding 0.1 % m/m and minimum room (Also refer Ch.8, Cl. 2.15.2) and Pt.6,
viscosity of 2 cSt operation at the required Ch.2, Sec.2:
capacity for normal operation of propulsion
machinery, or, - oil fuel transfer pump;
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Chapter 3 Part 4
Page 20 of 24 Pumping and Piping
Section 5
5.1 Expansion and drainage relief valves, installed on the low pressure side,
immediately after pressure reducing valve,
5.1.1 In all steam piping systems, ample having sufficient discharge capacity to protect
provision is to be made for expansion and the piping against excessive pressure.
contraction to take place without unduly
straining the pipes. 5.4 Steam supply to auxiliaries
5.1.2 The slope of the pipes and the number 5.4.1 The steam supply to steering gear and
and position of the drain valves or cocks are to essential auxiliaries is to be so arranged that it is
be such that water can be efficiently drained not affected in the event of main steam supply to
from any portion of the steam piping system, propulsion machinery or cargo oil pumps being
when the ship is on even keel and/or designed shut off.
trim and is either upright or has a list of not more
than 5 degrees. 5.5 Steam for fire extinguishing in cargo
holds
5.1.3 Drain valves or cocks are to be readily
accessible. 5.5.1 Where steam is used for fire extinguishing
in cargo holds, provision is to be made to
5.2 Steam pipes in way of holds, shaft and prevent damage to cargo by leakage of steam or
pipe tunnels drip. Details of proposed precautionary measu-
res are to be submitted for approval.
5.2.1 In general, steam pipes are not to be led
through spaces which may be used for carrying 5.6 Condensate pumps
cargo. But where it is impracticable to avoid
steam pipes passing through cargo spaces, the 5.6.1 Two or more extraction pumps are to be
pipes are to be efficiently insulated, secured and provided for dealing with the condensate from
protected against mechanical damage. Plans for the main and auxiliary condensers, at least one
such arrangements are to be submitted for of which is to be independently driven. Where
consideration. one of the independent feed pumps is fitted with
direct suctions from the condensers and a
5.2.2 Where the steam pipes pass through shaft discharge to the feed tank, it may be accepted
tunnels and pipe tunnels, these are to be as an independently driven extraction pump.
efficiently secured and insulated in such a way
that the lagging surface temperature does not 5.6.2 Condensate pumps are to be provided
exceed 60°C. with valves or cocks, interposed between the
pumps and the suctions and the discharge
5.3 Relief valves pipes, so that any pump may be opened up for
overhaul while the others continue in operation.
5.3.1 Auxiliary steam lines not designed to
withstand boiler pressure are to be fitted with
Section 6
6.2.2 In multiple screw ships in which there is 6.5.1 All ships fitted with boilers are to be
only one independently driven feed pump, each provided with storage space for reserve feed
main engine is to be provided with a feed pump. water. Capacity of these tanks is to be at least
twice the hourly evaporation rate of the boilers.
6.2.3 Where only one independent feed pump
has been provided, a harbour feed pump or an 6.5.2 Feed water tanks are to be separated from
injector is to be fitted to provide second means oil tanks by cofferdam.
of feed to the boilers which are in use when the
main engines are not working. 6.6 Evaporators
6.2.4 The harbour feed pump, as required by 6.6.1 For main boilers, one or more evaporators,
6.2.3, may be used as general service pump, of adequate capacity, are to be provided.
provided that it is not connected to tanks
containing oil, or to tanks, cofferdams and bilges
which may contain oily water.
Section 7
c) Where a sea inlet scoop arrangement is 7.5.1 Sea-water cooling systems for main and
fitted, and there is only one independent auxiliary machinery are to be connected to at
condenser circulating pump, a further pump, least two cooling water inlets, preferably on
or a connection to the largest available opposite sides of the ship.
pump suitable for circulation duties, is to be
fitted to provide the second means of 7.5.2 Where sea water is used for the direct
circulation when the ship is maneuvering. cooling of main engines and auxiliaries, the sea
The pump is to be connected ready for water suction pipes are to be provided with
immediate use; strainers which can be cleaned without
interrupting the cooling water supply.
d) Where fresh water cooling is employed for
main/or auxiliary engines, a standby means
Section 8
8.1.2 Lubricating oil systems are to be entirely 8.2.4 Independently driven rotary type pumps
separated from other systems. This are to be fitted with non- return valves on the
requirement, however, does not apply to discharge side of the pumps.
hydraulic governing and maneuvering systems
for main and auxiliary engines. 8.2.5 A relief valve in close circuit is to be fitted
on the pump discharge if the pump is capable of
8.1.3 Lubricating oil tanks are to be separated developing a pressure exceeding the design
from other tanks containing water, fuel oil or pressure of the system, the relief valve is to
cargo oil, by means of cofferdams. effectively limit the pump discharge pressure to
the design pressure of the system.
8.1.4 For fire protection requirements also refer
Pt.6, Ch.2, 1.2.3. 8.3 Control of pumps and alarms
minutes, and, in case of propulsion turbo- 8.6 Valves and cocks on lubricating oil tanks
generators, until the unloaded turbine comes to
rest from its maximum rated running speed. 8.6.1 The provisions of 4.4.4, 4.4.5 and 4.4.6
are also to apply to lubricating oil tanks except
8.5 Filters those having a capacity less than 500 litres,
storage tanks on which valves are closed during
8.5.1 In systems, where lubricating oil is the normal operation mode of the ship, or where
circulated under pressure, provision is to be it is determined that an unintended operation of
made for efficient filtration of the oil. For non- a quick closing valve on the oil lubricating tank
redundant units, for essential services, it must would endanger the safe operation of the main
be possible to clean the filters without stopping propulsion and essential auxiliary machinery.
the unit or reducing the supply of filtered oil to
the units. 8.6.2 Where an engine lubricating oil drain tank
extends to the bottom shell plating in ships that
8.5.2 In the case of propulsion turbines and their are required to be provided with a double
gears, arrangements are to be made for bottom, a shutoff valve is to be fitted in the drain
lubricating oil to pass through magnetic strainers pipe between the engine crank case and the
and fine filters. double bottom lubricating oil tank. This valve is
to be capable of being closed from an
accessible position above the level of the lower
platform (floor plates).
End of Chapter
Chapter 4
Contents
Section
1 General
2 Steam Turbines
3 Gas Turbines
4 Oil Engines
5 Gearing
6 Main Propulsion Shafting
7 Propellers
8 Vibrations and Alignment
9 Thrusters
10 Turbochargers
Section 1
General
1.1.1 The requirements of this Chapter are 1.3.1 Arrangements are to be provided to turn
applicable to all ships but may be modified for the prime movers of main propulsion systems,
ships classed for restricted services or for reduction gears and auxiliary drives. Suitable
special services. interlocks are to be provided.
1.1.2 Prime movers of less than 100 [kW] 1.4 Power ratings
capacity may be accepted based upon
manufacturer's certificate provided the prime 1.4.1 Where requirements to dimensions in this
movers are of an approved type. Chapter are based on power and revolutions per
minute, the values to be applied are maximum
1.1.3 Attention is drawn to any relevant statutory continuous power measured on engine output
requirements of the country in which the ship is shaft and corresponding revolutions per minute.
to be registered.
1.4.2 The maximum continuous power for which
1.1.4 Prime movers and power transmission the engine is to be approved is defined in ISO
systems not specified in this Chapter will be 3046/I for oil engines and ISO 3977 for gas
specially considered by IRS. turbines.
for a short period of time (15 minutes). The specification may be type approved in
overload power refers to the power of the accordance with “IRS certification scheme for
generator set. type approval of products”.
Section 2
Steam Turbines
- Block diagram with functional 2.3.2 Grey cast iron is not to be used for
description of control and monitoring temperatures exceeding 260°C.
system;
2.3.3 Turbine rotors and discs are to be of
- Lubricating oil system; forged steel. For carbon and carbon-manganese
steel forgings, the specified minimum tensile
- Operating instructions manual; and strength is to be selected within the limits of 400
2
and 600 [N/mm ]. For alloy steel rotor forgings,
- Test programmes. the specified minimum tensile strength is to be
selected within the limits of 500 and 800
2
[N/mm ]. For discs and other alloy steel
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forgings, the specified minimum tensile strength 2.4.7 Joints in rotors and major joints in
is to be selected within the limits of 500 and cylinders are to be designed as full-strength
2
1000 [N/mm ]. welds and for complete fusion of the joint.
2.3.4 For alloy steels, details of the proposed 2.4.8 Adequate preheating is to be employed for
chemical composition, heat treatment and mild steel cylinders and components and where
mechanical properties are to be submitted for the metal thickness exceeds 44 [mm], and for all
approval. low alloy steel cylinders and components and for
any part where necessitated by joint restraint.
2.3.5 When it is proposed to use material of
higher tensile strength, full details are to be 2.4.9 Stress relief heat treatment is to be applied
submitted for approval. to all cylinders and associated components on
completion of the welding of all joints and
2.4 Design and construction attached structures. For details of stress relief
procedures, temperature and duration, See
2.4.1 In the design and arrangement of turbine Ch.10.
machinery, adequate provision is to be made for
the relative thermal expansion of the various 2.4.10 Surveyors are to be satisfied that the
turbine parts, and special attention is to be given desired quality of welding is attainable with the
to minimizing casing and rotor distortion under proposed welding equipment and procedure,
all operating conditions. and for this purpose test specimens
representative of the welded joints are to be
2.4.2 Turbine bearings are to be so disposed provided for radiographic examination and
and supported that lubrication is not adversely mechanical tests.
affected by heat flow from adjacent hot parts of
the turbine. Effective means are to be provided 2.4.11 Smooth fillets are to be provided at
for intercepting oil leakage and preventing oil abrupt changes of section of rotors, spindles,
from reaching high temperature glands and discs, blade roots and tensions. The rivet holes
casings and steam pipes pockets are to be in blade shrouds are to be rounded and
sufficiently large to prevent excessive radiused on top and bottom surfaces, and
accumulation and leakage of oil. tenons are to be radiused at their junction with
blade tips. Balancing holes in discs are to be
2.4.3 The design analysis, if required, is to well rounded and polished.
include a full vibration analysis with
measurements as necessary, covering vibration 2.4.12 Surveyors are to be satisfied as to the
of the rotor as well as blade vibrations. workmanship and riveting of blades to shroud
bands, and that the blade tenons are free from
2.4.4 Turbine rotors, cylinders and associated cracks, particularly with high strength blade
components fabricated by means of welding will material. Test samples are to be sectioned and
be considered for acceptance if constructed by examined, and pull-off tests made if considered
firms whose works are properly equipped to necessary by Surveyors.
undertake welding to equivalent standards, for
rotors and cylinders respectively, to those 2.4.13 Main turbine rotor discs fitted by shrinking
required by the Rules for Class 1 welded are to be secured with keys, dowels or other
pressure vessels, See Ch.10. approved means.
c) Main turbines are to be provided with a 2.13.1 Stability testing of turbine rotors
satisfactory emergency supply of lubricating
oil which will come into use automatically in a) All solid forged H.P. turbine rotors intended
case of lubricating oil pressure falling below for main propulsion service where the inlet
a predetermined value. The emergency steam temperature exceeds 400°C are to be
supply may be obtained from a gravity tank subjected to at least one thermal stability
containing sufficient oil to maintain adequate test. This requirement is also applicable to
lubrication until the turbine is brought to rest rotors constructed from two or more forged
or by equivalent means. If emergency components joined by welding. The test
pumps are used these are to be so may be carried out at the forge or turbine
arranged that their operation is not affected builders' works (a) after heat treatment and
by failure of the power supply. Suitable rough machining of the forging or (b) after
arrangements for cooling the bearings after final machining, or (c) after final machining
stopping may also be required. and blading of the rotor. The stabilizing test
temperature is to be not less than 28°C
2.12.2 Single screw ships above the maximum steam temperature to
which the rotor will be exposed and not
a) In single screw ships fitted with cross more than the tempering temperature of the
compound steam turbine installations in rotor material.
which two or more turbines are separately
coupled to the same main gear wheel, the b) Where main turbine rotors are subjected to
arrangements are to be such as to enable thermal stability tests at both forge and
safe navigation, when the steam supply to turbine builders' works the foregoing
any one of the turbines is required to be requirements are applicable to both tests. It
isolated. For this emergency operation is not required that auxiliary turbine rotors
purpose, the steam may be led direct to the be tested for thermal stability, but if such
L.P. turbine and either the H.P. or I.P. tests are carried out, the requirements for
turbine can exhaust direct to the condenser. main turbine rotors will be generally
Adequate arrangements and controls are to applicable.
be provided for these operating conditions
to ensure that the pressure and temperature 2.14 Balancing
of the steam will not exceed those which the
turbines and condenser can safely 2.14.1 All rotors as finished-bladed and
withstand. complete with half-coupling are to be
dynamically balanced to the Surveyor's
b) The necessary pipes and valves for these satisfaction, in a machine of sensitivity
arrangements are to be readily available appropriate to the size of rotor.
and properly marked. A fit up test of all
combinations of pipes and valves is to be 2.15 Hydraulic tests
performed prior to the first sea trials.
2.15.1 Maneuvering valves are to be tested to
c) The permissible power/speeds when twice the working pressure. The nozzle boxes of
operating without one of the turbines (all impulse turbines are to be tested to 1.5 times
combinations) is to be specified and the working pressure.
information provided on board.
2.15.2 The cylinders of all turbines are to be
d) The operation of the turbines under tested to 1.5 times the working pressure in the
emergency conditions is to be assessed for casing, or to 2.0 bar whichever is greater.
the potential influence on shaft alignment
and gear teeth loading conditions.
2.15.3 For test purposes, the cylinders may be 2.16 Indicators for movement
subdivided with temporary diaphragms for
distribution of test pressures. 2.16.1 Indicators for determining the axial
position of rotors relative to their casings, and
2.15.4 Condensers are to be tested in the steam for showing the longitudinal expansion of
space to 1.0 bar. The water space is to be casings at the sliding feet, if fitted, are to be
tested to the maximum pressure which the provided for main turbines. The latter indicators
pump can develop at ship's full draught with the should be fitted at both sides and be readily
discharge valve closed plus 0.7 bar with a visible.
minimum test pressure of 2.0 bar. Where the
operating conditions are not known, the test 2.17 Weardown gauges
pressure is to be not less than 3.4 bar.
2.17.1 Main and auxiliary turbines are to be
provided with bridge weardown gauges for
testing the alignment of the rotors.
Section 3
Gas Turbines
3.1 Scope
- Casings;
3.1.1 The requirements of this Section are
applicable to gas turbines for main propulsion - Combustion chambers and heat
and to those for essential auxiliary services. exchangers;
These requirements do not apply to exhaust gas
turbo-blowers. - Gasifiers;
3.1.2 The spare gear for gas turbines has not - Regenerators or recuperators;
been indicated in view of the variation in turbine
design and service conditions. In the - Rotors (turbine and compressor),
circumstances, a list of proposed spare gear is including discs, blades, bearings
to be submitted for consideration. couplings, and clutches;
3.3.1 Rotors and discs are to be of forged steel. 3.5.1 Components fabricated by means of
For carbon and carbon- manganese steel welding will be considered for acceptance if
forgings, the specified minimum tensile strength constructed by firms whose works are properly
is to be selected within the limits of 400 and 600 equipped to undertake welding of the standards
2
[N/mm ]. For alloy steel rotor forgings, the appropriate to the components according to the
specified minimum tensile strength is to be relevant requirements of Ch.10.
selected within the limits of 500 and 800
2
[N/mm ]. For discs and other alloy steel 3.5.2 Before work is commenced, manufacturers
forgings, the specified minimum tensile strength are to submit for consideration details of
is to be selected within the limits of 500 to 1000 proposed welding procedures and their
2
[N/mm ]. proposals for routine examination of joints by
non-destructive means.
3.3.2 For alloy steels, specifications giving the
proposed chemical composition and heat 3.5.3 Major joints are to be designed as full-
treatment are to be submitted for approval. strength welds and for complete fusion of the
joint.
3.3.3 When it is proposed to use a material of
higher tensile strength, full details are to be 3.5.4 Stress relief treatment is to be applied to
submitted for approval. all cylinders, rotors and associated components
on completion of the welding of all joints and
3.4 Design and construction attached structures. For details of stress relief
procedure, temperature and duration, See
3.4.1 All parts of turbines, compressors, etc., are Ch.10.
to have clearances and fits consistent with
adequate provision for the relative thermal 3.5.5 Surveyors are to be satisfied that the
expansion of the various components. Special desired quality of welding is attainable with the
attention is to be given to minimizing casing and proposed welding equipment and procedure,
rotor distortion under all operating conditions. and for this purpose test specimens
representative of the welded joints are to be
3.4.2 Turbine bearings are to be so disposed provided for radiographic examination and
and supported that lubrication is not adversely mechanical tests as required for steam turbines.
affected by heat flow from adjacent hot parts.
Effective means are to be provided for 3.6 Vibration
intercepting oil leakage and preventing oil from
reaching high temperature glands and casings. 3.6.1 Care is to be taken in the design and
manufacture of turbine and compressor rotors,
rotor discs and rotor blades to ensure freedom
from undue vibration within the operating speed
range. Calculations of the critical speeds giving
Indian Register of Shipping
Chapter 4 Part 4
Page 8 of 53 Prime Movers and Propulsion Shafting Systems
full details of the basic assumptions are to be variation of the tank in service to ensure that
submitted for consideration. Where critical turbine alignment will not be adversely affected.
speeds are found by calculation to occur within
the operating speed range, vibration tests may 3.11.4 Where the turbine is provided with an
be requested in order to verify the calculations. acoustic enclosure, this is to act as shield to
prevent contamination of machinery spaces
3.7 Containment from external hazards and contain the heat
emission from the gas generator. The enclosure
3.7.1 Consideration should be given to the need is to be structurally sound and is to be a self-
for containment, with a view to minimizing and contained unit with arrangements for ventilation,
localizing damage, in the event of rotor blade lighting and noise attenuation. The drainage
failure. arrangements in the enclosure are to be
provided to prevent build up of liquids. A self
3.8 Inlet and exhaust systems contained and independent fire fighting system
is to be provided for such enclosure. One or
3.8.1 The air-inlet system is to be designed to more observation window/s is/are to be provided
minimize the entrance of harmful foreign matter. for visual inspection of critical components such
as auxiliary gearbox and burner manifold.
3.8.2 The arrangement of the turbine exhaust
system is to be such as to prevent exhaust 3.12 Overhaul life
gases being drawn into the compressors.
3.12.1 The overhaul schedule recommended by
3.9 Fuel and salt deposits the manufacturer is to be submitted for
consideration.
3.9.1 When it is intended to burn non-distillate
fuels forming harmful deposits, adequate 3.13 Safety arrangements
provision should be made for periodic removal
of the deposits. 3.13.1 Overspeed protective devices
3.10.1 Means are to be provided for indicating a) Where a main propulsion installation
the temperature of the power turbine exhaust incorporates a reverse gear, electric
gases. transmission or controllable (reversible)
pitch propeller, a speed governor,
3.11 External influences independent of the overspeed protective
device, is to be fitted and is to be capable of
3.11.1 Pipes and ducting connected to casings controlling the speed of the unloaded power
are to be so designed that no excessive thrust turbine without bringing the overspeed
loads or moments are applied by them to the protective device into action.
compressors and turbines.
b) Where an auxiliary turbine is intended for
3.11.2 Platform gratings and fittings in way of driving an electric generator, a speed
the supports are to be so arranged that casing governor, independent of the overspeed
expansion is not restricted. protective device, is to be fitted which, with
fixed setting, is to control the speed within
3.11.3 Where main turbine seatings incorpo- 10 per cent momentary variation and 5 per
rating a tank structure are proposed, cent permanent variation when full load is
consideration is to be given to the temperature suddenly taken off or put on. The
Indian Register of Shipping
Rules and Regulations for the Construction and Classification of Steel Ships - 2014
Page 9 of 53
___________________________________________________________________________________
permanent speed variation of a.c. machines arrangements in the machinery space. The
intended for parallel operations are to be arrangements together with calculations
equal within a tolerance of 0.5 per cent. showing the capacities of the cylinders is to be
submitted for approval.
3.13.3 The following turbine services are to be
provided with automatic temperature controls so 3.13.7 Inlet and exhaust silencers are to be
as to maintain steady state conditions fitted to limit the sound power level at one meter
throughout the normal operating range of the from the gas turbine system to 110 dB for
main turbine: unmanned machinery spaces or to 90 dB for
manned machinery spaces.
- lubricating oil system;
- oil fuel supply (or automatic control of oil 3.14 Starting arrangements
fuel viscosity as an alternative); and
- exhaust gas. 3.14.1 Means are to be provided, preferably
automatic or interlocked, to clear all parts of the
3.13.4 Alarms and automatic shutdown devices gas turbine of the accumulation of liquid fuel, or
are to be provided in accordance with Table for purging gaseous fuel, before ignition
3.13.1. commences on starting, or recommences after
failure to start.
3.13.5 Hand trip gear for shutting off the fuel in
an emergency is to be provided locally at the 3.14.2 The starting arrangements can be
turbine control platform and where applicable, at pneumatic, hydraulic or electric. The starting air
the centralized control station. pipes system, safety fittings and number of
starts are to comply with the requirements for oil
3.13.6 All non-mobile gas turbines are to be engines as given in Section 4.11.
provided with independent, self contained
suitable foam or CO2 or water mist fire fighting 3.14.3 Starting devices are to be so arranged
system with detection ability to give warning that firing operation is discontinued and main
automatically at local and remote control fuel valve is closed within pre-determined time in
positions when activated. This system is to be case of ignition failure.
distinctly separate from the fire fighting
3.14.4 Where the gas turbine is arranged for air 3.17.2 Electric starting arrangements for
starting, the total air receiver capacity is to be auxiliary turbines are to have two separate
sufficient to provide, without replenishment, not batteries or be supplied by separate circuits
less than six consecutive starts. At least two air from the main turbine batteries when such are
receivers of equal capacity are to be provided. provided. Where one of the auxiliary turbines
For details of air receivers, see Chapter 5. For only is fitted with an electric starter one battery
multi engine installations three consecutive will be acceptable.
starts per engine are required.
3.17.3 The combined capacity of the batteries
3.15 Tests for starting the auxiliary turbines is to be
sufficient for at least three starts for each
3.15.1 Balancing turbine.
a) The rotors as finished-bladed and complete 3.17.4 The requirements for battery installations
with half-coupling are to be dynamically are given in Pt.4, Ch.8.
balanced to the Surveyor's satisfaction, in a
machine of sensitivity appropriate to the size 3.18 Type testing of gas turbine
of rotor.
3.18.1 Type tests are to be carried out in
3.15.2 Hydraulic tests accordance with the agreed test programme on
a representative machine comprising gas
a) All casings are to be tested to a hydraulic generator and power turbine and are to be
pressure equal to 1.5 times the highest witnessed by IRS surveyor. It may be carried out
pressure in the casing during normal at the manufacturer’s works or at any
operation or 1.5 times the pressure during establishment having suitable facilities
starting, whichever is the higher. For test acceptable to IRS.
purposes if necessary, the casings may be
subdivided with temporary diaphragms for 3.18.2 Where the gas turbine unit can be
distribution of test pressure. separated conveniently into a gas generator and
a power turbine, the type test is to include an
b) Where hydraulic tests cannot be carried out, initial test of the gas generator to ascertain that
the manufacturers are to submit, for the fuel consumption and gas horse power are
approval, alternative proposals for within ±2.5% of design maximum conditions at
determining the soundness of the rated speed.
component.
3.18.3 After completion of the initial test of the
c) Inter coolers and heat exchangers are to be gas generator, the gas generator and power
tested to 1.5 times the maximum working turbine are to be assembled together and
pressure on each side separately. prepared for the gas turbine type test.
3.16 Shop trials 3.18.4 On the over speed test, a propulsion gas
generator is to be run at not less than 10% in
3.16.1 Upon completion of fabrication and excess of gas generator speed corresponding to
assembly, each gas turbine is to be subjected to specified full power of the gas turbine engine for
a shop trial in accordance with the not less than 10 minutes continuously and the
manufacturer’s test schedule, which is to be power turbine disconnected from the
submitted for review before the trial. During the dynamometer is to be run at not less than 15%
trial, the turbine is to be brought up to its over in excess of the maximum designed speed for
speed limit to enable testing of the overspeed not less than 10 minutes continuously.
protective device.
3.18.5 Where it is impracticable to overspeed
3.17 Electric starting the complete installation, each rotor, completely
bladed and with all relevant parts such as half-
3.17.1 Where main turbines are fitted with couplings, shall be overspeed tested individually
electric starters, two batteries are to be fitted. at the appropriate speed.
Each battery is to be capable of starting the
turbines when cold and the combined capacity is 3.18.6 During the type tests at specified full
to be sufficient without recharging to provide the power the pressure and temperature of the gas
number of starts of the main turbines as at outlet from the gas generator is to be
required by 3.14.4. recorded and the gas mass flow is to be
i) Freedom from air and gas leaks. - A cold start is defined as a start after 2
ii) Operation of starting arrangements. hours or more of natural cooling with the
iii) Effectiveness of interlocks, if fitted. engine at rest.
iv) Satisfactory lubricating oil and fuel oil system
characteristics. - A warm start is defined as a start within 15
v) Wet and dry motoring. minutes of shutting down after the engine
vi Engine start following a failure to start. has been running for not less than two
vii) Operation of engine cleaning system. hours.
viii) Reliability of operation at minimum idling
speed. - An intentional failure to start is defined as
the performance of a normal starting
3.18.8 Starting tests are to be carried out to sequence with the ignition system
determine: deliberately rendered inoperative.
i) Time to light from cold. Note : i), ii), iii) and iv) are to be average of four
ii) Time to reach idling speed from cold. readings.
iii) Time to reach full output from idling speed.
Section 4
Oil Engines
4.2.1 The particulars to be submitted for all a) Bedplate and crankcase, (if welded) with
engines are to include the following: welding details and instructions;
f) Frame box, cast or welded with welding b) Carbon and carbon manganese steel
details and instructions (if cast design); forgings (normalized and tempered) : 400 -
2
600 [N/mm ];
g) Tie rod;
c) Carbon and carbon-manganese steel
h) Cylinder head assembly; forgings (quenched and tempered) : not
2
exceeding 700 [N/mm ];
i) Cylinder liner;
d) Alloy steel castings : not exceeding 700
2
j) Counterweights (if not integral with [N/mm ];
crankshaft) including fastening;
e) Alloy steel-forgings : not exceeding 1000
2
k) Connecting rod and connecting rod [N/mm ];
assembly;
f) Spheroidal or nodular graphite iron
2
l) Crosshead assembly; castings: 370 - 800 [N/mm ].
Table 4.3.1 : Components of engines for which material and non-destructive tests are required
Non-destructive tests
Material tests Magnetic particle
Components Ultrasonic
or liquid penetrant
Cylinder dia. of Cylinder dia. of Cylinder dia. of
engines engines engines
1 Crankshaft All All All
2 Crankshaft coupling flange (non-integral) for main
Above 400 mm - -
propulsion engines
3 Crankshaft coupling bolts Above 400 mm - -
4 Steel piston crowns Above 400 mm All Above 400 mm
5 Piston rods Above 400 mm Above 400 mm Above 400 mm
6 Connecting rods and bearing caps All Above 400 mm All
7 Crossheads Above 400 mm - -
8 Cylinder liner - steel parts Above 300 mm - -
9 Cylinder cover - cast steel Above 300 mm All Above 400 mm
10 Steel castings for welded bedplates All All All
11 Steel forgings for welded bedplates All - -
12 Plates for welded bedplates, frames, crankcases
All - -
and entablatures
13 Tie rods All - Above 400 mm
14 Supercharger shaft and rotor, including blades
(supercharger means turbochargers and engine
driven compressor including "Root Blower"). Above 300 mm - -
Auxiliary blowers are not considered as
supercharger
15 Bolts and studs for cylinder covers, crossheads,
Above 300 mm - Above 400 mm
main bearings, connecting rod bearings
16 Steel gear wheels for camshaft drives Above 400 mm - Above 400 mm
4.6 Design and construction 4.6.6 Piston rod glands, which are subjected to
pressure from scavenging air, are to be of a
4.6.1 The design and construction is to be such design ensuring that air will not leak into the
as to enable the oil engine to meet the general crankcase.
requirements with regard to environmental
conditions, functional capability and reliability. 4.7 Crankcase ventilation
4.6.2 Cylinders, cylinder liners, cylinder covers, 4.7.1 Ventilation of crankcase and any
pistons and other parts subject to high arrangement which could produce a flow of
temperature or pressure are to be of material external air within the crankcase, is in general
suitable for the stress and temperature to which not permitted except for dual fuel engines where
they are exposed. crankcase ventilation is to be provided in
accordance with 4.15.1.3. If forced extraction of
4.6.3 The engine bedplate or crankcase is to be the gases from crankcase is provided (e.g. for
of rigid and oil-tight construction. The bedplate is smoke-detection purposes), the vacuum in the
to be provided with sufficient number of holding crankcase is not to exceed 25 [mm] of water
down bolts to effectively secure it to the engine column.
seatings.
4.7.3 To avoid interconnection between 4.8.1.7 Plans showing details and arrangements
crankcases and the possible spread of fire of crankcase explosion relief valves are to be
following an explosion, crankcase ventilation submitted for approval in accordance with 4.2.2.
pipes and oil drain pipes for each engine are to
be independent of each other. 4.8.1.8 Valves are to be provided with suitable
markings that include the following information:
4.8 Safety devices
- Name and address of manufacturer
4.8.1 For crankcase: - Designation and size
- Month / Year of manufacture
4.8.1.1 Crankcases are to be provided with light - Approved installation orientation.
weight spring-loaded valves or other quick-
acting and self closing devices, of an approved 4.8.1.9 In engines having cylinders not
type, to relieve the crankcases of pressure in the exceeding 200 [mm] bore and having a
3
event of an internal explosion and to prevent crankcase gross volume not exceeding 0.6 [m ],
any inrush of air thereafter. The valves are to be relief valves may be omitted.
designed to open at a pressure not greater than
0.2 bar. 4.8.1.10 In engines having cylinders exceeding
200 [mm] bore, but not exceeding 250 [mm]
4.8.1.2 The valve lids are to be made of ductile bore, at least two relief valves are to be fitted,
material capable of withstanding the shock of each valve is to be located at or near the ends
contact with stoppers at the full open position. of the crankcase. Where the engine has more
The discharge from the valves is to be shielded than 8 crank throws an additional valve is to be
by flame guard or flame trap to minimise the fitted near the center of the engine.
possibility of danger and damage arising from
the emission of flame. 4.8.1.11 Engines, with cylinder bores exceeding
250 [mm], but not exceeding 300 [mm], are to
4.8.1.3 Crankcase explosion relief valves are to have at least one relief valve in way of each
be type tested in a configuration that represents alternate crank throw, with a minimum of two
the installation arrangements that will be used relief valves.
on an engine, in accordance with IRS
Classification Notes on “Guidance for Type 4.8.1.12 In engines having cylinders exceeding
Testing of Crankcase Explosion Relief Valves”. 300 [mm] bore, at least one relief valve is to be
fitted in way of each main crank throw.
4.8.1.4 Where crankcase relief valves are
provided with arrangements for shielding 4.8.1.13 Additional relief valves are to be fitted
emissions from the valve following an explosion, for separate spaces on the crankcase, such as
the valve is to be type tested to demonstrate gear or chain cases for camshaft or similar
that the shielding does not adversely affect the drives, when the gross volume of such spaces
3
operational effectiveness of the valve. exceeds 0.6 [m ].
4.8.1.5 Crankcase explosion relief valves are to 4.8.1.14 The free area of each crankcase relief
2
be provided with a copy of manufacturer’s valve is not to be less than 45 [cm ]. The
installation and maintenance manual that is combined free area of the relief valves fitted on
2 3
specific to the size and type of valve being the engine is not to be less than 115 [cm /m ] of
supplied for installation on a particular engine. the crankcase volume.
The manual is to contain the following
information: The free area of the relief valve is the minimum
flow area at any section through the valve, when
- Description of valve with details of the valve is fully open.
function and design limits.
- Copy of type test certificate. When calculating the gross volume of the
- Installation instructions. crankcase, the volume of stationary parts within
- Instructions for testing and renewal of the crankcase may be deducted.
any sealing arrangements.
- Actions required after a crankcase
explosion.
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Chapter 4 Part 4
Page 16 of 53 Prime Movers and Propulsion Shafting Systems
4.8.1.15 A warning notice is to be fitted in a 4.8.1.20 Each engine is to be provided with its
prominent position, preferably on a crankcase own independent oil mist detection arrangement
door on each side of the engine, or alternatively and a dedicated alarm.
at the engine room control location. This
warning notice is to specify that whenever 4.8.1.21 Oil mist detection and alarm systems
overheating is suspected in the crankcase, the are to be capable of being tested on the test bed
crankcase doors or sight holes are not to be and onboard under engine at standstill and
opened until a reasonable time has elapsed engine running at normal operating conditions in
after stopping the engine, sufficient to permit accordance with test procedures that are
adequate cooling within the crankcase. acceptable to IRS.
4.8.1.16 Where crankcase oil mist detection 4.8.1.22 Alarms and shutdowns for the oil mist
arrangements are to be fitted to engines (as per detection system are to be in accordance with
Pt.4, Ch.7 and Pt.5, Ch.22) they are to be of a Pt.5, Ch.22, Sec.3 and the system
type approved by IRS and tested in accordance arrangements are to comply with Pt.5, Ch.22,
with Note 1) and comply with 4.8.1.17 to Sec.2.
4.8.1.28. Engine bearing temperature monitors
or equivalent devices used as safety devices are 4.8.1.23 The oil mist detection arrangements are
to be type approved by IRS for such purposes. to provide an alarm indication in the event of a
foreseeable functional failure in the equipment
Note 1) : Classification Notes – “Type approval and installation arrangements.
of crankcase oil mist detection and alarm
equipment”. 4.8.1.24 The oil mist detection system is to
provide an indication when any lenses fitted in
4.8.1.17 The oil mist detection system and the equipment and used in determination of the
arrangements are to be installed in accordance oil mist level have been partially obscured to a
with the manufacturer’s and engine designer’s degree that will affect the reliability of the
instructions / recommendations. The following information and alarm indication.
particulars are to be included in the instructions:
4.8.1.25 Where oil mist detection equipment
- Schematic layout of engine oil mist includes the use of programmable electronic
detection and alarm system showing systems, the arrangements are to be in
location of engine crankcase sample points accordance with the rule requirements for such
and piping or cable arrangements together systems.
with dimensions of the pipe to the detector.
4.8.1.26 Plans of showing details and
- Evidence of study to justify the selected arrangements of oil mist detection and alarm
location of sample points and sample arrangements are to be submitted for approval
extraction rate (if applicable) in in accordance with Pt.4, Ch.7.
consideration of the crankcase
arrangements and geometry and the 4.8.1.27 The equipment together with detectors
predicted, crankcase atmosphere where oil is to be tested when installed on the test bed
mist can accumulate. and on board ship to demonstrate that the
detection and alarm system functionally
- The manufacturer’s maintenance and test operates. The testing arrangements are to be to
manual. the satisfaction of IRS.
- Information relating to type or in-service 4.8.1.28 Where sequential oil mist detection
testing of the engine with engine protection arrangements are provided the sampling
system test arrangements having approved frequency and time is to be as short as
types of oil mist detection equipment. reasonably practicable.
4.8.1.18 A copy of the oil mist detection 4.8.1.29 Where alternative methods are
equipment maintenance and test manual provided for the prevention of the build-up of oil
required by 4.8.1.17 is to be provided on board mist that may lead to a potentially explosive
ship. condition within the crankcase details are to be
submitted for consideration. The following
4.8.1.19 Oil mist detection and alarm information information is to be included in the details:
is to be capable of being read from a safe
location away from the engine. - Engine particulars – type, power, speed,
stroke, bore and crankcase volume.
is to be so adjusted that the speed does not Note : Steady state conditions are those at
exceed that for which the engine and its driven which the envelope of speed variation does to
machinery are to be classed by more than 20 exceed +1% of the declared speed at the new
per cent for main engines and 15 per cent for power.
auxiliary engines.
c) At all loads between no load and rated load
4.9 Governing the permanent speed variation is not to be
more than 5 per cent of the maximum rated
4.9.1 For main propulsion engines: speed;
An efficient governor is to be fitted to each main d) For generating sets operating in parallel, the
engine and so adjusted that the speed of the governing characteristics of the engine are
engine does not exceed that for which the to be such that within the limits of 20 per
engine is to be classed by more than 15 per cent and 100 per cent of total load, the load
cent. on any generating set does not normally
differ from its proportionate share of the total
When electronic speed governors of main load by more than
engines form part of a remote control system,
they are to comply with the following: i) 15 per cent of the rated output of
the largest machine; or
a) if lack of power to the governor may cause
major and sudden changes in the preset ii) 25 per cent of the rated output of
speed and direction of the thrust of the the individual machine in question,
propeller, back up power supply is to be whichever is less;
provided;
e) For generating sets intended to operate in
b) local control of engines is always to be parallel, it is to be possible to adjust the
possible; governor so that the load is kept within 5 per
cent of the rated load at normal frequency;
c) electronic speed governor and its actuators
are to be type tested as per IRS f) For alternating current installations, the
Classification Notes “Type Approval of permanent speed variation of the machines
Electrical Equipment used for Control, intended for parallel operations are to be
Protection, Safety and Internal equal within a tolerance of ± 0.5 per cent.
Communication in Marine Environment”,
and g) Application of electrical load in more than 2
load steps (See Fig.4.9.2) can only be
d) Also refer Cl.4.12.4.1c). permitted on the condition that
4.9.2 For auxiliary engines: - the design of the ship's electrical system
enables the use of such generator sets
Governors on diesel engines driving main or
emergency electric generators are to be capable - such a provision is made in the design
of automatically maintaining the speeds within stage and same is approved while
following limits: scrutinising the drawings
a) Momentary variations of 10 per cent of the - the safety of the ship's electrical system
maximum rated speed when the rated load in the event of parallel operation and
of the generator is suddenly thrown off; failure of a generator is to be
demonstrated at ship's trials.
b) Momentary variations of 10 per cent of the
maximum rated speed when 50 per cent of
the rated load is suddenly thrown on
followed by the remaining 50 per cent load
after an interval sufficient to restore the
speed to steady state. Steady state
conditions should be achieved in not more
than 5 seconds;
4.9.3 Emergency generator sets must satisfy the requirements of Ch.3 in so far as these are
above governor conditions even when : applicable.
a) their total consumer load is applied 4.10.2 Exhaust pipes which are led overboard
suddenly, or near the waterline are to be protected against
the possibility of water finding its way inboard.
b) their total consumer load is applied in steps, Where the exhaust is cooled by water spray, the
subject to following: exhaust pipes are to be self-draining overboard.
- the total load is supplied within 45 4.10.3 Exhaust pipes of two or more engines are
seconds since power failure of the main not to be connected together, but are to be led
switchboard separately to the atmosphere unless arranged to
prevent the return of gases to an idle engine.
- the maximum step load is declared and
demonstrated 4.11 Engine starting arrangements
approved type may be accepted as a means of 4.11.2.5 Air compressor inlets are to be located
providing the initial start. in an atmosphere reasonably free from oil
vapour or, alternatively, an air duct from outside
4.11.2 Compressed air starting systems: the machinery space is to be led to the
compressors.
4.11.2.1 Two or more starting and maneuvering
air compressors of sufficient total capacity for 4.11.2.6 The air discharge pipe from the
the requirements of the main engines are to be compressors is to be led direct to the starting air
fitted. At least one of the compressors is to be receivers. Provision is to be made for
driven independent of the main propulsion unit intercepting and draining oil and water in the air
and is to have a capacity not less than 50 per discharge for which purpose a separator or filter
cent of the total required capacity. The total is to be fitted in the discharge pipe between
capacity of air compressors is to be sufficient to compressors and receivers.
supply within one hour the quantity of air needed
to satisfy the requirement of 4.11.2.9 by 4.11.2.7 The starting air pipe system from air
charging the receivers from atmospheric receivers to main and auxiliary engines is to be
pressure. The main air compressors are to be of entirely separate from the compressor discharge
approximately the same size. system. Stop valves on the air receivers are to
permit slow opening to avoid sudden pressure
4.11.2.2 The compressors are to be so designed rises in the piping system. Valve chests and
that the temperature of the air discharged to the fittings in the piping systems are to be of ductile
starting air receivers will not substantially material.
exceed 93°C in service. A small fusible plug or
an alarm device operating at 121°C is to be 4.11.2.8 Drain valves for removing
provided on each compressor to give warning of accumulations of oil and water are to be fitted on
excessive air temperature. The emergency air compressors, separators, filters and air
compressor need not comply with these receivers. In the case of any low-level pipelines,
requirements. drain valves are to be fitted to suitably located
drain pots or separators.
4.11.2.3 Each compressor is to be fitted with a
safety valve so proportioned and adjusted that 4.11.2.9 The total air receiver capacity is to be
accumulation of pressure, with the outlet valve sufficient to provide, without replenishment,
closed, will not exceed 10 per cent of the number of starts as per Table 4.11.1.
maximum working pressure.
a) If starting system serves two or more of the
4.11.2.4 The castings of the cooling water above specified purposes, the capacity of
spaces are to be fitted with a safety valve or the system is to be the sum of the capacity
bursting disc so that ample relief will be provided required.
in the event of the bursting of an air cooler tube.
b) At least two air receivers of about equal
capacity are to be provided.
4.12.1.4 A type test carried out for a particular investigations carried out during the pre-
type of engine at any place, at any manufacturer production stages.
will be accepted for all engines of the same type
built by licensees and licensers. 4.12.1.7 The type test is subdivided into three
stages, namely:
4.12.1.5 Engines which are subjected to type
testing are to be tested in accordance to the - State A - Internal tests
scope as specified herein. Functional tests and collection of operation
values including test hours during the
4.12.1.6 It is assumed that" internal tests, the relevant results of which
are to be presented to the Surveyors during
- the engine is optimised as required for the type test.
the condition of the type; Testing hours of components which are
inspected shall be stated.
- the investigations and measurements
required for reliable engine operation - Stage B - Type approval test
have been carried out during internal Type approval test in the presence of the
tests by the engine manufacturer; and Surveyors.
4.12.3 Emergency operation situations - Part loads, e.g. 75%, 50%, 25% of rated
power and speed according to nominal
4.12.3.1 For turbocharged engines the propeller curve corresponding to points 6, 7
achievable continuous output is to be and 8 and at rated speed with constant
determined in the case of turbocharger damage governor setting corresponding to points 9,
as under: 10 and 11.
- Starting tests, for non-reversible engines b) At 110 per cent load at 1.032R : for 45
and/or starting and reversing tests, for minutes after having reached steady
reversible engines. conditions;
- Piston removed and dismantled; c) 75 per cent, 50 per cent, 25 per cent load
and idle run;
- Crosshead bearing, dismantled;
d) Starting and governor tests and proving of
- Crank bearing and main bearing, safety cutouts such as overspeed, shutdown
dismantled; device, etc.
NOTES:
- Cylinder liner in the installed condition;
1. For all stages, the engine is going to be
- Cylinder head, valves dismantled; tested, the pertaining operation values are
to be measured and recorded by the engine
- Control gear, camshaft and crankcase with manufacturer. All results are to be compiled
opened covers. in an acceptance protocol to be issued by
the engine manufacturer.
NOTE:
If deemed necessary by the Surveyors further 2. In each case all measurements conducted
dismantling of the engine may be required. at various load points are to carried out at
steady operating conditions. The readings
4.13 Work's trials (acceptance test) for 100% power (rated power at rated
speed) are to be taken twice at an interval of
4.13.1 Engines are, in general, to be shop- at least 30 minutes.
tested at the Maker's Works under the
supervision and to the satisfaction of Surveyors.
In general following tests are to be carried out:
Indian Register of Shipping
Rules and Regulations for the Construction and Classification of Steel Ships - 2014
Page 25 of 53
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ii) At engine speed R1 = 1.032 R : 30
3. After running on test bed, the fuel delivery minutes (where the engine
system of engines driving generators must adjustment permits). See 4.13.1.1(b)
be adjusted such that overload (110 per
cent) power can be given in service after iii) At minimum on-load speed
installation on board, so that the governing
characteristics including the activation of iv) Starting and reversing manoeuvres
generator protective devices can be fulfilled
at all times. For engines driving propellers v) In reverse direction of propeller
the fuel delivery system must be adjusted so rotation at a minimum engine speed
that engines can be loaded to 100% of the of R2 = 0.7 R for 10 minutes
power.
vi) Monitoring, alarm and safety
4.13.1.3 For Auxiliary Engines systems.
4.13.2 The data to be measured and recorded, i) 100% power (rated propulsion power)
when testing the engine at various load points is at least 4 hours; and at normal
to include all necessary parameters for the continuous cruise propulsion power at
engine operation. The crankshaft deflection is to least 2 hours
be checked when this check is required by the ii) 110% power (rated propulsion power)
manufacturer during operating life of the engine. : 30 minutes
iii) In reverse direction of propeller
4.13.3 The scope of the trials may be expanded rotation during the dock or sea trials
depending on the engine application. at a minimum speed of 70% of the
nominal propeller speed: 10 minutes
4.13.4 Integration Tests : For electronically iv) Starting manoeuvres
controlled diesel engines integration tests are to v) Monitoring, alarm and safety
verify that the response of the complete systems;
mechanical, hydraulic and electronic system is
as identified from FMEA study carried out. Note : Tests are to be based on the rated
(Refer 4.2.2). electrical powers of the electric propulsion
motors.
4.14 Shipboard trials
d) Engines driving auxiliaries
4.14.1 After the conclusion of the running-in
programme, prescribed by the engine i) Engines driving generators or
manufacturer, engines are to undergo the trials important auxiliaries are to be
as specified below: subjected to an operational test for at
least 4 hours. During the test, the set
4.14.1.1 Scope of trials concerned is required to operate at its
rated power for an extended period.
a) Main propulsion engines driving fixed
propellers ii) It is to be demonstrated that the
engine is capable of supplying 100%
i) At rated engine speed R : at least 4 of its rated power and in the case of
hours; and at engine speed shipboard generating sets account
corresponding to normal continuous shall be taken of the times needed to
cruise power: at least 2 hours actuate the generator's overload
protection system.
e) The suitability of engine burning residual or b) If a trunk piston type engine is used as DFD
other special fuels is to be demonstrated, if engine, the crankcase is to be protected by
machinery installation is arranged to burn the following measures:
such fuels.
i) Ventilation is to be provided to prevent the
4.14.1.2 In addition the scope of the trials may accumulation of leaked gas, the outlet for
be expanded in consideration of the special which is to be led to a safe location in the
operating conditions, such as towing, trawling open space through flame arrester.
etc.
ii) Gas detecting or equivalent equipment. (It
4.15 Dual fuel diesel engines is recommended that means for automatic
injection of inert gas are to be provided).
4.15.1 Control and safety systems for Dual
Fuel Diesel (DFD) engines iii) Oil mist detector.
a) DFD engines are to be of the dual-fuel type a) Explosion relief valves or other appropriate
employing pilot fuel ignition and to be protection system against explosion are to
capable of immediate change-over to oil fuel be provided in the exhaust, scavenge and
only. air inlet manifolds.
b) Oil fuel only is to be used when starting the b) The exhaust gas pipes from DFD engines
engine. are not to be connected to the exhaust
pipes of other engines or systems.
c) Oil fuel only, in principle, is to be used when
the operation of an engine is unstable 4.15.1.6 Starting air line
and/or during manoeuvring and port
operations. a) Starting air branch pipes to each cylinder
are to be provided with effective flame
d) In case of shut-off of the gas fuel supply, the arresters.
engines are to be capable of continuous
operation by oil fuel only. 4.15.1.7 Combustion monitoring
4.15.1.8 Gas fuel supply to engine to below the inner pipe pressure
(however, an interlocked gas valve
a) Flame arresters are to be provided at the connected to vent outlet is to be
inlet to the gas supply manifold for the opened).
engine.
2) Construction and strength of the
b) Arrangements are to be made so that the outer pipes are to comply with the
gas supply to the engine can be shut-off requirements of Pt.5, Ch.4, Sec.5,
manually from manoeuvring platform or any Cl.5.2 of the 'Rules and Regulations
other control position. for the Construction and
Classification of Steel Ships'.
c) The arrangement and installation of the gas
piping are to provide the necessary flexibility 3) It is to be so arranged that the inside
for the gas supply piping to accommodate of the gas fuel supply piping system
the oscillating movements of DFD engine, between the master gas valve and
without risk of fatigue failure. the DFD engine is to be
automatically purged with inert gas,
d) The connections of gas line and protection when the master gas valve is closed;
pipes or ducts required in 4.15.1.9(a) to the or
gas fuel injection valves are to provide
complete coverage by the protection pipe or ii) The system when complying with
ducts. Cl. 16.3.1.2 of Pt.5, Ch.4, Sec.16 of the
'Rules and Regulations for the
4.15.1.9 Gas fuel supply piping systems construction and Classification of Steel
Ships' and in addition, with 1) through 4)
a) Gas fuel piping may pass through or extend given below:
into machinery spaces or gas-safe spaces
other than accommodation spaces, service 1) Materials, construction and strength
spaces and control locations provided that of protection pipes or ducts and
they fulfill one of the following: mechanical ventilation systems are
to be sufficiently durable against
i) The system when complying with bursting and rapid expansion of high
16.3.1.1 of Pt.5, Ch.4, Sec.16 of the pressure gas in the event of gas
'Rules and Regulations for the pipe burst.
Construction and Classification of Steel
Ships' and in addition, with 1), 2) and 3) 2) The capacity of mechanical
given below: ventilating system is to be
determined considering the flow rate
1) The pressure in the space between of gas fuel and construction and
concentric pipes is monitored arrangement of protective pipes or
continuously. Alarm is to be issued ducts, as deemed appropriate by the
and automatic valves specified in Cl. Rules of IRS.
16.3.6 of Pt.5, Ch.4, Sec.16 of the
'Rules and Regulations for the 3) The air intakes of mechanical
Construction and Classification of ventilating systems are to be
Steel Ships' and the master gas fuel provided with non-return devices
valves specified in Cl.16.3.7 of Pt.5, effective for gas fuel leaks. However,
Ch.4, Sec.16 of the 'Rules and if a gas detector is fitted at the air
Regulations for the construction and intakes, these requirements may be
Classification of Steel Ships' are to dispensed with.
be closed before the pressure drops
c) All valves and expansion joints used in high iv) Abnormality specified in 4.15.1.11(a).
pressure gas fuel supply lines are to be of
an approved type. c) The master gas valve is to close
automatically upon activation of the
d) Joints on entire length of the gas fuel supply interlocked gas valves.
lines are to be butt-welded joints with full
penetration and to be fully radiographed, 4.15.1.11 Emergency stop of the DFD
except where specially approved by IRS. engines
e) Pipe joints other than welded joints at the a) DFD engine is to stopped before the gas
locations specially approved by IRS are to concentration detected by the gas detectors
comply with the appropriate National or specified in Pt.5, Ch.4, Sec.16, Cl.16.2.2 of
International standards or those whose the 'Rules and Regulations for the
structural strength has been verified through Construction and Classification of Steel
tests and analysis as deemed appropriate Ships', reaches 60% of lower flammable
by IRS. limit.
f) For all butt-welded joints of high pressure 4.15.1.12 Gas fuel make-up plant and related
gas fuel supply lines, post-weld heat storage tanks
treatment are to be performed depending on
the kind of material. a) Construction, control and safety system of
high pressure gas compressors, pressure
4.15.1.10 Shut-off of gas fuel supply vessels and heat exchangers constituting a
gas fuel make-up plant are to be arranged
a) In addition to the causes specified in Pt.5, to the satisfaction of IRS.
Ch.4, Sec.16, Cl. 16.3.6 of the 'Rules and
Regulations for the construction and b) The possibility for fatigue failure of the high
Classification of Steel Ships' supply of gas pressure gas piping due to vibration is to be
fuel to DFD engines is to be shut off by the considered.
interlocked gas valves in case following
abnormality occurs: c) The possibility for pulsation of gas fuel
supply pressure caused by the high
i) Abnormality specified in 4.15.1.7 pressure gas compressor is to be
considered.
ii) DFD engine stops from any cause
Section 5
Gearing
5.1.3 For torsional vibration requirements, See d) Helix angles at generating pitch diameters;
Sec.8.
e) Normal pitches of teeth at generating pitch
5.1.4 Rated power of gear is the maximum diameters;
transmitted power at which the gear is designed
to operate continuously at its rated speed. f) Tip diameters;
5.1.6 The gear rating is the rating for which the i) Pressure angles of teeth (normal or
gear is designed to transmit it’s rated torque. transverse) at generating pitch diameters;
A summary of the results of these analyses for 5.4.3 Where castings are used for wheel
each operating mode is to be submitted for centres, any radial slots in the periphery are to
review. be fitted with permanent chocks before
shrinking-on the rim.
5.3 Materials
5.4.4 Where bolts are used to secure side plates
5.3.1 Specifications for materials of pinions, to rim and hub, the bolts should be tight fit with
pinion sleeves, wheel rims, gear wheels and the holes and the nuts should be suitably locked
shafting giving chemical composition, heat by means other than welding.
treatment and mechanical properties are to be
submitted for approval with the plans of gearing 5.4.5 When welding is employed in the
and are to be in accordance with Pt.2. construction of wheels, the welding procedure is
to be approved by the Surveyors before work is
5.3.2 Where the teeth of a pinion or gear wheel commenced. For this purpose, welding
are to be surface hardened, the proposed procedure approval tests are to be carried out
specification and details of the procedure are to with satisfactory results. Such tests are to be
be submitted for approval. representative of the joint configuration and
materials. Wheels are to be stress relieved after
5.3.3 In the selection of materials for pinions and welding. All welds are to have a satisfactory
wheels consideration should be given to their surface finish and contour. Magnetic particle or
compatibility in operation. In general, for gears liquid penetrant examination of all important
of through hardened steels, except in the case welding joints is to be carried out to the
of low reduction ratios, provision should also be satisfaction of the Surveyors.
made for a hardness differential between pinion
teeth and wheel teeth. For this purpose the 5.4.6 In general arrangements are to be made
specified minimum tensile strength of the wheel so that the interior structure of the wheel may be
materials should not be more than 85 per cent of examined. Alternative proposals will be specially
that of the pinion. considered.
5.3.4 Subject to 5.3.3, the specified minimum 5.5 Accuracy of gear cutting and alignment
tensile strength of steel gear forgings is to be
selected within the following limits: 5.5.1 Gears are to be cut only on machines
which are maintained at a high standard of
- Pinions and pinion sleeves - 550-1050 accuracy. Hobbing machines used in the
2
[N/mm ]; production of large gears are to be operated
under conditions of temperature control with a
- Gear wheels and rims - 400-850 total temperature variations not exceeding 2°C
2
[N/mm ]. for the finishing cut. The blank should be
allowed sufficient time to stabilize to the
A tensile strength range is also to be specified machine temperature before cutting
2
and is not to exceed 120 [N/mm ] when the commences.
specified minimum tensile strength is 600
2
[N/mm ] or less. For higher strength steels, the 5.5.2 The accuracy of gear-cutting of pinions
2
range is not to exceed 150 [N/mm ]. and wheels is to be demonstrated to the
satisfaction of the Surveyors. For this purpose,
5.3.5 Unless otherwise agreed, the specified records of measurements of pitch error,
minimum tensile strength of the core is to be undulations, axial pitch errors, tooth thickness
2
800 [N/mm ] for induction-hardened or nitrided and backlash should be available for review by
2
gearing and 750 [N/mm ] for carburized gearing. Surveyors on request.
Section 6
6.1.1 The requirements of this Section apply to 6.2.1 Alternative calculation methods will be
shafting for main propulsion of straight forged considered provided these calculations take into
design and which are driven by rotating account all relevant loads in the complete
machines such as diesel engines, turbines or dynamic shafting system under all permissible
electric motors. The requirements for couplings, operating conditions giving due consideration to
coupling bolts, keys, keyways, sternbushes and the dimensions and arrangements of all shafting
associated components are also included. The connections. The alternative calculation method
diameter of shafting as calculated may require is to also take into account design criteria for
to be modified as a result of alignment continuous and transient operating loads for
considerations and vibration characteristics (See dimensional adequacy for fatigue strength and
Sec.8) or the inclusion of stress raisers, other peak operating loads for yield strength. Refer
than those contained in this section. 6.2.2 to 6.2.5 as guidance for alternative
calculations.
The requirements given in this section do not
cover shafts intended for following application. 6.2.2 The two important considerations that are
essential for the design of propulsion shafting
- gearing shafts are:
- electric motor shafts
- generator rotor shafts a) Fatigue
- turbine rotor shafts. b) Stress concentration and notch
sensitivity.
6.1.2 The scantlings of shafts that are integral to
equipment, such as for gear boxes, podded Fatigue : The deterioration of the properties of
drives, electrical motors and/or generators, material which takes place under conditions
thrusters, turbines and which in general involving fluctuating stresses. Fatigue failures
incorporate particular design features are to be generally occur at loads, which if applied
determined taking into account appropriate statically would be below the elastic limit. The
additional criteria including that for stiffness, fatigue limit of a material is the stress which will
high temperature application etc. The not produce failure, even if many fluctuations of
requirements given in this section may be it are imposed.
applied if such shafts are subjected mainly to
torsion and are having traditional design Stress concentration in shafts : Basic stress
features. analysis calculations assume that the
components are smooth, have a uniform section
6.1.3 For additional strengthening for shafts in and have no irregularities. In practice virtually all
ships classed for navigation in waters with ice engineering components have to have changes
condition, refer Pt.5, Ch.21 and for diesel engine in section and/or shape. Common examples are
crankshaft refer IRS Classification Note shoulders on shafts, oil holes, key ways and
“Crankshaft for Internal Combustion Engines”. screw threads. Any discontinuity changes the
stress distribution in the vicinity of the
Indian Register of Shipping
Rules and Regulations for the Construction and Classification of Steel Ships - 2014
Page 33 of 53
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7
discontinuity, so that the basic stress analysis b) High cycle fatigue criterion (typically > 10 ),
equations no longer apply. Such ‘discontinuities’ i.e. torsional vibration stresses permitted for
or ‘stress raisers’ cause local increase of stress continuous operation as well as reverse
referred to as ‘stress concentration’. bending stresses.
The limits for torsional vibration stresses are
For static loading the theoretical or geometric given in 8.4.2.
stress concentration factors Kt or Kts relate to
actual maximum stress at the discontinuity to c) The accumulated fatigue due to torsional
the nominal stress as follows: vibration when passing through a barred
speed range or any other transient condition
Kt = maximum direct stress/nominal direct stress with associated stresses beyond those
Kts = maximum shear stress/nominal shear permitted for continuous operation is
stress. addressed by the criterion for transient
stresses in 8.4.2.
The subscript ‘t’ denotes that the stress
concentration value is a theoretical calculation 6.2.4 The factors k (for low cycle fatigue) and ck
based only on the geometry of the component (for high cycle fatigue) as given in Table 6.5.1
and discontinuity. and Table 8.4.2 respectively take into account
the influence of:
Some materials are not as sensitive to notches
as implied by the theoretical stress - The stress concentration factors (scf)
concentration factor. For these materials a relative to the stress concentration for a
reduced value of stress concentration factor Kf flange with fillet radius of 0.08do (geometric
may be used where the maximum stress = Kf x stress concentration of approximately 1.45).
nominal stress. The value of Kf which depends
on notch sensitivity ‘q’ is to be determined using x
1.45 scf
the following equation: ck ≈ and k ≈
scf 1.45
q = (Kf - 1) / (Kt - 1) where q is between 0 and 1.
where the exponent x considers low cycle notch
If q = 0, then Kf = 1 as the material has no sensitivity.
sensitivity to notches. If q = 1, then Kf = Kt and
the material is fully notch sensitive. - The chosen values of the notch sensitivity
are mainly representative for soft steels (σB
When designing, usual practice is to first find Kt < 600), while the influence of steep stress
from the geometry of the component, then gradient s in combination with high strength
specify the material and determine the notch steels may be underestimated.
sensitivity, q from the chart for the notch radius.
- The size factor CD being a function of
For cyclic loading, the theoretical stress diameter only does not purely represent a
concentration factor is to be defined as statistical size influence, but rather a
combination of this statistical influence and
endurance limit without stress concentration the notch sensitivity.
K t1 =
endurance limit with stress concentration
6.2.5 The stress concentration factor (scf) at the
end of slots can be determined by means of the
Using the notch sensitivity factor ‘q’ in cyclic following empirical formulae:
loading of shaft, fatigue stress concentration
factor Kf is calculated as : (l − e)/d
scf = α t(hole) + 0.8 .
Kf = 1 + q (Kt1 – 1) di e
1 − .
6.2.3 The alternative calculation methods are to d d
take into account following fatigue related issues
as have been considered in rule formulations: where,
4
a) Low cycle fatigue criterion (typically < 10 ), e = slot width
i.e. the primary cycles represented by zero l = length of the slot
to full load and back to zero, including do = outer diameter
reversing torque if applicable. di = inner diameter (Refer figure given under
Table 6.5.1).
- slots at 120 or 180 or 360 degrees apart. 6.4.1 The materials are to comply with the
relevant requirements of Pt.2, Ch.5. The
- slots with semicircular ends. (Though multi- specified minimum tensile strength of forgings is
radii slot end can reduce the local stresses, to be selected within the following general limits:
this is not included in this empirical formula).
a) Carbon and carbon-manganese steel 400-
2
- slots with no edge rounding (except 760 [N/mm ];
chamfering), as any edge rounding
2
increases the scf slightly. b) Alloy steels - 400-800 [N/mm ];
α t(hole) = factor representing the stress Where shafts may experience vibratory stresses
close to the permissible stresses for transient
concentration of radial hole of diameter e: operation, the materials are to have a specified
2
minimum tensile strength of 500 [N/mm ].
2 2 2
e e e d
= 2.3 − 3 . + 15 . + 10 . . i 6.4.2 If materials with greater specified or actual
d d d d tensile strength than the limitations given in
6.4.1 are used, no consideration will be given for
6.3 Plans and particulars reduction of shaft diameter or acceptance of
higher permissible vibratory stresses, than those
6.3.1 The following plans, in triplicate, together stated in 6.4 to 6.6.
with the necessary particulars of the machinery,
including the maximum power and revolutions 6.4.3 Ultrasonic tests are required on shaft
per minute, are to be submitted for approval forgings where the diameter is 250 [mm] or
before the work is commenced. greater.
- Power take-off arrangement if any (e.g. 6.5 Intermediate and thrust shafts
shaft generator), propulsion boosters or
similar equipment rated for 100 [kW] and 6.5.1 The diameter, d, of the shaft is to be not
above; less than determined by the following formula:
- Final gear shaft;
- Thrust shaft;
P 560
- Intermediate shafting, shaft bearings; d = Fk 3 [mm]
- Tube shaft, where applicable; n σB + 160
- Tail shaft;
- Stern tube, shaft seals and Stern bush; where,
- Stern tube lubrication system;
- Couplings (integral, demountable, keyed or F = 95 for turbine installations, electric
shrink-fit), coupling bolts and keys; propulsion installations and oil engine
- Flexible coupling including constructional installations with slip type couplings;
details, static and dynamic torsional
stiffness, damping characteristic, rated = 100 for other oil engine installations;
power, torque and RPM, allowable vibratory
torque for continuous and transient k = shaft design factors as given in Table 6.5.1;
operation and allowable misalignment for
continuous operations; σB = specified minimum tensile strength of the
- Cardan shafts, if fitted. 2
material [N/mm ] as per 6.4.1.
6.3.2 The specified minimum tensile strength of P = maximum shaft power, in [kW];
each shaft is to be stated.
n = Revolutions per minutes corresponding to
6.3.3 A shafting arrangement plan indicating the maximum shaft power giving maximum torque.
relative position of the main engines, flywheel,
flexible coupling, gearing, thrust block, line 6.5.2 For shafts with design features other than
shafting and bearings, stern tube, 'A' brackets stated in Table 6.5.1, the value of k will be
and propeller, as applicable, is to be submitted specially considered.
for information.
Table 6.5.1 : Shaft design factors k for line shafts and thrust shafts
2) k refers to the plain shaft section only. Where shafts may experience vibratory stresses close to
the permissible stresses for continuous operation, an increase in diameter to the shrink fit
diameter is to be provided, e.g. a diameter increase of 1 to 2% and a blending radius nearly
equal to the change in diameter are to be provided.
3) At a distance of not less than 0.2d from the end of the keyway the shaft diameter may be
reduced to the diameter calculated with k = 1.0. Fillet radii in the transverse section of the
bottom of the key way are not to be less than 0.0125d.
4) It is recommended that keyways are in general not to be used in installations with a slow speed
crosshead or 2-stroke engines with a barred speed range.
2
6.6 Tailshafts and stern tube shafts [N/mm ] (for carbon, carbon manganese and
alloy steels);
6.6.1 The diameter, dp, of the tailshaft
immediately forward of the forward face of the P and n are defined in 6.5.
propeller boss or, if applicable, the forward face
of the tailshaft flange, is to be not less than 6.6.2 The diameter, dp of the tailshaft
determined by the following formula: determined in accordance with the formula in
6.6.1 is to extend over a length not less than
that to the forward edge of the bearing
P 560
d p = 100 k 3 [mm] immediately forward of the propeller or 2.5 dp
n σB + 160 whichever is the greater.
1)
Table 6.6.1 : Shaft design factors k for tailshafts and stern tube shafts
Note : 1) Fillet radii in the transverse section at the bottom of the keyway are not to be less than
0.0125dp
6.12.3 The resulting equivalent von Mises stress 6.14.2 The thickness of the continuous liner
in the assembly is not to be greater than the between the bearings is not be less than 0.75t.
yield strength of the component material.
6.14.3 Continuous liners are preferably to be
6.12.4 Reference marks are to be provided on cast in one length. If made of several lengths,
the adjacent surfaces of parts secured by the joining of the separate pieces is to be made
shrinkage alone. by welding through the whole thickness of liner
before shrinking. In general, the lead content of
6.13 Coupling bolts the gunmetal of each length forming a butt
welded liner is not to exceed 0.5 per cent. The
6.13.1 The diameter of the fitted bolts at the composition of the electrode or filler rods is to be
joining faces of the coupling is to be not less substantially lead free.
than that given by the following formula:
6.14.4 The liners are to withstand a hydraulic
pressure of 2.0 bar after rough machining.
d (T + 160)
3
d b = 0.65
iD Tb 6.14.5 The liners are to be carefully shrunk or
forced upon the shaft by hydraulic pressure, and
they are not to be secured by pins.
where,
6.14.6 Effective means are to be provided for
db = diameter of the fitted coupling bolts [mm];
preventing water from reaching the shaft at the
part between the after end of the liner and the
d = required diameter [mm], of the intermediate
propeller boss.
shaft taking into account ice strengthening
requirements, if applicable;
6.14.7 If the liner does not fit the shaft tightly
between the bearing portions in the stern tube,
the space between the shaft and the liner is to
6.15.3 The distance between the top of the cone c) For bearings which are grease lubricated,
and the forward end of the keyway is to be not the length of bearing is to be not less than 4
less than 0.2 of the diameter of the tailshaft at times the diameter required for the tailshaft;
the top of the cone.
d) For water lubricated bearings lined with two
6.15.4 The effective sectional area of the key in or more circumferentially spaced sectors of
d3 an approved plastics material, in which it
2
shear, is to be not less than [mm ] can be shown that the sectors operate on
2.6 d 1 hydrodynamic principles, the length of the
bearing is to be such that the nominal
where, bearing pressure will not exceed 0.55
2
[N/mm ]. The length of the bearing is not to
d = diameter [mm], required for the intermediate be less than twice its diameter;
shaft determined in accordance with 6.4, based
on material having a specified minimum tensile e) For approved oil lubricated bearings of
2
strength of 400 [N/mm ] and k = 1; synthetic rubber, reinforced resin or plastic
materials, the length of the bearing is to be
d1 = diameter of shaft at mid-length of the key not less than 2.0 times the rule diameter of
[mm]. the shaft in way of the bearing. The length
of the bearing may be reduced provided the
6.16 Stern tube and bearings nominal pressure is not more than 6 bar as
determined by static bearing reaction
6.16.1 The length of the bearing in the calculation taking into account shaft and
sternbush next to and supporting the propeller is propeller weight which is deemed to be
to be as follows: exerted solely on the aft bearing divided by
the projected area of the shaft. In any case
a) For water lubricated bearings which are the length is not to be less than 1.5 times
lined with lignum vitae, rubber composition the actual diameter. Where the material has
or staves of approved plastic material; the proven satisfactory testing and operating
length is to be not less than 4 times the experience, consideration may be given to
diameter required for the tailshaft under the an increased bearing pressure.
liner;
6.16.2 Forced water lubrication is to be provided
b) For bearings which are white-metal lined, oil for all bearings lined with rubber or plastics and
lubricated and provided with an approved for those bearings lined with lignum vitae where
type of oil sealing gland; the shaft diameter is 380 [mm] or over. The
supply water may come from a circulating pump
or other pressure source. The water grooves in
the bearings are to be of ample section and of a
Indian Register of Shipping
Chapter 4 Part 4
Page 40 of 53 Prime Movers and Propulsion Shafting Systems
6.16.3 The shut off valve or cock controlling the - 30,000 hours for other bearings.
supply of water is to be fitted direct to the after
peak bulkhead, or to the sterntube where the Where L10h is the basic rating life in hours which
water supply enters the sterntube forward of the 90% of a sufficiently large group of apparently
bulkhead. identical bearings is expected to attain.
6.16.4 Where a tank supplying lubricating oil to 6.18 Shaft bearing materials
the sterntube is fitted, it is to be located above
the load water line and is to be provided with a 6.18.1 Shaft bearing fitted in stern bushes and
low level alarm device in the engine room. shaft bossings in “A” and “P” brackets are to be
constructed from an approved material and
6.16.5 Where sternbush bearings are oil effectively secured to prevent rotational and
lubricated, provision is to be made for cooling axial movement in the stern tube(s) and stern
the oil by maintaining water in the after peak bush(es)
tank above the level of the sterntube or by other
approved means. Means of ascertaining the 6.19 Glass Reinforced Plastic coating
temperature of the oil in the sternbush are also
to be provided. 6.19.1 The tail shaft may be protected by a
For vessels with TAILSHAFT CONDITION fiberglass reinforced plastic coating between
MONITORING (TCM) notation, at least two liners in accordance with the following
independent temperature sensors or other procedure, which effectively prevents sea water
approved arrangements are to be provided for from contacting the steel shaft. In such cases,
measuring the aft bearing temperature. the tailshaft survey interval would be 5 years as
applicable for the tailshaft survey notation
6.16.6 The oil sealing glands used for sterntube TS(CL). The procedure is to be approved in
bearings, which are oil lubricated, are to be of each case:
approved type.
a) Coatings are to consist of at least 4
6.16.7 An arrangement for readily obtaining plies of cross-woven glass tape
accurate oil samples is to be provided. The impregnated with resin or equivalent
sampling point is to be taken from the lowest process.
point in the lub.oil system as far as practicable.
Also the arrangements are to be such as to b) The shaft is to be cleaned with solvent
permit the effective removal of the contaminants or grit blasted.
st
from the oil lubricating system. c) Shaft is to be examined and 1 coat is
to be given in presence of Surveyors.
6.16.8 Stern seals are to be of the axially direct
face type. Soft packing glands are to be used d) Shaft is to be subjected to spark test
only if specified by Owners. after coating. There should be freedom
from porosity.
6.16.9 Where bulkhead glands are fitted, a
watertight sealing arrangement is to be e) Effective means are to be provided to
provided. Bulkhead seals is not to be formed by prevent water gaining access to the
a bulkhead mounted plummer bearing. metallic region of the shaft.
f) It is to be ensured that provision is
6.16.10 Plummer bearings are to be either made for overlapping and adequate
bulkhead mounted or of pedestal type. bonding of the coating.
6.17 Roller element bearings g) The end of the liner is to stepped and
tapered as required to protect the end of
6.17.1 Roller element bearings are to have the wrapping.
design life, L10h not less than:
Section 7
Propellers
b) Revolutions per minute of the propeller at In case of highly skewed propellers with skew
maximum power, R; angle greater than 50 degree and controllable
pitch propeller skew angle greater than 25
c) Propeller diameter, D [m]; degrees, propeller load and stress analysis
proving adequacy of blade strength are to be
d) Pitch at 25 per cent radius (for solid submitted.
propellers only), P0.25 [m];
7.3 Materials
e) Pitch at 35 per cent radius (for controllable
pitch propellers only), P0.35 [m]; 7.3.1 Castings for propellers and propeller
blades are to comply with the requirement of
f) Pitch at 70 per cent radius, P0.7 [m]; Pt.2, Ch.8. The specified minimum tensile
strength is to be not less than stated in Table
g) Length of blade section of the expanded 7.4.1.
cylindrical section at 25 per cent radius (for
solid propeller only), L0.25 [mm]; 7.3.2 When it is proposed to use materials which
are not included in Table 7.4.1, details of the
h) Length of blade section of expanded chemical composition, mechanical properties
cylindrical section at 35 per cent radius (for and density are to be submitted for approval.
controllable pitch propellers only) L0.35 [mm];
7.4 Design
i) Rake at blade tip measured at shaft axis
(backward rake positive, forward rake 7.4.1 Minimum blade thickness
negative), K [mm];
7.4.1.1 Where the propeller blades are of
j) Number of blades, N; conventional design, the thickness, t, of the
propeller blades at 25 per cent radius for solid
k) Developed area ratio, a. propellers, at 35 per cent for controllable pitch
propellers, neglecting any increase due to fillets,
is to be not less than:
2
Materials Specified min. UTS [N/mm ] f w
Manganese bronze Grade Cu 1 440 20.6 8.3
Ni-Manganese bronze Grade Cu 2 440 20.9 8.0
Ni-Aluminium bronze Grade Cu 3 590 25.7 7.5
Mn-Aluminium bronze Grade Cu 4 630 23.25 7.5
Cast iron 250 11.77 7.2
Carbon and low alloy steels 400 14.0 7.9
Note : The value of f may be increased by 10 percent for twin screw and outboard propellers of triple
screw ships.
as
t 0.35 = 847
AP
+
1.6 BKC s =
C n CRN C Cn LT
Section 8
8.1 Scope
8.1.2 Unless otherwise advised, it is the
8.1.1 The requirements of this Section are responsibility of the Shipbuilder as the main
applicable to the following systems: contractor to ensure, in co-operation with the
Engine builders, that the information required by
a) Main oil engine propulsion systems, except this Section is prepared and submitted.
in the case of ships classed for smooth
water service, when fitted with engines 8.2 Basic system requirements
having powers less than 200 [kW].
8.2.1 The systems are to be free from excessive
b) Auxiliary oil engine machinery systems used torsional, axial and lateral vibration, and are to
for essential services, where the power be aligned in accordance with tolerances agreed
developed by auxiliary engines is 200 [kW] with the respective manufacturers.
and over.
8.2.2 Where changes are subsequently made to
c) Main propulsion systems formed by turbines a dynamic system which has been approved,
or electric motors geared to the shafting and revised calculations are to be submitted for
situated aft. consideration.
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Chapter 4 Part 4
Page 44 of 53 Prime Movers and Propulsion Shafting Systems
8.4.1.1 Torsional vibration calculations, including 8.4.2.3 For continuous operation the permissible
an analysis of the vibratory torques and stresses stresses due to alternating torsional vibrations
for the dynamic systems formed by the oil are not to exceed the following values:
engines, turbines, motors, generators, flexible
couplings, gearing, shafting and propeller, σB + 160
where applicable, including all branches, are to τ1 = ± C k C D (3 − 2λ 2 ) for λ < 0.9
be submitted for approval together with the 18
associated plans.
σB + 160
8.4.1.2 Particulars of the division of power τ1 = ± 1.38 C k C D for 0.9 ≤ λ < 1.05
developed throughout the speed range for
18
turbines or from all intended combinations of
where,
operation in oil engine installations having more
than one engine and/or with power take-off
systems are to be submitted. τ1 = permissible stress due to torsional
2
vibrations for continuous operation [N/mm ];
8.4.1.3 Any special speed requirements for
σB = tensile strength of shaft material [N/mm ];
2
prolonged periods in service are to be indicated,
e.g., range of trawling revolutions per minute,
range of operation revolutions per minute with a For calculation purposes, this value is not to be
controllable pitch propeller, idling speed, etc. taken greater than:
•
2
8.4.1.4 The calculations and/or measurements 600 [N/mm ] for carbon and carbon
carried out on oil engine installations containing manganese steels; and
•
2
transmission items sensitive to vibratory torque, 800 [N/mm ] for alloy steels;
e.g. gearing, flexible couplings, or generator
rotors and their drives, are to take into account Ck = factor for different shaft design features as
the effects of engine malfunction commonly given in Table 8.4.2;
experienced in service, such as cylinder(s) not -0.2
firing. CD = size factor = 0.35 + 0.93d ;
8.4.1.5 Restricted speed ranges will be imposed do = shaft outside diameter under consideration
in regions of speed where stresses are [mm];
considered to be excessive for continuous
running. Similar restrictions will be imposed, or λ = speed ratio = n/no;
other protective measures required to be taken,
where vibratory torques are considered to be n = speed in rpm under consideration at rated
excessive for particular machinery items. power;
Flange mounted or
keyless taper fitted
flange and straight
In way of bearing
1
Between forward
Keyway, tapered
Integral coupling
On both sides of
Longitudinal slot
bearing is used
connection
propellers
section
2)
Ck = 1.0 1.0 0.60 0.45 0.50 0.30 0.85 0.85 0.55 0.55 0.80
Note:
1) The ck value is valid for 1, 2 and 3 slots and they are to be arranged 360, 180 or 120 degrees
apart from each other respectively.
2) Ck = 0.3 is a safe approximation within the limitations given in note No.6 under Table 6.5.1). If the
slot dimensions are outside of the above limitations, or if the use of another ck is desired, the
actual stress concentration factor (scf) is to be documented or determined from para No.3 of
Appendix. In which case:
Ck = 1.45/scf
The scf is defined as the ratio between the maximum local principal stress and √3 times
the nominal torsional stress (determined for the bored shaft without slots).
8.4.2.4 Where a vessel, because of its type of vibrations are not, in any case, to exceed the
employment, is operated predominantly in the values given by the following formula:
lower speed range, special consideration may
be given to the permissible stresses for 1.7 τ 1
continuous operation. τ2 = for λ ≤ 0.8
Ck
8.4.2.5 Where the stresses exceed the limiting
values of τ1 for continuous operation, restricted where,
speed ranges are to be imposed which are only
allowed to be passed through rapidly. τ2 = permissible stress due to torsional
vibrations for transient running.
8.4.2.6 Restricted speed ranges are not
acceptable, in the speed range between 0.8 to 8.5 Axial vibrations
1.05 of the rated speed. The limits of the barred
speed range are to be calculated in accordance 8.5.1 For all main propulsion shafting systems,
with the following formula unless proved to be the Shipbuilders are to ensure that amplitudes
otherwise. due to axial vibrations are satisfactory
throughout the speed range, so far as
16 N c (18 − λ ) N c practicable. Where appropriate, amplitudes may
≤n≤ be reduced by the use of suitable vibration
18 − λ 16 dampers or phasing of propeller and engine, etc.
where,
8.5.2 Unless previous experience of similar
installation shows it to be unnecessary,
nc = critical speed in [rpm].
calculations of the shafting system are to be
carried out. These calculations are to include the
8.4.2.7 For transient running the permissible
effect of the thrust block seating and the
stresses due to the alternating torsional
surrounding hull structure taking part in the
vibration. The result of these calculations or the
8.6.3 The results of these calculations, or the i) Propulsion shafting with power take-
evidence of previous experience, is to be off or with booster power
submitted for consideration. arrangements.
ii) Propulsion shafting for which the tail
8.6.4 Where calculations indicate the possibility shaft bearings are to be slope
of excessive lateral vibration amplitudes within bored.
the range of working speeds, measurements iii) Propulsion shaft having diameter
using an appropriate recognized technique may 300mm. and above in way of after
be required to be taken from the shafting system most stern tube bearing
for the purpose of determining the need for iv) Propulsion shafting arrangement
restricted speed ranges. requiring long shaft line.
- Forces which may affect the reliability of - Theoretically aligned cold and hot
the propulsion shafting system including conditions of the shaft with specified
weight of the propeller and shafts, alignment tolerances.
- Thermal expansion,
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Rules and Regulations for the Construction and Classification of Steel Ships - 2014
Page 47 of 53
___________________________________________________________________________________
- Bearing loads under all operating association with other stresses in the
conditions are within the acceptable shaft.
limits specified by the bearing
manufacturer. - Forces and moments on propulsion
equipment are within the limits specified
- Bearing reactions are always positive by the machinery manufacturers.
(i.e. supporting the shaft).
8.7.4 Shaft alignment is to be verified by
- Shear forces and bending moments on measurement.
the shaft are within acceptable limits in
Section 9
Thrusters
9.1.1 The requirements of this section are a) Thruster prime mover type and operational
applicable to: power/speed envelop.
- fixed thruster for propulsion b) Rating and type of motor for the azimuthing
mechanism (e.g. type hydraulic or electric).
- steerable thruster units (azimuth
thrusters) for propulsion and steering c) Gearing calculations for the azimuthing and
propulsion mechanism which is to be
- tunnel thruster for transverse propulsion designed in accordance with classification
aid to manoeuvring. notes on the design of gearing. Calculation
for bevel gears is to be on the basis of a
9.2 Plans and particulars conversion to equivalent helical gear.
9.4.1.2 The requirements associated with the iii) The following minimum factor of safety
structural and watertight integrity and the values are to be achieved:
installation arrangement are to be in accordance
with Pt.3. Surface stress SHmin = 1.2
i) Under dynamic operating conditions, the 9.4.3.2 The scantlings of the nozzle stock or
gear is to be considered for: steering tube are to be such that the equivalent
stress, σ,does not exceed 118/k [N/mm ] i.e.
2
the maximum bending moment, BM, on the a) Arrangements to maintain the cleanliness of
nozzle stock or steering tube. the hydraulic fluid, taking into consideration
the type and design of the hydraulic system.
For nozzles without bottom support :
b) A fixed storage tank having sufficient
capacity to recharge at least one azimuth
BM = Fr2 + T 2 x a [Nm] power actuating system including the
reservoir. The piping from the storage tank
T = Maximum thrust developed by the thruster is to be permanent and arranged in such a
[N] manner as to allow recharging from within
the thruster space.
2
Fr = design lateral force [N/mm ] as per 9.4.3.1
c) Where the lubricating oil for the azimuth
a = Vertical distance from centre line of nozzle thrusters is circulated under pressure,
to the section under consideration [m] (See provision is to be made for the efficient
Fig.9.4.3.2). filtration of the oil. The filters are to be
capable of being cleaned without stopping
τt is the torsional shear stress [N/mm ]
2
the thruster or reducing the supply of filtered
calculated using the torque Qr as per 9.4.3.1. oil.
9.6.1 General
Table 9.6.2
Item Alarm Note
Thruster, azimuth or tunnel Indicators, see 9.6.2.2
Azimuthing motor Power failure, single Also running indication on bridge and at machinery
phase control location
Propeller pitch motor Power failure In case of failure the propeller pitch should be locked in
full ahead position. Also running indication on bridge
and at machinery control location
Electric propulsion motor Overload, power Also running indication on bridge and at machinery
failure control location
Control system Failure
Hydraulic oil supply tank level Low
Hydraulic oil system pressure Low
Hydraulic oil system High Where oil cooler is fitted
temperature
Hydraulic oil filters differential High Where oil filters are fitted
pressure
Lubricating oil supply Low If separate forced lubrication
pressure
Section 10
Turbochargers
10.2.5 Calculation and analyses - at least one hour of hot running test at
maximum permissible speed and
- Design basis and design analyses for temperature,
turbine and compressor rotors and
blading including calculations and test - verification of performance tests specified in
results to substantiate the suitability and 10.6.6 and
strength of components for the intended
service. - opening the turbocharger for examination
after the test.
10.3 Design
10.4 Piping systems for turbocharger
10.3.1 Turbochargers intended for engines with
rating below 100 [kW] will be accepted on the 10.4.1 The lubricating oil and cooling water
basis of manufacturer’s type test data. The test piping systems of turbochargers are to be in
data are to be in accordance with 10.3.3. accordance with the provisions of Ch.3 Sec.7
Considerations will be given also to design and Sec.8 of this Part respectively.
criteria and engineering analyses being
10.5.1 Air inlet of turbocharger is to be fitted with Rotors are to be dynamically balanced at a
filter. speed equal to the natural period of the
balancing machine and rotor combined.
10.5.2 Hot surfaces likely to come into contact
with the crew are to be water-jacketed or 10.6.6 Shop trial
effectively insulated. Where the temperature of
hot surfaces is likely to exceed 220°C and Upon completion of fabrication and assembly,
where any leakage, under pressure or each turbocharger is to be subjected to a shop
otherwise, of fuel oil, lubricating oil or other trial, either on a test bed or on a test engine, in
flammable liquid is likely to come into contact accordance with the manufacturer’s test
with such surfaces, they are to be suitably schedule, which is to be submitted for review
insulated with non-combustible materials that before the trial. During the trial, the following
are impervious to such liquid. Insulation material tests are to be conducted:
not impervious to oil is to be encased in sheet
metal or an equivalent impervious sheath. - Impeller and inducer wheels are to be over
speed tested for 3 minutes either:
10.5.3 Pipe or duct connections to the
turbocharger casing are to be made in such a o On a test bed at 20% above the
way as to prevent the transmission of excessive maximum operating speed at
loads or moments to the turbochargers. ambient temperature, or
o On a test engine at 10% above the
10.6 Testing, inspection and certification of maximum operating speed at
turbochargers operating temperature.
10.6.1 Shop inspection and Tests - A mechanical running test for at least 20
minutes at maximum operating speed and
The following shop inspection and tests are to operating temperature, or a test run on the
be witnessed by a surveyor for turbochargers of engine for which the turbocharger is
engines with rating greater than 100 [kW] intended, for 20 minutes at 110% of the
engine’s rated output.
10.6.2 Material tests
10.7 Certification of turbochargers
The materials are to meet requirements given in
Part 2 of the Rules. Materials used in the 10.7.1 Each turbocharger required to be certified
construction of turbines are to be tested in the by 10.1 is:
presence of a Surveyor in accordance with the
provisions of 10.2.4. This requirement does not i) to have its design approved by IRS for
apply to independently driven auxiliary blowers which purpose, plans and data as
that are not required during continuous required by 10.2 are to be submitted to
operation of the engine. IRS for approval and a unit of the same
type is to be satisfactorily type tested
10.6.3 Welded fabrication (see 10.3.3).
All welded fabrication is to be conducted with ii) to be surveyed during its construction
qualified welding procedures, by qualified for compliance with the design
welders and with welding consumables approved, along with, but not limited to,
acceptable to the Surveyors. material tests, hydrostatic tests,
dynamic balancing, performance tests,
10.6.4 Hydrostatic tests etc. as indicated in 10.6, all to be carried
out to the satisfaction of the Surveyor.
The cooling spaces of each gas inlet and outlet
casing are to be hydrostatically tested to 1.5
times the working pressure but not to be less
than 4 bars.
End of Chapter
Chapter 5
Contents
Section
1 General
2 Design Requirements
3 Fittings and Mountings
4 Hydraulic Tests
Section 1
General
1.1.1 The requirements of this Chapter are 1.2.1 The design pressure is the maximum
applicable to pressure vessels of seamless and permissible working pressure and is to be not
fusion welded construction, and their mountings less than the highest set pressure of any safety
and fittings, for the following uses : valve.
- vapours or gases, e.g. air receivers, 1.3.1 The metal temperature, T, used to
hydrophore or similar vessels, CO2 evaluate the allowable stress, σ, is to be taken
containers, etc. and having pV ≥ 1.5, as the actual metal temperature expected under
where p is the design pressure in bar operating conditions for the pressure part
3
and V is the volume of the vessel [m ]. concerned, and is to be stated by the
manufacturer when plans of the pressure parts
1.1.2 Consideration will be given to are submitted for consideration.
arrangements or details of boilers, pressure
vessels and equipment which can be shown to 1.3.2 For boilers, the design metal temperature
comply with other recognized standards, is not to be taken less than the following values,
provided they are not less effective. unless justified by an exact calculation of the
temperature drop and is in no case to be taken
less than 250°C:
b) For pressure parts heated by hot gases, T 1.4 Plans and particulars
is to be taken as not less than 25°C in
excess of the maximum temperature of the 1.4.1 The following plans, in triplicate, for boiler
internal fluid; and pressure vessels are to be submitted for
approval, in so far as applicable:
c) For combustion chambers of the type used
in horizontal wet-back boilers, T is to be a) General arrangement, including arrange-
taken as not less than 50°C in excess of the ment of valves and fittings;
maximum temperature of the internal fluid;
b) Sectional assembly;
d) For furnaces, fire boxes, rear-tube plates of
dry-back boilers and pressure parts subject c) Seating arrangements;
to similar rates of heat transfer, T is to be
taken as not less than 90°C in excess of the d) Steam, water drum and header details;
maximum temperature of the internal fluid;
e) Water wall details;
e) For boiler, superheater, reheater and
economizer tubes, the design temperature f) Steam and superheater tubing, including the
is to be taken as under : tube support arrangements;
j) Details of heat treatment and testing of J = joint factor applicable to the welded seams
welds; or ligament efficiency between tube holes,
expressed as a fraction;
k) Calculations of thicknesses, when required;
p = design pressure, in bar;
l) Test pressures.
Ri = inside radius [mm];
1.5 Classification of pressure vessels
Ro = outside radius [mm];
1.5.1 For Rule purposes, boilers and pressure
vessels are graded as shown in Table 1.5.1. ro = outside knuckle radius [mm];
1.5.2 Pressure vessels which are constructed in ri = inside knuckle radius [mm];
accordance with the requirements of Class 2 or
Class 3 will, if manufactured in accordance with s = pitch [mm];
the requirements of a superior class, be
approved with the scantlings appropriate to that T = design temperature, °C;
class.
t = minimum thickness [mm];
1.5.3 In special circumstances relating to service
σ = allowable stress [N/mm ].
2
conditions, materials, operating temperature, the
carriage of dangerous gases and liquids, etc., it
may be required that certain pressure vessels 1.7 Materials
be manufactured in accordance with the
requirements of a superior class. 1.7.1 Materials used in the construction of Class
1 & 2 pressure vessels are to be manufactured
1.6 Definition of symbols and tested in accordance with the requirements
of Pt.2 under the supervision of IRS Surveyors.
1.6.1 The symbols used in the various formulae
in this Chapter are defined as follows and are Materials for Class 3 pressure vessels will be
applicable to the specific part of the pressure accepted with manufacturer's certificate.
under consideration :
Steam-heated steam
Boilers Other pressure vessels
generators
15000
Class 1 p > 3.5 p > p > 50 or t > 38
Di + 1000
20000
15000 < p ≤ 50 or 16 < t ≤ 38 or
Class 2 p ≤ 3.5 p ≤ Di + 1000
Di + 1000
material temperature > 150°C
Pressure vessels not included in Class
Class 3
1 and 2
Note:
- copper alloy valve and fittings - when D 1.8.1 The term "allowable stress",σ, is the stress
>50 [mm] and pD > 1000 to be used in the formulae for calculation of
scantlings of pressure parts.
- Where p is the design pressure in bar
and D is the nominal diameter in [mm]. 1.8.2 The allowable stress, σ, is to be the lowest
of the following values:
1.7.2 The specified minimum tensile strength of
carbon and carbon manganese steel plates, Et E R S
pipes, forgings and castings is to be within the = or 20 or 20 or R
following general limits : 1.6 1.8 2.7 1.6
a) Carbon and carbon-manganese steels - 320 1.8.3 The allowable stress for steel castings is to
2
- 460 [N/mm ]; be taken as 80 per cent of the value determined
by the method indicated in 1.8.2, using the
2
b) Low alloy steels - 400 - 500 [N/mm ]. appropriate values for cast steel.
1.7.5 Semi-killed, fully killed and fine grain, 1.8.4 Where steel castings, which have been
normal strength structural steels complying with tested in accordance with Pt.2, are also
the requirements of Pt.2, Ch.3 will be accepted subjected to non-destructive tests, consideration
for following Class 3 pressure vessels when: will be given to increasing the allowable stress
using a factor up to 90 per cent in lieu of the 80
15000 per cent referred to in 1.8.3. Particulars of the
p < non-destructive test proposals are to be
D i + 2000 submitted for consideration.
1.10.1 Where pressure parts are of such 1.12 Minimum shell thickness
irregular shape that it is impracticable to design
their scantlings by the application of formulae 1.12.1 Only plus tolerances are allowed on the
given in this Chapter, the suitability of their design shell thickness.
construction is to be determined by hydraulic
proof test of a prototype or by an agreed 1.12.2 The thickness after forming of any shell
alternative method. Di
or head is not to be less than 3+ [mm] for
1.11 Adverse working conditions
1500
carbon, carbon-manganese and low-alloy steels
or 3 [mm] for stainless steel and non-ferrous
1.11.1 Where working conditions are adverse,
materials. For pressure vessels, where the
special consideration may be required to be
cylindrical part is made of a pipe, a smaller
given to increasing the scantlings derived from
minimum thickness may be approved. See also
the formulae, e.g. by increasing the corrosion or
Sec.2 for minimum thicknesses of plates in case
other allowance at present shown in the
of boilers.
formulae, or by adopting a design pressure
higher than defined in 1.2, to offset the possible
1.13 Heat treatment, non-destructive
reduction of life in service caused by the
examination and routine tests
adverse conditions. In this connection, where
necessary, account should also be taken of any
1.13.1 Details regarding heat treatment, non-
excess of loading resulting from :
destructive examination and routine tests are to
be in accordance with the requirements of
a) impact loads, including rapidly fluctuating
Ch.10.
pressures;
Section 2
Design Requirements
2.1 Cylindrical shells and drums subject to t, p, Ri and σ are defined in Sec.1;
internal pressure
J = efficiency of ligaments between tube holes
2.1.1 Minimum thickness or other openings in the shell or the joint factor
of the longitudinal joints (expressed as a
2.1.1.1 The minimum thickness, t, of a fraction), as defined in Sec.1, whichever applies.
cylindrical shell is to be determined by the In the case of seamless shells clear of tube
following formula: holes or other openings, J = 1.0.
s-d
J=
s
b) for irregular drilling (See Fig.2.1.2.2)
S1 + S 2 − 2 d
J=
S1 + S 2
where,
s1 = the shorter of any two adjacent pitches 2.1.2.4 Where tube holes are drilled in a
[mm]; cylindrical shell along a diagonal line with
respect to the longitudinal axis, the efficiency, J,
s2 = the longer of any two adjacent pitches of the ligament is to be determined as in 2.1.2.5
[mm]. to 2.1.2.8.
2.1.2.2 When applying the formula in 2.1.2.1, 2.1.2.5 For spacing of tube holes on a diagonal
the double pitch (s1 + s2) chosen is to be that line as shown in Fig.2.1.2.3, or in a regular saw-
which makes J a minimum, and in no case is s2 tooth pattern as shown in Fig.2.1.2.4, J is to be
to be taken as greater than twice s1. obtained from the series of curves given in Fig
2.1.2.6 where a and b, as shown in Fig.2.1.2.3
2.1.2.3 Where the circumferential pitch between and Fig.2.1.2.4, are measured, in millimeters, on
tube holes measured on the mean of the the median line of the plate , and d is as defined
external and internal drum or header diameters in 2.1.2.1.
is such that the ligament efficiency determined
by the formula in 2.1.2.1 is less than one- half of
the ligament efficiency of the longitudinal axis, J
where,
2.1.2.6 The data for Fig.2.1.2.6 is based on the
following: d = diameter of tube holes [mm].
d Cosα
B = 0.5 1 − (
Sin α + 1
2
) where,
p Do
K=
18.2 σ t
where,
where, where,
C = 0.8 di t b
σs
Y+Z ≥X
σ
where, 2.1.5.3 Area X is to be such that the
reinforcement is provided on all planes through
X = the area to be compensated and is indicated the center of the opening and normal to the shell
by X in Fig.2.1.5.1; surface, and is to be calculated as the product of
the radius of the hole cut in the shell and the
Y = the compensating area available in the shell thickness, A, that would be required for an
material and is indicated by Y in Fig.2.1.5.1; equivalent seamless unpierced shell.
Z = the compensating area available in the 2.1.5.4 Area Y is to be measured in the same
standpipe material and is indicated by Z in plane as area X, and is to be calculated as the
Fig.2.1.5.1; product of the difference between the actual
shell thickness and the equivalent unpierced
σs = the allowable stress of the standpipe shell thickness, A, and the dimension from the
material at design temperature; edge of the opening in shell to limit D.
2.1.5.5 Area Z is to be measured in the same 2.3 Dished ends subject to pressure on
plane as area X, and is to be calculated as concave side
follows:
2.3 1 Minimum thickness
- For that part of standpipe which projects
outside the shell, calculate the full cross- 2.3.1.1 The thickness, t, of semi-ellipsoidal,
sectional area of the stem up to a distance torispherical and hemispherical unstayed ends,
C from the actual outer surface of the shell dished from plate, having pressure on the
plate, and deduct from it the cross-sectional concave side and satisfying the conditions listed
area which the stem would have if its below, is to be determined by the following
thickness was as calculated in accordance formula:
with 2.7.1;
p DoK
- plus, in the case of set- through nozzles t= + 0.75 [mm]
(see Fig.2.1.5.1 (a) and (b), the full cross- 20 σ J
sectional area of that part of the stem which
projects inside the shell up to a distance of where,
C, from the inside surface of the shell;
p, Do, σ and J are defined in Sec.1;
- plus, the cross-sectional area of all
K = a shape factor in accordance with 2.3.2 and
- appropriate fillet welds; Fig.2.3.1.1.
2.2.1.2 The formula in 2.2.1.1 is applicable only 2.3.1.6 For boilers (fired and exhaust gas
where the resulting thickness does not exceed heated), economisers, superheaters, reheaters,
half the internal radius. steam receivers, steam heated steam
generators and similar vessels, the minimum
2.2.2 Openings thickness of the head, t, is to be not less than
9.5 [mm]. In special cases where it is proposed
2.2.2.1 Openings in spherical shells are to to use less than 9.5 [mm] thickness, the
comply with the relevant requirements of 2.3. proposals will be subject to special
consideration.
t = minimum thickness, after dishing [mm]; 2.3.5.2 Reinforcing material within the following
limits may be taken as effective reinforcement:
Do = outside diameter of dished end [mm].
a) The effective width l1, of reinforcement is not
2.3.3.3 The following requirements must in any to exceed 2 R i t or 0.5 do whichever is the
case be satisfied:
lesser;
t
≤ 0.1 b) The effective length l2 of a reinforcing ring is
Do not exceed do tb ;
d
≤ 0.7 where,
Do
Ri = The internal radius of the spherical part of a
torispherical end [mm]; or
2.3.3.4 From Fig.2.3.1.1 for any selected ratio
H/Do, the curve for unpierced ends gives a value
= the internal radius of the meridian of the
d ellipse at the center of the opening, of a semi-
for as well as for K. Openings giving a
Do t ellipsoidal end, [mm], and is given by the
following formula:
d
value of not greater than the value so
Do t [ a 4 − x 2 (a 2 − b 2 )]1.5
obtained may thus be pierced through an end a4 b
designed as unpierced without any increase in
thickness. where,
allowable stress of reinforcing plate at design temperature Dc = inside diameter, in [mm], of conical section
or end at the position under consideration, see
allowable stress of end plate at design temperature
Fig.2.4.1.1;
2.4 Conical ends subject to internal pressure α1, α2, α3 = angle of slope of conical section (at
the point under consideration) to the vessel axis,
2.4.1 Minimum thickness see Fig.2.4.1.1.
2.4.1.1 The minimum thickness, t, of the 2.4.1.4 Conical ends may be constructed of
cylinder, knuckle and conical section at the several ring sections of decreasing thickness, as
junction and within the distance L from the determined by the corresponding decreasing
junction is to be determined by the following diameter.
formula, but in no case is to be less than the
thickness determined by 2.4.1.3:-
2.4.1.5 The thickness of conical sections having 2.7 Particular design requirements for
an angle of inclination to the vessel axis of more boilers, superheaters, economizers, steam
than 75 degrees is to be determined as for a flat receivers and similar vessels
plate.
2.7.1 Boiler tubes subject to internal
2.5 Unstayed flat end plates pressure
2.6.1.1 The minimum wall thickness of t, p, Do and σ are as defined in Sec.1. The
standpipes and branches is to be not less than thickness is in no case to be less than that
that determined by 2.7.1. In determining the wall shown in Table 2.7.1.
thickness of branches, internal pressure in
addition to loads by connected piping and 2.7.1.2 If the tube is ordered with a minus
vibrations are to be taken into account. The tolerance, the minimum thickness according to
thickness, however, is not to be less than: the formula in 2.7.1.1 is to be increased by the
necessary amount. Where tubes are bent, the
t = 0.04 Do + 2.5 [mm] thickness of the thinnest part of the tube is not to
be less than the calculated thickness, unless it
where, can be demonstrated that the method of
bending results in no decrease in strength at the
t and Do are as defined in Sec.1. bend as compared with the straight tube. In
connection with any new method of bending, the
2.6.1.2 In no case need the wall thickness manufacturer is to prove that this condition is
exceed that of the shell. satisfied.
2.6.1.3 Where standpipe or branch is connected 2.7.1.3 For boiler, superheater and economizer
by screwing, the thickness is to be measured at tubes, the wall thickness required for the drum
the root of the threads. or header connection or tube stub is to be
calculated as part of the tube.
2.7.2.1 The wall thickness of tubes with outside t, p, Do and σ are as defined in Sec.1;
diameter 100 [mm] and less is not to be less
than: The nominal thickness of plain boiler tubes is,
however, in no case to be less than given in
p Do Table 2.7.2.
t= [mm]
157 σ
2.7.2.3 Plain tubes may be seal welded at both 2.7.3.1 Circular headers
ends, seal welded at the inlet end and expanded
at the outlet end or expanded at both the ends. 2.7.3.1.1 The minimum thickness of circular
Where the tubes are seal welded, the tubes are section headers is to be calculated in
to be expanded into the tube plates in addition accordance with 2.1.
to welding.
2.7.3.2 Rectangular section headers
2.7.2.4 Where plain tubes are expanded only,
the process is to be carried out with roller 2.7.3.2.1 The thickness of flat surfaces of
expanders, and the expanded portion of the rectangular solid forged headers is to be not
tube is to be parallel through the full thickness of less than (t + 0.75) [mm], where t = the greatest
the tube plate. In addition to expanding, tubes basic thickness, in [mm], derived by the use of
may be bellmouthed or beaded at the inlet end. Fig.2.7.3.1.
2.7.2.5 Where the total number of tubes are 2.7.3.2.2 Fig.2.7.3.1 shows values of t/B
arranged in one nest and no stay tubes are corresponding to the values of term K, for
fitted, the ends of all tubes are to be welded or parameters of A/B;
expanded and beaded at the inlet end, and
welded or expanded at the outlet end. where,
2.7.2.6 The spacing of the tube holes is to be A = the distance, in [mm], between centerline of
such that the minimum width, in [mm], of any the openings and the limit of the effective width,
ligament between the tube holes is not less B, of the header. Where there is more than one
than: row of holes, A is the distance to the row
showing the lowest efficiency;
0.125 d + 12.5 [mm]
B = the effective width, in [mm], of the pierced
where, surface under consideration measured between
the supporting sides of the headers, minus one
corner radius. The effective width is not to be 2.7.3.3.2 Ends attached by welding are to be
taken as less than 0.9 of the full distance designed as follows:-
between the sides;
a) Dished Ends: these are to be in accordance
10σ J with 2.3
K=
p b) Flat Ends: the minimum thickness of flat end
plates is to be determined by the following
where, formula:-
- the stress at the corner of the header, where di = internal diameter of circular header or least
A/B = 0 and J = 1, see Fig.2.7.3.1; width between walls of rectangular header [mm];
- and the stress in the ligaments between C = a constant depending on method of end
tube holes or other openings piercing the attachment, see Fig.2.7.3.2
flat face of the header.
For end plates welded as shown in Fig.2.7.3.2
2.7.3.2.4 The corner radius is not to be less than (a):
6.5 [mm].
C = 0.19 for circular headers;
2.7.3.2.5 Where the header surfaces are
machined locally at hand holes, the total = 0.32 for rectangular headers;
thickness may be reduced by a maximum of 4
[mm]. For end plates welded as shown in Fig.2.7.3.2
(b) and (c):
2.7.3.2.6 Except for small areas not exceeding
2
325 [mm ], where a reduction of designed C = 0.28 for circular headers;
thickness up to 50 per cent may be permitted,
the thickness derived from the use of Fig.2.7.3.1 = 0.40 for rectangular headers.
is to be the minimum. Such minimum is in no
case to be less than 7.5 [mm] or where tube 2.7.3.3.3 Where flat end plates are bolted to
holes are drilled, to be less than:- flanges attached to the ends of headers, the
flanges and end plates are to be in accordance
t = 0.5 d + 6.35 [mm] with recognized pipe flange standards.
d = the diameter of the tube holes [mm]. 2.7.4.1 Stayed flat surfaces
2.7.3.3 Header ends 2.7.4.1.1 Where flat end plates are flanged for
connection to the shell, the inside radius of
2.7.3.3.1 The shape and thickness of ends flanging is to be not less than 1.75 times the
forged integrally with the bodies of headers are thickness of the plate, with a minimum of 38
to be the subject of special consideration. [mm].
Where sufficient experience of previous
satisfactory service of headers with integrally 2.7.4.1.2 Where combustion chamber of firebox
forged ends cannot be shown, the suitability of a plates are flanged for connection to the wrapper
proposed form of end is to be proved in plate, the inside radius of flanging is to be equal
accordance with 1.10. to the thickness of the plate, with a minimum of
25 [mm].
where,
d = A
2
+ B 2 where the stays are regularly
pitched
2.7.4.1.8 Alternative methods of support will be 2.7.4.1.10 Where the flat top plates of
specially considered. combustion chambers are supported by welded-
on girders, the equation in 2.7.4.1.6 is to apply
2.7.4.1.9 Where a flat plate has a manhole or as follows:
sighthole and the opening is strengthened by
flanging, the total depth, H, of the flange, a) In the case of welded-on girders provided
measured from the outer surface of the plate, is with waterways;
to be not less than:
C = 0.42;
H= tW
d = X2 + Y2
where,
where,
H = depth of flange [mm];
X = width of waterway in the girder plus the
t = thickness of plate [mm]; thickness of the girder [mm];
C = 0.51;
d = D;
where,
p
t = Cd + 0.75 [mm]
2.7.4.2.3 Where stay tubes are required to be 10σ 1
fitted, the thickness of those parts of the tube
plates within the tube nests is to be determined where,
by the following formula:
t = thickness of the tube plate [mm];
p
t = CM + 0.75 [mm] p = design pressure [N/mm ];
2
10σ 1
σ1 = 0.85 σ, where σ is as defined in Sec.1;
where,
M = mean pitch, in [mm], of the stay tubes B = pitch [mm], of the stay tubes in boundary
supporting any positions of the plate (being the rows of wide water space;
sum of the four sides of any quadrilateral divided
by 4); C = 0.42, if the plates are not exposed to flame;
C = 0.42 for plates not exposed to flame with = 0.46, if the plates are exposed to flame.
stay tube secured as shown in Fig.2.7.4.5;
2.7.4.3.2 The values of C and the method of
C = 0.46 for plates exposed to flame. securing the stay tubes are as indicated in
2.7.4.2.3.
2.7.4.2.4 Where the area of the tube nest does
2
not exceed 0.65 [m ] in the case of direct fired 2.7.4.3.3 Where stay tubes are irregularly
2
boilers, or 2.0 [m ] in the case of waste heat pitched, d is to be taken as the diameter of the
boilers, and stay tubes are not fitted, the largest circle which can be drawn through any
thickness of the plate is to be determined by the three points of support without enclosing
formula in 2.7.4.2.3; another point of support. Where various forms of
supports are used, the value of C is to be the
where, mean of the values for the respective methods
adopted.
M = Four times the mean pitch [mm], of the plain
tubes in the nest; 2.7.4.3.4 For the portions of the end plates
between the top rows of tubes and steam space
C = 0.45 for plates not exposed to flame; stays, the formula in 2.7.4.3.1 is to apply, B
being taken as the distance between the
= 0.49 for plates exposed to flame. centerline of the top row of tubes and the center
of the bar stays or other point of support, and A
2.7.4.2.5 The thickness, t, of any tube plate in A1 + A 2
being taken as where A1 is the
the tube area is to be not less than: 2
horizontal distance between the centers of bar
2.7.4.4 Combustion chamber tube plates 2.7.4.6.1 The width of margin, b, of a flat plate
under compression which may be regarded as being supported by
the shell, furnaces or flues to which the flat plate
2.7.4.4.1 The thickness of combustion chamber is attached is not to exceed that determined by
tube plates under compression due to the the following formula:
pressure on the top plate, based on a
compressive stress not exceeding 960 bar is to C(t − 0.75)
be determined by the following formula: b= [mm]
p
pWs
t= [mm] where,
1930(s − d)
t and p are as defined in Sec.1;
where,
b = width of margin [mm];
t and p are as defined in Sec.1;
C = 31.0 for plates not exposed to flame;
W = internal width of combustion chamber [mm],
measured from tube plate to back chamber = 28.8 for plates exposed to flame.
plate;
2.7.4.6.2 Where an unflanged flat plate is
s = pitch of tubes [mm], measured horizontally welded directly to shell, furnaces or flues and it
where tubes are chain pitched, or diagonally is not practicable to effect the full penetration
where the tubes are staggered pitched and the weld from both sides of the flat plate, the
diagonal pitch is less than the horizontal pitch; constant C used in formula in 2.7.4.6.1 is to be:
d = internal diameter of plain tubes. C = 23.6 for plates not exposed to flame;
2.7.4.5 Girders for combustion chamber top = 22.3 for plates exposed to flame.
plates
2.7.4.6.3 In the case of plates which are flanged,
2.7.4.5.1 The formula in 2.7.4.5.2 is applicable the margin is to be measured from the
to plate girders welded continuously to the top commencement of curvature of flanging, or from
combustion chamber plates by means of a full a line 3.5 times the thickness of the plate,
penetration weld. measured from the outside of the plate,
whichever is nearer to the flange.
2.7.4.5.2 The proportion of steel plate girders
supporting the tops of combustion chambers is 2.7.4.6.4 Where the flat plate is not flanged for
to be determined by the following formula: attachment to the shell, furnaces or flues, the
margin is to be measured from the inside of the
0.32 p l 2 s shell or the outside of the furnaces or flues,
t= [mm] whichever is applicable.
d 2 R 20
2.7.4.6.5 In no case is the diameter, D, in [mm], 2.7.5 Flat plates and ends of vertical boilers
of the circle forming the boundary of the margin
supported by the uptake of a vertical boiler to be 2.7.5.1 Tube plates of vertical boilers
greater than determined by the following
formula: 2.7.5.1.1 Where vertical boilers have a nest or
nests of horizontal tubes, so that there is direct
tension on the tube plates due to the vertical
345
D= + d 2 [mm] load on the boiler ends or to their acting as
p horizontal ties across the shell, the thickness of
the tube plates in way of the outer rows of tubes
where, are to be determined by the following formula:
R20 = specified minimum tensile strength of tube 2.7.5.2.2 For the combustion chamber tube
2
plate [N/mm ]; plate the minimum number of gussets are to be:
J = efficiency of ligaments between tube holes in - 1 gusset where C exceeds 255 000
the outer vertical rows (expressed as a fraction);
- 2 gussets where C exceeds 350 000
s−d
= - 3 gussets where C exceeds 420 000
s
2.7.5.2.3 For the smoke box tube plate the
where, minimum number of gussets are to be:
s = vertical pitch of tubes [mm]; - 1 gusset where C exceeds 255 000
d = diameter of tube holes [mm]. - 2 gussets where C exceeds 420 000
2.7.5.1.2 Each alternate tube in the outer 2.7.5.2.4 The shell plates to which the sides of
vertical rows of tubes is to be a stay tube. the tube plates are connected are to be not less
Further, the arrangement of stay tubes in the than 1.5 [mm] thicker than is required by the
nests is to be such that the thickness of the tube formula applicable to shell plates with
plates meets the requirements of 2.7.4.2. and continuous circularity; and where gussets or
2.7.4.3. other stays are not fitted to the shelves, the
strength of the parts of the circumferential
2.7.5.1.3 Where the vertical height of the tube seams at the top and bottom of these plates
plates between the top and bottom shelves from the outside of one tube plate to the outside
exceeds 0.65 times the internal diameter of the of the other, is to be sufficient to withstand the
boiler, the staying of the tube plates, and the whole load on the boiler end with a factor of
scantlings of the tube plates and shell plates to safety of not less than 4.5 related to R20 (where
which the sides of the tube plates are connected R20 is the specified minimum tensile strength
will require to be specially considered. It is 2
of the shell plates [N/mm ].
recommended, however, that for this type of
boiler the vertical height of the tube plates 2.7.5.3 Dished and flanged ends for vertical
between the top and bottom shelves should not boilers
exceed 1.25 times the internal diameter of the
boiler. 2.7.5.3.1 The minimum thickness, t, of dished
and flanged ends for vertical boilers which are
2.7.5.2 Horizontal shelves of tube plates subject to pressure on the concave side and are
forming part of the shell supported by central uptakes is to be
determined by the following formula:
2.7.5.2.1 For vertical boilers of the type referred
to in2.7.5.1, in order to withstand the vertical
PRi
load due to pressure on the boiler ends, the t= + 0.75 [mm]
horizontal shelves of the tube plates are to be 10σ 2
supported by gussets in accordance with the
following formula: where,
Di = inside diameter of the boiler [mm]; 2.7.5.3.3 The inside knuckle radius, ri, of the arc
joining the cylindrical flange to the spherical
surface of the end is to be not less than four
Indian Register of Shipping
Chapter 5 Part 4
Page 30 of 41 Boilers and Pressure Vessels
times the thickness of the end plate, and in no are supported by central uptake, is to be
case less than 65 [mm]. determined by the following formula:
d = diameter, in [mm], of the largest circle σ = specified minimum 0.2 per cent proof stress
2
which can be drawn through three points of in [N/mm ], at a temperature 90°C above the
support without enclosing another point of saturated steam temperature corresponding to
support; the design pressure for the steel actually used.
c = the mean of the values for the respective 2.7.5.6.2 The inside radius of curvature, Ri, see
points of support through which the circle Fig.2.3.1.2 (a), of the end plate is to be not
passes. greater than the external diameter of the
cylinder to which it is attached.
2.7.5.5 Dished and flanges ends for
supported vertical boiler furnaces 2.7.5.6.3 The inside knuckle radius, ri, see
Fig.2.3.1.2 (a), of the arc joining the cylindrical
2.7.5.5.1 The minimum thickness, t, of dished flange to the spherical surface of the end is to
and flanged ends for vertical boiler furnaces that be not less than four times the thickness of the
are subject to pressure on the convex side and end plate and in no case less than 65 [mm].
p D o (L + 160)
2.7.6 Cylindrical furnaces subject to external t= + 0.75 [mm]
pressure 102400
2.7.6.1 Maximum thickness CpD o L
t= + + 0.75 [mm]
2.7.6.1.1 Furnaces, plain or corrugated, are not 1100 320
to exceed 22.5 [mm] in thickness.
where,
2.7.6.2 Corrugated furnaces
t and p are as defined in Sec.1;
2.7.6.2.1 The minimum thickness, t, of
corrugated furnaces is to be determined by the Do = external diameter of the furnace, flue or
following formula: combustion chamber [mm];
t = thickness, of the furnace plate measured at 2.7.6.4 Plain furnaces of vertical boilers
the bottom of the corrugations [mm];
2.7.6.4.1 The thickness of plain furnaces not
C = 1060 for Fox, Morision and Deighton exceeding 1700 [mm] in external diameter is to
corrugations; be determined by the formulae given in
2.7.6.3.1, the greater of the two thicknesses
= 1130 for suspension and bulb corrugations. being taken;
CpR o
t= + 0.75 [mm]
608
where,
2x
C= or 0.85, whichever is greater
x +σ
where,
2.7.7 Stay tubes and bar stays for cylindrical 2.7.7.3.3 Where there are no stay tubes in the
boilers tube nest, the area to be supported by a bar
stay is to extend to the tangential boundary of
2.7.7.1 Stay tubes the tube nest.
2.7.7.1.3 Welded-in stay tubes are to be 2.8.1.2 Manholes in cylindrical shells should
expanded into tube plate in addition to welding. preferably have their shorter axes arranged
longitudinally, and are to be located clear of the
2.7.7.1.4 Stay tubes may be welded into the welded joints in the shell.
boiler after stress relief, provided they are not
adjacent in the same tube nest. 2.8.1.3 Doors for manholes and sightholes are
to be formed from steel plate or of other
2.7.7.2 Combustion chamber and longitu- approved construction, and all jointing surfaces
dinal bar stays. are to be machined.
2.7.7.2.1 The permissible stress in combustion 2.8.1.4 Doors of the internal type are to be
chamber and other similar bar stays, calculated provided with spigots which have a clearance of
on minimum sectional area, is not to exceed 62 not more than 1.5 [mm] all round, i.e. the axes of
2
[N/mm ]. the opening are not to exceed those of the door
by more than 3 [mm].
2.7.7.2.2 The diameter of any stay is to be not
less than 19 [mm]. 2.8.1.5 Doors of the internal type for openings
not larger than 230 x 180 [mm] need be fitted
2.7.7.2.3 The permissible stress in longitudinal with only one stud, which may be forged integral
stays, calculated on the minimum cross- with the door. Larger doors are to be provided
sectional area, is not to exceed: with two studs screwed through the door and
fitted with nuts on the inside. Alternatively, bolts
minimum specified tensile strength [N/mm 2 ] may be used, screwed through the door with the
heads inside. Other methods of attachment may
5.3 be accepted, provided that details are submitted
for consideration.
2.7.7.2.4 In no case is the diameter of the
longitudinal stays at any section to be less than 2.8.1.6 The crossbars or dogs for doors are to
25 [mm]. be of steel.
2.7.7.3 Loads on stay tubes and bar stays 2.8.1.7 Circular flat cover plates may be fitted to
raised circular manhole frames not exceeding
2.7.7.3.1 Stay tubes and bar stays are to be 400 [mm] diameter, and for an approved design
designed to carry the whole load due to pressure not exceeding 18 bar. Thickness of the
pressure on the area to be supported. frames are to be not less than 19 [mm] in all
parts. The circular cover plates and joint flanges
for such frames are to be not less than:-
Indian Register of Shipping
Chapter 5 Part 4
Page 34 of 41 Boilers and Pressure Vessels
2.8.1.9 For the purpose of calculation, the 2.9.2.2 Every shell type economizer is to be
pressure may be assumed to act on the whole provided with a means of indicating the internal
area within the pitch circle of the bolts. pressure and to be located so that the pressure
can be easily read from a position from which
2.8.1.10 For smaller circular openings in the pressure may be controlled.
headers and similar fittings, an approved type of
plug may be used. 2.9.2.3 Every shell type economizer is to be
provided with removable lagging at the
2.8.2 Additional requirements for boilers, circumference of the tube end plates to enable
superheaters, economizers, and similar ultrasonic examination of the tube plate to shell
vessels connection.
2.8.2.2 Cylindrical boilers are to be provided, 2.9.4.1 The manufacturer is to provide operating
where possible, with means for ingress to permit instructions for each economizer and is to
examination and cleaning of the inner surfaces include reference to:
of plates and tubes exposed to flame. Where the
boilers are too small to permit this there are to - Feed water treatment and sampling
be sightholes and mudholes sufficiently large arrangements.
and numerous to allow the inside to be
satisfactorily cleaned. - Operating temperatures – exhaust gas and
feed water temperatures.
2.8.2.3 Where the cross tubes of vertical boilers
are large, there is to be a sight hole in the shell - Operating pressure.
opposite to one end of each tube sufficiently
large to allow the tube to be examined and - Inspection and cleaning procedures.
cleaned. These sight holes are to be in positions
accessible for that purpose. - Records of maintenance and inspection.
- Periodical operational checks of the safety - Procedures for maintenance and overhaul
devices to be carried out by the operating of safety valves.
personnel and to be documented
accordingly.
Section 3
3.2.1.1 Boilers and steam generators are to be 3.2.1.8 Each safety valve chest is to be drained
fitted with not less than two safety valves, each by a pipe fitted to the lowest part and led with a
having a minimum internal diameter of 25 [mm], downward gradient to the bilges or to a tank,
but those having a total heating surface of less clear of the boilers. No valves or cocks are to be
2
than 50 [m ] may have one valve not less than fitted to these drain pipes. It is recommended
50 [mm] diameter. that the bore of the drain pipes be not less than
19 [mm].
3.2.1.9
Where a superheater, reheater or economizer is
a) Where a shell type economizer is capable of fitted with a valve between one of these and the
being isolated from the steam plant system, it is boiler, the unit is to have appropriate safety
to be provided with at least one safety valve and valves. Such safety valves are not to be
2
when it has a total heating surface of 50 [m ] or regarded as safety valves for the boiler.
more, it is to be provided with at least two safety
valves. 3.2.1.13 Where it is impracticable to attach
safety valves directly to the superheater, the
b) Such safety valves for shell type exhaust gas valves are to be located as near as possible
heated economizers are to incorporate features thereto and fitted to a branch piece connected to
that will ensure pressure relief even with solid the superheater outlet pipe.
matter deposits on the valve and guide, or
features that will prevent the accumulation of 3.2.1.14 In high temperature installations the
solid matter in way of the valve and in the drains from safety valves are to be led to a tank
clearance between the valve spindle and guide. or other place where high temperature steam
can be safely discharged.
c) Alternatively a bursting disc discharging to
suitable waste steam pipe is to be fitted in 3.2.1.15 The designed discharge capacities of
addition to the valve. The alternative the safety valves on each boiler and steam
arrangements for ensuring pressure relief in the generators are to be found from the following
event of solid matter on the valve and guide are formulae :
to function at a pressure not exceeding 1.25
times the economizer approved design pressure Saturated steam safety valves
and are to have sufficient capacity to prevent
damage to the economizer when operating at its AC (p + 1.03)
design heat input level. Full particulars of the E=
proposed arrangements are to be submitted for 98.1
consideration.
Superheated steam safety valves
d) To avoid the accumulation of solid matter
deposits on the outlet side of safety valves and AC (p + 1.03) vs
bursting discs, the discharge pipes and safety E=
valve / bursting disc housings are to be fitted 98.1 vh
with drainage arrangements from the lowest part
and led with a downward gradient to the bilges where,
or to a tank, clear of the economizer, where it
will not pose threat to either personnel or E = the maker's specified peak load
machinery. evaporation, in [kg/hour] (including all
evaporation from waterwalls, integral, or
e) Where a steam receiver is fitted with safety steaming economizers and other heating
valves to relieve the steam output of the surfaces in direct communication with the
economizer and the economizer cannot be boiler). In no case is the designed evaporation
2
isolated from the receiver, the requirements of to be based on less than 29 [kg/m ] hour of
2
3.2.1.9 (b) & (c) may be waived. heating surface for fired boiler and 14.5 [kg/m ]
hour for exhaust gas heated boilers;
3.2.1.10 Full details of the proposed
arrangements to satisfy 3.2.1.9(a) to 3.2.1.9(e) A = for ordinary, high lift or improved high lift
2
are to be submitted for approval. safety valves, the aggregate area, in [mm ], of
the orifices through the seatings of the valves,
3.2.1.11 In case of watertube boilers, each neglecting the area of guides and other
saturated steam drum and each superheater are obstructions;
to be provided with at least one safety valve.
= for full lift safety valves, the net aggregate
2
3.2.1.12 When a boiler is fitted with an integral area, in [mm ], through the seats after deducting
superheater without any intervening stop valve, the area of the guides or other obstructions
the safety valve(s) on the superheater may be when fully lifted;
considered as boiler safety valve(s). The safety
valves are to be so proportioned and positioned C = 4.8 for valves of ordinary type, having a
that when relieving, sufficient steam is forced minimum lift of D/24;
through the superheater to prevent damage to
the heater.
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= 7.2 for valves of high lift type, having a valves to be set to a pressure higher than 3 per
minimum lift of D/16; cent above the design pressure of the boiler.
= 9.6 for valves of improved high lift type 3.2.1.19 Tests for accumulation of pressure are
having a minimum lift of D/12; to be carried out. The boiler pressure is not to
rise more than 10 per cent above the design
= 19.2 for valves of full lift type having a pressure, when the boiler stop valves are closed
minimum lift of D/4; under full firing conditions. The duration of the
accumulation test is to be 15 minutes for smoke-
D = bore of valve seat [mm]; tube boilers and 7 minutes for water-tube
boilers. During this test, no more feed water is to
p = design pressure, in bar; be supplied than is necessary to maintain a safe
working water level.
3
= specific volume of saturated steam [m /kg];
3.2.1.20 For ordinary, high lift and improved high
Vh = specific volume of superheated steam lift type valves, the cross-sectional area of the
3
[m /kg]. waste steam pipe and passages leading to it is
to be at least 10 per cent greater than the
3.2.1.16 When the discharge capacity of a aggregate area of the safety valves as used in
safety valve of approved design has been the formulae in 3.2.1.15. For full lift and other
established by type tests, carried out in the approved valves of high discharge capacity, the
presence of the Surveyors or by an independent cross-sectional area of the waste steam pipe
authority recognized by IRS, on valves and passages is to be not less than 0.1C times
representative of the range of sizes and the aggregate valve area.
pressures intended for marine application,
consideration will be given to the use of a 3.2.1.21 The cross-sectional area of the main
constant higher than C=19.2, based on 90 per waste steam pipe is to be not less than the
cent of the measured capacity up to a maximum combined cross-sectional areas of the branch
of C = 45 for full lift safety valves. waste steam pipes leading thereto from the
boiler safety valves. In case of water tube
3.2.1.17 Where boilers are not fitted with boilers, each boiler should have a separate
superheater, the safety valves are to be set to waste steam system to atmosphere.
open at a pressure of not more than 3 per cent
above the approved design pressure, and in no 3.2.1.22 Waste steam pipes are to be led to the
case at a pressure higher than : atmosphere and are to be adequately supported
and provided with suitable expansion joints,
a) the design pressure of the steam piping; or bends or other means to relieve the safety valve
chests of undue loading.
b) the least sum of the design pressure of the
machinery connected to the boiler and the 3.2.1.23 The scantlings of waste steam pipes
pressure drop in the piping between this and silencers are to be suitable for the
machinery and the boiler. maximum pressure to which the pipes may be
subjected in service, and in any case not less
3.2.1.18 Where boilers are fitted with than 10.0 bar.
superheaters, the safety valves on the
superheaters are to be set to a pressure not 3.2.1.24 Silencers fitted to waste steam pipes
higher than : are to be so designed that the clear area
through the baffle plates is not less than that
a) the design pressure of the steam piping; or required for pipes.
b) the least sum of the design pressure of the 3.2.1.25 The safety valves of each exhaust gas
machinery connected to the boiler and the heated economizer/and each exhaust gas
pressure drop in the piping between this heated boiler which may be used as an
machinery and the boiler. economizer are to be provided with entirely
separate waste steam pipes.
The safety valves on the boiler drum are to be
set to a pressure not less than the superheater 3.2.1.26 External drains and exhaust steam
valve setting plus 0.35 bar plus the pressure vents to atmosphere are not to be led to waste
drop through the superheater, when the boiler steam pipes.
stop valves are closed and the superheater
safety valves are relieving at their rated
capacity. In no case, however, are the safety
Indian Register of Shipping
Chapter 5 Part 4
Page 38 of 41 Boilers and Pressure Vessels
3.2.1.27 It is recommended that a scale trap and discharge from safety valves or fusion plugs on
means for cleaning be provided at the base of air receivers is to be led to open deck outside
each waste steam pipe. machinery spaces, alternatively, the quantity of
gas for fire fighting purposes is to be increased
3.2.1.28 In installations operating with a high to such an extent that the efficiency of the fire
degree of superheat, consideration is to be extinguishing installation is not affected.
given to the high temperatures which waste
steam pipes, silencers and surrounding spaces 3.3 Stop valves
will attain when the superheater safety valves
are blowing during accumulation tests and in 3.3.1 Boilers and steam generators
service. Adequate protection against heat
effects is to be provided to Surveyor's 3.3.1.1 One main stop valve is to be fitted to
satisfaction. each boiler and located as near the boiler as
practicable. There are to be as few auxiliary stop
3.2.1.29 Waste steam pipes are to be led well valves as possible so as to avoid piercing the
clear of electric cables and any parts or boiler shell than is absolutely necessary.
structures sensitive to heat or likely to distort,
the pipes are to be insulated where necessary. 3.3.1.2 Where two or more boilers are
connected together :
3.2.2 For pressure vessels other than boilers
and steam generators a) the steam connections for each boiler are to
be provided with two stop valves with a
3.2.2.1 Each pressure vessel system or each drain connection between them. The valve
pressure vessel which can be isolated, is to be nearest to the boiler is to be a non-return
provided with arrangements to prevent valve;
overpressure.
b) essential services are to be capable of
3.2.2.2 Pressure vessels intended to operate being supplied from at least two boilers.
completely filled with liquid are to have a liquid
relief valve unless otherwise protected against 3.3.2 Pressure vessels other than boilers and
overpressure. steam generators
3.2.2.3 Where a pressure vessel is fitted with 3.3.2.1 Each pressure vessel or system is to be
heating coils, and fracture in the coils may fitted with a stop valve situated as close as
increase the normal pressure of fluid in the possible to the shell.
pressure vessel, the relieving capacity of the
safety device is to be sufficient to take into 3.4 Water level indicators
account the fracture of one tube.
3.4.1 Every boiler and steam-heated steam
3.2.2.4 The total capacity of the safety valves, generator is to be fitted with at least two
fitted to any pressure vessel or system of independent means of indicating the water level
pressure vessels, is to be sufficient to discharge in it, one of which is to be a gauge glass. The
the maximum quantity of fluid (liquid or gaseous) other means is to be either an additional gauge
that can be generated or supplied without glass or an approved equivalent device.
causing a rise in the pressure of more than 10
per cent above the design pressure. 3.4.2 Where a steam and water drum exceeding
4 [m] in length is fitted athwartships, two gauge
3.2.2.5 The safety valves are to be set to open glasses are to be fitted in suitable positions, one
at a pressure of not more than 3 per cent above near each end of the drum.
the design pressure.
3.4.3 The water gauges are to be readily
3.2.2.6 The use of bursting discs or a accessible and placed so that the water level is
combination of bursting discs and safety valves clearly visible. The lowest visible part of the
instead of safety valves is subject to special glass of the water gauge is to be situated at the
consideration in each case. lowest safe working water level.
3.2.2.7 The discharge from safety valves is to be a) In the case of water-tube boilers, the water
led to a place where no hazard will be created gauge glasses are to be located so that
by the contents being discharged. water is just showing when the water level in
the steam drum is just above the top row of
3.2.2.8 Where a gas is used for fire tubes when the boiler is cold (generally
extinguishing in the machinery spaces, the about 25 [mm] above).
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3.5 Low water level fuel shut-off and alarm
b) In water-tube boilers, the tubes of which are
not entirely drowned when cold, the water 3.5.1 Each fired boiler is to be fitted with a
gauge glasses are to be placed, to the system of water level detection which is to be
Surveyor's satisfaction, in the positions independent of any other mounting on the boiler
which have been found by experience to and which will operate audible and visible
indicate satisfactorily that the water content alarms and shut-off automatically the fuel supply
is sufficient for safety when the boiler is to the burners when the water level falls to a
worked under all service conditions. predetermined low level.
c) The level of the highest part of the effective 3.6 Feed check valves
heating surfaces, e.g. combustion chamber
top of a horizontal boiler and the furnace 3.6.1 Each main boiler or auxiliary boiler for
crown of a vertical boiler, is to be clearly essential services and each steam-heated
marked in a position adjacent to the water steam generator is to have two independent
gauge glass. feed pipes; each feed pipe is to be provided with
two feed check valves. Boiler heated exclusively
3.4.4 The length of the water gauge glasses is by exhaust gases may have only one feed pipe
to be sufficient for verifying the water levels in and with one feed check valve.
case of alarm and oil supply cut-off.
3.6.2 The feed check valves are to be attached,
3.4.5 The cocks of all water gauges are to be wherever practicable, direct to the boiler, but
operable from positions free from danger in the where the arrangements necessitate the use of
event of the glass breaking. standpipes between the boiler and the check
valves, these pipes are to be of steel or other
3.4.6 If the water gauges are not fitted directly to approved material. For boiler feed water
the shell of the boiler, but to stand pillars or systems, See Ch.3, Sec.6.
columns, it is desirable that these pillars or
columns should be bolted directly to the shell of 3.6.3 In boilers, where economizer forms an
the boiler. If they are connected to the boiler by integral part of the boiler, and where the
means of pipes, the pipes are to be fitted with arrangements necessitate the use of a common
terminal cocks, not valves, secured direct to the inlet pipe on the economizer for both main and
boiler shell. auxiliary feed systems, this pipe is to be as short
as practicable, and the arrangement of check
a) For boilers exceeding 3 [m] in diameter, the valves is to be such that either feed line can be
pillars are to be not less than 63 mm, and effectively isolated without interruption of the
the connecting pipes not less than 38 [mm] feed water supply to the boiler.
internal diameter. For boilers exceeding 2.3
[m] but not exceeding 3 [m] in diameter, the 3.6.4 The feed check valves are to be fitted with
pillars are to be not less than 50 [mm] and efficient gearing, whereby they can be
the pipes not less than 32 [mm] internal satisfactorily worked from the stokehold floor, or
diameter. other convenient position.
b) The upper ends of the connecting pipes are 3.6.5 Standpipes on boiler, for feed inlet, are to
to be so arranged that there is no pocket or be designed with an internal pipe to prevent
bend where an accumulation of water from direct contact between the feed pipe and the
the condensation of the steam can lodge. boiler shell or end plates with the object of
They should not pass through the uptake if minimizing thermal stresses in these plates.
they can be otherwise arranged. If, Similar arrangements are to be provided for
however, this condition cannot be complied desuperheater and other connections, where
with, they may pass through it by means of significant temperature difference occur in
a passage at least 50 [mm] clear of the pipe service.
all round, open for ventilation.
3.7 Pressure gauges For cylindrical boilers the size of the valve may
be generally 0.0085 times the diameter of the
3.7.1 Each boiler and superheater is to be boiler.
provided with a steam-pressure gauge.
3.8.4 Blow-down valves and scum valves
3.7.2 The pressure gauges are to be placed (where the latter are fitted) of two or more boiler
where they are easily read. The highest may be connected to one common discharge,
permissible working pressure is to be marked off but where thus arranged there are to be screw-
on pressure gauge in red. down non- return valves fitted for each boiler to
prevent the possibility of the contents of one
3.8 Blow-down and scum valves boiler passing to another.
3.8.1 Each boiler is to be fitted with at least one 3.8.5 The blow-down cock or valve on the ship's
blow-down valve secured to the lower part of the side is to be fitted in a readily accessible
boiler. position, above the level of the floor plates, and
is to be arranged such that it can be readily
3.8.2 Where it is not practicable to attach the seen whether it is open or shut. The cock handle
blow-down valve direct to water-tube boilers, the is not to be removable unless the cock is shut,
valve may be placed immediately outside the and if a valve is fitted, the wheel is to be fixed to
boiler casing with a steel pipe of substantial the spindle.
thickness fitted between the boiler and valve.
The pipe and valve are to be suitably supported 3.9 Salinometer valve or cock
and any pipe which may be exposed to direct
heat from the furnace is to be adequately 3.9.1 Each boiler is to be provided with a
protected. salinometer valve or cock secured direct to the
boiler in a convenient position. The valve or
3.8.3 The blow-down valve and its connections cock is not to be on the water gauge standpipe.
to the sea need not be more than 38 [mm], and
is to be not less than 19 [mm] internal diameter.
Section 4
Hydraulic Tests
where,
End of Chapter
Chapter 6
Steering Gear
Contents
Section
1 General
2 Performance
3 Construction and Design
4 Steering Control Systems
5 Electric Power Circuits, Electric Control Circuits, Monitoring and Alarms
6 Emergency Power
7 Testing and Trials
8 Additional Requirements
9 Guidelines for the Acceptance of Non-duplicated Rudder Actuators for Tanker,
Chemical Tankers or Gas Carriers of 10,000 tons gross and upwards but of less
than 100,000 tonnes Deadweight
Section 1
General
1.2.1 Steering gear control systems means c) in the case of other hydraulic steering gear,
the equipment by which orders are transmitted a driving engine and connected pump.
from the navigating bridge to the steering gear
power units. Steering gear control systems IR1.2.3 For the purposes of non-traditional
comprise transmitters, receivers, hydraulic steering arrangements such as azimuthing
control pumps and their associated motors, propellers, waterjets, etc, the above definitions
motor controllers, piping and cables. may be applied as appropriate. The steering
gear power unit relates to the equipment for
changing the direction of thrust and does not a) Readily accessible and, as far as
include those for generating the thrust. practicable separated from machinery
spaces;
1.2.4 Auxiliary steering gear means the
equipment other than any part of the main b) Provided with suitable arrangements to
steering gear necessary to steer the ship in the ensure working access to steering gear
event of failure of the main steering gear but not machinery and controls. These
including the tiller, quadrant or components arrangements are to include handrails and
serving the same purpose. gratings or other non-slip surfaces to ensure
suitable working conditions in the event of
1.2.5 Power actuating system means the hydraulic fluid leakage.
hydraulic equipment provided for supplying
power to turn the rudder stock, comprising a 1.5 Plans
steering gear power unit or units, together with
associated pipes and fittings, and a rudder 1.5.1 Before starting construction, all relevant
actuator. The power actuating systems may plans and specifications are to be submitted for
share common mechanical components, i.e. approval in triplicate.
tiller, quadrant and rudder stock, or components
serving the same purpose. 1.5.2 These plans should give details of
scantlings and materials of the steering gear
1.2.6 Maximum ahead service speed means together with proposed rated torque and all relief
the greatest speed which the ship is designed to valve settings.
maintain in service at sea at her deepest
seagoing draught. 1.6 Materials
1.2.7 Rudder actuator means the compo- 1.6.1 All the steering gear components the
nent(s) which converts directly hydraulic rudder stock and/or components of other
pressure into mechanical action to move the steering arrangements for directional control are
rudder. to be of sound and reliable construction to the
Surveyor's satisfaction of IRS.
1.2.8 Maximum working pressure means the
expected pressure in the system when steering 1.6.2 All components transmitting mechanical
gear is operated to comply with 2.1.2(b). forces to the rudder stock are to be tested
according to the requirements of Pt.2.
1.2.9 Declared steering angle limits in the
case of non-traditional steering arrangements 1.6.3 Ram; cylinders; pressure housing of rotary
such as azimuthing propellers, waterjets, etc. vane type actuators; hydraulic power piping;
are the operational limits in terms of maximum valves; flanges and fittings; and all steering gear
steering angle, or equivalent, according to components transmitting mechanical forces to
manufacturers guidelines for safe operation, the rudder stock (such as tillers, quadrants, or
also taking into account the vessel’s speed or similar components) are to be of steel or other
propeller torque/speed or other limitation. The approved ductile material, duly tested in
"declared steering angle limits" are to be accordance with the requirements of Pt.2. In
declared by the directional control system general, such material is not to have an
manufacturer for each ship specific non- elongation of less than 12 per cent nor a tensile
2
traditional steering mean. Ship's manoeuvrability strength in excess of 650 [N/mm ]. The use of
tests, such as Res. MSC.137(76) are to be ductile (nodular) iron castings will be acceptable
carried out with steering angles not exceeding provided the material has an elongation of not
the declared steering angle limits. less than 12 per cent.
Section 2
Performance
2.1 Requirements for traditional type of more than 60 seconds with the ship at its
steering gears deepest seagoing draught and running
ahead at one half of the maximum ahead
2.1.1 Unless the main steering gear comprises service speed or 7 knots, whichever is the
of two or more identical power units, in greater; and
accordance with 2.1.4 or 8.1.1, every ship is to
be provided with a main steering gear and an c) Operated by power where necessary to
auxiliary steering gear in accordance with the meet the requirements of (b) and in any
requirements of the Rules. The main steering case when the Rules, excluding
gear and the auxiliary steering gear are to be so strengthening for navigation in ice, require a
arranged that the failure of one of them will not rudder stock over 230 [mm] diameter in way
render the other one inoperative. of the tiller. (See 2.1.1).
The rudder stock diameters mentioned in 2.1.4 Where the main steering gear comprises
2.1.2c), 2.1.3c) and 6.1.1 are to be taken as two or more identical power units, an auxiliary
having been calculated for mild steel with yield steering gear need not be fitted, provided that :
2
strength of 235 [N/mm ].
a) In a passenger ship, the main steering gear
2.1.2 The main steering gear and rudder stock is capable of operating the rudder as
are to be : required by 2.1.2 (b) while any one of the
power units is out of operation;
a) Of adequate strength and capable of
steering the ship at maximum ahead speed b) In a cargo ship, the main steering gear is
which is to be demonstrated in accordance capable of operating the rudder as required
with 7.2; by 2.1.2 (b) while operating with all power
units;
b) Capable of putting the rudder over from 35°
on one side to 35° on the other side with the c) The main steering gear is arranged so that
ship at its deepest seagoing draught and after a single failure in its piping system or in
running ahead at maximum ahead service one of the power units the defect can be
speed and under the same conditions, from isolated so that steering capability is
35° on either side to 30° on the other side in regained.
not more than 28 seconds;
2.1.5 Main and auxiliary steering gear power
c) Operated by power where necessary to units are to be:
meet the requirements of (b) and in any
case when the Rules, excluding a) Arranged to re-start automatically when
strengthening for navigation in ice, require a power is restored after a power failure;
rudder stock over 120 [mm] diameter in way
of the tiller (See 2.1.1); and b) Capable of being brought into operation
from a position on the navigating bridge. In
d) So designed that they will not be damaged the event of a power failure to any one of
at maximum astern speed; however, this the steering gear power units, an audible
design requirement need not be proved by and visual alarm is to be given on the
trials at maximum astern speed and navigating bridge;
maximum rudder angle.
c) Arranged so that transfer between units can
2.1.3 The auxiliary steering gear is to be : be readily effected.
a) Of adequate strength and capable of 2.1.6 Steering gear, other than of the hydraulic
steering the ship at navigable speed and of type, will be accepted provided the standards
being brought speedily into action in an are considered equivalent to the requirements of
emergency: this Section.
b) Capable of putting the rudder over from 15 2.1.7 Manually operated gears are only
on one side to 15 on the other side in not acceptable when the operation does not require
2.2.1 For a ship fitted with multiple steering b) In a cargo ship, the main steering
systems, such as but not limited to azimuthing arrangements are capable of operating the
propulsors or water jet propulsion systems, the ship’s directional control system as
requirement in 2.1.1 is considered satisfied if required by paragraph 2.2.2.b while
each of the steering systems is equipped with its operating with all power units;
own steering gear.
c) The main steering arrangements are
2.2.2 The main steering arrangements for ship arranged so that after a single failure in its
directional control are to be: piping or in one of the power units the
defect can be isolated so that steering
a) of adequate strength and capable of capability can be maintained or speedily
steering the ship at maximum ahead speed regained.
which is to be demonstrated in accordance
with 7.2 (Also refer Ch.4, Sec.9); 2.2.5 In a ship fitted with multiple steering
systems, such as but not limited to azimuthing
b) capable of changing direction of the ship’s propulsors or water jet propulsion systems, an
directional control system from one side to auxiliary steering gear need not be fitted,
the other at declared steering angle limits at provided that :
an average rotational speed of not less than
2.3°/s with the ship running ahead at a) In a passenger ship, each of the
maximum ahead service speed; steering systems is fitted with two or
more identical power units, capable of
c) for all ships, operated by power; satisfying the requirements in 2.2.2.b
while any one of the power units is out
d) so designed that they will not be of operation;
damaged at maximum astern speed (Also
refer Ch.4, Sec.9); b) In a cargo ship, each of the steering
systems is fitted with one or more
2.2.3 The auxiliary steering arrangements for identical power units, capable of
ship directional control are to be: satisfying the requirements in 2.2.2.b
while operating with all power units;
a) of adequate strength and capable of
steering the ship at navigable speed and of c) Each of the steering systems is
being brought speedily into action in an arranged so that after a single failure in
emergency: its piping or in one of the power units,
ship steering capability (but not
b) capable of changing direction of the ship’s individual steering system operation)
directional control system from one side to can be maintained or speedily regained
the other at declared steering angle limits at (e.g. by the possibility of positioning the
an average rotational speed, of not less failed steering system in a neutral
than 0.5°/s; with the ship running ahead at position in an emergency, if needed).
one half of the maximum ahead service
speed or 7 knots, whichever is the greater; 2.2.6 Main and auxiliary steering gear power
and units are to be:
c) for all ships, operated by power where a) Arranged to re-start automatically when
necessary to meet the requirements of power is restored after a power failure;
2.2.3.b and in any ship having propulsive
power of more than 2,500 kW per thruster b) Capable of being brought into operation from
unit. a position on the navigating bridge. In the event
of a power failure to any one of the steering gear
2.2.4 Where the main steering arrangements for power units, an audible and visual alarm is to be
ship directional control comprises two or more given on the navigating bridge;
identical power units, auxiliary steering
arrangements need not be fitted, provided that:
Indian Register of Shipping
Chapter 6 Part 4
Page 6 of 14 Steering Gear
Section 3
3.1.1 Rudder actuators other than those covered σB = specified minimum tensile strength of
by 8.3 and Sec.9 are to be designed in material at ambient temperature
accordance with the relevant requirement of
Ch.5 for Class 1 pressure vessels σY = specified minimum yield stress or 0.2 per
(notwithstanding any exemptions for hydraulic cent proof stress of the material, at ambient
cylinders). temperature
3.1.2 Accumulators, if fitted, are to comply with A and B are given by the following table :
the requirements of Ch.5.
3.2.6 Hydraulic power operated steering gears a) The setting pressure is not to be less than
are to be provided with the following :- 1.25 times the maximum working pressure.
Section 4
4.1.3 The angular position of the rudder is to : IR4.2.3.3 Steering mode selector switch
a) If the main steering gear is power operated, If a joint steering mode selector switch (uniaxial
be indicated on the navigating bridge. The switch) is employed for both steering gear
rudder angle indication is to be independent control systems, the connections for the circuits
of the steering gear control system. of the control systems are to be divided
accordingly and separated from each other by
b) Be recognizable in the steering gear an isolating plate or by air gap.
compartment.
IR4.2.3.4 Follow-up amplifier
4.1.4 Appropriate operating instructions with a
block diagram showing the change-over In the case of double follow-up control, the
procedures for steering gear control systems amplifiers are to be designed and fed so as to
and steering gear actuating systems are to be be electrically and mechanically separated. In
permanently displayed in the wheelhouse and in the case of non follow-up control and follow-up
the steering gear compartment. control, it is to be ensured that the follow-up
amplifiers are protected selectively
4.1.5 Where the system failure alarms for
hydraulic lock (See Ch.7) are provided, IR4.2.3.5 Additional control systems
appropriate instructions are to be placed on the
navigating bridge to shut down the system at Control circuits for additional control systems,
fault. e.g. steering lever or autopilot are to be
designed for all pole disconnection.
IR4.2 Mechanical, hydraulic and electrical
independency and failure detection and IR4.2.3.6 Feed-back units and limit switches
response of steering control systems
The feed-back units and limit switches, if any,
IR4.2.1 Two independent steering gear control for the steering gear control systems are to be
systems are to be provided and so arranged that separated electrically and mechanically
a mechanical, hydraulic or electrical failure in connected to the rudder stock or actuator
one of them will not render the other one separately.
inoperative.
IR4.2.3.7 Hydraulic control components
IR4.2.2 The term “steering gear control system”
as defined in 1.2.1 is to be understood as Hydraulic system components in the power
“steering control system” covering “the actuating or hydraulic servo systems controlling
equipment required to control the steering gear the power systems of the steering gear (e.g.
power actuating system”. solenoid valves, magnetic valves) are to be
considered as part of the steering gear control
IR4.2.3 Separation of control systems and system and are to be duplicated and separated.
components
Hydraulic system components in the steering
gear control system that are part of a power unit
may be regarded as being duplicated and
separated when there are two or more separate
Indian Register of Shipping
Rules and Regulations for the Construction and Classification of Steel Ships - 2014
Page 9 of 14
___________________________________________________________________________________
power units provided and the piping to each
power unit can be isolated. Guidance Note:
“Hydraulic locking” includes all situations where
IR4.2.4 Failure detection and response of two hydraulic systems (usually identical) oppose
control systems each other in such a way that it may lead to loss
of steering. It can either be caused by pressure
IR4.2.4.1 Failure detection in the two hydraulic systems working against
each other or by hydraulic “by-pass” meaning
IR4.2.4.1.1 The most probable failures that may that the systems puncture each other and cause
cause reduced or erroneous system pressure drop on both sides or make it
performance are to be detected and are to impossible to build up pressure.
consider at least the following:
IR4.2.4.1.2 Alternatively to IR4.2.4.1.1 ii) and iii)
i) Power supply failure depending on the rudder characteristic, critical
ii) Loop failures in closed loop deviations between rudder order and response
systems, both command and are to be indicated visually and audibly as
feedback loops (normally short steering failure alarm on the navigating bridge.
circuit, broken connections and
earth faults) The following parameters are to be monitored:
iii) If programmable electronic systems
are used: Direction : Actual rudder position follows
the set value
1. data communication errors Delay : Rudder’s actual position
2. computer hardware and reaches set position within
software failures acceptable time limits
Accuracy : The end actual position is to
Also refer to Ch.7, 6.4 system correspond to the set value
category III). within the design offset
iv) Hydraulic locking considering order tolerances
given by steering wheel or lever.
IR4.2.4.1.3 System response upon failure
All failures detected are to initiate an audible
and visual alarm on the navigation bridge. The most probable failures, e.g. loss of power or
Hydraulic locking is to be always warned loop failure is to result in the least critical of any
individually as required in Ch.7, Table 1.9.1, new possible conditions.
unless system design makes manual action
unnecessary.
Section 5
5.1.2 Circuits obtaining their power supply via an 5.1.4 Each electric or electrohydraulic steering
electronic converter, e.g. for speed control and gear comprising one or more power units is to
which are limited to full load current for be served by at least two exclusive circuits fed
continuous rating are exempt from the directly from the main switchboard; however one
requirement to provide protection against of the circuits may be supplied through the
Section 6
Emergency Power
Section 7
Section 8
Additional Requirements
8.1 For tankers, chemical tankers or gas fluid from one system is to be capable
carriers of 10,000 tons gross and upwards of being detected and the defective
and every ship of 70,000 tons gross and system automatically isolated so that
upwards the other actuating system or systems
remain fully operational.
8.1.1 The main steering gear is to comprise two
or more identical power units complying with the c) Steering gears other than of the hydraulic
provisions of 2.1.4. type are to achieve equivalent standards.
8.2 For tankers, chemical tankers or gas 8.3 For tankers, chemical tankers or gas
carriers of 10,000 tons gross and upwards carriers of 10,000 tons gross and upwards
but of less than 100,000 tonnes deadweight
8.2.1 Subject to 8.3, the following are to be
complied with : 8.3.1 Solutions other than those set out in 8.2.1
which need not apply the single failure criterion
a) The main steering gear is to be so arranged to the rudder actuator or actuators, may be
that in the event of loss of steering capability permitted provided that an equivalent safety
due to a single failure in any part of one of standard is achieved and that:
the power actuating systems of the main
steering gear, excluding the tiller, quadrant a) Following loss of steering capability due to a
or components serving the same purpose, single failure of any part of the piping
or seizure of rudder actuators, steering system or in one of the power units, steering
capability is to be regained in not more than capability is regained within 45 seconds;
45 seconds after the loss of one power and
actuating system.
b) Where the steering gear includes only a
b) The main steering gear is to comprise single rudder actuator special consideration
either; is given to stress analysis for the design
including fatigue analysis and fracture
i) two independent and separate power mechanics analysis, as appropriate, the
actuating systems, each capable of material used, the installation of sealing
meeting the requirements of 2.1.2 (b); arrangements and the testing and
or inspection and provision of effective
maintenance. In consideration of the
ii) at least two identical power actuating foregoing, regard will be given to the
systems which, acting simultaneously "GUIDELINES" in Sec.9.
in normal operation are capable of
meeting the requirements of 2.1.2(b). 8.3.2 Manufacturers of steering gear who intend
Where necessary to comply with their product to, comply with the requirements of
these requirements, inter- connection the Sec.9 are to submit full details when plans
of hydraulic power actuating systems are forwarded for approval.
is to be provided. Loss of hydraulic
Section 9
End of Chapter
Chapter 7
Control Engineering
Contents
Section
1 General
2 Control - System Characteristics
3 Requirements for various Machinery Installations
4 Tests and Trials
5 Machinery Operated from a Centralised Control Station – ‘CCS’ Notation
6 Programmable Electronic Systems
Section 1
General
1.1.1 The requirements of this Chapter are in 1.2.1 When it is desired to fit a centralized
general to be complied with for all machinery control system having one or more control
plants where instrumentation is required locations and embodying various degrees of
according to other Chapters of the Rules. In automatic and remote control of the propulsion
addition, the requirements apply to the following, plant or associated ship's service systems, the
when installed :- control and monitoring systems are to be
designed, assembled and installed in
a) remote control systems for propulsion accordance with the requirements given in
machinery, controllable pitch propeller, and Section 5, to assure operation as effective as
steering gear; could be obtained with the same systems
arranged for manual control and monitoring by
b) safety systems for propulsion plants and watchkeeping personnel.
electric power generating plants;
1.3 Plans and particulars
c) instrumentation equipment of boiler plants.
1.3.1 Plans and specifications for the control
d) Safety systems for emergency diesel systems, are to be submitted, in triplicate, for
engines. approval and are to at least include the following
information:
1.1.2 For vessels intended to operate with
unattended machinery spaces, refer to Pt.5. a) machinery arrangement plans showing
locations control in relation to controlled
1.1.3 Alarm systems are to satisfy the units;
environmental requirements of IRS
Classification Notes “Type Approval of Electrical b) arrangements and details of control
Equipment used for Control, Protection, Safety consoles including front views, installation
and Internal Communication in Marine arrangements together with schematic
Environment”. diagrams for all power, control and
monitoring systems including their functions;
1.4 Operational guidance manual 1.6.1.2 Effective means are to be provided for
monitoring and controlling direction of rotation or
1.4.1 An operational guidance manual is to be propeller pitch and speed of propeller for the
provided on board the vessel for reference and safe operation of the plant from standby
is to contain the necessary system technical condition at departure through normal operation
information and give operating instructions for to "finished with engines" at the end of the
normal and emergency operations. voyage.
1.6.3 Order of control-location command 1.9.1.1 Instrumentation and alarms at the main
control location are to provide all information
1.6.3.1 When the propulsion machinery is necessary for monitoring the operation of the
arranged to be controlled from two or more propulsion, electrical and emergency systems,
locations, the main control location is to have generally in accordance with Table 1.9.1.
means for transferring control from a secondary
location to the main location at all times and 1.9.2 Secondary control location
blocking any unauthorized control from any
secondary location. Consideration will be given 1.9.2.1 Instrumentation and alarms for the
to special cases where it may be necessary for bridge control locations and other secondary
a secondary control location to have command control locations are to be generally in
over control transfers between control locations. accordance with Table 1.9.2.
1.6.4.1 Transfer of control from one location to 1.10.1 The alarms and displays required by
another, except as required by 1.6.3.1, is to be Table 1.9.1 and Table 1.9.2 for essential
possible only with acknowledgement by the services are to be readily distinguishable from
receiving locations. The main control location other alarms (e.g. fire alarm) and are to be
and the secondary control location are to have grouped functionally in so far as practicable.
an indicator showing which location is in control. Alarms are to have individual visual presentation
with preferably a common audible signal.
1.7 Secondary control locations
1.10.2 In general, alarms and displays not
1.7.1 In general, secondary control locations for required by Table 1.9.1 and Table 1.9.2 or not
the control of propulsion machinery from the concerned with the management of the
bridge or other locations on board are to be kept propulsion machinery (non- essential alarms)
as simple as possible and provided with only are to be grouped separately from the essential
those indicators and controls necessary for the alarms. Audible signals for non-essential alarms,
effective control of speed and direction of the if provided, are to be of a character distinct from
propulsion engines, and of the controllable-pitch that for essential alarms.
propeller where fitted, for normal operation.
1.10.3 The number of colours used to indicate
1.7.2 Precautions are to be taken to ensure that status of plant operation is to be kept to a
the engine is not normally operated in a barred minimum. A uniform code is to be used so that
speed range. like colours indicate like functions or status of
operation in the controlled plant or system.
1.7.3 If the control system automatically shuts
down the main propulsion engine for any 1.10.4 Alarm systems are to be designed so that
reason, this is to be alarmed at the main control they cannot remain deactivated when the
location and each secondary control location. monitoring system has returned to the normal
Restoration of normal operating conditions is to running condition. Alarm systems are to provide
be possible only after manual reset. Automatic both audible and visual alarm upon each fault
restarting is not to be possible. condition. Alarms, due to fault condition in
machinery, are to remain active until
1.8 Control console construction acknowledged and if arrangements are made to
mute audible alarms they are not to extinguish
1.8.1 Control consoles are to be preferably self- visual alarms. Acknowledgement of visual
supported with the sides and backs suitably alarms is to be clearly indicated. Alarms are to
protected. Where necessary, protection is to be be of the self-monitoring type so that a circuit
provided for consoles which might be subject to failure will cause an alarm condition and are to
damage by leaks or falling objects. have provisions for testing all audible and visual
alarms and indicating lamps.
Table 1.9.1 : Displays, indications and alarms for main control location
Alarm
System Remote Display Remarks
activation
Main boilers
Main steam superheater Temperature
1 High -
outlet Pressure
Pressure Low
2 Fuel oil to burners -
Viscosity (temperature) High (low)
3 Master fuel oil cut-off valve - Closed -
4 Atomizing medium Pressure Outside limits -
5 Forced draft Pressure (water column) Failure -
6 Water level Level High, low
-
Low-low
7 Feed pump discharge Pressure -
8 Feed water salinity Salinity - -
Main turbine
1 Steam, ahead chest Pressure - -
2 Steam, astern chest Pressure - -
3 Steam, gland steam Pressure - -
L.O. to turbines and Temperature High
4 -
reduction gears Pressure Low
5 L.O. sump level - Low -
6 L.O. gravity tank Level Low -
Bearings, turbine, thrust and
7 Temperature High -
reduction gear (individual)
8 Main condensate pump Running Failure -
9 Main condenser Vacuum Low -
10 Main circulator Running Failure -
11 Condensate level - High -
12 Deaerator feed tank Level Low -
13 Astern guardian valve Position Failure to open -
14 Vibration - Excessive -
15 Rotor axial displacement - Excessive -
16 Shaft roll over - Stopped -
17 Scoop valve Position - -
Main circulator sea suction
18 Position - -
valve
Turbogenerator
L.O. to turbine and reduction Pressure Low
1 -
gear Temperature High
2 Bearings Temperature High -
3 Aux. Condenser Vacuum Low -
4 Aux. Condensate pump Running - -
5 Aux. Circulating pump running - -
Alarm
System Remote Display Remarks
activation
Main diesel engines
Pressure Low
1 L.O. to engine See Note 1
Temperature High
Differential pressure across
2 Pressure High -
L.O. discharge filter
3 L.O. to reduction gear Pressure Low -
4 L.O. at reduction gear Temperature High -
Oil mist concentration in
See Note 2,
5 crankcase or temperature of - High
17
bearings
6 L.O. drain tank level - Low-high See Note 3
7 Cylinder lubrication - Failure See Note 1
8 Cooling water to cylinders Pressure or flow Low See Note 10
9 Cylinder cooling water outlet Temperature High See Note 4
Level of cylinder cooling
10 - Low -
water in expansion tank
11 Piston coolant Pressure Low See Note 5
Flow of piston coolant
through each piston and
Flow, temperature (or Low-high
12 temperature in manifold (or See Note 5
temperature) (high)
temperature of coolant at
each piston outlet)
Level of piston coolant in
13 - Low See Note 5
expansion tank
Pressure Low
14 Fuel valve coolant -
Temperature High
Level of fuel valve coolant in
15 - Low -
expansion tank
16 Sea water coolant Pressure Low See Note 10
17 F.O. to injection pumps Pressure Low -
Low-high
18 F.O. to engine Temperature or viscosity See Note 8
(Low-high)
Level of F.O. in daily service
19 - Low-high See Note 6
tank
20 Charging air Temperature Low-high See Note 7
Deviation of each cylinder
from average and exhaust
21 Temperature High See Note 9
gas temperature of each
engine
Fire in scavenging belt, for
22 - Activated See Note 11
two stoke engines
23 Starting air Pressure Low -
24 Overspeed - Activated -
Alarm
System Remote Display Remarks
activation
Diesel generators
1 F.O. to engines Pressure Failure -
Pressure Low
2 L.O. to engines -
Temperature High
3 Starting air Pressure Low -
4 Exhaust gas Temperature - -
Temperature High
5 Cooling medium, outlet See Note 10
Pressure Low
Level in cooling water
6 expansion tank, if not - Low -
connected to main system
7 overspeed - Activated -
Steering gear
1 Rudder position Indication - See Note 13
2 Steering gear power units - Failure -
Running and stopped Overload and
3 Steering gear motors See Note 14
indication single phase
4 Control system power - Failure -
Steering gear hydraulic oil
5 - Low See Note 15
tank level
6 Auto pilot indication Running indication Failure -
7 Hydraulic lock - Fault See Note 16
Addition services as applicable
1 Control electric power available Failure -
2 Control air supply Pressure Low -
3 Hydraulic control system Pressure Low -
4 Control location in operation In command indication - -
5 Propeller pitch indicator Pitch - -
6 Propeller speed, direction RPM, direction - -
7 Stern tube L.O. tank level - Low -
8 F.O. service or settling tank - Low, high -
F.O. settling tank
9 - High -
temperature
Volts amperes Off limits
10 Generators, ship service -
Frequency High off limits
11 Fuel oil service pump Running - -
12 Console air conditioning - Failure -
13 Automatic shut down - Shut-down -
14 Turning gear Engaged - -
15 Fire main Pressure - -
16 Bilge pump Running - -
17 Bilge level - High -
18 Clutch air or oil pressure - Low -
Notes:
1 Individual alarms are required where separate lubricating oil systems (e.g. for camshaft, rocker
arms, turbocharger, etc.) are installed. For turbochargers with an integrated self-contained oil
lubrication system such alarm is not required.
2 Main bearings and thrust bearings of propulsion engines having a cylinder bore over 300 [mm] are
to be monitored for high temperature by individual sensors connected to a single alarm.
3 Where separate lubricating oil systems are installed, individual level alarms are required for the
tanks.
4 Where one common cooling space without individual stop valves is employed for all cylinder jackets,
one temperature alarm for the common cooling water outlet will be approved.
6 High-level alarm is required only if suitable overflow arrangements are not provided.
7 Both the displays and alarms are not required if automatic temperature control is not necessary.
Low temperature alarm may be replaced by an alarm for water detection in the charging air duct.
9 Alarm for slow speed engines (under 300 RPM) and medium speed engines above 4000 bhp.
12 Alarms required for steering gear need to be fitted only on the bridge.
13 The rudder angle indication is to be on the navigation bridge and independent of the steering gear
control system.
14 Steering gear motors running indicators are to be fitted both on the bridge and main control location.
16 Where more than one system (either power or control) can be operated simultaneously each system
is to be monitored and the system at fault is to be identified.
17 If engine power is ≥ 2250 [kW] or cylinder bore > 300 [mm] following is to be provided:
- Shut down with alarm for medium and high speed engines.
- IRS may permit overriding of auto shut off or slow down arrangements, provided consequences
of overriding auto shut off or slow down are established and documented.
Table 1.9.2 : Displays, indications and alarms for secondary control location
Section 2
2.1.3 The power for monitoring, alarms and 2.2.2 Semiconductor devices are to be selected
emergency action is to be supplied automatically on the basis of expected shipboard ambient air-
from an emergency source upon failure of ship's temperature ranges of 0°C-50°C for interior
service power supply. An audio / visual alarm is compartments and 0°C-60°C inside of consoles.
to be provided at the main control location to Silicon and selenium semiconductor devices are
indicate failure of power supply. to be used in preference to germanium which
may be used, where its characteristics are
2.1.4 Cables and console wiring for control and favoured for a circuit provided care is taken to
monitoring are to be of the flame-retarding type ensure satisfactory operation under shipboard
and are to be stranded except that solid conditions.
conductors may be used in low energy circuits,
where they are properly supported and not 2.2.3 Steady-state voltage variations of 10 per
subject to undue vibration or movements. cent and frequency variations of ± 5 per cent
from the nominal console feeder rating are not
2.2.4 The design and arrangement of all devices 2.3.2 All control piping is to be readily accessible
is to provide ready accessibility to parts and supported so as to protect the piping and
requiring inspection, adjustment or periodic associated accessories from mechanical
replacement. Where devices are parts of sub- damage, vibration and shock. The control piping
circuits assembled in physically-identical is to be suitably marked to indicate the character
modular units for easy mounting on and removal of its service.
from the console, suitable arrangements such
as matched plug-in modules with coded plugs 2.3.3 The hydraulic pumps are to be fitted in
are to be provided to facilitate correct duplicate and have pressure relief protection on
replacement of modules in the console. the discharge side. The pump suctions are to be
from a reservoir of sufficient capacity to contain
2.2.5 Built-in circuitry is to be provided for use in all the fluid when drained from the system,
the testing of module functions. maintain the fluid level at an effective working
height and allow air and foreign matter to
2.2.6 Consideration is to be given to minimize, separate out. The pump suctions are to be sized
as far as practicable, the probability that failure and positioned to prevent cavitation or starvation
of any one component or device in the control of a pump. A duplex filter which can be cleaned
circuitry will cause unsafe operation of the plant. without interrupting the oil supply is to be fitted
on the discharge side of the pumps.
2.2.7 Control levers or wheels are to be readily
identifiable as to function and position and are to 2.4 Pneumatic controls
be arranged for a logical sequence of
operations. Suitable interlocks are to be 2.4.1 Air compressors, actuators, motors and
provided to prevent incorrect operation. accessories are to be suitable for the intended
duty and have working and other parts which will
2.2.8 When logic circuits are used for sequential not be damaged or rendered ineffective by
start-up or for operating individual plant, corrosion.
components, indicators are to be provided at the
control console to show the successful 2.4.2 All control piping is to be readily accessible
completion of the sequence of operations by the and supported so as to protect the piping and
logic circuit and start-up and operation of the associated accessories from mechanical
component. If some particular step is not carried damage, vibration and shock. The control piping
out during the sequence, the sequence is to is to be suitably marked to indicate the character
stop at this point. Manual override is to be fitted of its service.
in vital functions to permit control in case of
failure of a logical circuit. 2.4.3 Compressed air for pneumatic control is to
be available from at least two air compressors.
2.2.9 Electrically-powered actuators for the The starting air system may be used as a
execution of control commands are to be source of control air. The air pressure to the
suitable for shipboard use, and have working pneumatic control system is to be automatically
and other parts which would not be damaged or maintained at the level required for the operation
rendered ineffective by corrosion. The windings of the installation and low air pressure is to set
are to be treated to resist oil and water and the off an alarm at the main control location. Means
enclosures are to be suitable for the location. are to be provided in the delivery from the
The ratings of coils is to be based on ambient air compressors to assure clean, dry and oil-free air
temperature of 50°C when located in the to the pneumatic controls.
machinery spaces and 40°C when located
outside such spaces. The power supply for 2.5 Ship motion effects
electrical actuators is to be from the same
source as the power to the control systems. 2.5.1 All control, actuating, monitoring and alarm
devices are to be able to operate successfully
when inclined at an angle of 30° in any direction 2.6.6 Means of control, independent of the
from the vertical and when subjected to vibratory bridge control system, are to be provided on the
frequencies of 2 to 80 Hz, in conjunction with bridge to enable the propulsion machinery to be
peak to peak amplitudes of 2 [mm] for stopped in an emergency.
frequencies 2 to 13.2 Hz and an acceleration of
0.7 g for frequencies of 13.2 to 80 Hz. Care is to 2.6.7 Audible and visual alarms are to operate
be taken to ensure that mounting arrangements on the bridge and in the locations required by
for the components will not amplify shipboard Pt.5, Ch.22 if any power supply to the bridge
vibrations. control system fails. Where practicable the
preset speed and direction of thrust are to be
2.6 Bridge control for main propulsion maintained until corrective action is taken.
machinery
2.6.8 At least two means of communication are
2.6.1 Where a bridge control system for main to be provided between the bridge and the main
propulsion machinery is to be fitted, the control location in the machinery space. One of
requirements of 2.6.2 to 2.6.8 are to be these means may be the bridge control system;
complied with. the other is to be independent of the main
electrical power supply. See also Pt.4, Ch.1,
2.6.2 Means are to be provided to ensure Sec.2, Cl. 2.5.
satisfactory control of propulsion from the bridge
in both the ahead and astern directions. 2.7 Valve control system
2.6.3 Instrumentation to indicate the following is 2.7.1 Where bilge, ballast, oil fuel transfer and
to be fitted on the bridge: sea valves for engine services are operated by
remote or automatic control, the requirements of
a) Propeller speed. 2.7.2 to 2.7.5 are to be satisfied.
b) Direction of rotation of propeller for a
fixed pitch, propeller or pitch position for 2.7.2 Failure of actuator power is not to permit a
controllable pitch propeller. valve to move to an unsafe condition.
c) Clutch position where applicable.
d) Shaft brake position where applicable. 2.7.3 Positive indication is to be provided at the
e) Engine speed. remote control location for the service to show
the actual valve position or alternatively that the
2.6.4 The propeller speed, direction of rotation valve is fully open or closed.
and, if applicable, the propeller pitch are to be
controlled from the bridge under all normal sea 2.7.4 Equipment located in places which may be
going and manoeuvring conditions. flooded is to be capable of operating when
submerged.
2.6.5 Remote control of the propulsion
machinery is to be from one control location at 2.7.5 A secondary means of operating the
any one time. See also 1.6.3. Main propulsion valves, which may be by local manual control, is
control units on the navigating bridge may be to be provided.
interconnected. Means are to be provided at the
main machinery control location to ensure 2.7.6 For requirements applicable to closing
smooth transfer of control between the bridge appliances on scuppers and sanitary
and machinery control locations. discharges, see Pt.3, Ch.13.
Section 3
indicate that the propeller shaft has been 3.2.4.3 Precautions are to be taken to ensure
stopped too long on a standby or stop that it is not possible to continuously run the
maneuver. main engine in a barred speed range.
3.2.3.1 Automatic control arrangements for gas 3.3.1 These requirements apply to diesel
turbine modules are to be provided to regulate engines which are required to be immediately
the quantity of fuel flowing to the burners during available in an emergency and capable of being
starting, over the operating power range and controlled remotely or automatically operated.
when stopping the gas turbine, in a controlled Information is to be submitted alongwith
manner and with in the safe operating envelope instructions to test alarm and safety systems
of the gas turbine. The arrangement is to have demonstrating compliance with the
provision to collect, condition and transmit both requirements.
primary and secondary surveillance signals to
the local and remote operating locations. 3.3.2 Alarms and safeguards are to be fitted in
accordance with Table 3.3.2.
3.2.3.2 The control system is to be provided with
control functions at the component level to allow 3.3.3 The safety and alarm systems are to be
direct manual control of the fuel flow and engine designed to ‘fail safe’. The characteristics of the
shut down in the event of failure of the electrical ‘fail safe’ operation are to be evaluated on the
power supplies or a critical failure of the engine basis not only of the system and its associated
control system. machinery, but also the complete installation, as
well as the ship.
3.2.3.3 Each gas turbine module is to be
provided control unit comprising of minimum 3.3.4 Regardless of the engine output, if
instrumentation necessary for monitoring, shutdowns additional to those specified in Table
control and surveillance for safe operation both 3.3.2 are provided except for the overspeed
local and remote positions with facility for shutdown, they are to be automatically
transfer of control authority through a suitable overridden when the engine is in automatic or
selector switch. remote control mode during navigation.
The alarms and automatic shut down devices to 3.3.5 The alarm system is to function in
be provided are as indicated in Pt.4, Ch.4, Table accordance with Pt.5, Ch.22, with additional
3.13.1. requirements that grouped alarms are to be
arranged on the bridge. (See Pt.5, Ch.22,
3.2.4 Diesel engines Cl.2.4.14).
3.2.4.1 In the event of the lubricating oil 3.3.6 In addition to the fuel oil control from
pressure dropping to a preset level, there is to outside the space, a local means of engine
be an automatic changeover to a standby shutdown is to be provided.
lubricating oil pump or a reduction in main
engine speed to a predetermined level. In the 3.3.7 Local indications of at least those
event of a loss of lubricating oil pressure parameters listed in Table 3.3.2 are to be
engines are to stop automatically. provided within the same space as the diesel
engines and are to remain operational in the
3.2.4.2 Engine alarms are to be in accordance event of failure of the alarm and safety systems.
with Table 1.9.1 and Table 1.9.2.
Note 1 : For engines having a power of more than 2250 kW or a cylinder bore of more than 300 [mm].
Section 4
Section 5
5.1.2 The arrangements are to be such that 5.2.3 Indication of all essential parameters
corrective actions can be taken at the control necessary for the safe and effective operation of
location in the event of machinery faults, e.g. the machinery is to be provided, e.g.
stopping of machinery, starting of standby temperatures, pressures, tank levels, speeds,
machinery, adjustments of operating powers etc.
parameters, etc. These actions may be effected
by either remote manual or automatic control. 5.2.4 Indication of the operational status of
running and standby machinery is to be
5.1.3 The controls, alarms and safeguards provided.
required by this chapter and Pt.5, Ch.22, as
applicable, are to be provided at the control 5.2.5 At the centralized control station, means of
location. A fire detection system satisfying the communication with the bridge area, the
requirements of Pt.5, Ch.22, Sec.2.13 is, also to accommodation for engineering personnel and if
be provided. necessary, the machinery space are to be
provided.
Section 6
6.1.2 The requirements given in this section do 6.2.9 Access to system configuration, programs
not apply to navigation and loading instruments. and data is to be restricted by physical and/or
logical means providing effective security
6.2 General against unathorised alteration.
6.2.1 Programmable electronic systems are to 6.2.10 Where date and time information is
fulfill the requirements of the system under required by the equipment, this is to be provided
control for all normally anticipated operating by means of a battery powered clock with
conditions, taking into account human safety, restricted access for alteration. Date and time of
environmental impact, damage to vessel as well information is to be fully represented and
as equipment, usability of programmable utilized.
electronic systems and operability of non-
computer devices and systems, etc. 6.2.11 Displays and controls are to be protected
against liquid ingress due to spillage or
6.2.2 Programmable electronic equipment is to spraying.
revert to a defined safe state on initial start up or
re-start in the event of failure. 6.2.12 User interfaces are to be designed in
accordance with appropriate ergonomic
6.2.3 In the event of failure of any principles to meet user needs and enable timely
programmable electronic equipment, the system access to desired information or control of
and any other system to which it is connected, is functions. A system overview is to be readily
to fail to a defined safe state or maintain safe available.
operation, as applicable.
6.2.13 The keyboard is to be divided logically
6.2.4 Where programmable electronic into functional areas. Alphanumeric, paging and
equipment shares resources, e.g. a data specific system keys are to be grouped
communication link, with any control, alarm or separately.
safety system for essential services or safety
critical system, software is to meet the 6.2.14 Where a function may be accessed from
requirements of 6.3.1.5. more than one interface, the arrangement of
displays and controls is to be consistent.
6.2.5 Emergency stops are to be hard-wired and
independent of any programmable electronic 6.2.15 The size, colour and density of
equipment. Alternatively, the system providing information displayed to the operator are to be
emergency stop functions is to comply with the such that information may be easily read from
requirements of 6.3.1.1 and/or 6.3.1.5. the normal operator position under all
operational lighting conditions.
6.2.7 Programmable electronic equipment is to
be provided with self-monitoring capabilities 6.2.16 Display units are to comply with the
such that hardware and functional failures will requirements of International Electro technical
initiate an audible and visual alarm in Commission Standard IEC 950:1991, “Safety of
accordance with the requirements of 1.10 and information technology equipment, including
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Chapter 7 Part 4
Page 18 of 24 Control Engineering
6.5 Data communication links of data communication link which make use of a
shared medium to transfer control, alarm or
6.5.1 Where control, alarm or safety systems safety related data between distributed
use shared data communication links to transfer programmable electronic equipment or systems,
data, the requirements of 6.5.2 to 6.5.12 are to for system Categories II and III.
be complied with. The requirements apply to
local area networks, field buses and other types
6.5.11 The installation is to provide adequate Note : Consideration should be given to system
protection against mechanical damage and operation in the event of port state and local
electromagnetic interference. regulations that pertain to the use of radio-
frequency transmission prohibiting the operation
Notes:
2.3 Failure analysis for safety related functions only (e.g. FMEA)
The analysis is to be carried out using appropriate means, e.g.
- Fault tree analysis
- Risk analysis
- FMEA or FMECA.
The purpose is to demonstrate that for single failures, systems will fail to safety and that systems
in operation will not be lost or degraded beyond acceptable performance criteria when specified
by IRS.
3.2 Analysis regarding existence and fulfillment of programming procedures for safety related
functions
Specific assurance methods are to be planned for verification and validation of satisfaction of
requirements, e.g.
- Diverse programs
- Program analysis and testing to detect formal errors and discrepancies of the description
- Simple structure.
4. Hardware tests
Tests according to Classification Notes “Type Approval of Electrical Equipment used for Control,
Protection, Safety and Internal Communication in Marine Environment” are to be conducted.
Special consideration may be given to tests witnessed and approved by another IACS member
society.
5. Software tests
6. Performance tests
7. On-board tests
7.3 For wireless data communication equipment, tests during harbour and sea trials are to be
conducted to demonstrate that radio-frequency transmission does not cause failure of any
equipment and does not itself fail as a result of electromagnetic interference during expected
operating conditions.
8. Modifications
End of Chapter
Chapter 8
Electrical Installations
Contents
Section
1 General Requirements
2 System Design
3 Cables and Busbar Trunking Systems
4 Switchgear and Control Gear Assemblies
5 Rotating Machines - Construction and Testing
6 Converting Equipment
7 Miscellaneous Equipment
8 Electric Propulsion Systems
9 Crew and Passenger Emergency Safety Systems
10 Ship Safety Systems
11 Electrical Equipment for use in Explosive Gas/Combustible Dust Atmospheres
12 High Voltage Systems
13 Trials
Section 1
General Requirements
1.2.5 Main switchboard is a switchboard which a) Schematic diagram of the electrical system
is directly supplied by the main source of including information such as cable sizes,
electrical power and is intended to distribute type of insulation, normal working currents,
electrical energy to ship's services. line drop of voltages and details of
protection devices together with rating and
1.2.6 Emergency switchboard is a switchboard interrupting capacity of circuit breakers and
which in the event of failure of the main fuses;
electrical power supply system is directly
supplied by the emergency source of electrical b) Calculations of prospective short circuit
power or transitional source of emergency current of main busbars and secondary side
power and is intended to distribute electrical of transformers (Additionally load schedule
energy to the emergency services. is to be submitted for information);
1.2.7 Emergency source of electrical power is c) Construction details, sectional views, type,
a source of electrical power, intended to supply rating, make of rotating machines rated at
the emergency switchboard in the event of 100 [kW] and above, where welding is to be
failure of the supply from the main source of applied to shafts of machines and plans
electrical power. showing the construction;
1.3.4 For refrigerated cargo installations having g) Plans of electric slip couplings, if fitted,
HY class notation, motors are to be tested and showing details of construction and
certificates furnished by the manufacturers. scantlings together with diagrams of control
Motors of 100 [kW] or over are to be surveyed gear and other electrical components;
by the Surveyors during manufacture and
testing. h) For tankers and similar vessels, a general
arrangement of the ship showing hazardous
spaces and the location of the electrical
equipment in such spaces. A schedule of
safe type electrical equipment located in
hazardous spaces giving details of the type
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of equipment fitted, the certifying authority - Control, monitoring and safety
and copies of the certificates. devices/systems of equipment for primary
essential services.
1.4.2 Additional information may be required for
vessels engaged in special services or of a 1.5.1.3 Secondary Essential Services
novel design.
Secondary Essential Services are those
1.5 Essential and other services services which need not necessarily be in
continuous operation to maintain propulsion and
1.5.1 Essential services steering but which are necessary for maintaining
the vessel's safety. Example of equipment for
1.5.1.1 Essential services are divided into secondary essential services are as follows:
following types of services:
- Windlass
a) "Primary Essential Services" and - Fuel oil transfer pumps and fuel oil
treatment equipment
b) "Secondary Essential Services". - Lubricating oil transfer pumps and
lubrication oil treatment equipment
Definitions and examples of such services are - Pre-heaters for heavy fuel oil
given in 1.5.1.2 and 1.5.1.3. - Starting air and control air compressors
- Bilge, ballast and heeling pumps
1.5.1.2 Primary Essential Services - Fire pumps and other fire extinguishing
medium pumps
Primary Essential Services are those services - Ventilating fans for engine and boiler rooms
which need to be in continuous operation to - Services considered necessary to maintain
maintain propulsion and steering. Examples of dangerous spaces in a safe condition
equipment for primary essential services are as - Navigation lights, aids and signals
follows: - Internal safety communication equipment
- Fire detection and alarm system
- Steering gears - Lighting system
- Pumps for controllable pitch propellers - Electrical equipment for watertight closing
- Scavenging air blower, fuel oil supply appliances
pumps, fuel valve cooling pumps, lubricating - Electric generators and associated power
oil pumps and cooling water pumps for main sources supplying the above equipment
and auxiliary engines and turbines - Hydraulic pumps supplying the above
necessary for propulsion equipment
- Forced draught fans, feed water pumps, - Control, monitoring and safety systems for
water circulating pumps, vacuum pumps cargo containment systems
and condensate pumps for steam plants on - Control, monitoring and safety devices /
steam turbine ships, and also for auxiliary systems of equipment for secondary
boilers on ships where steam is used for essential services.
equipment supplying primary essential - Equipment used for cooling and maintaining
services lesser ambient temperature (refer Ch.1,
- Oil burning installations for steam plants on 1.7.4)
steam turbine ships and for auxiliary boilers
where steam is used for equipment 1.5.2 Services such as following are considered
supplying primary essential services necessary for minimum comfortable conditions
- Azimuth thrusters which are the sole means of habitability :
for propulsion/steering and associated
lubricating oil pumps, cooling water pumps - cooking;
- Electrical equipment for electric propulsion
plant with lubricating oil pumps and cooling - heating;
water pumps
- Electric generators and associated power - domestic refrigeration;
sources supplying the above mentioned
equipment - mechanical ventilation;
- Hydraulic pumps supplying the above
mentioned equipment - sanitary and fresh water;
- Viscosity control equipment for heavy fuel
oil - electric generators and associated
power sources supplying the above
mentioned equipment.
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1.5.3 Services such as following, which are in 1.7.2 All connections for current-carrying parts
addition to 1.5.1 and 1.5.2, are considered and earthing connections are to be fixed so that
necessary to maintain the ship in a normal they cannot loosen by vibrations. This also
seagoing operational and habitable condition : applies to fixing of mechanical parts when found
necessary.
- cargo handling and cargo gear
equipment; 1.8 Voltage and frequency variations
- hotel services, other than those required 1.8.1 All electrical appliances supplied from the
for habitable conditions; main or emergency systems are to be so
designed and manufactured that they are
- thrusters, other than those for dynamic capable of operating satisfactorily under the
positioning. normally occurring variations in voltage and
frequency. Unless otherwise stated in national
1.6 Ambient reference conditions or international standards, provided the
variations comply with as stated below, all
1.6.1 For details regarding ambient reference equipment are to operate satisfactorily with the
conditions, See Ch.1. variations from its rated value as shown in the
following Tables 1.8.1 to 1.8.3.
1.7 Vibrations, accelerations
a) For alternating current components; voltage
1.7.1 Electrical equipment is to be constructed and frequency variations shown in Table
to withstand when subjected to following : 1.8.1 are to be assumed.
vibrations within the frequency range 5 - 50 Hz b) For direct current components supplied by
and with vibration velocity amplitude 20 d.c. generators or converted by rectifiers,
[mm/sec]. voltage variations shown in Table 1.8.2 are
to be assumed.
peak accelerations caused by the ship's
movements in waves - ± 0.6 g for vessels of c) For direct current components supplied by
length exceeding 90 [m] and ± 1 g for other electrical batteries, voltage variations shown
vessels. in Table 1.8.3 are to be assumed.
Table 1.8.1 : Voltage and frequency variations for a.c. distribution systems
Parameters Variations
Voltage tolerance (continuous) ±10%
Voltage cyclic variation deviation 5%
Voltage ripple (a.c., r.m.s., over steady d.c. voltage) 10%
Systems Variations
Components connected to the battery during charging (see Note)
+30%, -25%
Components not connected to the battery during charging
+20%, -25%
1.8.2 Any special system, e.g. electronic circuits, 1.9.6 The operation of all electrical equipment
whose function cannot operate satisfactorily and the lubrication arrangements are to be
within the limits given in 1.8.1 are not be efficient under such conditions of vibration and
supplied directly from the system but by shock as arise in normal practice.
alternative means, e.g. through stabilized
supply. 1.9.7 All nuts and bolts/screws used to connect
or secure current- carrying parts and working
1.8.3 Contactors and similar electro-magnetic parts are to be effectively locked, to prevent
devices are not to drop out at or above 85 per them from working loose due to vibration.
cent rated voltage.
1.9.8 Generators, motors, conductors and
1.9 Location and construction generally any electrical equipment producing an
external magnetic field are to be placed at such
1.9.1 Electrical equipment is to be placed in distance from the magnetic compass or any
accessible and adequately lighted spaces clear other equipment likely to be affected by such
of flammable material and heat sources such as magnetic field or are to be so screened that the
boilers, heated tanks etc. The spaces should be interfering external magnetic field is negligible
well ventilated, free from accumulations of (deviation less than 0.5°), even when circuits are
flammable dusts, vapours or gases and acid switched on and off.
fumes. The equipment should not be exposed to
risk of mechanical injury or damage from water, 1.9.9 Where electric power is used for
excessive moisture, steam, oil or any other propulsion, the equipment is to be so arranged
dangerous fluid. Where necessarily exposed to that it will operate satisfactorily in the event of
such hazards, the equipment is to be suitably partial flooding by bilge water above the tank top
constructed or enclosed. up to the floor plate level. See also Ch.3, Sec.2.
1.9.2 Live parts are to be efficiently shielded 1.10 Design and construction
from any accidental contact.
1.10.1 Design, construction and installation of
1.9.3 All electrical apparatus and equipment is electrical propelling machinery and associated
to be constructed and installed so as to avoid equipment together with auxiliary services
injury or electrical shock when handled or essential for the safety of ship are to be done in
touched in the course of normal operation. accordance with the relevant requirements of
this Chapter and are to be surveyed and tested
1.9.4 Insulating materials and insulated windings by the Surveyors.
are to be resistant to tracking, moisture, sea air,
oil vapour and any other similar conditions, 1.10.2 Design and installation of other
unless special precautions are taken to protect equipment is to be such as to ensure minimising
them. the risk of fire due to its failure. As a minimum, it
should comply with a National or International
1.9.5 Equipment is not to remain alive through Standard, revised where necessary for ambient
the control circuits and/or pilot lamps when conditions.
switched off by the control switch. This does not
apply to synchronising switches and/or plugs. 1.10.3 Subject to inspection and testing by the
Surveyors, compliance with the recommen-
dations of the International Electrical
Commission (IEC) publication 92 : "Electro- components are constructed for this voltage.
technical Installation in Ships" or equivalent The wider choice available of such
national standards, may be accepted as meeting components suitable for a voltage upto
the requirements of this Chapter. 250V is not to be overlooked,
1.10.4 Where the Rules require electrical d) Internal circuits of radio, television and
equipment to be of a 'safe type', such equipment navigation equipment or the external
is to be certified for the gases/vapours involved. transmission circuits of radio and radar
The construction and type testing is to be in equipment. These may be however subject
accordance with IEC publication 79 : "Electrical to statutory regulations.
Apparatus for Explosive Gas Atmospheres", or
an equivalent national standard. 1.11.3 Installations with higher voltages than
specified above may be accepted for special
1.11 Voltages purposes (e.g. cold cathode discharge lamps,
for large auxiliary machinery and for propulsion
1.11.1 Standard voltages as recommended by machinery) after special consideration, in each
IEC for shipboard installations, will in general be case, and subject to the provisions of Sec.13 of
accepted subject to the following limits : this Chapter.
a) For power and the heating equipment, 1.12 Electrical equipment for use in
permanently installed and connected to explosive gas atmospheres
fixed wiring, except for space heaters
(radiators) in accommodation spaces - 1.12.1 Where the Rules require electrical
1000V; equipment to be of a "safe type", such
equipment is to be certified for the
b) For lighting (including signal lamps), space gases/vapours involved. The equipment should
heaters in accommodation spaces, socket- conform to IEC publication 79, "Electrical
outlets, portable appliances and other Apparatus for Explosive Gas Atmospheres", or
consumers supplied by flexible cables and an equivalent national standard.
for communication and instrumentation
equipment - 250V. 1.12.2 Certified safe type equipment includes
the following types of protection :
1.11.2 The requirements of 1.11.1 may be
waived for the following applications : Intrinsically safe Ex "i"
Accesso
ries
Control Transfor
Rotating Heating such as
Switchb gear and mers Lighting Socket
Location machi- appli- switches
oards motor and fittings outlets
nes ances connecti
starters rectifiers
on
boxes
Engine and boiler rooms
above the floor IP 22 IP 22 IP 22 IP 22 IP 22 IP 22 IP 44 IP 44
dry control rooms IP 22 IP 22 IP 22 IP 22 IP 22 IP 22 IP 22 IP 22
below the floor N N IP 44 N IP 44 IP 44 N IP 44
closed compartments for
fuel oil and lub.oil IP 44 IP 44 IP 44 IP 44 IP 44 IP 44 N IP 44
separators
Fuel oil tanks N N N N N N N N
Ballast and other water
N N IP 68 N N IP 68 N N
tanks, bilge wells
Ventilation ducts N N IP 44 N N N N N
Deckhouses, forecastle
spaces, steering gear
IP 22 IP 22 IP 22 IP 22 IP 22 IP 22 IP 44 IP 44
compartments and similar
spaces
Ballast pump rooms and
similar rooms below the IP 44 IP 44 IP 44 IP 44 IP 44 IP 44 IP 56 IP 56
loadline
Cargo holds N N IP 44 N IP 55 N IP 56 IP 56
Open deck, keel ducts IP 56 IP 56 IP 56 IP 56 IP 55 IP 56 IP 56 IP 56
Battery rooms, lamp
rooms, paint stores, stores N N EX N EX EX N EX
for welding gas bottles
Dry accommodation
IP 20 IP 20 IP 20 IP 20 IP 20 IP 20 IP 20 IP 20
spaces
Batch rooms and showers N N N N IP 44 IP 44 N IP 56
Galleys, laundries and
IP 44 IP 44 IP 44 IP 44 IP 44 IP 44 IP 44 IP 44
similar rooms
Fig. 1.13.2
- Fire detection systems. are installed and run continuously within the
high fire risk area to keep the fire integrity. See
- Fire-extinguishing systems and fire- Fig.1.17.2.
extinguishing media release alarms.
b) By running cables in two loops or distributing
- Low location lighting, see Pt.6, Ch.4, cables radially as widely apart as practicable
Sec.2. and so arranged that in the event of damage by
fire atleast one of loops or radial distributions
- Public address systems. remains operational.
- Remote emergency stop/shutdown Systems that are self monitoring, fail safe or
arrangements for systems which may duplicated with cable runs as widely separated
support the propagation of fire and/or as is practicable may be exempted.
explosion.
Section 2
System Design
2.3 Voltage and frequency variations - 95 - 105 per cent of rated frequency under
steady load conditions; and
2.3.1 For installations supplied by generators,
the voltage on the main switchboard's bus-bars - 90 - 110 per cent of rated frequency under
is to be kept between 97.5 and 102.5 per cent of transient load conditions.
a) Power supplied control circuits and instrumentation circuits, where technical or safety reasons
require connection to earth, provided the current in the hull is limited to not more than 5 amps in
both normal and fault conditions.
c) Limited and locally earthed systems, provided that any possible resulting current does not flow
directly through any of the dangerous spaces.
d) Alternating current power networks of 1000 Volts root mean square (line to line) and over, provided
that any possible resulting current does not flow directly through any of the dangerous spaces.
st
e) The electrical systems shall be specially considered for existing vessels built before 1 October,
1994.
b) Limited and locally earthed systems, such as starting and ignition systems of internal combustion
engines, provided that any possible resulting current does not flow directly through any of the
dangerous spaces.
c) Insulation level monitoring devices, provided the circulation current does not exceed 30 mA under
the most unfavourable conditions.
Note 5 : All final subcircuits, i.e. all circuits fitted after the last protective device are to be of two insulated
wires the hull return being achieved by connecting to the hull, one of the busbars of the distribution
board from which wires originate.
2.5.4 In addition, the generating sets are to be iii) The secondary essential services
such as to ensure that with any one generator or mentioned in 1.5.1.3 may be included in
its primary source of power out of operation, the load shedding provided:
remaining generating sets are to be capable of
providing the electrical services necessary to a) Following systems, required for
start the main propulsion plant from a dead ship safety, are not disrupted:
condition. The emergency source of power may - lighting systems,
be used for the purpose of starting from a dead - navigation lights, aids and
ship condition if its capability alone or combined signals,
with that of any other source of electrical power - internal safety communication
is sufficient to provide at the same time those equipment,
services required to be supplied by 2.8. - fire detection and alarm systems
- electrical equipment for watertight
2.5.5 Where the main source of electrical power closing appliances.
is essential for the propulsion and steering of the
ship, the system is to be arranged such that the
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e) Fire detectors are to be installed in the 2.8.7 Starting arrangements for emergency
location where the emergency generator generating sets
set and emergency switchboard are
installed. 2.8.7.1 Emergency generating sets are to be
capable of being readily started in their cold
f) Means are to be provided to readily condition at a temperature of 0°C. If this is
change over to emergency mode from impracticable, or if lower temperatures are likely
harbour mode. to be encountered, provision acceptable to IRS
is to be made for the maintenance of heating
g) Control, monitoring and supply circuits, arrangements, to ensure ready starting of the
for the purpose of the use of the generating sets.
emergency generator in port are to be
so arranged and protected that any 2.8.7.2 Each emergency generating set
electrical fault will not influence the arranged to be automatically started is to be
operation of the main and emergency equipped with starting devices approved by IRS
services. with a stored energy capability of at least three
consecutive starts. A second source of energy is
h) When necessary for safe operation, the to be provided for an additional three starts
emergency switchboard is to be fitted within 30 minutes unless manual starting can be
with switches to isolate the circuits. demonstrated to be effective.
2.8.5 The emergency generator and other c) all of these starting, charging and energy
means needed to restore the propulsion are to storing devices are to be located in the
have a capacity such that the necessary emergency generator space; these devices
propulsion starting energy is available within 30 are not to be used for any purpose other
minutes of blackout/dead ship condition. For the than the operation of the emergency
purpose of this requirement "Blackout" is to be generating set. This does not preclude the
understood to mean a "dead ship" condition. supply to the air receiver of the emergency
Emergency generator stored starting energy is generating set from the main or auxiliary
not to be directly used for starting the propulsion compressed air system through the non-
plant, the main source of electrical power and/or return valve fitted in the emergency
other essential auxiliaries (emergency generator generator space.
excluded). The requirement of propulsion
starting energy being available within 30 2.8.7.4 Where automatic starting is not required,
minutes would remain applicable even when manual starting is permissible, such as manual
there is no emergency generator installed. cranking, inertia starters, manually charged
hydraulic accumulators, or powder charge
For steam ships, the 30 minute time limit is the cartridges, where they can be demonstrated as
time from blackout / dead ship condition to being effective.
lighting of the first boiler.
2.8.7.5 When manual starting is not practicable,
2.8.6 Use of emergency generator during lay the requirements of 2.8.7.2 and 2.8.7.3 are to be
time in port for the supply of the ship mains as complied with except that starting may be
stated in para 2.8.4 will be specially considered manually initiated.
on submission of details of safeguards to ensure
its continued availability for its intended
emergency duties.
iv) in the machinery spaces and main - The means of communication which
generating stations including their control is provided between the officer of the
positions; watch and the person responsible for
closing any watertight door which is
v) in all control stations, machinery control not capable of being closed from a
rooms, and at each main and emergency central control station.
switchboard;
- The public address system or other
vi) at all stowage positions for firemen's effective means of communication
outfits; which is provided throughout the
accommodation, public and service
vii) at the steering gear; and spaces.
viii) at the fire pump, the sprinkler pump and - The means of communication which
the emergency bilge pump referred to in is provided between the navigating
2.8.8.1(d) and at the starting position of bridge and the main fire control
their motors. station.
e) For the period of time required by Ch.6, b) Where the emergency source of electrical
Sec.6, the steering gear if required to be so power is an accumulator battery, it is to be
supplied. capable of:
b) Where the system on the load side of the 2.8.9 Cargo ships
converter or inverter is a.c. : limits as given
in 1.8.1. 2.8.9.1 The electrical power available is to be
sufficient to supply all those services that are
2.8.8.5 The emergency switchboard is to be essential for safety in an emergency, due regard
installed as near as is practicable to the being paid to such services as may have to be
emergency source of electrical power. operated simultaneously. The emergency
source of electrical power is to be capable,
2.8.8.6 Where the emergency source of having regard to starting currents and the
electrical power is a generator, the emergency transitory nature of certain loads, of supplying
switchboard is to be located in the same space simultaneously at least the following services for
unless the operation of the emergency the periods specified herein, if they depend
switchboard would thereby be impaired. upon an electrical source for their operation:
i) the navigation lights and other lights a) Where the emergency source of electrical
required by the International Regulations power is a generator, it is to be:
for Preventing Collisions at Sea in force;
and i) driven by a suitable prime-mover with an
independent supply of fuel, having a
ii) on ships constructed on or after 1 flashpoint (closed cup test) of not less
February 1995, the VHF radio installation; than 43°C;
and if applicable
ii) started automatically upon failure of the
- the MF radio installation; main source of electrical power supply
unless a transitional source of emergency
- the ship earth station; and electrical power in accordance with
2.8.9.5(a)(iii) is provided; where the
- the MF/HF radio installations. emergency generator is automatically
started, it is to be automatically connected
d) For a period of 18 hours; unless such to the emergency switchboard; those
services have an independent supply for the services referred to in 2.8.9.6 are then to
period of 18 hours from an accumulator be connected automatically to the
battery suitably located for use in an emergency generator; and unless a
emergency: second independent means of starting the
emergency generator is provided the
i) all internal communication equipment as single source of stored energy is to be
required in an emergency which is protected to preclude its complete
generally as indicated in 2.8.8.1 c) i); depletion by the automatic starting
system; and
ii) the shipborne navigational equipment,
where such provision is unreasonable or iii) provided with a transitional source of
impracticable IRS may waive this emergency electrical power as specified
requirement for ships of less than 5,000 in 2.8.9.6 unless an emergency generator
tons gross tonnage; is provided capable both of supplying the
services mentioned in 2.8.9.6 and of
iii) the fire detection and fire alarm system; being automatically started and supplying
and the required load as quickly as is safe and
practicable subject to a maximum of 45
iv) intermittent operation of the daylight seconds.
signaling lamp, the ship's whistle, the
manual fire alarms, and all internal signals b) Where the emergency source of electrical
that are required in an emergency. power is an accumulator battery it is to be
capable of:
2.8.9.2 For period of 18 hours one of the fire
pumps required by Pt.6, Ch.3, if dependent i) carrying the emergency electrical load
upon the emergency generator for its source of without recharging while maintaining the
power. voltage of the battery throughout the
discharge period within 12 per cent above
2.8.9.3 For the period of time required by Ch.6, or below its nominal voltage;
Sec.6, the steering gear where it is required to
be so supplied. ii) automatically connecting to the
emergency switchboard in the event of
2.8.9.4 In a ship engaged regularly in voyages failure of the main source of electrical
of short duration, IRS if satisfied that an power; and
adequate standard of safety would be attained
may accept a lesser period than the 18 hour iii) immediately supplying at least those
period specified in paragraphs 2.8.9.1(b) to services specified in 2.8.9.6.
2.8.9.1(d) and 2.8.9.2 but not less than 12
hours. 2.8.9.6 The transitional source of emergency
electrical power where required by 2.8.9.5(a) is
2.8.9.5 The emergency source of electrical to consist of an accumulator battery suitably
power may be either a generator or an located for use in an emergency which is to
accumulator battery, which is to comply with the operate without recharging while maintaining the
following: voltage of the battery throughout the discharge
period within 12 per cent above or below its
nominal voltage and be of sufficient capacity
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and is to be so arranged as to supply 2.8.9.11 The emergency switchboard is to be
automatically in the event of failure of either the supplied during normal operation from the main
main or the emergency source of electrical switchboard by an interconnector feeder which
power for half an hour at least the following is to be adequately protected at the main
services if they depend upon an electrical switchboard against overload and short circuit
source for their operation: and which is to be disconnected automatically at
the emergency switchboard upon failure of the
a) the lighting required by 2.8.9.1(a) to main source of electrical power. Where the
2.8.9.1(c). For this transitional phase, the system is arranged for feedback operation, the
required emergency electric lighting, in interconnector feeder is also to be protected at
respect of the machinery space and the emergency switchboard at least against
accommodation and service spaces may be short circuit.
provided by permanently fixed, individual,
automatically charged, relay operated 2.8.9.12 In order to ensure ready availability of
accumulator lamps; and the emergency source of electrical power,
arrangements are to be made where necessary
b) all services required by 2.8.9.1(d) (i, iii and to disconnect automatically non-emergency
iv) unless such services have an circuits from the emergency switchboard to
independent supply for the period specified ensure that electrical power will be available
from an accumulator battery suitably located automatically to the emergency circuits.
for use in an emergency.
2.8.9.13 The emergency generator and its
2.8.9.7 Where the emergency and/or transitional prime-mover and any emergency accumulator
emergency loads are supplied from a battery via battery is to be so designed and arranged as to
an electronic converter or inverter the maximum ensure that they will function at full rated power
permitted voltage variations are to be taken as when the ship is upright and when inclined at
those on the load side of the converter or any angle of list up to 22.5° or when inclined up
inverter. to 10° either in the fore or aft direction, or is in
any combination of angles within those limits.
The above mentioned voltage variants are not to Also refer to Part 4, Chapter 1, Table 1.7.1.
exceed the following limits, as applicable:
2.8.9.14 Provision is to be made for the periodic
a) Where the system on the load side of the testing of the complete emergency system and
converter or inverter is d.c. : limits as given is to include the testing of automatic starting
in 2.8.9.6. arrangements.
Where the system on the load side of the 2.9 Requirements for uninterrupted power
converter or inverter is a.c. : limits as given in system (UPS) units as alternative and/or
1.8.1. transitional source of power
Line interactive UPS unit – an off-line UPS unit b) No additional circuits are to be connected to
where the bypass line switches to stored energy the UPS unit without verification that the
power when the input power goes outside the UPS unit has adequate capacity. The UPS
preset voltage and frequency limits. battery capacity is, at all times, to be
capable of supplying the designated loads
On-line UPS unit – a UPS unit where under for the time specified in the regulations.
normal operation the output load is powered
from the inverter and will therefore continue to c) On restoration of the input power, the rating
operate without break in the event of the supply of the charge unit shall be sufficient to
input failing or going outside preset limits. recharge the batteries while maintaining the
output supply to the load equipment.
2.9.3 Design and construction
2.9.6 Testing and survey
a) UPS units are to be constructed in
accordance with IEC 62040 or an a) UPS units of 50 kVA and over are to be
acceptable and relevant national or surveyed during manufacturing and
international standard. testing.
b) The operation of the UPS is not to depend b) Appropriate testing is to be carried out
upon external services. to demonstrate that the UPS unit is
suitable for its intended environment.
c) The type of UPS unit employed, whether This is expected to include as a
off-line, line interactive or on-line, is to be minimum the following tests:
appropriate to the power supply
requirements of the connected load - Functionality, including operation of
equipment. alarms;
- Temperature rise;
d) An external bypass is to be provided. - Ventilation rate
- Battery capacity.
e) The UPS unit is to be monitored and audible
and visual alarm is to be given in a normally c) Where the supply is to be maintained
attended location for – without a break following a power input
failure, this is to be verified after
- Power supply failure (voltage and installation by an appropriate test.
frequency) to the connected load,
- Earth fault, 2.10 Essential services
- Operation of battery protective device,
- When the battery is being discharged, 2.10.1 Where essential services are duplicated,
and they are to be served by individual circuits
- When the bypass is in operation for on- separated throughout their length as widely as is
line UPS units. practicable and without the use of common
feeders, protective devices or control circuits.
2.9.4 Location
2.11 Diversity factor
a) The UPS unit is to be suitably located for
use in an emergency. 2.11.1 Circuits supplying two or more final sub-
circuits are to be rated in accordance with the
b) UPS units utilizing valve regulated sealed total connected load subject, where justified, to
batteries may be located in compartments the application of a diversity factor. Where spare
with normal electrical equipment, provided ways (feeders) are provided on a section or
the ventilation arrangements are in distribution board, an allowance for future
accordance with the requirements to IEC increase of load is to be added to the total
2.11.2 The diversity factor may be applied when 2.13.1 A separate final sub-circuit is to be
calculating cable size and when calculating the provided for every motor required for essential
rating of switchgear and fusegear. services and for every motor of 1 [kW] or more.
2.11.3 The Diversity factors are not applicable to 2.13.1 Motors of permanently installed
supply cables to distribution switchboards for submersible bilge pumps are to be connected to
lighting and heating. the emergency switchboard, (if fitted).
2.11.4 The calculation of the diversity factor is to 2.13.2 Cables and their connections to such
be submitted along with all relevant data. pumps are to be capable of operating under a
head of water equal to their distance below the
2.12 Lighting circuits bulkhead deck. The cables are to be suitable for
operation in permanently wet situations, and
2.12.1 Lighting circuits are to be supplied by installed in continuous lengths from above the
final sub-circuits, which are separate from those bulkhead deck to the motor terminals.
for heating and power. This provision need not
be applied to cabin fans and small wardrobe 2.13.3 Under all circumstances it is to be
heaters. possible to start the motor of a permanently
installed submersible bilge pump from a position
2.12.2 A final sub-circuit of rating exceeding 15 above the bulkhead deck.
A is not to supply more than one point.
If an additional starter is provided at the motor, it
2.12.3 A final sub-circuit of rating 15 A or less is is to be so arranged as to permit, in all cases,
not to supply more than the following number of remote starting.
lighting points:-
2.14 Motor controls
10 for .………. 24 - 55 V circuits
2.14.1 Every electric motor is to be provided
14 for .………. 110 - 127 V circuits with an efficient means of starting and stopping
so placed as to be easily accessible to the
24 for .………. 220 - 250 V circuits. person controlling the motor.
This provision is not applicable to final sub- 2.14.2 Every motor required for essential
circuits for cornice lighting, panel lighting and services and every motor of 0.5 [kW] or more is
electric signs where lampholders are closely to be provided with the control apparatus as
grouped; in such cases, the number of points is mentioned in 2.14.4 to 2.14.8.
unrestricted provided the maximum operating
current in the sub-circuit does not exceed 10 A. 2.13.3 When motor control gear is being
selected, the maximum current of the motor is to
2.12.4 Lighting for machinery spaces, control be taken as its rated full load current.
stations, work spaces, public spaces, corridors
and stairways leading to boat decks should be 2.14.4 Efficient means of isolation are to be
supplied from at least two final sub-circuits in provided so that all voltage may be cut off from
such a way that failure of any one of the circuits the motor and any associated apparatus
does not leave the spaces in darkness. including any automatic circuit breaker.
2.12.5 For lighting in hazardous areas, switches 2.14.5 Where the primary means of isolation
are to be of the double-pole type and wherever (viz. that provided at the switchboard, section
practicable, located in a non-hazardous area. If board or distribution fuse board) is remote from
fitted in hazardous areas, these switches are to a motor, one of the following provisions is to be
be of flameproof type. made :
c) Provision made so that the fuses in each 2.16 Fire detection and extinguishing
line can be readily removed and retained by systems
authorized personnel.
2.16.1 Electrical equipment used in operating
2.14.6 Means to prevent the undesired fire detecting systems is to be served by two
restarting after a stoppage due to low volts or circuits, one fed from the main power supply
complete loss of volts are to be provided. This system and the other from the emergency power
does not apply to motors where a dangerous supply system. These feeders are to be
condition might result from the failure to restart connected to an automatic change-over switch
automatically e.g. steering gear motor. It is, installed in the vicinity of the fire detection panel.
however, to be ensured that the total starting
current of motors having automatic re-start will 2.16.2 Where an electrically driven fire pump is
not cause excessive voltage drop or overcurrent supplied power from the emergency
on the installation. switchboard, the supply cable to such pump is
not to pass through the main machinery spaces.
2.14.7 Means for automatic disconnection of the
supply in the event of excess current due to 2.17 Lift circuits
mechanical overloading of the motor are to be
provided. (This does not apply to steering gear 2.17.1 Lifts or hoists to be used by passengers
motors and thruster motors. Overload alarms and/or crew are to be supplied from the main
are to be provided for these motors. For switchboard, either directly or through a section
requirements regarding steering gear motors, board, by circuits which do not supply any other
See Ch.6). appliance.
2.14.8 Where fuses are installed to protect 2.17.2 Cable or cables supplying current to
polyphase motor circuits, means are to be motors of lifts or hoists are not to be
provided to protect the motor against incorporated within the flexible trailing cable
unacceptable overload in the case of single used in connection with the control and safety
phasing. devices.
2.15 Remote stops for ventilation fans and 2.18 Heating and cooking equipment
pumps
2.18.1 Every heating or cooking appliance is to
2.15.1 Ventilating fans for machinery spaces are be controlled as a complete unit by a multi-pole
to be provided with means for stopping them linked switch mounted in the vicinity of the
from easily accessible control stations located appliance.
outside such spaces. (Also refer Pt.6, Ch.2,
2.2.1.2). 2.18.2 In the case of small heaters, for individual
cabins or similar small dry accommodation
2.15.2 Motors driving forced and induced spaces where the floor coverings, bulkheads
draught fans, independently driven pumps and ceiling linings are of insulating materials, a
delivering oil to main propulsion machinery for single pole switch is acceptable.
bearing lubrication and piston cooling, oil fuel
transfer pumps, oil fuel unit pumps and other 2.18.3 Heating arrangements of the exposed
similar fuel pumps, fuel and lubricating oil element type are not to be used in any location.
purifiers and their attached pumps are to be
fitted with remote controls situated outside the 2.18.4 Means of cutting off power to the galley
space concerned so that the electrical supply except lighting circuits, in the event of a fire, are
thereto can be disconnected in the event of fire to be provided outside the galley exits, at
arising in the space in which they are located. positions which will not readily be rendered
(Also refer Ch.3, Cl. 4.11.1) and Pt.6, Ch.2, inaccessible by such a fire.
Sec.2.
2.19 Temporary external supply/shore
2.15.3 Where overboard discharges from connection
cooling water or similar pumps are likely to
jeopardize the safe launching of lifeboats or life 2.19.1 Where arrangements are provided for the
rafts, under any condition of loading of the ship, supply of electric power from a source on shore
then the motors driving these pumps are to be or elsewhere, a connection box is to be installed
provided with suitably located remote shut-off in an easily accessible location in a manner
arrangements. suitable for the convenient reception of flexible
cables from the external source. This box should
contain a circuit-breaker or isolating switch and
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Rules and Regulations for the Construction and Classification of Steel Ships - 2014
Page 25 of 70
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fuses and terminals of ample size and suitable
shape to facilitate a satisfactory connection. The b) Continuity of service so as to maintain,
mechanical stress of the portable cable is to be through the discriminative action of the
conveyed directly to the metallic framework and protective devices, the supply to essential
not to electrical connectors. Suitable cables, and all other services not directly affected
permanently fixed, are to be provided, by the fault.
connecting the circuit breaker/isolating switch in
the connection box to a linked switch and/or 2.21.2 Protection against overload
circuit breaker at the main switchboard.
2.21.2.1 Protection against overloads may be
2.19.2 For alternating current systems an provided by circuit-breakers, automatic switches
earthed terminal is to be provided for the or fuses. The tripping characteristics of these
reception of three-phase external supplies with devices are to be appropriate to the system.
earthed neutrals. Fuses rated above 320 A are not to be used for
protection against overload, but may be used for
2.19.3 The external connection is to be provided short-circuit protection.
with an indicator at the main switchboard in
order to show when the cable is energized. 2.21.2.2 The rating or appropriate setting of the
overload protective device for each circuit
2.19.4 Means are to be provided for checking should be permanently indicated at the location
the polarity (for direct current) or the phase of the protective device.
sequence (for three-phase alternating current) of
the incoming supply. This device should be 2.21.2.3 The overload releases of circuit-
connected between the incoming connectors breakers for generators and the setting of
and the interrupting device in the connection preferential trip relays are to be adjustable or, if
box. of the non-adjustable type, are to be readily
replaceable by others of different values.
2.19.5 A notice is to be provided at the
connection box giving complete information on 2.21.3 Protection against short-circuit
the system of supply and the normal voltage
(and frequency for alternating current) of the 2.21.3.1 Protection against short-circuit currents
ship's installed system. Full details of the is to be provided by circuit-breakers or fuses.
procedure for effecting the connection are to be
given on this notice. 2.21.3.2 The breaking capacity of every
protective device is to be not less than the
2.19.6 Alternate arrangements for providing a maximum value of the short-circuit current which
temporary external supply will be specially can flow at the point of installation at the instant
considered. of contact separation.
2.20 Permanent external supply 2.21.3.3 The making capacity of every circuit-
breaker or switch intended to be capable of
2.20.1 Details are to be submitted for being closed, if necessary, on short circuit, is to
consideration in each specific case. be not less than the maximum value of the
short-circuit current at the point of installation.
2.21 Protection On alternating current this maximum value
corresponds to the peak value allowing for
2.21.1 General maximum asymmetry.
2.21.1.1 All installations are to be protected 2.21.3.4 Every protective device or contactor not
against accidental over-currents including short intended for short circuit interruption is to be
circuits and other electrical faults. The choice, adequate for the maximum short-circuit current
location and characteristics of the protective which can occur at the point of installation
device are to provide complete and co-ordinated having regard to the time required for the short
protection to ensure: circuit to be removed.
a) Elimination of the fault to reduce damage to 2.21.3.5 In the absence of precise data of
the system and hazard of fire. rotating machines the following short-circuit
currents at the machine terminals are to be
assumed. The short circuit current is to be the
sum of short circuit currents of generators and
that of motors;
- Ten times full load current for 2.21.5.3 No fuse, non-linked switch or non-
generators normally connected linked circuit-breaker is to be inserted in an
(including spare) - symmetrical RMS, earthed conductor. Any switch or circuit-breaker
fitted is to operate simultaneously in the earthed
- Three times full load current for motors conductor and the insulated conductors.
simultaneously in service.
2.21.5.4 These requirements do not preclude
2.21.4 Combined circuit-breakers and fuses the provision (for test purposes) of an isolating
link to be used only when the other conductors
2.21.4.1 The use of a circuit-breaker of breaking are isolated.
capacity less than the prospective short-circuit
current at the point of installation is permitted, 2.21.6 Protection of generators
provided that it is preceded on the generator
side by fuses, or by a circuit-breaker having at 2.21.6.1 In addition to over-current protection,
least the necessary breaking capacity. The the provisions of 2.21.6.2 to 2.21.6.7 are to be
generator breakers are not to be used for this adhered to as a minimum.
purpose.
2.21.6.2 For generators not arranged to run in
2.21.4.2 Fused circuit-breakers with fuses parallel :
connected to the load side may be used where
operation of the circuit-breaker and fuses is co- - A multi-pole circuit-breaker arranged to
ordinated. open simultaneously all insulated poles or in
the case of generators rated at less than 50
2.21.4.3 The characteristics of the arrangement [kW] a multi-pole linked switch with a fuse in
are to be such that: each insulated pole on the generator side.
The fuse rating in such cases is to be
a) When the short-circuit current is broken, the maximum 125 per cent of the generator
circuit-breaker on the load side is not to be rated current.
damaged and is to be capable of further
service, 2.21.6.3 For generators arranged to run in
parallel:
b) When the circuit-breaker is closed on the
short-circuit current, the remainder of the - A circuit-breaker arranged to open
installation is not to be damaged. However, simultaneously all insulated poles. This
it is admissible that the circuit-breaker on circuit-breaker is to be provided with :
the load side may require servicing after the
fault has been cleared. a) For direct current generators, instantaneous
reverse-current protection operating at not
2.21.5 Protection of circuits more than 15 percent rated current,
Fig.2.21.9.2
Section 3
IEC60331-23 : Electric data cables 3.5.1 Routine tests are to include at least
IEC60331-25 : Optical fiber cables.
- measurement of electrical resistance of
3.4.4 Where electric cables are installed in conductors;
locations exposed to the weather, in damp and
in wet situations, in machinery compartments, - high voltage test;
3.7.1 The rated operating temperature of the 3.9.3 In assessing the current rating of lighting
insulating material is to be at least 10°C higher circuits, every lampholder is to be assessed at
than the maximum ambient temperature liable to the maximum load likely to be connected to it,
be produced in the space where the cable is with a minimum of 60 W, unless the fitting is so
installed. connected as to take only a lamp rated at less
than 60 W.
3.8 Choice of protective covering
3.9.4 Cables supplying winches, cranes,
3.8.1 Cables fitted in the following locations are windlasses and capstans are to be suitably
to have an impervious sheath. In permanently rated for their duty. Unless the duty is such as to
wet situations, metallic sheaths are to be used require a longer time rating, cables for winch or
for cables with hydroscopic insulation. crane motors may be half hour rated on the
basis of the half hour [kW] rating of the motors.
- Decks exposed to weather; Cables for windlass and capstan motors are to
be not less than one hour rated on the basis of
- Bathrooms; the one hour [kW] rating of the motor. In all
cases the rating is to be subject to the voltage
- Refrigerated spaces; drop being within the specified limits.
- Machinery spaces; and 3.9.5 The current ratings given in Table 3.9.1
are based on the maximum operating conductor
- Any other location where water temperatures, given in Table 3.3.1. Where a
condensation or harmful vapour (e.g. oil more precise evaluation of current rating has
vapour) may be present. been carried out based on experimental or
calculated data, details may be submitted for
3.8.2 All cables are to be of flame-retardant type approval.
or fire-resisting type, except that non flame-
Table 3.9.1 : Electric cable current rating, normal operation, based on ambient temp. of 45°C
3.10 Correction factors for current rating ambient temperature the correction factors
shown in Table 3.10.1 are to be applied.
3.10.1 Bunching of cables : Where more than
six cables belonging to the same circuit are 3.10.3 Intermittent Service : Where the load is
bunched together a correction factor of 0.85 is to intermittent, the correction factors in Table
be applied. 3.10.2 may be applied for half hour and one
hour ratings. In no case is a shorter rating than
3.10.2 Ambient temperature : The current one half hour rating to be used, whatever the
ratings in Table 3.9.1 are based on an ambient degree of intermittency.
temperature of 45°C. For other values of
3.11.3 Where a duplicate supply is required and 3.11.10 Where electric cables are installed in
provided for any particular service, the two refrigerated spaces they are not to be covered
cables are to follow different routes which are with thermal insulation but may be placed
separated throughout their length as widely as is directly on the face of the refrigeration chamber,
practicable, to minimise the probability of provided that precautions are taken to prevent
simultaneous damage to the two circuits. The the electric cables being used as casual means
provision is also applicable to control circuits. of suspension.
3.11.4 Generator cables are as far as 3.11.11 Cable runs are normally not to include
practicable to be divided between two or more joints. However, if a joint is necessary it is to be
cable runs. These cable runs are to be carried out with prior approval and with due
separated as far apart as practicable. consideration to methods of splicing that retain
the original mechanical and electrical properties
3.11.5 Cables supplying essential or important of the cable and which ensure that all
consumers are generally not to be installed in conductors are adequately secured, insulated
rooms where there is an excessive fire hazard and protected from atmospheric action.
such as paint stores, galleys, etc. purifiers, Terminals and busbars are to be of dimensions
welding-gas bottles etc. adequate for the cable rating.
3.11.6 Cables having insulating materials with 3.11.12 Where electric cables are installed in
different maximum-rated conductor bunches, provision is to be made to limit the
temperatures are not to be bunched together, propagation of fire, which may be achieved by
or, where this is not practicable, the cables are either of the following:
to be operated so that no cable reaches
temperature higher than that permitted for the a) Cables which have been tested in
lowest temperature-rated cable in the group. accordance with IEC 60332-3 Category A
or a test procedure for cables installed in
bunches equivalent thereto.
Table 3.11.1 : Minimum internal radii of bends in cables for fixed wiring
3.12 Mechanical protection of cables straps such that in the event of a fire they, and
the cables affixed, are prevented from falling
3.12.1 Cables exposed to risk of mechanical and causing an injury to personnel and/or an
damage are to be protected by metal channels obstruction to any escape route. The spacing of
or casing or enclosed in steel conduit unless the their metallic fixing and straps is generally not to
protective covering (e.g. armour or sheath) is exceed 2.0 m.
adequate to withstand the possible damage.
3.12.5.2 When used on open deck, they are
3.12.2 Cables, in spaces where there is additionally to be protected against ultra-violet
exceptional risk of mechanical damage (e.g. on light.
weather decks, in cargo hold areas and inside
the cargo holds) and also below the floor in 3.12.5.3 The load on the plastics cable
engine and boiler rooms, are to be suitably trays/protective casings is to be within the Safe
protected, even if armoured, unless the steel Working Load (SWL) and the spacing of
structure affords adequate protection. support, in general, is not to exceed 2 metres.
3.12.3 Metal casings for mechanical protection 3.12.5.4 The sum of the total cross-sectional
of cables are to be efficiently protected against area of the cables, based on their external
corrosion. diameter, is not to exceed 40% of the internal
cross-sectional area of the protective casing.
3.12.4 Non metallic protective casings and This does not apply to a single cable in a
fixings are to be flame retardant in accordance protective casing.
with the requirements of IEC Publication 92-101.
Note : Cable trays/protective casings made of
3.12.5 If cable trays/protective casings are made plastic materials are to be approved in
of plastics materials, then they are to comply accordance with the Classification Notes issued
with the requirements in 3.12.5.1 to 3.12.5.4. by IRS.
3.16 Installation of cables in pipes and 3.17.2 PVC insulated cables are not to be
conduits installed in refrigerated spaces.
3.16.1 Installation of cables in pipes and 3.17.3 Cables installed in refrigerated spaces
conduits is to be carried out in such a manner are to have a watertight or impervious sheath
that there is no damage to the cable covering. and are to be protected against mechanical
damage. If an armoured cable is used, the
3.16.2 Metal conduit systems are to be earthed armour, unless galvanised or of non-corrosive
and are to be mechanically and electrically material, is to be protected against corrosion by
continuous across joints. Individual short lengths an additional moisture-resisting covering.
of conduit need not be earthed.
3.17.4 Cables are not to be embedded in or
3.16.3 The internal radius of bend of pipes and covered by the thermal insulation. They may be
conduit is to be not less than that laid down for fixed to galvanised perforated plates with a
cables, provided that for pipes exceeding 64 space left between the back of the plate and the
[mm] diameter the internal radius of bend is not wall of the room.
less than twice the diameter of the pipe.
3.17.5 Where cables entering a refrigerated
3.16.4 The drawing-in factor (ratio of the sum of space have to pass through the thermal
the cross-sectional areas of the cables, based insulation, they are to be installed at right angle
on their external diameter, to the internal cross- to such insulation and are to be protected by a
section area of the pipe) is not to exceed 0.4. pipe, sealed at each end. Alternatively, the
cables may be passed through solid door
3.16.5 Expansion joints are to be provided frames, the necessary holes being sealed at
where necessary. each end.
3.16.6 Cable pipes and conduits are to be 3.17.6 Precautions are to be taken to prevent
adequately and effectively protected against the placing of hooks around the cable as a
corrosion. Where necessary, openings are to be casual means of suspension.
provided at the highest and lowest points to
permit air circulation and to prevent 3.17.7 Supporting strips, plating or hangers
accumulation of water. used for securing the cables are to be
galvanised or otherwise protected against
3.16.7 Cable pipes are to be effectively corrosion.
supported, particularly in areas where they are
likely to be subject to heavy vibrations. 3.18 Cables for alternating current
3.16.8 Cables in a conduit should belong to the 3.18.1 Generally, multi-core cables are to be
same temperature class. used in A.C. installations. Where it is necessary
to use single-core cables for alternating current
3.16.9 Where cables are laid in trunks, the circuits rated in excess of 20 A the requirements
trunks are to be so constructed as not to afford of 3.18.2 to 3.18.9 are to be complied with.
passage for fire from one deck or compartment
to another. 3.18.2 Cables are to be either non-armoured or
armoured with non- magnetic material.
3.16.10 Cables used for cold cathode luminous
discharge lamps are not to be installed in metal 3.18.3 If installed in pipe or conduit, cables
conduit unless protected by metal sheath or belonging to the same circuit are to be installed
screen. in the same conduit, unless the conduit or pipe
is of non-magnetic material.
Section 4
4.1.1 Location and installation 4.1.2.1 Switchboards are to have roof with
degree of protection IP 22 and are to be of dead
4.1.1.1 Switchboards are to be installed in front type.
accessible and well ventilated dry spaces free
from flammable gases and acid fumes. On systems with voltages above 50 V up to and
including 1000 V, front and rear dead type
4.1.1.2 Switchboards are to be secured to a switchboards are to be used.
solid foundation and protected against shocks
and damage due to leaks and falling objects. 4.1.2.2 All main switchboards are to be guarded
They are to be self-supported, or be braced to by hand rails either made of hardwood or
the bulkhead or the deck above. In case the insulated. Where access is provided behind a
latter method is used, the means of bracing is to main switchboard, the handrails on the rear are
allow normal deflections of the deck without to be horizontal, and so placed that one cannot
buckling the control cell or assembly structure. accidentally fall into the switchboard. Further,
insulated mats or gratings are to be laid on the
4.1.1.3 Pipes should not be installed directly floor of passage-ways in front of and to the rear
above or in front of or behind switchboards. If of switchboards. Instruments and handles or
such piping is unavoidable, suitable protection is push buttons for switchgear are to be placed on
to be provided in these positions. the front of the switchboard (except for isolating
switches, if used). All other parts which require
4.1.1.4 An adequate, unobstructed working operation, are to be accessible and so placed
space is to be left in front of switchboards. At the that the risk of accidental touching of current
rear, a clearance of at least 0.6 m is to be carrying parts, or accidental making of short-
maintained except that this may be reduced to circuits and earthings, is reduced as far as
0.5 m in way of stiffeners or frames. If practicable.
switchboards are enclosed at the rear and are
fully serviceable from the front, clearance at the 4.1.2.3 Section boards (sub-switchboards) and
rear will not be required unless necessary for distribution boards are to be enclosed unless
cooling. they are installed in a cupboard or compartment
to which only authorised personnel have access,
4.1.1.5 The main switchboard is to be so placed in which case the cupboard may serve as an
relative to one main generating station that, as enclosure.
far as practicable, the integrity of the normal
electrical supply may be affected only by a fire 4.1.2.4 Framework, panels and doors of
or other casualty in one space. The main switchboards are generally to be of steel or
switchboard is to be located as close as aluminium alloy, and are to be of rigid
practicable to the main generating station, within construction.
the same machinery space and the same
vertical and horizontal A60 fire boundaries. An 4.1.2.5 All parts of the main switchboard are to
environmental enclosure for main switchboard, be accessible for maintenance work.
such as may be provided by a machinery control
room situated within the main boundaries of the 4.1.2.6 Equipment for each generator and for
space, is not to be considered as separating the different distribution systems are to be placed in
switchboards from the generators. separate cubicles (panels) or are to be
separated from each other by partitions clearly
4.1.1.6 Where essential services for steering marked with the actual voltages.
and propulsion are supplied from section boards
these and any transformers, converters and 4.1.2.7 Doors, behind which equipment requiring
similar appliances constituting an essential part operation is placed, are to be hinged.
of electrical supply system are also to satisfy Arrangement is also to be provided to keep the
4.1.1.5. hinged doors open.
4.1.2.8 Cable entrances are generally to be from adequate clearance and creepage distance, in
below or from the side. Cable entries from the accordance with Section 1, to ensure that there
top may be accepted provided watertight glands is no risk of flash-over under normal service
are used. conditions. Where necessary these distances
may have to be increased to allow for the
4.1.2.9 Where the main source of electrical electro-magnetic forces involved.
power is essential for propulsion of the ship, the
main busbars are to be subdivided into at least 4.1.4.5 Connections from bus-bars and from
two parts which are normally to be connected by generator circuit terminals to all circuit breakers
circuit breakers (with or without tripping and fuses are to be installed "short-circuit proof",
mechanism), disconnecting links or switch by i.e. either bare conductors, or insulated
which busbars can be split and reconnected conductors or single-core cable without metallic
easily and safely. Bolted links (e.g. bolted bus sheath/armour /braid are used and these are
bar sections) are not acceptable. So far is mounted on supports of insulating material and
practicable, the connection of generating sets with adequate distance between the different
and any other duplicated equipment is to be poles (phases) and to earthed parts.
equally divided among the busbar divisions.
Equivalent arrangements to the satisfaction of 4.1.4.6 Horizontally installed bus-bars and bare
IRS may be accepted. conductors are to be protected by screens, if
they are placed so low that it could be a risk,
4.1.3 Marking and labels e.g. by tools falling on them.
4.1.4.1 Busbars and their connections are to be 4.1.6.2 For generators arranged to run in
of copper, all connections being so made as to parallel at least one ammeter for each generator
prevent deterioration of the joint by corrosion or and two voltmeters are to be provided. One of
oxidation. these voltmeters is to be permanently connected
to the busbars and the other is to be provided
4.1.4.2 The sizes of busbars and their with a change-over switch to enable it to be
connections are to be calculated to ensure that connected to any one generator.
their mean temperature rise does not exceed by
more than 45°C from the ambient temperature, 4.1.6.3 For compound wound generators fitted
when running continuously at the normal rating. with equalizer connections, the ammeter is to be
connected to the pole opposite to that connec-
4.1.4.3 Busbars, together with their connections ted to the series winding of the generator.
and supports, are to be capable of withstanding,
without detrimental effect, the mechanical 4.1.7 Instruments for alternating current
stresses which will arise during short-circuits. generators
Further, provision is to be made to allow the
busbars to expand without causing any 4.1.7.1 For alternating current generators not
abnormal stress on their supports. arranged to run in parallel, each generator is to
be provided with at least one voltmeter, one
4.1.4.4 Busbars and other bare conductors are frequency meter, and one ammeter with an
to be mounted on non- deteriorating and non- ammeter switch to enable the current in each
hygroscopic insulating material, maintaining phase to be read or an ammeter in each phase.
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Generators above 50 kVA are to be provided 4.1.9 Instrument transformers
with a wattmeter.
4.1.9.1 The secondary windings of instrument
4.1.7.2 For alternating current generators transformers are to be earthed.
arranged to run in parallel, each generator is to
be provided with a wattmeter, and an ammeter 4.1.10 Circuit-breakers
in each phase conductor or an ammeter with a
selector switch to enable measurement of 4.1.10.1 Circuit-breakers are to comply with IEC
current in each phase. Publication 947-1 and 947-2, "Low Voltage
Distribution Switchgear" or an equivalent
4.1.7.3 For paralleling of the generators, two national standard, amended where necessary
voltmeters, two frequency meters and a for ambient temperature.
synchronising aid comprising either a
synchroscope and lamps, or an equivalent 4.1.10.2 Test reports, based on the
arrangement, are to be provided. One voltmeter requirements of IEC Publication 947-1 and 947-
and one frequency meter are to be connected 2 or an equivalent national standard, are to be
permanently to the busbars, the other voltmeter submitted for consideration when required.
and frequency meter are to be provided with
arrangements to enable the voltage and 4.1.10.3 Circuit-breakers are to be of the trip-
frequency of any generator to be measured. free type i.e. the breaking action initiated by
short-circuit and overcurrent relays, or by
4.1.8 Instrument scales undervoltage coil, when fitted, is to be fulfilled
independently of the position or operation of
4.1.8.1 In general main switchboard instruments manual handle or of other closing devices.
are to be of accuracy class 1.5 and other Further the arrangement is to be such that
switchboard instruments are to be of accuracy automatic repeated breakings/makings by short-
class 2.5. circuits and overcurrents cannot occur.
4.1.8.2 The upper limit of the scale of every 4.1.10.4 Each circuit opening device is to be so
voltmeter is to be approximately 120 per cent of arranged that accidental closing and opening
the normal voltage of the circuit, and the normal does not occur.
voltage is to be clearly indicated.
4.1.10.5 Handles and operating mechanisms
4.1.8.3 The upper limit of the scale of every are to be so arranged that the hand of the
ammeter is to be approximately 130 per cent of operator cannot accidentally touch live metal or
the normal rating of the circuit in which it is be injured through an arc arising from the switch
installed. Normal full load is to be clearly or circuit-breaker, or the rupturing of a fuse. If
indicated. switches are enclosed their handles are not to
operate through unprotected slots.
4.1.8.4 Ammeters for use with direct current
generators, and wattmeters for use with 4.1.11 Fuses
alternating current generators, which may be
operated in parallel, are to be capable of 4.1.11.1 Fuses are to comply with IEC
indicating 15 per cent reverse-current or Publication 269 "Low Voltage Fuse with High
reverse-power respectively. Breaking Capacity" or an equivalent national
standard, amended where necessary for
4.1.8.5 The upper limit of the scale of every ambient temperature.
wattmeter is to be approximately 130 per cent of
the rated full load of the circuit in which it is 4.1.11.2 A report, giving details of test
installed. Rated full load is to be clearly performance, fusing characteristics, temperature
indicated. and insulation tests and details of the
specification to which the fuse has been tested
4.1.8.6 Frequency meters are to be capable of is to be submitted for consideration when
indicating a variation in the frequency from required.
minus 8 per cent to plus 8 per cent of the
nominal frequency of the installation. 4.1.11.3 Fuse-links and fuse-bases are to be
marked with particulars of rated current and
4.1.8.7 Instruments are to have effective rated voltage. Each fuse position is to be
screening, for example, by metal enclosures, in permanently and indelibly labeled with the
order to diminish faulty readings caused by current-carrying capacity of the circuit protected
induction from adjacent current-carrying parts. by it and with the appropriate approved size of
fuse.
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Chapter 8 Part 4
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4.2.2 All parts which require operation in normal 4.3.5 Transferring of power supply to an
use are to be placed on the front or easily alternate circuit should not render the
accessible from behind front doors. audio/visual alarms inoperative. Means should
be provided to test the audio/visual alarms.
When such parts are placed behind front doors,
the interior front is to comply with enclosure type 4.3.6 Any statutory requirements of the country
IP 20, except that fuses with accessible current- of registration are to be complied with and, on
carrying parts may be permitted, provided that application to IRS, may be accepted as an
the door is lockable. alternative to the above.
4.2.3 Switchboards, supplied from different 4.3.7 The voltage drop between the power
supply circuits, are not to be placed in the same supply terminals and load terminals for
enclosure unless these are separated by navigation lights is to be not more than 2.5 per
partitions of flame retardant material. cent of the rated voltage to ensure required
output and colour.
4.2.4 Switchboards, which are provided with two
or more supply circuits arranged for automatic
standby connection, are to be provided with
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4.4 Control gear arrangements are to be such that arcs occurring
by short-circuit in one cubicle cannot spread to
4.4.1 Control gear is to comply with IEC 60947 bus-bars.
“Low-voltage switchgear and control gear” or an
equivalent national standard, amended where 4.5 Testing
necessary for ambient temperature.
4.5.1 Switchgear and control gear assemblies
4.4.2 Control gear, including isolating and with supply voltage of 60 V and above are to be
reversing switches, is to be so arranged that tested as follows:
shunt field circuits are not disconnected without
adequate discharging path being provided. - High voltage test with 1000 V plus twice
the rated voltage with a minimum of
4.4.3 Control gear for essential and important 2000 V. The test voltage is to be
motors are to be separated from each other and supplied for 1 minute at any frequency
from other current carrying parts by screens. between 25 and 100 Hz.
The arrangement is to be such that maintenance
work can be carried out on each unit without - Insulation resistance measuring.
danger when isolated.
4.5.2 Switchgear and control gear assemblies
4.4.4 When installed in main switchboards motor with supply voltage less than 60 V are to be
control gear is to be placed in separate cubicles tested in accordance with 4.5.1 except that the
separated from all other parts of the switchboard test voltage is to be 500 V.
by partitions of flame retardant material. The
Section 5
5.1.2 For all the rotating machines for essential 5.1.7 Where welding is proposed to be applied
services, manufacturer's test records are to be to shafts of machines for securing armature
provided (See also Sec.1). For other machines arms or spiders, stress relieving is to be carried
they are to be available upon request. out after welding. The proposal is to be
submitted for scrutiny and approval.
5.1.3 Shaft materials for electric propulsion
motors and for main engine driven generators 5.1.8 The construction of alternating machines,
where the shaft is part of the propulsion are to be capable of withstanding a sudden
shafting, is to comply with applicable short circuit at their terminals under any
requirements of Pt.2, and to be certified by IRS. operating condition.
Shaft material for other machines is to be in
accordance with either Pt.2 or recognised 5.1.9 Effective means are to be provided to
international or national standard. prevent the accumulation of moisture and
condensation within the machines when they
5.1.4 The rotating parts are to be so balanced are stopped with a provision that such means
that when running at any speed in the normal are switched on at stand-still and switched off at
working range the vibration level does not starting.
exceed the levels specified in IEC 60034.
5.1.10 Coolers : Water-air heat exchangers of
5.1.5 The lubrication arrangement for bearings rotating machines are to be of the double tube
are to be effective under all operating conditions type. In a normally attended position a visual
including the maximum ship inclinations and audible alarm is to be given to monitor
specified in Ch.1 and there are to be effective water cooler leakage.
means to ensure that lubricant does not reach
Notes:-
1 T = Thermometer method
R = Resistance method
ETD = Embedded Temperature Detector
2 When the commutators, sliprings or bearings of machines provided with water coolers are not in the enclosed air circuits-
cooled by the water cooler, but are cooled by the ambient cooling air, the permissible temperature rise above the ambient
cooling air should be the same as for ventilated machines.
3 When Class F or Class H insulation is employed, the permitted temperature rises are respectively 20°C and 40°C higher than
the values given for Class B insulation.
4 Classes of insulation are to be in accordance with IEC Publication 85 (1957) - "Recommendations for the classification of
material for the insulation of electrical machinery and apparatus in relation to their thermal stability in service".
5.3.4 The limits of temperature rise of electric voltage. The voltage is to recover to rated
slip couplings are to be in accordance with voltage within a time not exceeding 1.5 seconds.
Table 5.3.1, except that when a squirrel cage
element is used the temperature of this element 5.4.4 The transient voltage rise at the terminals
is not to reach an injurious value. The of a generator is not to exceed 20 per cent of
temperature of the field windings is not to rated voltage when rated KVA at a power factor
exceed these limits at all speeds of operation. not greater than 0.8 is thrown off.
Arrangements for reducing the excitation of self
ventilated couplings at low operational speeds 5.4.5 Generators are to be capable of
are permissible. maintaining under steady state short circuit
conditions a current of at least three times the
5.3.5 Alternating current machines of 5000 kVA full load rated current for a duration of at least
output and above and propulsion motors having two seconds or where precise data is available
a total axial core length of 1m or more (including for the duration of any longer time delay which
the ventilating duct), are to have at least three may be provided by a tripping device for
embedded temperature detectors. With discrimination purposes.
multicore machines the total length is to be
taken as the sum of the individual core lengths. 5.4.6 Generators required to run in parallel are
to be stable from no load [kW] up to the total
5.4 Generator control combined full load [kW] of the group, and load
sharing is to be such that the load on any
5.4.1 Each alternating current generator, unless generator does not normally differ from its
of the self-regulating type, is to be provided with proportionate share of the total load by more
automatic means of voltage regulation; voltage than 15 per cent of the rated output [kW] of the
build-up is not to require an external source of largest machine or 25 per cent of the rated
power. output [kW] of the individual machine, whichever
is less.
5.4.2 The voltage regulation of any alternating
current generator with its regulating equipment 5.4.7 When generators are operated in parallel,
is to be such that at all loads, from zero to full the kVA loads of the individual generating sets
load at rated power factor, the rated voltage is are not to differ from the proportionate share of
maintained within ±2.5 per cent under steady the total kVA load by more than 5 per cent of the
conditions. There is to be provision at the rated kVA output of the largest machines.
voltage regulator to adjust the generator no load
voltage. 5.4.8 Generators running in parallel may have a
common neutral connection to earth provided
5.4.3 Generators, and their excitation systems, they are suitably designed to avoid excessive
when operating at rated speed and voltage on circulating currents.
no-load are to be capable of absorbing the This is particularly important if the generators
suddenly switched, balanced, current demand of are of different size and make.
the largest motor or load at a power factor not Generators in which the third harmonic content
greater than 0.4 with a transient voltage dip of the waveform does not exceed 5 per cent
which does not exceed 15 per cent of rated may be considered adequate.
5.6 Brushgear
Note : This would mostly occur with a neutral
bus with a single grounding resistor with the 5.6.1 The final running position of brushgear is
associated neutral switching. Where individual to be clearly and permanently marked.
resistors are used, circulation of the third
harmonic currents between paralleled 5.6.2 Direct current motors and generators are
generators is minimized. to operate with fixed brush setting from no load
to the momentary overload specified without
5.5 Overloads injurious sparking, or damage to the commutator
or brushes. The commutation is to be checked
5.5.1 Machines are generally to be capable of with an excess current of 20 per cent and for a
withstanding, on test, without injury, the period of time sufficient to judge its quality.
following overload conditions :
5.6.3 Alternating current commutator motors are
a) D.C. generators - an excess current of 50 to operate over the specified range of load and
per cent for 15 seconds after attaining the speed without injurious sparking.
temperature rise corresponding to rated
load, the terminal voltage being maintained 5.7 Inspection and testing
as near the rated value as possible. This
requirement does not apply to the overload 5.7.1 On all machines intended for essential
torque capacity of the prime mover. services, tests specified in Table 5.7.1 are to be
carried out. See also Section 1 'Surveys',
b) A.C. generators - an excess current of 50 subsection 1.3. Any other relevant tests required
per cent for 2 minutes, at 0.6 power factor, by the national standards are also to be carried
after attaining the temperature rise out.
corresponding to rated load, the terminal
voltage and frequency being maintained as Type tests are to be carried out on a prototype
near the rated values as possible. This machine or on the first of a batch of machines
requirement does not apply to the overload and routine tests carried out on subsequent
torque capacity of the prime mover. machines.
c) Motors - At rated speed or in the case of a 5.7.2 The high voltage test is to be carried out at
range of speeds, at the highest and lowest 1000 plus twice the rated voltage with a
speeds, under gradual increase of torque, minimum of 2000 V on new machines,
the voltage and frequency being maintained preferably at the conclusion of the temperature
as near to their rated value as possible, the rise test. The test is to be applied between the
appropriate excess torque given below. windings and the frame with the core connected
Synchronous motors and synchronous to the frame and to any windings or sections of
induction motors are required to withstand windings not under test. Where both ends of
the excess torque without falling out of each phase are brought out to accessible
synchronism and without adjustment of the separate terminals, each phase is to be tested
excitation current preset at the value separately. The test is to be made with
corresponding to rated load. alternating voltage at any convenient frequency
between 25 and 100 Hz of approximately sine
d.c. motors 50 per cent for 15 wave form. The test is to be commenced at a
seconds voltage of not more than one half of the full-test
polyphase a.c. 50 per cent for 15 voltage and is to be increased progressively to
synchronous motors seconds full value, the time allowed for the increase of
polyphase a.c. 35 per cent for 15 the voltage from half to full value being not less
synchronous seconds than 10 seconds. The full test voltage is then to
induction motors be maintained for one minute and then reduced
polyphase a.c. 60 per cent for 15 to one half full value before switching off.
induction motors seconds
5.7.3 When additional high voltage tests are
d) Propulsion machines - Overload tests for required on a machine which has already
propulsion machines will be given special passed its tests or on machines after repair, the
consideration for each installation. voltage of such further tests is to be 75 per cent
of the value given in 5.7.2.
(1) For machines of less than 100 kW, type tests on prototype machine is acceptable. For 100 kW or
more, tests on at least the first of each batch of machines are to be carried out.
(2) The report of machines routine tested is to contain the manufacturer's serial number of the machine
which has been type tested and the test results.
(3) Verification of steady short-circuit condition applies to synchronous machines only.
(4) Only applicable for machines of essential services rated above 100 kW. For routine tests,
overcurrent test may be carried out in lieu of overload test.
(5) Not applicable for squirrel cage motors.
Table 5.7.4: Minimum values of test voltages and corresponding insulation resistances
Related Voltage VR (V) Minimum Test Voltage (V) Minimum InsulationResistance (MΩ)
VR ≤ 250 2 x VR 1
250 < VR ≤ 1000 500 1
1000 < VR ≤ 7200 1000 (VR / 1000) + 1
7200 < VR ≤ 15000 5000 (VR / 1000) + 1
Section 6
Converting Equipment
d) Insulation resistance : The insulation 6.2.9 Test and monitoring facilities are to be
resistance of each winding in turn to all the provided to permit identification of control circuit
other windings, core, frame and tank or faults and faulty components.
casing connected together and to earth is to
be measured after the high voltage test and 6.2.10 Protection devices fitted for converter
recorded together with the temperature of equipment protection are to ensure that, under
the transformer at the time of the test. fault conditions, the protective action of circuit
breakers, fuses or control systems is such that
e) Temperature rise : One transformer of each there is no further damage to the convertor or
size and type is to be given a temperature the installation.
rise test. For transformers of rating 100 KVA
and above, it will be accepted that the 6.2.11 Converter equipment, including any
temperature rise test is made on one of associated transformers, reactors, capacitors
several identical transformers manufactured and filters, if provided, is to be so arranged that
and tested at the same time. the harmonic distortion, and voltage spikes,
introduced in to the ships electrical system are
6.2 Semiconductor equipment restricted to a level necessary to ensure that it
causes no malfunction of equipment connected
6.2.1 The requirements of 6.2.2 to 6.2.16 apply to the electrical installation.
to semiconductor equipment rated for 5 [kW]
upwards. 6.2.12 Overvoltage spikes or oscillations caused
by commutation or other phenomena, are not to
6.2.2 Semiconductor equipment is to comply result in the supply voltage waveform deviating
with the requirements of IEC 146: from the superimposed equivalent sine wave by
Semiconductor convertors, or an acceptable and more than 10 percent of the maximum value of
relevant national standard amended where the equivalent sine wave.
necessary for ambient temperature.
6.2.13 When converter equipment is operated in
6.2.3 Semiconductor static power converter parallel, load sharing is to be such that under
equipment is to be rated for the required duty normal operating conditions overloading of any
having regard to peak loads, system transients unit does not occur and the combination of
and overvoltage. parallel equipment is stable throughout the
operating range.
6.2.4 Converter equipment may be air or liquid
cooled and is to be so arranged that it cannot 6.2.14 When converter equipment has parallel
remain loaded unless effective cooling is circuits there is to be provision to ensure that the
maintained. Alternatively the load may be load is disturbed uniformly between the parallel
automatically reduced to a level commensurate paths.
with the cooling available.
6.2.15 Transformers, reactors, and other circuit voltage is to be 900 V; for system
devices associated with convertor equipment voltage over 90 V the test voltage is to
are to be suitable for the distorted voltage and be twice the system voltage plus 1000
current waveforms to which they may be V;
subjected.
- functional tests;
6.2.16 Tests at the manufacturer's works are to
include - temperature rise test; and
- high voltage test for one minute applied - such other agreed tests as are
between terminals and earthed parts at necessary to demonstrate the suitability
a frequency between 25 - 100 Hz. For of the equipment for its intended duty.
system voltage up to 60 V the test Details of tests are to be submitted for
voltage is to be 600 V; for system consideration when required.
voltage between 60 - 90 V the test
Section 7
Miscellaneous Equipment
4)
that there is adequate ventilation and that
IRS requirements relevant to the location 7.2.1.2 Lighting fittings installed in engine rooms
and installation of vented types batteries are or similar spaces where they are exposed to the
complied with. risk of mechanical damage are to be provided
with suitable grilled mechanical guards to
d) Details of the schedule and of the protect their lamps and glass globes against
procedures are to be included in the ship’s such damage.
safety management system and be
integrated into the ship’s operational 7.2.1.3 Precautions are to be taken so that a
maintenance routine. lamp for one voltage cannot be inserted in a
lampholder for another voltage.
Notes:
7.2.2 Incandescent lighting
1) Shelf life is the duration of storage under
specified conditions at the end of which a 7.2.2.1 The voltage of tungsten filament
battery retains the ability to give a specified lampholders is not to exceed:
performance.
a) Bayonet fitting
2) A vented battery is one in which the cells
have a cover provided with an opening Normal B22 250 V
through which products of electrolysis and
evaporation are allowed to escape freely Small (single contact) B15 s 130 V
from the cells to atmosphere.
Small (double contact) B15 d 130 V
3) A valve-regulated battery is one in which
cells are closed but have an arrangement b) Screw fitting
(valve) which allows the escape of gas if the
internal pressure exceeds a predetermined Goliath E40 250 V
value.
Medium E27 250 V
4) The ventilation arrangements for installation
of vented type batteries which have Small E14 250 V
charging power higher than 2kW are to be
such that the quantity of air expelled is at Miniature E10 24 V
least equal to:
7.2.2.2 Lamps are to be in accordance with the
Q = 110 l n following :
7.2 Luminaries - construction and testing 7.2.3.1 The ratings of tubular fluorescent lamps
are not to exceed 250 V and 80 W.
7.2.1 General
7.2.3.2 Fittings, reactors, capacitors and other
7.2.1.1 Lighting which is essential for safety and auxiliaries are not to be mounted on surfaces
working is to comply with the following which are subject to high temperatures.
provisions.
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7.2.3.3 Capacitors of 0.5mF and above are to be circuited whether the plug is in or out, and so
provided with a means of prompt discharge on that a pin of the plug cannot be made to earth
disconnection of the supply. either pole of the socket outlet.
7.3.1.1 Enclosures are to be of metal or of 7.4.3 Each separate element rated more than 15
flame-retardant insulating materials. A is considered as a separate consumer, for
which a separate circuit from a switchboard or
7.3.2 Inspection and draw boxes distribution board is required.
7.5.2 Construction
7.5.2.3 In steel ships fitted with wooden masts,
7.5.2.1 In wooden and composite ships fitted the lightning conductors are to be composed of
with wooden masts, the lightning conductors are copper tape or rope terminating in a spike in
to be composed of continuous copper tape accordance with 7.5.2.1. At the lower end this
and/or rope, having a Section not under 100 copper tape or rope is to be securely clamped to
2
[mm ]. These are to be riveted with copper rivets the nearest metal forming part of hull of the ship.
or fastened with copper clamps to an
appropriate copper spike not less than 13 [mm] 7.5.2.4 Lightning conductors are to be run as
in diameter and projecting at least 150 [mm] straight as possible, and sharp bends in the
above the top of the mast. If tape is used the conductors are to be avoided. All clamps used
lower end of the tape is to terminate at the point are to be of brass or copper, preferably of the
at which the shrouds leave the mast, and is to serrated contact type, and efficiently locked.
be securely clamped to a copper rope of not Soldered connections are not acceptable.
less than 13 [mm] diameter. This copper rope is
to be led down the shrouds and is to be securely 7.5.2.5 The resistance of the lightning
clamped to a copper plate having an area of at conductors, measured between the mast head
2
least 0.2 [m ]. This copper plate is to be fixed to and the position on the earth plate or hull to
the ship's hull well below the light load waterline which the lightning conductor is earthed, is not
in such a manner that it is to be immersed under to exceed 0.02 ohms.
all conditions of heel.
7.5.2.6 Suitable means should be provided to
7.5.2.2 In wooden and composite ships fitted enable ships when in drydock or on a slipway to
with steel masts, each mast is to be connected have their lightning conductors or steel hulls
to a copper plate in accordance with 7.5.2.1. connected to an efficient earth on shore. When
The copper rope is to be securely attached to the ships are in floating docks, suitable means
and in good electrical contact with the mast at or should be provided for earthing these lightning
above the point at which the shrouds leave the conductors to the sea.
mast.
Section 8
8.1.4 The torsional vibration characteristics of 8.1.8 Motors and generators of 400 [kW] or over
the propulsion system are to be submitted as are to be provided with means of heating the
required by Ch.4, as applicable. windings to prevent condensation when idle. If
steam pipes are used for this purpose the joints
8.1.5 Cooling water and lubricating oil systems are not to be within the machine.
are to comply with Ch.3, where applicable.
8.2 Excitation
8.1.6 Where the arrangements permit a
propulsion motor to be connected to a 8.2.1 Systems dependent on the auxiliary
generating plant having a continuous rating generators for excitation are to be capable of
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maneuvering and of maintaining power at all made so that in case of leakage, steam or oil
times with a fall of 10 per cent excitation voltage may not come into contact with the energized
at the busbars. parts.
8.2.2 Where motor driven exciters, boosters, 8.3.7 Alternative arrangements will be specially
balancers or rectifiers are provided for excitation considered.
purposes, provision for an alternative supply of
excitation is to be made. Where two machines 8.4 Cables
are used, each of at least 50 per cent of the
required power, it will be sufficient to provide 8.4.1 Conductors in circuits essential for
one spare machine. maneuvering or maintenance of propelling
power are to be stranded, having not less than
8.2.3 Negative boosters are to be provided with seven strands, and are to have a nominal cross-
2
overspeed protection where necessary. sectional area of not less than 2.5 [mm ].
8.2.4 In direct current constant pressure 8.4.2 Cables which are connected to the slip
systems, arrangements for generator and motor rings of synchronous motors are to be suitably
excitation are to be such that if the motor insulated for the voltage to which they are
excitation circuit is opened by a switch or subjected during maneuvering.
contactor, the generator excitation is
simultaneously interrupted, or the generator 8.4.3 Cable ends are to be fitted with connectors
voltage is immediately reduced to zero. or connecting sockets of appropriate size and in
such a manner as to inhibit corrosion. They are
8.3 Maneuvering controls to be arranged and supported in a manner
suitable for withstanding the electro-mechanical
8.3.1 In addition to the requirements of Ch.7, the forces due to a short circuit.
following provisions are to be complied with.
8.5 Overload and short circuit protection
8.3.2 Where bridge or deck control is employed,
alternative control in the engine room is to be 8.5.1 Provision is to be made for protection
provided. against severe overloads, and electrical faults
likely to result in damage to the plant.
8.3.3 Suitable interlocks, operating preferably by
mechanical means, are to be provided to 8.5.2 The overload protection in excitation
prevent damage to the plant as a result of circuits should not lead to opening of the circuit.
incorrect switching, such as the opening of
switches or contactors not intended to be 8.6 Earth leakage detection
operated while carrying current or such as the
simultaneous closing of the ahead and astern 8.6.1 The main propulsion circuit is to be
circuits. provided with means for detecting earth faults.
For direct current equipments exceeding 500 V
8.3.4 Provision is to be made for the manual and for all alternating current equipments, aural
operation, without undue manual effort, of all and visual alarms are to be automatically
maneuvering contactors, switches, field operated on the occurrence of an earth fault, but
regulators and controllers. Where electric, the operation of such devices is not to interrupt
pneumatic or hydraulic aid is used for normal the power supply. A switch may be provided to
operation, failure of such aid is not to result in switch off the aural devices, but in such cases
interruption of power to the propeller shaft and the visual alarm is to remain switched on to
any such device is to be capable of purely indicate that the aural device is switched off.
manual operation without delay. This latter Alternative arrangements will be specially
requirement does not apply to bridge control considered.
equipment.
8.6.2 If an earth connection is used for operating
8.3.5 In propulsion installations with two or more the detector arrangements, then in direct current
generators or two or more motors on one line of systems the earth circuit is to be automatically
shafting the propulsion circuit is to be so opened in order to stop the circulation of fault
arranged that any of these machines can be cut current. In alternating current systems, the fault
out of the circuit without preventing the others current is to be interrupted or limited to a safe
from working. value.
8.3.6 Where steam and oil gauges are mounted 8.6.3 Earth leakage devices are to be arranged
on the main control station, provisions are to be to function for all earth faults exceeding 5 A. In
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Section 9
9.1.6 Where emergency lighting fittings are 9.3.2 Where the public address system forms
connected to dimmers, provision is to be made, part of the internal communication equipment
upon the loss of the main lighting, to required in an emergency it is to be fed by
automatically restore them to their normal level exclusive circuits, one from the main source of
of illumination. electrical power and one from an emergency
source of electrical power with automatic
9.1.7 Fittings are to be specially marked to change-over facilities located adjacent to the
indicate that they form part of the emergency public address system.
lighting system.
9.3.3 Amplifiers are to be continuously rated for
9.2 General emergency alarm system the maximum power that they are required to
deliver into the system for audio and, where
9.2.1 An electrically operated bell or klaxon or alarms are to be sounded through the public
other equivalent warning system installed in address system, for tone signals.
addition to the ship's whistle or siren, for
sounding the general emergency alarm signal is 9.3.4 Loudspeakers are to be continuously rated
to comply with the requirement of this Section. for their proportionate share of amplifier output.
9.2.2 The system is to be capable of operation 9.3.5 Amplifiers and loudspeakers are to be
from at least the navigating bridge and at a selected and arranged to prevent feedback and
position adjacent to the alarm signal distribution other interference.
panel.
9.3.6 Where the public address system does not
9.2.3 The alarm system is to be fed by exclusive form part of the internal communication
circuits, one from the main source of electrical equipment required in an emergency, provision
power and one from an emergency source of is to be made, at a position adjacent to the
electrical power with automatic change-over emergency system control panel, to silence the
facilities located in, or adjacent to the main public address system.
alarm signal distribution panel.
9.3.7 The public address system may be used
9.2.4 The alarm system is to be audible for sounding the general emergency alarm and
throughout all the accommodation and normal the fire alarm provided that in addition to the
crew working spaces with all doors and requirements of 9.2.
accesses closed and is to have a sound
pressure level, in the 1/3-octave band above the a) the emergency system is given automatic
fundamental, of not less than 75dB(A) and at priority over any other system input;
least 10 dB(A) above normal ambient noise
levels, with the ship underway in moderate b) there are means to automatically override
weather, when measured at the sleeping any volume controls so as to ensure the
positions in the cabins and one metre from the specified sound pressure levels are met;
source. An audible alarm level of 120 dB(A) is
not to be exceeded in any space. c) there are multiple amplifiers having their
power supplies so arranged that a single
9.2.5 With the exception of bells, the alarm is to fault will not cause the loss of more than
have a signal frequency between 200 Hz and one amplifier;
2.5 kHz.
d) there are segregated cable routes to public
9.2.6 Where the special alarm fitted to summon rooms, alleyways, stairways, and control
the crew from the navigation bridge, of fire stations so arranged that any single
control station, forms part of the ship's general electrical fault or a fire in any one main
alarm system, it is to be capable of being vertical fire zone as defined by Pt.6, Ch.3,
sounded independently of the alarm to the other than the zone in which the public
passenger spaces. address control station is located, will not
interfere with the sounding of the
emergency alarm through the remaining
system;
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Section 10
Section 11
ii) flammable liquid having a flashpoint f) zones within a 3 [m] radius of flanged joints,
exceeding 60°C, heated or raised by or glands or other openings defined by
ambient conditions to a temperature 11.4.2(b); in the case of gas or vapour
within 15°C of its flashpoint; having a relative density of more than 0.5,
the dangerous zone is considered to extend
iii) flammable gas. vertically downwards as described under
(e);
b) piping systems or equipment containing fluid
defined by (a) and having flanged joints or g) zones within a 1.5 [m] radius of the
glands or other openings through which ventilation outlets of spaces regarded as
leakage of fluid may occur under normal open areas containing items defined under
operating conditions; 11.4.2(d);
c) spaces containing solids, such as coal or h) zones within a 1.5 [m] radius of flanged
grain, liable to release flammable gas and/or joints, or glands or other openings defined
combustible dust; by 11.4.2(d) and (e);
11.4.3 The following zones or spaces are 11.6.1 Where an enclosed or semi-enclosed
regarded as dangerous: space is provided with mechanical ventilation
ensuring at least 12 air changes/hour, and
a) the interiors of those spaces or tanks leaving no areas of stagnant air, it may be
defined by 11.4.2(a) and (c); regarded in consideration of dangerous zones,
as an open area.
b) spaces separated by a single bulkhead or
deck from a cargo defined by 11.4.2(a); 11.6.2 Where the rate of ventilation air flow, in
relation to the maximum rate of release of
flammable substances reasonably to be
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expected under normal conditions, is sufficient 11.8.2 In addition to other requirements in this
to prevent the concentration of flammable chapter, cables in dangerous zones or spaces,
substances approaching their lower explosive or which may be exposed to cargo oil, oil vapour
limit, consideration may be given to regarding as or gas, are to be either:
non-dangerous, the space, ventilation and other
openings into it, and the zone around the a) mineral insulated with copper sheath, or
equipment contained within.
b) armoured or braided (for mechanical
11.7 Pressurisation protection and earth detection) with non-
metallic impervious sheath.
11.7.1 A space having access to a dangerous
space or zone as defined under 11.4.3(c) to (i) 11.9 Requirements for tankers intended for
may be regarded as non-dangerous if fulfilling the carriage in bulk of oil cargoes having a
all the following conditions: flash point not exceeding 60°C (closed cup
test)
a) access is by means of an air-lock, having
gas-tight steel doors, the inner of which as a 11.9.1 The following requirements define the
minimum, is self-closing without any hold- electrical equipment permitted within dangerous
back arrangement; spaces and zones and are in addition to the
requirements of 11.1 to 11.8.
b) it is maintained at an overpressure relative
to the external hazardous area by ventilation 11.9.2 The requirements for cargo tanks also
from a non-dangerous area; apply to cargo slops tanks.
c) the relative air pressure within the space is 11.9.3 The relevant gas group and temperature
continuously monitored and, so arranged, class for safe type equipment in the defined
that in the event of loss of overpressure an locations are IIA T3.
alarm is given and the electrical supply to all
equipment not of a safe type is 11.9.4 Where intrinsically-safe equipment is
automatically disconnected. Where the shut- required, consideration will be given to the use
down of equipment could introduce a of simple apparatus incorporated in intrinsically-
hazard, an alarm may be given, in lieu of safe circuits, as defined in 11.2.2(b).
shutdown, upon loss of overpressure, and a
means of disconnection of non-safe type 11.9.5 Cargo tanks: intrinsically-safe equipment
electrical equipment, capable of being of category 'ia':
controlled from a manned station, provided
in conjunction with an agreed operational 11.9.6 Cofferdams adjoining cargo tanks
procedure; where the means of
disconnection is located within the space a) intrinsically-safe equipment of category 'ia';
then it is to be effected by equipment of a
safe type; b) electric depth-sounding devices hermetically
enclosed, located clear of the cargo tank
d) any electrical equipment required to operate bulkhead, with cables installed in heavy
upon loss of overpressure, lighting fittings gauge steel pipes with gastight joints up to
and equipment within the air-lock, is to be of the main deck;
a safe type;
c) cables for impressed current cathodic
e) means are to be provided to prevent protection systems (for external hull
electrical equipment other than of a safe protection only) installed in heavy gauge
type, being energized until the atmosphere steel pipes with gas tight joints up to the
within the space is made safe, by air upper deck;
renewal of at least 10 times the capacity of
the space. d) through runs of cables, installed in heavy
gauge steel pipes with gas tight joints.
11.8 Cable and cable installation
11.9.7 Cargo pump rooms:
11.8.1 Electric cables are not to be installed in
dangerous zones or spaces, except where a) intrinsically-safe equipment;
specifically permitted by 11.9. to 11.11 or when
associated with intrinsically-safe circuits. b) electrical equipment as defined in 11.9.6(b)
and (c);
a) Zone 1- Areas on open deck, or semi- a) where a space of the type defined by
enclosed spaces on open deck within 3 [m] 11.9.13 is provided with a self closing door
of any cargo oil tank outlet or vapour outlet for the opening onto the main deck and has
(e.g. cargo tank or cofferdam hatch; sight mechanical ventilation, the air intake for
port; tank cleaning opening; ullage opening; which is remote from any dangerous space
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11.11.1 See Pt.5 for relevant Rules for Ships for c) the requirements of 11.12.3(b) apply to
Liquid Chemicals. circuits terminating in the space.
11.12 Special requirements for ships with 11.13 Requirements of electrical equipment
spaces for carrying vehicles with fuel in their allowed in paint stores and in the enclosed
tanks, for their own propulsion spaces leading to paint stores
11.12.1 Passenger ships with special category 11.13.1 Electrical equipment is to be installed in
spaces above the bulkhead deck for carrying paint stores and in ventilation ducts serving such
vehicles: spaces only when it is essential for operational
services.
a) electrical equipment fitted within a height of
45 [cm] above the vehicle deck, or any Certified safe type equipment of the following
platform on which vehicles are carried, or type is acceptable:
within the exhaust ventilation trunking of the
special category space, is to be of a safe a) intrinsically safe Ex 'i'
type;
b) flameproof Ex 'd'
b) electrical equipment situated elsewhere
within the space is to have an enclosure of c) pressurised Ex 'p'
ingress protection rating of at least IP55.
(See IEC Publication 529: Classification of d) increased safety Ex 'e'
Degrees of Protection Provided by
Enclosures), if not of a safe type. e) special protection Ex 's'.
11.12.2 Passenger ships with special category Cables (through-runs or terminating cables) of
spaces below the bulkhead deck for carrying armoured type or installed in metallic conduits
vehicles: electrical equipment fitted within the are to be used.
space and within the space's exhaust ventilation
trunking, is to be of certified safe type. 11.13.2 The minimum requirements for the
certified safe type equipment are as follows:
11.12.3 Passenger ship with cargo spaces,
other than special category spaces, for carrying - explosion group II B
vehicles:
- temperature class T3.
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___________________________________________________________________________________
11.13.3 Switches, protective devices, motor 11.13.5 The enclosed spaces giving access to
control gear of electrical equipment installed in a the paint store may be considered as non-
paint store are to interrupt all poles or phases hazardous, provided that:
and preferably are to be located in non-
hazardous space. - the door to the paint store is a gastight
door with self-closing devices without
11.13.4 In the areas on open deck within 1 m of holding back arrangements,
inlet and exhaust ventilation openings or within 3
m of exhaust mechanical ventilation outlets, the - the paint store is provided with an
following electrical equipment may be installed: acceptable, independent, natural
ventilation system ventilated from a safe
- electrical equipment with the type of area,
protection as permitted in paint stores or
- warning notices are fitted adjacent to
- equipment of protection class Ex 'n' or the paint store entrance stating that the
store contains flammable liquids.
- appliances which do not generate arcs
in service and whose surface does not Note: The paint stores and inlet and exhaust
reach unacceptably high temperature or ventilation ducts under 11.13.1 are classified as
Zone-1 and areas on open deck under 11.13.4
- appliances with simplified pressurised as Zone 2, as defined in IEC Standard 60092-
enclosures or vapour-proof enclosures 502, Electrical Installation in Ships - Part 502 :
(minimum class of protection IP55) Tankers-special features.
whose surface does not reach
unacceptably high temperature A watertight door may be considered as being
gastight.
- cables as specified in 11.13.1.
Section 12
12.1.2 The nominal voltage is the voltage 12.3.2 Services which are duplicated are to be
between phases. divided between the sections.
12.1.3 Where necessary for special application, 12.3.3 In a neutral earthed system, in case of
higher voltages may be accepted by IRS. earth fault the current is not to be greater than
full load current of the largest generator on the
12.2 High voltage and low-voltage switchboard or relevant switchboard section and
segregation not less than three times the minimum current
required to operate any device against earth
12.2.1 Equipment with voltage above 1 kV is not fault. It is to be assured that at least one source
to be installed in the same enclosure as low neutral to ground connection is available
voltage equipment, unless segregation or other whenever the system is in the energized mode.
suitable measures are taken to ensure that
access to low voltage equipment is obtained 12.3.4 Electrical equipment in directly earthed
without danger. neutral or other neutral earthed systems is to
withstand the current due to a single phase fault
12.3 System design against earth for time necessary to trip the
protection device.
12.3.1 It is to be possible to split the main
switchboard into atleast two independent 12.3.5 Means of disconnection are to be fitted in
sections, by means of at least one circuit the neutral earthing connection of each
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generator so that the generator may be against approaching or contact with live or
disconnected for maintenance and for insulation moving parts of at least IP4X is required.
resistance measurement.
12.4.4 The degree of protection of enclosures of
12.3.6 All earthing impedances are to be transformers is to be at least IP23.
connected to the hull. The connection to the hull
is to be so arranged that any circulating currents 12.4.5 For Transformers installed in spaces
in the earth connections do not interfere with accessible to unqualified personnel a degree of
radio, radar, communication and control protection of at least IP4X is required. For
equipment circuits. transformers not contained in enclosures, see
clause 12.14.1.
12.3.7 In the divided systems with neutral
earthed, connection of the neutral to the hull is 12.4.6 The degree of protection of metal
to be provided for each section. enclosed switchgear, controlgear assemblies
and static converters is to be atleast IP32. For
12.4 Degrees of protection switchgear, control gear assemblies and static
converters installed in spaces accessible to
12.4.1 Each part of the electrical installation is to unqualified personnel, a degree of protection of
be provided with a degree of protection at least IP4X is required.
appropriate to the location, and as a minimum
the requirements of IEC Publication 60092-201 12.5 Air clearances
are to be followed.
12.5.1 In general, for Non Type Tested
12.4.2 The degree of protection of enclosures of equipment phase-to-phase air clearances and
rotating electrical machines is to be at least phase-to-earth air clearances between non-
IP23. The degree of protection of terminals is to insulated parts are to be as specified in Table
be at least IP44. 12.5.1.
Table 12.5.1
12.6.1 Creepage distance between live parts 12.7.1 Faults on the generator side of circuit
and between live parts and earthed metal parts breaker : Protective devices are to be provided
for standard components are to be in against phase-to-phase faults in the cables
accordance with relevant IEC Publication for the connecting the generators to the main
nominal voltage of the system the nature of the switchboard and against interwinding faults
insulation material and the transient overvoltage within the generators. The protective devices
developed by switch and fault conditions. are to trip the generator circuit breaker and to
automatically de-excite the generator. In
12.6.2 For non-standardised parts within the distribution systems with a neutral earthed,
busbar section of a switchgear assembly, the phase to earth faults are also to be treated as
minimum creepage distance is to be at least 25 above.
[mm/kV] and behind current limiting devices 16
[mm/kV].
12.11.5 Earthing and short-circuiting : For 12.13.2.2 High voltage cables are to be
maintenance purposes an adequate number of segregated from cables operating at different
earthing and short-circuiting devices are to be voltage ratings and from each other, in
provided to enable circuits to be worked upon particular, they are not to be run in the same
with safety. cable bunch, nor in the same ducts or pipes, or,
in the same box. Where high voltage cables of
12.12 Auxiliary systems different voltage ratings are installed on the
same cable tray, the air clearance between
12.12.1 Source and capacity of supply : If cables is not be less than the minimum air
electrical energy and/or physical energy is clearance for the higher voltage side in 12.6.
required for the operation of circuit breakers and However, high voltage cables are not to be
switches, a store supply of such energy is to be installed on the same cable tray for the cables
provided for at least two operations of all the operating at the nominal system voltage of 1 kV
components. and less.
However, the tripping due to overload or short-
circuit, and under-voltage is to be independent 12.13.2.3 High voltage cables, in general, are to
of any stored electrical energy sources. This be installed on carrier plating when they are
does not preclude shunt tripping provided that provided with a continuous metallic sheath or
alarms are activated upon lack of continuity in armour which is effectively bonded to earth;
the release circuits and power supply failures. otherwise they are to be installed for their entire
length in metallic casings effectively bonded to
12.12.2 Number of external supply sources : earth.
When external source of supply is necessary for
auxiliary circuits, at least two external sources of 12.13.2.4 Terminations in all conductors of high
supply are to be provided and so arranged that voltage cables are to be, as far as practicable,
a failure or loss of one source will not cause the effectively covered with suitable insulating
loss of more than one generator set and/or set material. In terminal boxes, if conductors are not
of essential services. insulated, phases are to be separated from
earth and from each other by substantial
Where necessary one source of supply is to be barriers of suitable insulating materials.
from the emergency source of electrical power
for the start up from dead ship condition. High voltage cables of the radial field type, i.e.
having a conductive layer to control the electric
12.12.3 High voltage test : A power-frequency field within the insulation, are to have
voltage test is to be carried out on any terminations which provide electric stress
switchgear and controlgear assemblies. control.
Terminations are to be of a type compatible with
The test procedure and voltages are to be the insulation and jacket material of the cable
according to the IEC Publication 60298. and are to be provided with means to ground all
metallic shielding components (i.e. tapes, wires
12.13 Installation etc.)
12.13.1 Electrical equipment : Where equip- 12.13.2.5 High voltage cables are to be readily
ment is not contained in an enclosure but a identifiable by suitable marking.
room forms the enclosure of the equipment, the
access doors are to be so interlocked that they 12.13.2.6 Before a new high voltage cable
cannot be opened until the supply is isolated installation or an addition to an existing
and the equipment earthed down. At the installation is put into service, a voltage
entrance of the spaces where high-voltage withstand test is to be satisfactorily carried out
electrical equipment is installed, a suitable on each completed cable and its accessories.
marking is to be placed which indicates danger
of high voltage. As regard the high-voltage The test is to be carried out after an insulation
electrical equipment installed out-side above resistance test.
mentioned spaces, the similar marking is to be
provided.
The test voltage is to be maintained for a Note : Tests specified in IEC Publication 60092-
minimum of 15 minutes. 354 will be considered adequate.
Section 13
Trials
End of Chapter
Chapter 10
Contents
Section
1 General
2 Fusion Welded Pressure Vessels
3 Welded Pressure Pipes
Section 1
General
1.1.2 The term 'fusion weld', for the purpose of 1.2.3 The welding plant and equipment are to be
these requirements, is applicable to welded maintained in an efficient working condition.
joints made by manual, semi-automatic or
automatic electric arc welding processes. 1.2.4 The procedures are to include the regular
Special consideration will be given to the systematic supervision of all welding, and the
proposed use of other fusion welding processes. welders are to be subjected by the works'
supervisors to periodic tests for quality of
1.2.General requirements for welding plant workmanship. Records of these tests are to be
and welding quality kept and are to be available for inspection by the
Surveyors.
1.2.1 The welding plant and equipment are to be
installed under cover and so arranged that all 1.2.5 All welding is to be to the satisfaction of
welding is carried out in positions free from the Surveyors.
draughts and adverse weather conditions.
Section 2
2.1 Manufacture of Class 1 and Class 2 equipment and procedures and to arrange for
fusion welded pressure vessels carrying out preliminary tests as stated in 2.3.
2.1.1 Fusion welded pressure vessels 2.1.2 In the case of Class 1 approval,
constructed to Class 1 and Class 2 arrangements are to be made for the survey
requirements will be accepted only if during construction and testing of a full size
manufactured by firms equipped and competent welded pressure vessel.
to undertake high quality welding. In order that
firms may be approved for this purpose, it will be 2.1.3 The welding plant and equipment are to be
necessary for the Surveyors to visit the works suitable for undertaking work of the standard
for the purpose of inspecting the welding plant, required for Class 1 and Class 2.
2.2 Manufacture of Class 3 fusion welded d) Impact - For Class 1 application and for
pressure vessels steels in Groups 2 and 3;
2.2.1 Class 3 pressure vessels will be accepted e) Fatigue - For Class 1 application and for
if constructed by firms whose works are steels in Groups 2 and 3;
equipped to undertake the welding of pressure
vessels of this Class. Preliminary tests would f) Micrographs, at 100 and 300 magnifications,
require to be carried out as stated in 2.4. of weld center, fusion zone and parent plate,
for Class 1 application and for steels in
2.3 Preliminary tests for Class 1 and Class 2 Group 2 and 3;
fusion welded pressure vessels
g) Macrograph of full section weld;
2.3.1 Preliminary tests to demonstrate the
quality of welding are to be carried out by the h) Chemical analysis of deposited weld metal;
firm under supervision of the Surveyors. The
test requirements will be based on the types of i) Chemical analysis of test plates.
steels and on the welding process to be used.
For approval purposes, the types of rolled steel 2.3.5 Where the welding is carried out by an
plates specified in Pt.2, Ch.3 are grouped as established and approved process, the fatigue
follows : tests and micrographs in 2.3.4(e) and (f) will not,
in general, be required. Furthermore, as an
Group 1 : Carbon and carbon-manganese alternative to 2.3.4(i), a guaranteed analysis
steels - specified minimum obtained from the steelmaker will be accepted.
tensile strength not exceeding
2
500 [N/mm ]; 2.3.6 If a firm intends to manufacture pressure
vessels either of a different group of steel or by
Group 2 : Carbon and carbon-manganese means of a different welding process from that
steels - Specified minimum used in the preliminary tests on which the
tensile strength 500-520 original approval was based, further tests will be
2
[N/mm ]; required to cover the proposed welding
procedure. In such cases full details of the
Group 3 : Alloy steels. material, plate thickness and welding process
proposed are to be submitted for consideration,
when the requirements for further preliminary
tests will be indicated.
e) For each specimen the weld reinforcement c) The tensile strength obtained is to be not
is to be removed by grinding or machining less than the minimum specified tensile
so that the outer and inner surfaces of the strength for the plate material.
weld are flush with the surface of the plate;
2.5.13 Specimen no. 4 : Macro-specimen. The
f) The specimen is to be mounted on roller following conditions are to be satisfied :
supports with the centre of the weld midway
between the supports. A former, with its axis a) Macrograph of a complete cross-section of
perpendicular to the specimen, is to bend the weld, including the heat affected zone, is
the specimen by pushing it through the clear to show a satisfactory penetration and
space between the supports. The diameter fusion, and an absence of significant
of the former and the clear space between inclusions or other defects;
the supports will depend upon thickness of
the specimens, and these dimensions are b) Should there be any doubt as to the
shown in the following table in terms of the condition of the weld as shown by macro-
thickness, t, of the specimen; etching, the area concerned is to be
examined by a micrograph.
Minimum
specified 2.5.14 Specimen no. 5 : Charpy V-notch impact
Clear space
tensile Diameter of test - Class 1 pressure vessels only
between
strength of former
supports
plate The following conditions are to be satisfied :
2
[N/mm ]
< 460 2t 4.2t a) Three Charpy V-notch impact test
specimens are to be cut transversely to the
≥ 460 < 510 3t 5.2t weld, parallel to the plate surface and at
≥ 510 < 620 4t 6.2t mid-plate thickness. The notch is to be cut
at approximately the centre of the weld, and
the axis of the notch is to be perpendicular
g) After bending, there is to be no crack or to the surface of the plate. See Fig.2.5.5;
defect exceeding 1.5 [mm] measured across the
specimen or 3 [mm] measured along the b) The dimensions and tolerances of the
specimen. Premature failure at the edges of the specimens are to be in accordance with Pt.2
specimen will not lead to rejection. Ch.2;
2.5.12 Specimen no. 3 : Tensile test for joint. c) The average energy value obtained from the
The following conditions are to be satisfied : Charpy V-notch test specimen is to be not
less than 27 J when the temperature of the
a) One reduced section tensile test specimen specimen at the time of the test does not
is to be cut transversely to the weld or, in exceed 50°C;
the thick plate, as many tensile test
specimens as may be necessary to d) Where it is proposed to use impact tests
investigate the tensile strength throughout other than the Charpy V-notch type, details
the whole thickness of the joint; are to be submitted for consideration;
The weld reinforcement is to be removed by
grinding or machining so that the outer and e) The foregoing impact test are not applicable
inner surfaces of the weld are flush with the to pressure vessels operating at low metal
surface of the plate. The dimensions of the temperatures, and for such cases the
reduced section tensile test specimens are results of the weld metal impact tests will be
shown in Fig.2.5.4. The width, B, at the specially considered.
reduced section is to be at least 25 [mm];
2.5.15 The test assemblies are to be heat
b) Where the plate thickness exceeds 30 [mm], treated in accordance with 2.10.
the tensile test may be effected on several
reduced section specimens, each with a 2.5.16 If any of the tests fail, further two re-test
thickness of at least 30 [mm] and a width at specimens are to be prepared and tested.
the effective cross-section of at least 25 Should any of these two further re-test also fail,
[mm]; the reasons for the failure are to be investigated
and the results are to be submitted to IRS for
review.
2.7.2.4 Before welding is commenced, it is to be removed and the surface dressed smooth by
ascertained that the plate edges are in grinding prior to radiography.
alignment within the following limits :
2.7.3.1 All consumables intended for use in the 2.7.5 Fitting of tubes to drums and headers
welding of pressure vessels are to be stored in a
dry place and are to be treated in accordance 2.7.5.1 The tube holes in drums or headers are
with the manufacturer's instructions. to be formed in such a way that tubes can be
effectively tightened in them. Where the tube
2.7.3.2 In order to ensure that the quality of ends are not normal to the tube plates, there is
welding consumables is being consistently to be a neck or belt of parallel seating of at least
maintained, they are to be subjected to a regular 13 [mm] in depth, measured in a plane through
system of periodic testing and inspection. the axis of the tube at the holes. Where the
tubes are practically normal to their plates, this
2.7.3.3 Where routine tests are frequently parallel seating is to be not less than 10 [mm] in
carried out in respect of pressure vessels made depth.
in the normal course of production, such tests
may be regarded as meeting the requirements 2.7.5.2 Tubes are to be carefully fitted in the
of 2.7.3.2. tube holes and secured by means of welding,
expanding and bevelling or by other approved
2.7.4 Forming shell sections and end plates methods. The tubes are to project through the
neck or belt of parallel seating by at least 6 [mm]
2.7.4.1 Plates for shell sections and end plates and, where they are secured from drawing out
are to be formed to the required shape by any by means of bellmouthing only, the included
process that will not impair the quality of the angle of belling is to be not less than 30
material. Tests to demonstrate the suitability of a degrees.
process may be required at the discretion of the
Surveyors. 2.7.6 Attachments and fittings
2.7.4.2 Shell plates are to be formed to the 2.7.6.1 All lugs, brackets, branches, manhole
correct contour up to the extreme edges of the frames and reinforcements around openings
plates. and other members are to conform to the shape
of the surface to which they are attached.
2.7.4.3 So far as possible, hot and cold forming
is to be carried out by machine. Forming by 2.7.6.2 Doubling plates with well rounded
hammering, with or without local heating, is not corners are to be fitted in way of attachments
to be employed. such as lifting lugs, supporting brackets and
feet, to minimise load concentrations on
2.7.4.4 All plates which have been hot formed or pressure shells and ends. Compensating plates,
locally heated for forming are to be normalized pads, brackets, and supporting feet are to
on completion of this operation. If, however, hot bedded closely to the surface before being
forming is carried out entirely at a temperature welded, and are to be provided with a 'tell-tale'
within the normalizing range, subsequent heat hole not greater than 9.5 [mm] in diameter, open
treatment will not be required for carbon and to the atmosphere to provide for the release of
carbon- manganese steels. In both instances entrapped air during heat treatment of the
alloy steels may, in addition, be required to be vessel, or as a means of indicating any leakage
tempered. during hydraulic testing and in service
2.7.4.5 All plates which have been cold formed 2.7.6.3 The attachment by welding of such
to an internal radius less than 10 times the plate fittings to the main pressure shell after post-weld
thickness are to be given an appropriate heat heat treatment is not permitted, except where
treatment. the material involved is mild steel, when welding
Indian Register of Shipping
Chapter 10 Part 4
Page 10 of 17 Requirements for Fusion Welding
2.7.6.4 Where the fittings referred to in 2.7.6.3, 2.7.7.2 In assessing the out-of-roundness of
together with flats and other attachments for pressure vessels, the difference between the
supporting internal and external components, maximum and minimum internal diameter
are welded to the main pressure shell, the measured at one cross-section is not to exceed
welding is to be of comparable standard to that the amount given in Table 2.7.7.1.
required for the vessel, and the material used is
to be of compatible composition. 2.7.7.3 The profile, measured on the inside or
outside of the shell by means of a gauge of
2.7.6.5 The finish of all welds attaching pressure designed form of the shell, and having a length
parts and non-pressure parts to the main equal to one-quarter of the internal diameter of
pressure shell is to be such as to allow the vessel, is not to depart from the designed
satisfactory examination of the welds. In the form by more than the amount given in Table
case of Class 1 pressure vessels, these welds 2.7.7.1 This amount corresponds to, x, in
are to be ground smooth, if necessary, to Fig.2.7.7.1.
provide a suitable finish for crack detection
tests, which are to be carried out to the
2.8.1 Radiographic examination 2.8.1.3 Where the surface finish of any weld
which has to be radiographed is such that it will
2.8.1.1 The extent of the radiographic prevent accurate radiographic examination, the
examination of welded seams of Class 1 and surface is to be machined or ground to provide a
Class 2 pressure vessels is to be as follows : smooth contour to the Surveyor's satisfaction.
2.8.1.9 Image quality indicators of the wire type 2.9.2.1 In the case of Class 2 pressure vessels,
are to be placed across the weld, and the when a spot radiograph reveals unacceptable
smallest diameter wire which can be seen in the defects in the welded seam, at least two further
radiograph is to have a diameter not greater radiographs are to be made in the length of weld
than 1.5 per cent of the weld thickness if the represented by the first radiograph, in locations
weld thickness is between 10 [mm] and 50 selected by the Surveyor. If these reveal no
[mm], and not greater than 1.25 per cent of the further unacceptable defects, the defects
weld metal thickness if the thickness is between revealed by the first radiograph are to be
50 and 200 [mm]. repaired and re-radiographed. If the check
radiographs reveal unacceptable defects, then
2.8.1.10 The use of gamma-rays may be either :
permitted in certain circumstances, and details
should be submitted for consideration and a) the whole length of weld represented is to
approval. be cut out and rewelded, then subjected to
spot radiography as if it were a new weld,
2.8.1.11 Radiographs are to be examined by the and the original test plates associated with
Surveyors on the original films using a viewing the weld are to be similarly treated; or
device of suitable illuminating power.
b) the whole length of the weld represented is
to be radiographed. Unacceptable defects
are to be repaired and are to be shown by
radiography to have been eliminated.
2.10.2.5 Where materials other than those ensure the heat treatment of the entire length of
detailed in Table 2.10.2 are used for pressure the longitudinal seam.
vessel construction, full details of the proposed
heat treatment are to be submitted for 2.10.2.7 Where it is proposed to adopt special
consideration. methods of heat treatment, full particulars are to
be submitted for consideration. In such cases it
2.10.2.6 Where pressure vessels are of such may be necessary to carry out tests to show the
dimensions that the whole length cannot be effect of the proposed heat treatment.
accommodated in the furnace at one time, the
pressure vessels may be heated in sections,
provided that sufficient overlap is allowed to
Section 3
3.1.1 Manual or semi-automatic electric arc Slip-on sleeve and socket welded joints are to
welding is to be used for butt and socket welded have sleeves, sockets and weldments of
joints in pipes, for branch pieces and for the adequate dimensions conforming to IRS Rules
attachment of flanges. Oxy-acetylene welding or recognized standard.
may also be used, but, in general, is suitable
only for butt joints in pipes not exceeding 100 Slip-on sleeve and socket welded joints may be
[mm] diameter or 9.5 [mm] thickness. used in Class III piping systems, of any outside
diameter.
3.1.2 Where pressure pipelines are assembled
and butt welded in place, the piping is to be In particular cases, slip-on sleeve and socket
arranged well clear of adjacent structures to welded joints may be allowed by IRS for piping
allow sufficient access for preheating welding, systems of Class I and Class II having outside
heat-treatment and examination of the joints. diameter less than or equal to 88.9 [mm] except
for piping systems conveying toxic media or
Joint preparation, tolerances and edge services where fatigue, severe erosion or
preparation, are to be appropriate to the welding crevice corrosion is expected to occur.
process and in accordance with recognized
standards and/or approved drawings. The 3.1.5 Acceptable methods of flange attachment
preparation of edges is to be carried out by are illustrated in Fig.2.3.1 in Ch.2.
mechanical means and where flame cutting is
used, oxide scales, notches are to be removed 3.1.6 Welding consumables meeting the rule
by grinding or chipping back to sound metal. requirements and, where used, fusible root
inserts, are to be suitable for the materials being
3.1.3 Butt welded joints shall be full penetration joined.
type with details according to the following:
3.1.7 All welds in high pressure and high
a) For class I piping: temperature pipelines are to have a smooth
surface finish and even contour, if necessary
- Double vee groove joint or they are to be made smooth by grinding.
Mn ≥ 20 (2)
C+ ≤ 0.40 100
6
0.3 Mo > 13 (2) 100
1 Cr – 0.5 Mo < 13 100
≥ 13 150
2.25 Cr – 1 Mo and 0.5 Cr – 0.5 Mo – 0.25 V (1) < 13 150
≥ 13 200
Notes :
1. For these materials, preheating may be omitted for thicknesses upto 6 [mm] if the results of
hardness tests carried out on welding procedure qualification are considered acceptable by IRS.
2. For welding in ambient temperature below 0°C, the minimum preheating temperature is required
regardless of the thickness unless specifically approved by IRS.
The values given in the Table 3.1.2 are based examined for defects by the appropriate method
on the use of low hydrogen processes. Higher specified in 3.2.2 to 3.2.4. The test welds are
preheating temperatures may be employed then to be sectioned at positions selected by the
when low hydrogen processes are not used. Surveyor, one surface of each section being
prepared, etched and examined for defects in
3.1.9 The welding procedure proposed for the the weld and heat effected zones.
attachment of flanges, valve chests and other
fittings to pipes, pipes-to-pipes and the 3.1.11 In the case of pipes of branch pieces of
fabrication of branch pieces, whether in carbon alloy steel, mechanical tests and tests to
or alloy steel, is to be approved by the destruction may also be required to demonstrate
Surveyors in the first instance before work is that the joints are of adequate strength.
commenced. For this purpose representative
specimens of such parts will be required for 3.1.12 Check tests of the quality of the welding
examination and testing. are to be carried out periodically at the
discretion of the Surveyors.
Tack welds forming part of the finished weld are
to be made using approved, welding procedure. 3.2 Non-destructive examination of welded
pipes
3.1.10 The assembly for the weld procedure test
and the welding technique should simulate the 3.2.1 In addition to visual examination of pipes
conditions under which the work is to be done welds by the Surveyors, non-destructive
on the installation. Test welds are to be examination of butt and fillet welds is to be
Indian Register of Shipping
Chapter 10 Part 4
Page 16 of 17 Requirements for Fusion Welding
carried out in accordance with 3.2.2 to 3.2.5 to 3.2.2 Butt welds are to be subjected to
the satisfaction of the Surveyors. radiographic examination in accordance with
Table 3.2.1. For radiographic examinations and
Radiographic and ultrasonic examination is to required standards of sensitivity, See 2.8.
be carried out with an appropriate technique by
trained operators using an approved procedure 3.2.3 The use of ultrasonic examination in lieu of
depending on the criticality of the joint. radiographic examination as required by 3.2.2
will be specially considered.
Table 3.2.2 : Magnetic particle or liquid penetrant flaw detection testing of fillet welds
3.2.4 Fillet welds are to be subjected to pieces are to be heat treated on completion of
magnetic particle or liquid penetrant flaw fusion welding.
detection testing in accordance with Table 3.2.2.
3.3.2 Recommended soaking temperatures and
The equipment is to be suitable for flaw periods for post-weld heat treatment are given in
detection and may require calibration against Table 3.3.1.
standard samples. The acceptance criteria for
welds is to be generally in accordance with the 3.3.3 Any proposal to use oxy-acetylene welding
national or international standard. for the fabrication of pipes and branch pieces
will be the subject of special consideration. Due
3.2.5 Defects in welds are to be rectified and re- consideration should be given to the need for
examined by the appropriate test method, all to normalizing and tempering after such welding.
the satisfaction of the Surveyors.
3.4 Heat treatment after forming of pipes
3.2.6 Ultrasonic examination may be required in
special cases in addition to above non- 3.4.1 Heat treatment should preferably be
destructive testing. carried out in a suitable furnace provided with
temperature recording equipment without
3.3 Post-weld heat treatment impairing the specified properties of the
materials. Tests may be carried out if necessary.
3.3.1 Carbon and carbon-manganese steel Localized heat treatment of welded joints
pipes and fabricated branch pieces having a extended sufficiently along the pipe length on
thickness exceeding 30 [mm] are to be heat either side of the joint, carried out with approved
treated on completion of fusion welding. All procedure, can be also accepted.
thicknesses of alloy steel pipes and branch
1. When steels with specified Charpy V notch impact properties at low temperature are used, the
thickness above which postweld heat treatment shall be applied may be increased by special
agreement with IRS.
2. Heat treatment may be omitted for pipes having thickness ≤ 8 [mm], diameter ≤ 100 [mm] and
minimum service temperature 450°C.
3. For C and C-Mn steels, stress relieving heat treatment may be omitted upto 30 [mm] thickness by
special agreement with IRS.
3.4.2 Hot forming should generally be carried for all grades other than carbon and carbon-
out within the normalizing temperature range of manganese steels having UTS 320, 360 and
2
850 – 1000°C for all grades. When carried out 410 [N/mm ].
within this temperature range no subsequent
heat treatment is required for carbon, carbon- 3.4.4 Stress relieving is to be carried out after
manganese and carbon-molybdenum steels. For welding for other than oxy-acetylene welding
Chrome-molybdenum and Carbon-molybdenum- process in accordance with Table 3.3.2.
vanadium steels, a subsequent stress relieving
heat treatment is to be carried out in accordance The stress relieving heat treatment is to consist
with Table 3.3.2. When the hot forming is carried in heating the piping slowly and uniformly to a
out outside the normalizing temperature range, temperature within the range indicated in the
a subsequent heat treatment in accordance with table, soaking at this temperature for a suitable
Table 3.3.1 is required. period, in general one hour per 25 [mm] of
thickness with minimum half an hour, cooling
3.4.3 After cold forming, when bent to a radius slowly and uniformly in the furnace to a
measured at the centerline of the pipe of less temperature not exceeding 400°C and
than four times the outside diameter, heat subsequently cooling in a still atmosphere.
treatment in accordance with Table 3.3.1 is
required. 3.4.5 For oxy-acetylene welding, heat treatment
is to be carried out depending upon the type of
In any case, a stress relieving heat treatment is steel in accordance with Table 3.3.1.
to be carried out in accordance with Table 3.3.2
End of Chapter
Chapter 11
Spare Gear
Contents
Section
1 General Requirements
2 Spare Parts Recommended for Main and Auxiliary Machinery Installations
Section 1
General Requirements
Section 2
2.1 List of minimum required spare parts electric generators for essential
services;
2.1.1 The spare parts recommended for main
and auxiliary machinery installations are shown Table 2.1.5 : Spare parts for main and
in the following Tables:- auxiliary boilers;
Table 2.1.3 : Spare parts for auxiliary steam 2.1.3 Where additional units of adequate
turbines; capacity are fitted, for auxiliary machinery of
each type required for essential services, no
Table 2.1.4 : Spare parts for auxiliary internal spare parts are required.
combustion engines driving
Number required
Sr. Ships for Ships for
Item Spare parts
No. unrestricted restricted
service service
Main bearings or shells for one bearing of each size
1 Main bearings 1 -
and type fitted, complete with shims, bolts and nuts
Pads for one face of Michell type thrust block, or 1 set 1 set
Complete white metal thrust shoe of solid ring type,
1 1
2 Main thrust block or
Inner and outer race with rollers, where roller thrust
1 1
bearings are fitted
Bottom end bearings or shells of each size and type
fitted, complete with shims, bolts and nuts, for one 1 set -
Connecting rod cylinder
3
bearings Top end bearings or shells of each size and type
fitted, complete with shims, bolts and nuts, for one 1 set -
cylinder
4 Cylinder liner Cylinder liner, complete with joint rings and gaskets 1 -
Cylinder cover, complete with valves, joint rings and
gaskets. For engines without covers the respective 1 -
5 Cylinder cover valves for one cylinder unit
Cylinder cover bolts and nuts for one cylinder Half set -
Exhaust valves, complete with casings, seats,
2 sets 1 set
springs and other fittings for one cylinder
Air inlet valves, complete with casings, seats,
1 set 1 set
springs and other fittings for one cylinder
Starting air valve, complete with casing, seat,
6 Cylinder valves 1 1
springs and other fittings
Cylinder overpressure sentinel valve, complete 1 1
1 set
Fuel valves of each size and type fitted complete
see 1/4 set
with all fittings, for one engine
foot note 1
Crosshead type: Piston of each type fitted, complete
with piston rod, stuffing box, skirt, rings, studs and 1 -
nuts
7 Pistons
Trunk piston type: Piston of each type fitted,
complete with skirt, rings, studs, nuts, gudgeon pin 1 -
and connecting rod
8 Piston rings Piston rings, for one cylinder 1 set -
Telescopic cooling pipes and fittings or their
9 Piston cooling 1 set -
equivalent, for one cylinder unit
Lubricator complete, of the largest size, with its
10 Cylinder lubricators 1 -
chain drive or gear wheels
Fuel pump complete, or when replacement at sea is
11 Fuel injection pumps practicable, a complete set of working parts for one 1 -
pump (plunger, sleeve, valves springs etc).
High pressure fuel pipe of each size and shape
12 Fuel injection piping 1 -
fitted, complete with couplings
Scavenge blowers 1 set
Rotors, rotor shafts, bearings, nozzle rings and gear
13 (including see -
wheels or equivalent working parts of other types
turbochargers) foot note 2
Suction and delivery valves for one pump of each
14 Scavenging system 1 set -
type fitted
Table 2.1.1 : Spare parts for main internal combustion engines (Contd.)
Number required
Sr. Ships for Ships for
Item Spare parts
No. unrestrict restricted
ed service service
Complete bearing bush, of each size fitted in the
1 set -
Reduction and/or reverse gear case assembly
15
gear Roller or ball race, of each size fitted in the gear
1 set -
case assembly
Piston rings of each size fitted 1 set -
Main engine driven air
16 Suction and delivery valves complete of each size
compressors Half set -
fitted
Special gaskets and packing of each size and type fitted for cylinder cover and
17 1 set -
cylinder liner for one cylinder
Footnotes :
1 (a) Engines with one or two fuel valves per cylinder: one set of valves, complete.
(b) Engines with 3 or more fuel valves per cylinder : two fuel valves complete per cylinder and a sufficient
number of valve parts, including the body, to form with those fitted in the complete valves, a full engine set.
2 The spare parts may be omitted where it has been demonstrated, at the builder's test bench for one engine of
the type concerned that the engine can be maneuvered satisfactorily with one blower out of action.
The requisite blanking and blocking arrangements for running with the blower out of action are to be available
on board.
Notes
1 The availability of other spare parts, such as gears and chains for camshaft drive, should be specially
considered and decided upon by the Owners.
2 When the spare parts are utilized, new spare parts are to be supplied as soon as possible.
Table 2.1.2 : Spare parts for steam turbines for main propulsion
Number required
Sr. Ships for Ships for
Item Spare parts
No. unrestricted restricted
service service
Bearing bushes, of each size and type fitted for
1 Main bearing the rotor, pinion and gear wheel shafts, for one 1 -
engine
Pads of each size for one face of Michell type
thrust or rings for turbine adjusting block, or each
2 Turbine thrust 1 set 1 set
size fitted for one engine. Assorted liners for 1
block where fitted
Pads for one face of Michell type thrust block, or 1 set 1 set
Complete white metal thrust shoe of solid ring
1 1
3 Main thrust block type, or
Inner and outer race with rollers where roller thrust
1 1
bearings are fitted
Carbon sealing rings, where fitted, with springs for
4 Turbine shaft 1 set 1 set
each size of sealing rings and type of gland
Strainer baskets or inserts for filters of special
5 Oil filters 1 set 1 set
design of each type and size
Notes
1 The availability of other spare parts should be specially considered and decided upon by the Owners.
2 When the spare parts are utilized, new spare parts are to be supplied as soon as possible.
Table 2.1.4 : Spare parts for auxiliary internal combustion engines driving electric
generators for essential services
Number required
Sr. Ships for Ships for
Item Spare parts
No. unrestricted restricted
service service
Main bearings or shells for one bearing of each
1 Main bearings size and type fitted, complete with shims, bolts 1 -
and nuts
Exhaust valves, complete with casings, seats,
2 sets -
springs and other fittings for one cylinder
Air inlet valves, complete with casings, seats,
1 set -
springs and other fittings for one cylinder
2 Cylinder valves Starting air valve, complete with casing, seat,
1 -
springs and other fittings
Cylinder overpressure sentinel valve, complete 1 -
Fuel valves of each size and type fitted complete
Half set -
with all fittings, for one engine
Bottom end bearings or shells of each size and
type fitted, complete with shims, bolts and nuts, for 1 set -
one cylinder
Top end bearings or shells of each size and type
3 Connecting rod bearings
fitted, complete with shims, bolts and nuts, for one 1 set -
cylinder
Trunk piston type : gudgeon pin with bush for one
1 set -
cylinder
4 Piston rings Piston rings, for one cylinder 1 set -
Telescopic cooling pipes and fittings or their
5 Piston cooling 1 set -
equivalent, for one cylinder unit
Fuel pump complete, or when replacement at sea
6 Fuel injection pumps is practicable, a complete set of working parts for 1 -
one pump (plunger, sleeve, valves springs etc).
High pressure fuel pipe of each size and shape
7 Fuel injection piping 1 -
fitted, complete with couplings
Special gaskets and packings of each size and
8 Gaskets and packings 1 set -
type fitted, for cylinder covers and cylinder
Number required
Sr. Ships for Ships for
Item Spare parts
No. unrestricted restricted
service service
Tube stoppers or plugs, of each size used, for
1 Tube stoppers or plugs 20 10
boiler superheater and economiser tubes
2 Fire bars Fire bars for one boiler, where coal fired 1 set Half set
3 Oil fuel burners Oil fuel burners complete, for one boiler 1 set 1 set
2 sets 2 sets
Gauge glasses of round type
per boiler per boiler
4 Gauge glasses 1 set for 1 set for
Gauge glasses of flat type every two every two
boilers boilers
Number required
Sr. Ships for Ships for
Item Spare parts
No. unrestricted restricted
service service
Pumps
1 Reciprocating pumps
1.1 Valves Valve with seats and springs, each size fitted 1 set 1 set
1.2 Piston rings Piston rings, each type and size for one piston 1 set 1 set
2 Centrifugal pumps
Air compressor
1 Piston rings Rings of each size fitted for one piston 1 set 1 set
Notes
1 The availability of other spare parts should be specially considered and decided upon by the Owners.
2 When the spare parts are utilized, new spare parts are to be supplied as soon as possible.
3 When a sufficiently rated standby pump is available, spare part for the pump may be dispensed with.
End of Chapter
Part 5
Special Ship Types
January 2014
Indian Register of Shipping
Contents
Volume
Chapter 7 Tugs I
Chapter 10 Dredgers I
Contents
Volume
Contents
1.1 Application, definitions, class notations and 2.9 Corrugated bulkheads - Construction
documentation
2.10 Corrugated bulkheads - Strength
1.2 Loading guidance information - additional
requirements 2.11 Protective coatings for cargo hold spaces
1.4 Requirements for the fitting of a forecastle 2.13 Hold, ballast and dry space water level
for bulk carriers, ore carriers and combination detectors
carriers
2.14 De-watering of forward spaces
1.5 Arrangements for access in the cargo area
and forward spaces 2.15 Dewatering capacity
1.7 General requirements for double side skin 3.1 Hull arrangement
construction
3.2 Longitudinal strength
2.3 Bottom structure - Scantlings and arran- 3.6 Additional requirements for ore carriers with
gements narrow wing tanks
2.6 Hopper side tank structure 4.2 Load cases and design loads
1.2 Documentation
Section 5 : Direct Strength Calculations
1.3 Materials and material protection
5.1 General
1.4 Definitions
5.2 Load cases and design loads
1.5 Intact stability of tankers during liquid
transfer operations 5.3 Allowable stresses
2.2 Tank arrangement 6.2 Piping systems for bilge, ballast, oil fuel etc.
2.3 Arrangement for access in the cargo area 6.3 Steam connection to cargo tanks
and forward spaces
6.4 Equipment in dangerous spaces
2.4 Technical provisions for means of access for
inspections 6.5 Non-sparking fans
2.5 Equipment in tanks and cofferdams 6.6 Eathing and bonding of cargo tanks and
piping systems for cargo of flash point not
2.6 Chain locker, anchor windlass and exceeding 60°C
emergency fire pump
2.7 Testing of cargo, ballast tanks and other Section 7 : Cargo Handling Systems
spaces in cargo region
7.1 General
2.8 Emergency towing arrangements
7.2 Cargo pumps
2.9 Cargo manifold gutter bars - freeing
arrangements and intact stability 7.3 Cargo piping systems
12.1 General
Section 11 : Inert Gas Systems
12.2 Structural arrangement
11.1 General
12.3 Hatch covers
11.2 Materials
12.4 Slop tanks
11.3 Gas supply
12.5 Cargo piping
11.4 Gas scrubber
Section 13 : Requirements Concerning use
11.5 Gas blowers of Crude Oil or Slops as Fuel for Tanker
Boilers
11.6 Gas distribution lines
Appendix A : List of oils*
11.7 Venting arrangements
Appendix B : List of cargoes other than oils
11.8 Instrumentation and alarms which can be carried out oil tankers
Introduction
2.3 Shipside discharges below the freeboard
Preamble (To the IBC Code) deck
3.4 Access to spaces in the cargo area 8.5 Cargo tank gas-freeing
Introduction
3.6 Air-locks
Preamble
3.7 Bilge and ballast and fuel oil arrangements
2.3 Shipside discharges below the freeboard IR4.6 Permissible stresses in way of supports of
deck type C cargo tanks
3.2 Accommodation, service and control station Section 5 : Process Pressure Vessels and
spaces Liquid, Vapour and Pressure Piping Systems
5.6 Cargo system valving requirements Section 11 : Fire Protection and Fire
Extinguishing
5.7 Ship's cargo hoses
11.1 Fire safety requirements
5.8 Cargo transfer methods
11.2 Fire water main equipment
5.9 Vapour return connections
11.3 Water spray system
Section 15 : Filling Limits for Cargo Tanks 17.12 Submerged electric cargo pumps
16.3 Gas fuel supply 17.20 Propylene oxide and mixtures of ethylene
oxide-propylene oxide with ethylene oxide
16.4 Gas make-up plant and related storage content of not more than 30 per cent by weight
tanks
17.21 Vinyl chloride
16.5 Special requirements for main boilers
17.6 Exclusion of air from vapour spaces 18.8 Cargo transfer operations
17.8 Inhibition
Section 19 : Summary of Minimum
17.9 Permanently installed toxic gas detectors Requirements
2.3 Measures to prevent brittle fracture Section 5 : Container Stowage and Securing
Arrangement
Chapter 7 : Tugs
Section 1 : General
Section 2 : Hull Arrangement and Strength 3.3 Quick release devices for tow hooks
Section 1 : General
2.7 Miscellaneous openings and their closing
1.1 Application devices
1.2 Documentation
Section 3 : Equipment and Cargo Handling
Arrangement
Section 2 : Hull Arrangement and Strength
3.1 Anchoring, mooring and towing equipment
2.1 General
3.2 Cement and mud handling systems
2.2 Longitudinal strength
Section 1 : General
2.3 Bottom and side shell structure 4.2 Drainage from refrigerated fish hold
Chapter 10 : Dredgers
1.2 Documentation
Section 3 : Pushing, Towing - Devices and
Connecting Elements
Section 2 : Hull Arrangement and Strength
3.1 General
2.1 General
Section 1 : General
2.7 Tank testing
1.1 Application
4.1 General
Section 2 : Hull Arrangement and Strength
4.2 Fire protection
2.1 General
4.3 Fire detection systems
2.2 Longitudinal strength
4.4 Fire pumps, hydrants and hoses
2.3 Transverse strength
4.5 Portable fire extinguishers
2.4 Buckling
4.6 Fixed gas fire extinguishing systems
2.5 Local strength
Section 2 : Hull Strengthening for First Year 2.10 Rudder and steering arrangements
Ice Conditions
2.3 Design loads 3.2 Ice classes HAT(B), HT(B), HM(B) and
Ha(B)
2.4 Shell plating
3.3 Ice class 'Ha'
2.5 Frames
1.5 Signboards and instruction manuals 2.10 Automatic stop of oil fired auxiliary boilers
2.7 Refrigerating machinery design pressures 3.4 Piping in way of refrigerated chambers
2.9 Refrigerant pressure vessels 3.6 Airtightness of insulation lining and air ducts
2.11 Oil separators, filters and refrigerant driers 3.8 Galvanizing of fixtures
Section 1 : General
3.2 Generators
1.1 Scope, application
3.3 Distribution arrangements
1.2 Definitions
3.4 Control system power supply
1.3 Classification notations : definition and
general principles 3.5 Auxiliary supplies
1.6 Performance capability of the DP system 4.2 System arrangement and functions
3.1 General
Section 1 : General
Section 2 : Construction
1.1 Application
2.1 Hull
1.2 Classification and class notations
2.2 Sea suctions
1.3 Scope of classification
2.3 Stability
1.4 Assumptions
2.4 Maneuverability
1.5 Submission of plans
2.5 Floodlights
1.6 Operation manual
2.6 Bunkering
1.7 Items to be manufactured under survey
1.5 Plans and particulars 2.9 Interface between diving system and the
ship or floating structure
1.6 Surveys and certification
2.10 Fire prevention, detection and extinction
Section 1 : General
3.3 Smit Type Brackets
1.1 Application
3.4 Bow fairleads
1.2 Documentation for approval
3.5 Pedestal roller fairleads
1.3 Documentation for information
3.6 Winches or capstans
1.1 Application
Section 4 : Vapour Balancing
1.2 Class notations
4.1 General
1.3 Definitions
4.2 Design and equipment
1.4 Documentation
6.1 Procedures
Section 3 : Instrumentation
1.3 Definitions and characteristics, systems and 2.3.2 Prevention of sea pollution by noxious
components liquid substances carried in bulk as cargo
1.3.9 Painting and antifouling systems 2.3.4 Prevention of sea pollution by sewage
2.3.5.4 Procedures
Section 2 : Clean Sea Notation
2.3.6 Prevention of sea pollution by other
2.1 Application sources
2.5.3 Inspection and testing after installation 3.9 Ship Environmental Management Plan
onboard
3.10 Inspections and tests
Section 3 : Clean Air Notation 3.11 Guidance Note for complying with Sulphur
emissions
3.1 Application
3.5 Emission of ozone depleting substances 4.4 Inspections, tests and surveys
3.2 Integration
Section 6 : Carriage Requirements
3.3 Data Exchange
Section 1 : Polar Class Descriptions and 2.14 Stem and stern frames
Application
2.15 Appendages
1.1 Application
2.16 Local details
1.2 Polar classes
2.17 Direct calculation
1.3 Upper and lower ice waterlines
2.18 Welding
2.7 Framing – Side longitudinals (longitudinally- 3.6 Machinery fastening loading accelerations
framed ships)
3.7 Auxiliary systems
2.8 Framing – Web frame and load-carrying
stringers 3.8 Sea inlets and cooling water systems
2.12 Materials
APPENDIX
2.13 Longitudinal strength
End of Chapter
Chapter 1
Contents
Section
1 General
2 Bulk Carriers
3 Ore Carriers
4 Direct Strength Calculations
5 Hatch Covers and Hatch Coamings of Cargo Holds
Section 1
General
1.1 Application, definitions, class notations apply to bulk carriers of "single side skin
and documentation construction" and of “double side skin
construction” as defined in 1.1.2.3.
1.1.1 Application
1.1.2 Definitions
1.1.1.1 The requirements of this chapter apply in
general to all bulk carriers as defined in 1.1.2.1 1.1.2.1 Bulk carrier means a ship which is
except for hull structures of those vessels intended primarily to carry dry cargo in bulk,
mentioned in 1.1.1.2 below. The requirements including such types as ore carriers and
are supplementary to those given for the combination carriers.
assignment of main character of class.
1.1.2.2 “Bulk carrier of single side skin
1.1.1.2 The IACS common structural rules construction” means a bulk carrier in which:
(CSR), for bulk carriers are to be applied to hull
structures of seagoing self propelled bulk a) any part of a cargo hold is bounded by the
carriers of unrestricted service and having a side shell; or
length L of 90 [m] and above, which are
constructed generally with single deck, double b) where one or more cargo holds are bounded
bottom, hopper side tanks and topside tanks by a double side skin, the width of which is less
and with single or double skin construction in than 760 [mm] in bulk carriers constructed
cargo area, excluding ore and combination before 1 January, 2000 and less than 1000 [mm]
carriers. The CSR is also applicable to hybrid in bulk carriers constructed on or after 1
bulk carriers, when at least one cargo hold is January, 2000 but before 1 July, 2006, the
constructed with hopper tank and top side tank. distance being measured perpendicular to the
side shell. Such ships include combination
Accordingly the following requirements of this carriers in which any part of a cargo hold is
chapter will not apply to CSR bulk carriers: bounded by the side shell.
Section 1 – Subsections 1.2, 1.3, 1.4 1.1.2.3 “Bulk carriers of double side skin
Section 2 – Subsections 2.1 to 2.11 construction” means a bulk carrier in which all
Section 3 – All subsections (3.1 to 3.6) cargo holds are bounded by a double-side skin,
Section 4 – All subsections (4.1 to 4.3) other than as defined in b) above.
Section 5 – All subsections (5.1 to 5.6).
1.1.2.4 “Double side skin” means a configuration
1.1.1.3 The requirements of SOLAS Chapter XII where each ship side is constructed by the side
- Additional safety measures for bulk carriers, shell and longitudinal bulkhead connecting the
double bottom and the deck. Hopper side tanks when draught in way of the hold is 0.6T or more.
and top-side tanks may, where fitted, be integral It is also implied that no hold will be empty when
parts of the double side skin construction. the draught in way of the hold is greater than
Double side skin construction is to comply with 0.6T.
the requirements of 1.8.
1.1.3.4 The notation "BULK CARRIER",
1.1.3 Class notations "Strengthened for heavy cargoes" implies that
the vessel is designed for heavier bulk cargo
1.1.3.1 When the IACS Common Structural loadings due to uneven distributions among the
Rules (CSR) are applied as mentioned in 1.1.1.2 cargo holds and any hold may be filled up to the
above, the vessel will be eligible to be assigned top of hatch coaming with bulk cargo of density
3
class notation ‘CSR’ and additional notations as at least upto 1.0 [t/m ] when draught in way of
per the Common Structural Rules, as applicable. the hold is 0.8T or more. It is also implied that
no hold will be empty when the draught in way
1.1.3.2 In general, bulk carriers other than those of the hold is greater than 0.8T.
to which CSR is applied built in compliance with
the above requirements, as applicable, will be 1.1.3.5 The notation "BULK CARRIER",
eligible to be assigned one of the following class "Strengthened for heavy cargoes, hold(s) ... (to
notations: be specified) ... may be empty" implies that the
vessel is also designed for heavy bulk cargo
BULK CARRIER, ESP loading in non-homogeneous loading conditions
BULK CARRIER, "Strengthened for heavy with approved arrangement of empty holds at
Cargoes", ESP the fully loaded draught T. Where found
BULK CARRIER, "Strengthened for heavy appropriate, the 'specification' of empty hold(s)
Cargoes, hold(s) ... (to be specified) ... may be may be suitably worded to include the requested
empty", ESP. combinations of empty holds. e.g. "(Any hold
may be empty)" or "(Holds 2, 4, 6 or 3, 5, 7 may
be empty)".
1.1.4 Documentation
1.2 Loading guidance information - h) Maximum allowable load on deck and hatch
additional requirements covers. If the vessel is not approved to carry
load on the deck or hatch covers, this is to
1.2.1 Bulk carriers, ore carriers and combination be clearly stated in the loading manual;
carriers of length 150 [m] and above, are to
comply with the following in addition to the i) The maximum rate of ballast change
general requirements given in Pt.3, Ch.5. together with the advice that a load plan is
to be agreed with the terminal on the basis
i) The loading manual is to contain the of the achievable rates of change of ballast.
additional information as per 1.2.2 and
also include additional loading 1.2.3 The following additional conditions,
conditions given in 1.2.3; and subdivided into departure and arrival conditions
as appropriate, are to be included in the Loading
ii) The computer-based loading instrument Manual:
is to have additional capabilities as per
1.2.4 and its approval is to subjected to a) Alternate light and heavy cargo loading
the additional conditions of approval conditions at maximum draught, where
given in 1.2.5. applicable;
1.2.2 Loading manual shall contain complete b) Homogeneous light and heavy cargo
information with respect to: loading conditions at maximum draught;
a) The loading conditions on which the design c) Ballast conditions. For vessels having
of the ship has been based, including ballast holds adjacent to topside wing,
permissible limits of still water bending hopper and double bottom tanks, it shall be
moments and shear forces; strengthwise acceptable that the ballast
holds are filled when the topside wing,
Indian Register of Shipping
Chapter 1 Part 5
Page 4 of 44 Dry Bulk Cargo Carriers
hopper and double bottom tanks are empty. - The maximum still water bending moment
Partial filling of the peak tanks is not and shear at the end of the step.
acceptable in the design ballast conditions
unless effective means are provided to - The ship's trim and draught at the end of the
prevent accidental overfilling; step.
d) Short voyage conditions where the vessel is 1.2.5 The digital loading instrument shall also be
to be loaded to maximum draught but with capable of ascertaining, as applicable, the
limited amount of bunkers; following:
e) Multiple port loading/unloading conditions; - The mass of cargo and double bottom
contents in way of each hold as a function of
f) Deck cargo conditions, where applicable; the draught at mid-hold position;
ρh = The density of cargo in a heavy bulk cargo Mh = maximum cargo mass [tonnes], to be
loading condition. carried in the hold under consideration when
carrying heavy bulk cargo of density ρh [t/m ].
3
where,
α = angle of sloping bulkhead with the horizontal a) For bulk carriers in general
plane, [degrees]
- D [m] for the foremost hold and for the
q = ρf . H [t/m ], or
2
transverse bulkhead between the two
foremost holds
= ρh . hc [t/m ]; whichever is greater.
2
- 0.9D [m] for other holds and for other
transverse bulkheads.
2
go = 9.81 [m/s ]
b) For bulk carriers which have been assigned
2
av = vertical acceleration [m/s ] as given in Pt.3, type B-0 freeboard and are of DWT <
Ch.4, Sec.2.3. 50,000 [tonnes]
1.3.3 The design loads for hold-flooded - 0.95D [m] for the foremost hold and for
conditions, when required, are to be taken as the transverse bulkhead between the
per Table 1.3.3 and Fig.1.3.3. two foremost holds
- 0.85D [m] for the other holds and for
In this context, the flooded waterline is to be other transverse bulkheads.
considered at a distance df [m] measured
vertically above the baseline with the ship in 1.3.4 Where the ship is to carry cargoes having
3
upright position. bulk density less than 1.78 [t/m ], in non-
homogeneous condition, the distance df in (a)
and (b) above may be reduced by 0.05D.
h cm − 10 (1 − µ ) h f ] . C .10 −3
II. Flooding of an empty hold 2
pf = 0.01 hf Ff = 0.005 . s . (df - dle)
III. Hold (loaded with bulk For calculation of the resultant loads in flooded conditions in
cargo) adjacent to the homogeneous mode as per 2.10.7
Fc = 0.5 ρ c . g o . s . C .
p c = ρ c . g o . h cm . C .10 −3
flooded hold
(d cm − d le ) 2 . 10 −3
df = as defined in 1.3.3 and where applicable, reduced as per 1.3.4
ρc = density [t/m ] of the bulk cargo in the hold. Unless the ship is designed to carry, in non-homogeneous conditions,
3
3
only iron ore or cargo of bulk density equal to or greater than 1.78 [t/m ], the maximum mass of cargo which may be
carried in the hold shall also be considered to fill that hold up to the top of hatch coaming. Also see Table 1.3.1.
hf = distance [m] from the load point to the flooded waterline
hcm = distance [m] from the load point to the mean plane of cargo surface
µ = permeability of the bulk cargo considered, also see Table 1.3.1
dcm = distance of mean plane of cargo surface from base line [m] see Fig.1.3.3
dle = distance of lower end of bulkhead, from base line [m]
= sum of height of the double bottom 'hDB' and the mean height of lower stool 'hLS'
s = corrugation spacing [mm], S1 as indicated in Fig.2.9.1
Note 1 : Most severe combinations of cargo induced loads and flooding loads are to be determined and used.
See 2.10.4.
Fig.1.4.2
1.5 Arrangements for access in the cargo access to the other parts of the tank, at least two
area and forward spaces hatchways and ladders are to be fitted.
1.5.1 The requirements in 1.5 and 1.6 apply to 1.5.6 Each cargo hold is to be provided with at
bulk carriers of single or double side skin least two means of access as far apart as
construction, with double bottom, hopper side practicable. In general, these accesses should
tanks and top side tanks fitted below the upper be arranged diagonally, for example one access
deck, ore carriers and combinations carriers of near the forward bulkhead on the port side, the
20,000 gross tonnage and over. other one near the aft bulkhead on the starboard
side.
1.5.2 Each space is to be provided with a means
of access to enable, throughout the life of the 1.5.7 For access through horizontal openings,
ship, overall and close-up inspections and hatches or manholes, the dimensions are to be
thickness measurements of the ship’s sufficient to allow a person wearing a self-
structures. Such means of access are to comply contained air-breathing apparatus and protective
with the requirements of the Technical equipment to ascend or descend any ladder
provisions for means of access for inspections, without obstruction and also provide a clear
specified in 1.6 opening to facilitate the hoisting of an injured
person from the bottom of the space.
Where a permanent means of access may be
susceptible to damage during normal cargo 1.5.8 A ship’s means of access to carry out
loading and unloading operations or where it is overall and close-up inspections and thickness
impracticable to fit permanent means of access, measurements is to be described in a Ship
the provision of movable or portable means of Structure Access Manual which is to consist of
access, as specified in 1.6 may be considered, two parts.
provided that the means of attaching, rigging,
suspending or supporting the portable means of The first part should include the following for
access forms a permanent part of the ship’s each space:
structure. All portable equipment may be
capable of being readily erected or deployed by a) plans showing the means of access to the
ship’s personnel. space, with appropriate technical
specifications and dimensions;
Each space for which close-up inspection is not
required such as fuel oil tanks and void spaces b) plans showing the means of access within
forward of cargo area, may be provided with a each space to enable an overall inspection
means of a access necessary for overall survey to be carried out, with appropriate technical
intended to report on the overall conditions of specifications and dimensions. The plans
the hull structure. are to indicate from where each area in the
space can be inspected;
1.5.3 The construction and materials of all
means of access and their attachment to the c) plans showing the means of access within
ship’s structure are to be approved by IRS. the space to enable close-up inspection to
be carried out, with appropriate technical
1.5.4 Access to cargo holds, cofferdams, ballast specifications and dimensions. The plans
tanks and other spaces in the cargo area is to are to indicate the positions of critical
be direct from the open deck and such as to structural areas, whether the means of
ensure their complete inspection. Access to access is permanent or portable and from
double bottom spaces or to forward ballast tanks where each area can be inspected. Critical
may be from a pipe tunnel, cargo hold, double structural areas are to be identified by
hull space or similar compartment not intended advanced calculation techniques for
for the carriage of hazardous cargoes. Access to structural strength and fatigue performance,
a double side skin spaces may be from a and service history of similar ships;
topside tank or double bottom tank.
d) instructions for regularly inspecting and
1.5.5 Tanks and subdivisions of tanks, having a maintaining the structural strength of all
length of 35 [m] or more are to be fitted with at means of access and means of attachment,
least two access hatchways and ladders, as far taking into account any corrosive
apart as practicable. Tanks less than 35 [m] in atmosphere that may be within the space;
length is to be served by at least one access
hatchway and ladder. When a tank is subdivided
by one or more swash bulkheads or similar
obstructions which do not allow ready means of
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Rules and Regulations for the Construction and Classification of Steel Ships - 2014
Page 9 of 44
___________________________________________________________________________________
For the purpose of ballast tanks of less than
e) instructions for safety guidance when rafting 5 [m] width forming double side spaces, the
is used for close-up inspections and horizontal plating structure is credited as a
thickness measurements; stringer and a longitudinal permanent
means of access, if it provides a continuous
f) instructions for the rigging and use of any passage of 600 [mm] or more in width past
portable means of access in a safe manner; frames or stiffeners on the side shell or
longitudinal bulkhead. Openings in stringer
g) an inventory of all portable means of plating utilized as permanent means of
access; and access are to be arranged with guard rails
or grid covers to provide safe passage on
The second part of the Ship Structure Access the stringer or safe access to each
Manual is to contain a form of record of transverse web.
periodical inspections and maintenance, and
change of inventory of portable equipment due e) Vertical ladder means a ladder of which the
to additions or replacement after construction. inclined angle is 70° and over up to 90°. A
The format of this part is to be approved at the vertical ladder is not to be skewed by more
time of construction of the ship. The manual is than 2°.
to include a re-approval procedure for any
changes to the permanent, portable or movable f) Overhead obstructions mean the deck or
means of access. stringer structure including stiffeners above
the means of access.
The Ship Structure Access Manual is to be
approved by IRS and an updated copy including g) Distance below deck head means the
all revisions / re-approvals is to be kept onboard. distance below the plating.
1.6 Technical provisions for means of access h) Cross deck means the transverse area
for inspections which is located inboard of the line of hatch
openings of the main deck and between
1.6.1 Definitions : For the purpose of these adjacent transverse hatch coamings.
technical provisions, the following definitions
apply: 1.6.2 Structural members subject to the close-up
inspections and thickness measurements of the
a) Rung means the step of vertical ladder or ship’s structure referred to in Pt.1, Ch.2, except
step on the vertical surface. those in double bottom spaces, are to be
provided with a permanent means of access to
b) Tread means the step of inclined ladder, or the extent as specified in Table 1.6.2(a) and
step for the vertical access opening. Table 1.6.2(b), as applicable. For wing ballast
tanks of ore carriers, approved alternative
c) Flight of an inclined ladder means the methods such as rafting may be used in
actual stringer length of an inclined ladder. combination with the fitted permanent means of
For vertical ladders, it is the distance access, provided that the structure allows for its
between the platforms. safe and effective use.
1.1 For each topside tank of which the height is 6 [m] and over, one longitudinal continuous
permanent means of access shall be provided along the side shell webs and installed at a minimum of
1.6 [m] to a maximum of 3 [m] below deck with a vertical access ladder in the vicinity of each access
to that tank.
1.2 If no access holes are provided through the transverse webs within 600 [mm] of the tank base and
the web frame rings have a web height greater than 1 [m] in way of side shell and sloping plating, then
stop rings/grab rails shall be provided to allow safe access over each transverse web frame ring.
1.3 Three permanent means of access, fitted at the end bay and middle bay of each tank, shall be
provided spanning from tank base up to the intersection of the sloping plate with the hatch side girder.
The existing longitudinal structure, if fitted on the sloping plate in the space may be used as part of
this means of access. If the longitudinal structures on the sloping plate are fitted outside of the tank a
means of access is to be provided.
1.4 For topside tanks of which the height is less than 6 [m], alternative means as defined in 1.6.10 of
the technical provisions or a portable means may be utilized in lieu of the permanent means of
access.
1.5 For each bilge hopper tank of which the height is 6 [m] and over, one longitudinal continuous
permanent means of access shall be provided along the side shell webs and installed at a minimum of
1.2 [m] below the top of the clear opening of the web ring with a vertical access ladder in the vicinity of
each access to the tank.
Note: The height of a bilge hopper tank located outside of the parallel part of vessel is to be
taken as the maximum of the clear vertical distance measured from the bottom plating to the
hopper plating of the tank.
1.5.1 An access ladder between the longitudinal continuous permanent means of access and the
bottom of the space shall be provided at each end of the tank.
1.5.2 Alternatively, the longitudinal continuous permanent means of access can be located through
the upper web plating above the clear opening of the web ring, at a minimum of 1.6 [m] below the
deck head, when this arrangement facilitates more suitable inspection of identified structurally critical
areas. An enlarged longitudinal frame of at least 600 [mm] clear width can be used for the purpose of
the walkway.
The foremost and aftermost bilge hopper ballast tanks with raised bottom of which the height is 6 [m]
and over, a combination of transverse and vertical means of access for access to the sloping plate of
hopper tank connection with side shell plating for each transverse web can be accepted in place of the
longitudinal permanent means of access.
1.5.3 For double side skin bulk carriers the longitudinal continuous permanent means of access may
be installed within 6 [m] from the knuckle point of the bilge, if used in combination with alternative
methods to gain access to the knuckle point.
1.6 If no access holes are provided through the transverse ring webs within 600 [mm] of the tank base
and the web frame rings have a web height greater than 1 [m] in way of side shell and tank base, then
step rungs/grab rails are to be provided to allow safe access over each transverse web frame ring.
1.7 For bilge hopper tanks of which the height is less than 6 [m], alternative means as defined in
1.6.10 or a portable means may be utilized in lieu of the permanent means of access. It is to be
demonstrated that such means of access can be deployed and made readily available in the areas
where needed.
1.8 Permanent means of access is to be provided in accordance with the applicable sections of Pt.5,
Ch.2, Table 2.4.2.
1.9 For fore peak tanks with a depth of 6 [m] or more at the centre line of the collision bulkhead, a
suitable means of access shall be provided for access to critical areas such as the underdeck
structure, stringers, collision bulkhead and side shell structure.
1.9.1 Stringers of less than 6 [m] in vertical distance from the deck head or a stringer immediately
above are considered to provide suitable access in combination with portable means of access.
1.9.2 In case the vertical distance between the deck head and stringers, stringers or the lowest
stringer and the tank bottom is 6 [m] or more, alternative means of access as defined in 1.6.10 is to be
provided.
1.1 Permanent means of access is to be fitted to provide access to the overhead structure at both
sides of the cross deck and in the vicinity of the centerline. Each means of access is to be accessible
from the cargo hold access mentioned in 1.5.6 or directly from the main deck and installed at a
minimum of 1.6 [m] to a maximum of 3 [m] below the deck. Means of access is to be provided to the
cross deck structures of the foremost and aftermost part of the cargo hold.
1.2 An athwartship permanent means of access fitted on the transverse bulkhead at a minimum 1.6
[m] to a maximum 3 [m] below the cross-deck head is accepted as equivalent to 1.1
1.3 Access to the permanent means of access to overhead structure of the cross deck may also be
via the upper stool.
1.4 Ships having transverse bulkheads with full upper stools (extending between top side tanks and
upto the hatch end beam) with access from the main deck which allows monitoring of all framing and
plates from inside, do not require permanent means of access of the cross deck.
1.5 Special attention is to be paid to the structural strength where any access opening is provided in
the main deck or cross deck. The requirements for access to cross deck structure are also applicable
to ore carriers.
1.6 Alternatively, movable means of access may be utilized for access to the overhead structure of
cross deck if its vertical distance is 17 [m] or less above the tank top. This movable means of access
need not be necessarily be carried on board the vessel, but is to be made available when required.
1.7 Permanent means of vertical access shall be provided in all cargo holds and built into the structure
to allow for an inspection of a minimum of 25% of the total number of hold frames port and starboard
equally distributed throughout the hold including at each end in way of transverse bulkheads. But in no
circumstance shall this arrangement be less than 3 permanent means of vertical access fitted to each
side (fore and aft ends of hold and mid-span). Permanent means of vertical access fitted between two
adjacent hold frames is counted for an access for the inspection of both hold frames. A means of
portable access may be used to gain access over the sloping plating of lower hopper ballast tanks.
1.8 In addition, portable or movable means of access are to be utilized for access to the remaining
hold frames upto their upper brackets and transverse bulkheads.
1.9 Portable or movable means of access may be utilized for access to hold frames upto their upper
bracket in place of the permanent means required in 1.6. These means of access are to be carried on
board the ship and able to be transported to location in cargo hold and safely erected by ship’s staff.
1.10 The width of vertical ladders for access to hold frames is to be at least 300 [mm], measured
between stringers.
1.11 A single vertical ladder over 6 [m] in length is acceptable for the inspection of the hold side
frames in a single skin construction.
1.12 For double side skin construction no vertical ladders for the inspection of the cargo hold surfaces
are required. Inspection of this structure should be provided from within the double hull space.
Fig.1.6.4
1.6.7 The width of inclined ladders between (Refer to Classification Notes : “Guidelines for
stringers are not to be less than 400 [mm] in approval / acceptance of alternative means of
general. However, the width of inclined ladders access to spaces in oil tankers, bulk carriers,
for access to a cargo hold is to be at least 450 ore carriers and combination carriers”).
[mm]. The treads are to be equally spaced at a
distance apart, measured vertically, of between Means for safe operation and rigging of such
200 [mm] and 300 [mm]. When steel is used, the equipment to and from and within these spaces
treads are to be formed of two square bars of are to be clearly described in the Ship Structure
not less than 22 [mm] by 22 [mm] in section, Access Manual.
fitted to form a horizontal step with the edges
pointing upward. The treads are to be carried 1.6.11 For access through horizontal openings,
through the side stringers and attached thereto hatches or manholes, the minimum clear
by double continuous welding. All inclined opening is not to be less than 600 [mm] x 600
ladders are to be provided with two course [mm], which may have corner radii of not more
handrails of substantial construction on both than 100 [mm]. Where a larger corner sections
sides, fitted at a convenient distance above the is desired to reduce the stress level around the
treads. Vertical height of handrails is not to be opening, the size of the opening is to be suitably
less than 890 [mm] from the center of the step increased to ensure the required size of clear
and two course handrails need only be provided opening e.g. 600 [mm] x 800 [mm] opening with
where the gap between stringer and top handrail 300 [mm] corner radius is acceptable.
is greater than 500 [mm].
When access to a cargo hold is arranged
1.6.8 For vertical ladders or spiral ladders, the through the cargo hatch, the top of the ladder is
width and construction should be in accordance to be placed as close as possible to the hatch
with accepted international or national coaming.
standards.
The width of vertical ladders is to be not less Access hatch coamings having a height greater
than 350 [mm] and the vertical distance between than 900 [mm] shall also have steps on the
the rungs is to be between 250 [mm] and 350 outside in conjunction with the ladder.
[mm]. The minimum climbing clearance in width
is to be 600[mm] other than for ladders between
hold frames.
The vertical ladders are to be secured at
intervals not exceeding 2.5 [m] apart to prevent
vibration.
Fig.1.7.1 : Distance between inner and outer shell in way of double-side skin
Section 2
Bulk Carriers
a) Single side skin bulk carriers of length - Maximum stillwater bending moment and
equal to or more than 150 [m] and shear force values in flooded conditions, at
designed to carry bulk cargoes having a the section under consideration.
3
density of 1000 [kg/m ] and above.
- The wave bending moment and wave shear
b) Double side skin bulk carriers of length force values for the flooded condition are to
equal to or more than 150 [m] in which be assumed equal to 80% of the most
any part of the longitudinal bulkhead is probable maximum lifetime values given in
located within B/5 or 11.5 [m] whichever Pt.3, Ch.5, Sec.2.2.
is less, inboard from the ship’s side at
right angle to the centre line at the - The structure is assumed to remain fully
assigned summer load line, designed to effective in resisting the applied loading.
carry bulk cargoes having a density of
3
1000 [kg/m ] and above. 2.2.7 The buckling strength of the structure
participating in longitudinal strength is to comply
2.2.3 The longitudinal strength calculations in the requirements given in Pt.3, Ch.3.
the flooded conditions are to be investigated for
each of the seagoing cargo and ballast loading 2.3 Bottom structure - Scantlings and arran-
conditions and the still water bending moment gements
and shear forces determined. Intermediate
conditions of loading encountered during ballast 2.3.1 The scantlings and arrangements are, in
water exchange need not be considered. Each general, to be as per Pt.3, Ch.7, except as given
cargo hold is to be considered individually below.
flooded upto the equilibrium waterline.
2.3.2 For bulk carriers with notation
2.2.4 For intact and flooded conditions featuring “Strengthened for heavy cargo” (with or without
uneven distribution of cargo loading (e.g. the additional empty hold notation) and for all
loading conditions with empty holds or ballast ships in way of cargo hold(s) designated for
Indian Register of Shipping
Rules and Regulations for the Construction and Classification of Steel Ships - 2014
Page 19 of 44
___________________________________________________________________________________
ballast, the spacing of plate floors in the double
2
bottom is generally not to exceed 2.5 [m]. = 60 [N/mm ] in general
2
2.3.3 The inner bottom plating is to be based on = 80 [N/mm ], for ore loaded holds between
the design loads given in section 1.3.2 for intact adjacent empty holds.
conditions and 1.3.3 for hold flooded conditions.
The permissible stress for hold flooded The requirements for section modulus of inner
conditions is to be as per Pt.3, Ch.7, Table 4.2.1 bottom longitudinals for hold flooded conditions
using the value of fB based on still water bending is to be similarly calculated. However, the
moment and wave bending moment in flooded permissible stress is to be obtained using the
conditions as given in 2.2.6. value of fB based on SWBM and WBM in
flooded conditions as per 2.2.6.
For bulk carriers with notation “Strengthened for
heavy cargo” (with or without the additional 2.3.5 Structural details in way of double bottom
empty hold notation) or the thickness of inner tank and hopper tank knuckle is to be given
bottom plating between the hopper or side tanks special attention during design/fabrication.
is not to be less than:
In all dry holds where the double bottom tank
t = (9.0 + 0.03L) √k + tc [mm] and hopper tank knuckle is of radiused
construction and the floor spacing is 2.5 [m] or
where, L need not be taken as greater than 200 greater, brackets as shown in Fig.2.3.5 are to be
[m]. arranged mid-length between floors in way of
the intersection. The brackets are to be attached
2.3.4 The section modulus of inner bottom to the adjacent inner bottom and hopper
longitudinals is to be based on the design loads longitudinals. The thickness of the brackets is to
given in 1.4.2 for intact conditions and 1.4.3 for be in accordance with Pt.3, Ch.7, Sec. 6.3.3 but
hold flooded conditions. For bulk carriers with need not exceed 15 [mm].
notation “Strengthened for heavy cargo” (with or
without the additional empty hold notation) the In way of floodable holds, two intermediate
section modulus of both the bottom and inner brackets as shown in Fig.2.3.5, are to be
bottom longitudinals (except in hopper side provided in all cases where the hopper to double
tanks) for intact conditions is to be obtained as bottom knuckle is radiused and one such
per Pt.3, Ch.7, Sec.6.3 using permissible intermediate bracket is to be provided where the
bending stress 'σ' value given below: double bottom tank and hopper tank knuckle is
of welded construction.
For bottom longitudinals in way of empty holds
where,
of the collars, the radius of the scallops For each loading condition, the maximum bulk
should not be less than 150 [mm]. See cargo density to be carried is to be considered in
Fig.2.3.6(a). Alternatively, the scallop may calculating the allowable hold loading limit.
be retained on the hopper tank side,
provided gusset plates are arranged in line
with the inner bottom plating. See
Fig.2.3.6(b)
τa
S f2 = A fh . .10 −3 [kN]
η2
where,
2
Af = sectional area [mm ], of the floor panel
adjacent to hoppers;
2
Afh = net sectional area [mm ], of the floor
panels in way of the openings in the outmost
bay (i.e. that bay which is closer to hopper);
t
0.8
σy
= 162 .σ y .
0.6
or ;
s 3
whichever is lesser.
Where, in the end holds, girders or floors run out For floors adjacent to the stools or transverse
and are not directly attached to the boundary σy
stool or hopper girder, their strength is to be bulkheads, τa may be taken as .
evaluated for the one end only. 3
2.4.4. where,
The thickness of the main frame lower bracket is 2.5.7 The dimensions of the lower and upper
to be 2 [mm] greater than the minimum frame brackets are not to be smaller than those shown
web thickness. In no case the thickness of the in Fig.2.5.7.
main frame lower brackets and upper brackets
is to be less than that provided for main frame The section modulus of the frame and bracket or
web. integral bracket and associated shell plating, at
the locations marked 'Zb' in Fig.2.5.7, is not to
2.5.4 Frames are to be fabricated symmetrical be less than twice the section modulus required
sections with integral upper and lower brackets for the frame in midspan area.
and are to be arranged with soft toes.
In all cases, the section moduli of the side 2.9.1 Where bulkheads are of corrugated
longitudinals and sloping bulkhead longitudinals construction, the angle of corrugation (i.e. of
which are connected to the supporting brackets webs with the plane of bulkheads) is not to be
are to be determined using the spacing 's' as less than 55, See Fig.2.9.1.
shown in Fig.2.5.9 and span taken between
transverses.
Fig. 2.9.3
Corrugation
tf
Corrugation
e
tf
tf
Stool Top
e
Stool Top
Fig.2.9.4 Permitted distance, e, from edge of stool top plate to surface of corrugation flange
2.10 Corrugated bulkheads - Strength 2.10.2 In way of ballast holds, the scantlings of
bulkhead are not to be less than those required
2.10.1 The scantlings of bulkheads are to be as for a deep tank.
per Pt.3, Ch.10, taking into account the dry bulk
cargo loading given in 1.3.2 and, where 2.10.3 The following requirements apply to
applicable as per 2.10.3, the loading in cargo vertically corrugated transverse watertight
hold flooded condition as given in 1.3.3. bulkheads bounding those cargo holds which
are required to be considered flooded for the
The most severe combinations of cargo induced Unless the ship is intended to carry, in non-
loads and flooding loads are to be used for the homogeneous conditions, only iron ore or cargo
check of the scantlings of each bulkheads, having bulk density equal or greater than 1.78
3
depending on the loading conditions [t/m ], the maximum mass of cargo which may
(homogeneous and non-homogeneous included be carried in the hold shall also be considered to
in the loading manual). fill that hold upto the upper deck level at
centreline.
Individual flooding of both loaded and empty
holds is to be considered. 2.10.7 At each point of the bulkhead structure,
the resultant pressure p and the resultant force
Non homogeneous part loading conditions F, to be considered for the scantlings of the
associated with multiport loading and unloading bulkhead, is given in Table 2.10.7:
operations for homogeneous loading conditions
need not be considered.
where, pressures pc,f, pc, pf and forces Fc,f, Fc - are attached to the corrugations and the top
and Ff are given in Table 1.3.3 and Fig.1.3.3. of the lower stool by one side penetration
welds or equivalent;
2.10.8 The design bending moment M, [kN-m], - have with a minimum slope of 45 and their
for the bulkhead corrugations is given by: lower edge is in line with the stool side
plating;
F.l - have thicknesses not less than 75% of that
M= of the corrugation flange;
8 - material properties are at least equal to that
of the corrugation flanges.
where,
2.10.10 For the purpose of the calculations,
F = resultant force, [kN], as per 2.10.7. gusset plates can be considered effective
provided they:
l = span of the corrugation, [m], See Fig.2.10.8
(a), (b) and (c). - act together with effective shedder plates
- have a height not less than half of the flange
The shear force Q, [kN], at the lower end of the width
bulkhead corrugations is given by: - are fitted in line with the stool side plating
- are generally welded to the top of the lower
Q = 0.8.F stool by full penetration welds, and to the
corrugations and shedder plates by one side
2.10.9 For the purpose of the calculations, the penetration welds or equivalent
shedder plates can be considered effective
provided they: - have thickness and material properties at
least equal to those of the flanges.
- are not knuckled;
2.10.11 The thickness of the lower part of 2.10.15, but not to be taken greater than 1.15
corrugations considered in the application of times Zle as defined above.
2.10.12 to 2.10.14 are to be maintained for a
distance from the inner bottom (if no lower stool (σy)le, (σy)m = minimum upper yield stress of the
is fitted) or the top of the lower stool not less material at the lower end of corrugations and at
than 0.15l; the midspan of corrugations respectively.
Q . h g − 0.5 . h g2 . s 1 . p g
The thickness of the middle part of the Z' le = Z g + 10 .
3
corrugations considered in the application of σy
2.10.12, 2.10.13 and 2.10.15 are to be
maintained to a distance from the deck (if no
where,
upper stool is fitted) or the bottom of the upper
stool not greater than 0.3l; 3
Zg = section modulus [cm ], of the corrugations
calculated, according to 2.10.15 in way of the
where 'l' is the span of the corrugation as
upper end of shedder or gusset plates, as
defined in 2.10.8.
applicable
The section modulus of the corrugation in the
remaining upper part of the bulkhead is not to be
Q = shear force [kN] as per 2.10.8
less than 75% of that required for the middle
part, corrected for difference in yield stresses, if
hg = height [m] of shedders or gusset plates, as
any.
applicable (See Fig.2.10.11 a, b, c, d & e)
2.10.12 The bending capacity of the
s1 = corrugation spacing [mm]. See Fig.2.9.1
corrugations is to comply with the following
relationship: 2
pg = resultant pressure [N/mm ] as per 2.10.7,
calculated in way of the middle of the shedders
M .10 3 or gusset plates, as applicable.
≤ 0.95
[0.5. Z le . (σ y ) le + Z m (σ y ) m ]
2.10.13 The net plate thickness to be used in
the calculations of scantlings as per 2.10.14 to
where, 2.10.17 is to be obtained by:
2.10.14 The section modulus of the lower end of hg = height of gusset plate [m]; but not to be
corrugation is to be calculated using the net 10
plate thicknesses and with the compression taken greater than . s gu .
flange having an effective flange width, bef [m] 7
not larger than: See Fig.2.10.11c, d and e.
2.12.5 Bulk carriers contracted before 1 July, b) In any ballast tank forward of the collision
1998 which have been assigned a reduced bulkhead giving an audible and visual alarm
freeboard in compliance with regulation 27(7) of when the liquid in the tank reaches a level
the International Convention on Load Lines, not exceeding 10% of the tank capacity. An
1966, may be considered as complying with the alarm overriding device is to be installed for
requirements of 2.12.2. activation when the tank is in use; and
2.12.6 Bulk carriers which have been assigned a c) In any dry or void space other than a chain
reduced freeboard in compliance with the cable locker, any part of which extends
provisions of paragraph (8) of the regulation forward of the foremost cargo hold, giving
equivalent to regulation 27 of the International an audible and visual alarm at a water level
Convention on Load Lines, 1966, adopted by of 0.1 [m] above the deck. Such alarms
resolution A.320(IX), as amended by resolution need not be provided in enclosed spaces if
A.514(13), may be considered as complying the volume of the space does not exceed
with the requirements of 2.12.1, 2.12.2 or 0.1% of the ship’s maximum displacement
2.12.3, as appropriate. volume.
2.12.7 On bulk carriers which have been The audible and visual alarms described in a),
assigned reduced freeboard in compliance with b) and c) above are to be located on the
the provisions of regulation 27(8) set out in navigation bridge.
Annex B of the Protocol of 1988 relating to the
International Convention on Load Lines, 1966, Note : The water level detectors are to be of
the condition of equilibrium after flooding shall approved type. For further details regarding
satisfy the relevant provisions of that Protocol. performance tests, sensor locations, installation
and other testing requirements refer
2.13 Hold, ballast and dry space water level classification notes: “Type approval, installation
detectors and testing of water level detectors on bulk
carriers and Single Hold Cargo Ships other than
2.13.1 All bulk carriers are to be fitted with water Bulk Carriers”.
level detectors as indicated in a), b) and c)
below: 2.14 De-watering of forward spaces
a) In each cargo hold, giving audible and visual 2.14.1 On bulk carriers, the means for draining
alarms, one when the water level above the and pumping ballast tanks forward of the
inner bottom in any hold reaches a height of collision bulkhead and bilges of dry spaces any
0.5 [m] and another at a height not less than part of which extends forward of the foremost
15% of the depth of the cargo hold but not cargo hold, is to be capable of being brought
more than 2 [m]. into operation from a readily accessible
enclosed space, the location of which is
accessible from the navigation bridge or
propulsion machinery control position without
2.14.4 The failure of either control system power 2.15 Dewatering capacity
or actuator power is not to alter the valve
position. 2.15.1 The dewatering system for ballast tanks
located forward of the collision bulkhead and for
2.14.5 Positive indication is to be provided at the bilges of dry spaces any part of which extends
remote control station to show that the valve is forward of the foremost cargo hold is to be
fully open or closed. designed to remove water from the forward
3
spaces at a rate of not less than 320A [m /h],
2
2.14.6 The dewatering arrangements are to be where A is the cross-sectional area in [m ] of the
such that any accumulated water can be drained largest air pipe or ventilator pipe connected from
directly by a pump or educator. the exposed deck to a closed forward space that
is required to be dewatered by these
2.14.7 When the dewatering arrangements are arrangements.
in operation, other systems essential for the
safety of the ship including fire-fighting and bilge
Section 3
Ore Carriers
3.3.1 The scantlings and arrangements are in 3.5.1 The arrangement and scantlings of deck
general, to be as per Pt.3 Ch.7 except as given plating inside line of ore hatchways are to be in
below. accordance with the requirements for bulk
carriers given in Sec.2.8.
3.3.2 Spacing of floors in the double bottom in
centre hold is not to exceed 2.5 [m] or 0.01L 3.5.2 When the hatch coamings are situated
whichever is greater. Additional side girders are inboard of the longitudinal bulkhead, the portion
to be provided below the centre hold so that the of the deck between the two is to be suitably
spacing of longitudinal girders generally does supported by longitudinals.
not exceed 3.6 [m].
3.6 Additional requirements for ore carriers
3.3.3 The spacing of bottom transverses in the with narrow wing tanks
wing tanks is not to exceed the greater of 0.02L
or 3.6 [m]. 3.6.1 For ore carriers of 150 [m] in length and
above, in which any part of longitudinal
3.3.4 The thickness of inner bottom plating in bulkhead is located within B/5 or 11.5 [m],
cargo holds is to be based on the design loads whichever less, inboard from ship side at right
given in Sec.1.3, however not to be less than: angle to the centerline at the assigned summer
load line, are to comply with the following
t = (9 + 0.012s) √k + tc [mm]. additional requirements given in 3.6.2 to 3.6.6.
3.4 Wing tank structure 3.6.2 The longitudinal strength in the hold
flooded condition is to comply with the
3.4.1 In wing tanks, primary bottom structure is requirements given in 2.2.3 to 2.2.7.
to be so arranged as to maintain structural
continuity of the hold double bottom structure in 3.6.3 The thickness of the inner bottom plating
the transverse direction. and the section modulus of inner bottom
longitudinals are to comply with the
3.4.2 The inner bottom plating is to be extended requirements given in 2.3.3 and 2.3.4
into the wing tank in the form of a horizontal respectively.
gusset plate. The gusset plates are to be of
sufficient width to provide effective scarfing of 3.6.4 The shear capacity of the double bottom is
the inner bottom into the wing tank structure. to comply with the requirements of 2.4.3 to
2.4.5.
3.4.3 At locations where bottom transverses are
not provided in line with plate floors in the hold 3.6.5 The thickness longitudinal bulkhead
double bottom, substantial brackets are to be plating and stiffeners are to be in accordance
arranged in line with such plate floors. These with Pt.3, Ch.10 using the design loads in hold
brackets are to extend transversely over at least flooded conditions given in Pt.3, Ch.10 section 5
three longitudinal spaces and vertically well using fs based on SWBM and WBM in hold
above the inner bottom level. flooded conditions.
3.4.4 In the wing tanks, bulkheads are to be 3.6.6 The construction and strength of
arranged in line with the centre hold bulkheads transverse corrugated bulkheads is to be as per
so that continuity of transverse strength is 2.9 and 2.10 respectively.
maintained.
Section 4
4.1.4 For deep girders, bulkhead panels, bracket c) Heavy ore cargo in hold, hold considered
zones etc. FEM or equivalent methods are to be flooded with adjacent hold empty - with
applied. For systems consisting of slender respect to double bottom of the loaded and
girders, calculations may be based on beam adjacent empty holds and transverse
theory. bulkhead in between.
In case of corrugated bulkheads, the dimension d) Maximum cargo in the hold filled upto the
of the elements used to model the corrugations top of hatch coaming, hold considered
may be the width of the flange, the first row of flooded - with respect of transverse
elements from the top of the stool is to have an bulkhead structure.
aspect ratio equal to 1 and for the other
elements, the aspect ratio is not to exceed 3; e) Specified cargo on deck and external sea
pressure on deck (in particular forward
4.1.5 The calculations are to reflect the holds) with respect to deck and top wing
structural response of 2 or 3-dimensional tank structure.
structure considered, with due attention to the
boundary conditions. The minimum longitudinal 4.2.3 Normally, harbour conditions need not be
extent of the model is to be half the hold length considered provided the minimum draught in
on either side of the transverse bulkhead and harbour with cargo hold filled, is not less than
transversely, the model is to extend over a two thirds of the draught in the associated
minimum of half the ship breadth. approved seagoing condition.
4.1.6 The calculations are to be carried out 4.2.4 The internal pressures on transverse
using net thicknesses obtained after deduction bulkheads and inner bottom are to be taken as
of applicable corrosion additions specified in per Sec.1.4. The external sea pressures are to
2.4.3 and 2.10.13 and those in Pt.3, Ch.3. be taken as per Pt.3.Ch.4 based on the draught
at midhold.
4.2 Load cases and design loads
4.3 Allowable stresses
4.2.1 The calculations are to be carried out for
realistic intact and flooded conditions which 4.3.1 The values of allowable stresses given
cause most severe loading on double bottom, below are subject to satisfactory buckling
bulkhead and top side structures. strength as per Pt.3, Ch.3 and Pt.3, Ch.10 for
bulkhead corrugations.
Section 5
The secondary stiffeners of the hatch coamings Material for the hatch covers and coamings is to
are to be continuous over the breadth and be steel according to the requirements for ship’s
length of the hatch coamings. hull.
The net minimum scantlings of hatch covers are 5.2 Hatch cover load model
to fulfill the strength criteria given in:
2
The pressure p, [N/mm ], on the hatch covers
- 5.3.3, for plating, panels is given by:
pFP = pressure at the forward perpendicular 5.3.2 Effective cross-sectional area of panel
= [49.1 + (L-100)a] . 10
-3 flanges for primary supporting members
2
a = 0.0726 for type B freeboard ships The effective flange area Af, [cm ], of the
0.356 for ships with reduced freeboard attached plating, to be considered for the
yielding and buckling checks of primary
LL = Freeboard length, [m], as defined in Pt.3, supporting members, when calculated by means
Ch.1, Sec.2 to be taken not greater than 340 [m] of a beam or grillage model, is obtained as the
sum of the effective flange areas of each side of
x = distance, [m], of the mid length of the hatch the girder web as appropriate:
cover under examination from the forward end
of L A F = ∑ (10b ef t)
nf
Where a position 1 hatchway is located at least
one superstructure standard height higher than where:
the freeboard deck, the pressure “p” may be
-3 2
34.3 x 10 [N/mm ]. nf = 2 if attached plate flange extends on both
sides of girder web
For ships less than 100 [m] in length
= 1 if attached plate flange extends on one
side of girder web only
L 5 x x −3
p = 15.8 + L 1 − . − 3.6 .10
3 3 LL LL t = net thickness of considered attached plate,
[mm]
σa = 0.8 σF p .10 -3
t = Fp 15.8s
τa = 0.46 σF 0.95 σ F
σF being the minimum upper yield stress, but to be not less than 1% of the spacing of the
2
[N/mm ], of the material. stiffener or 6 [mm] if that be greater.
The critical compressive buckling stress and the 5.3.4.2 Stiffeners are to be connected to
ideal elastic buckling stress are to be supporting primary members or cover edges by
determined as given in 6.1.2 and 6.2.1 double continuous fillet weld of area not less
respectively of Chapter 3. than:
b) Where the primary supporting member is Connection of the web plate of stiffeners or
perpendicular to the direction of secondary primary members to the attached plating and
stiffeners, ‘K’ value corresponding to plating flanges is to be by means of double continuous
with stiffeners in the direction perpendicular fillet welds within 150 [mm] from ends and also
to the compressive stress is to be in way of other areas of high shear stresses.
considered. The throat thickness in these areas is not to be
less than 0.4 web plate thickness.
5.3.3.3 Biaxial compressive stress in hatch
cover panels, when calculated by means of FEM For covers above cargo and ballast tanks, chain
shell element model, will be specially or staggered fillet welds on the tank side are not
considered. acceptable.
5.3.4 Net scantlings of secondary stiffeners 5.3.4.3 The compressive stress σc in the top
flange of secondary stiffeners, induced by the
5.3.4.1 The required minimum section modulus, bending of primary supporting members parallel
3
Z, [cm ], of secondary stiffeners of the hatch to the direction of secondary stiffeners, is not to
cover top plate, based on stiffener net member exceed 0.8 times the critical buckling stress σcr.
thickness, are given by: for the stiffener.
- σE for lateral buckling mode as given in 5.4 Hatch coamings and local details
6.2.3 of Ch.3, or
5.4.1 Load model
- σE for the torsional buckling mode as given 2
in 6.2.4 of Ch.3. The pressure pcoam, [N/mm ], on the No. 1
forward transverse hatch coaming is given by:
whichever is the lower.
-3 2
pcoam = 220 . 10 , [N/mm ], when a forecastle is
5.3.4.5 For flat bar secondary stiffeners and fitted in accordance with 1.4
stiffeners used solely to prevent buckling, the -3 2
ratio hw/tw is to be not greater than : = 290 . 10 , [N/mm ], in the other cases
2
0.5
The pressure pcoam, [N/mm ], on the other
235 coamings is given by:
15
σF -3
pcoam = 220 . 10 , [N/mm ].
2
where;
hw, tw are the height and net thickness of the 5.4.2 Local net plate thickness
stiffener respectively
The local net plate thickness t, [mm], of the
σF = minimum upper yield stress [N/mm ] of the
2
hatch coaming plating is given by:
material.
p coam .10 3
5.3.5 Net scantlings of primary supporting t = 14.9s S coam
members σ a,coam
5.3.5.1 The section modulus and web thickness
where:
of primary supporting members, based on
member net thickness, are to be such that the
s = secondary stiffener spacing, [m]
normal stress σ in both flanges and the shear
stress τ, in the web, do not exceed the allowable 2
pcoam = pressure, [N/mm ], as defined in 5.4.1
values σa and τa, respectively, defined in 5.3.1.
Scoam = safety factor to be taken equal to 1.15
The breadth of the primary supporting member
flange is to be not less than 40% of their depth σa,coam = 0.95 σF
for laterally unsupported spans greater than 3.0
[m]. Tripping brackets attached to the flange The local net plate thickness is to be not less
may be considered as a lateral support for than 9.5 [mm].
primary supporting members.
5.4.3 Net scantlings of longitudinal and
The flange outstand is not to exceed 15 times transverse secondary stiffeners
the flange thickness.
3
The required section modulus Z, [cm ], of the
5.3.6 Deflection limit and connections longitudinal or transverse secondary stiffeners of
between hatch cover panels the hatch coamings, based on net member
thickness, is given by:
Load bearing connections between the hatch
cover panels are to be fitted with the purpose of
1000S coam 2 sp coam .10 3
restricting the relative vertical displacements. Z=
mc p σ a.coam
The vertical deflection of primary supporting
members is to be not more than 0.0056ℓ, where
where:
ℓ is the greatest span of primary supporting
members.
m = 16 in general
= 12 for the end spans of stiffeners sniped at stress levels in 5.3.1 apply and are to be
the coaming corners checked at the highest stressed locations.
ℓ = span, [m], of secondary stiffeners The design of local details is to be suitable for
the purpose of transferring the pressures on the
s = spacing, [m], of secondary stiffeners hatch covers to the hatch coamings and,
through them, to the deck structures below.
2
pcoam = pressure [N/mm ] as defined in 5.4.1 Hatch coamings and supporting structures are
to be adequately stiffened to accommodate the
cp = ratio of the plastic section modulus to the loading from hatch covers, in longitudinal,
elastic section modulus of the secondary transverse and vertical directions.
stiffeners with an attached plate breadth, [mm],
equal to 40 t, where t is the plate net thickness Underdeck structures are to be checked against
the load transmitted by the stays, adopting the
= 1.16 in the absence of more precise same allowable stresses specified in 5.4.4.
evaluation
Unless otherwise stated, weld connections and
σa,coam = 0.95 σF. materials are to be dimensioned and selected in
accordance with the rule requirements.
5.4.4 Net scantlings of coaming stays
Double continuous welding is to be adopted for
The required minimum section modulus, Z, the connections of stay webs with deck plating
3
[cm ], and web thickness, tw, [mm] of coamings and the weld throat is to be not less than 0.44
stays designed as beams with flange connected tW, where tW is the gross thickness of the stay
to the deck or sniped and fitted with a bracket web.
(see Figures a) and b)) at their connection with
the deck, based on member net thickness, are Toes of stay webs are to be connected to the
given by: deck plating with deep penetration double bevel
welds extending over a distance not less than
1000H C2 sp coam 15% of the stay width.
Z= .10 3
2σ a.coam 5.5 Closing arrangements
For calculating the section modulus of coaming The net sectional area of each securing device
stays, their face plate area is to be taken into is not to be less than:
account only when it is welded with full 2
penetration welds to the deck plating and A = 1.4 a / f [cm ]
adequate underdeck structure is fitted to support
the stresses transmitted by it. where:
For other designs of coaming stays, such as, for a = spacing [m] of securing devices, not being
examples, those shown in Figures c) and d), the taken less than 2 [m]
σY = specified minimum upper yield stress Hatch covers are to be effectively secured, by
2
[N/mm ] of the steel used for fabrication, not to means of stoppers, against the transverse
2
be taken greater than 70% of the ultimate tensile forces arising from a pressure of 175 [kN/m ].
strength.
With the exclusion of No.1 hatch cover, hatch
e = 0.75 for σY > 235 covers are to be effectively secured, by means
of stoppers, against the longitudinal forces
= 1.0 for σY ≤ 235 acting on the forward end arising from a
2
pressure of 175 [kN/m ].
Rods or bolts are to have a net diameter not
less than 19 [mm] for hatchways exceeding 5 No. 1 hatch cover is to be effectively secured, by
2
[m ] in area. means of stoppers, against the longitudinal
forces acting on the forward end arising from a
2
Between cover and coaming and at cross-joints, pressure of 230 [kN/m ].
a packing line pressure sufficient to obtain
2
weathertightness is to be maintained by the This pressure may be reduced to 175 [kN/m ]
securing devices. when a forecastle is fitted in accordance with
1.4.
For packing line pressures exceeding 5 [N/mm],
the cross section area is to be increased in The equivalent stress:
direct proportion. The packing line pressure is to
be specified. i) in stoppers and their supporting structures,
and
The cover edge stiffness is to be sufficient to
maintain adequate sealing pressure between ii) calculated in the throat of the stopper welds
securing devices. The moment of inertia, I, of
edge elements is not to be less than: is not to exceed the allowable value of 0.8 σY.
4 4
I = 6pa [cm ] 5.5.3 Materials and welding
End of Chapter
Chapter 2
Oil Tankers
Contents
Section
1 General
2 Ship Arrangement
3 Longitudinal Strength
4 Hull Structure
5 Direct Strength Calculations
6 Pumping and Piping Systems
7 Cargo Handling Systems
8 Gas Freeing and Venting of Cargo Tank
9 Cargo Tank Level Measurement
10 Cargo Heating Arrangements
11 Inert Gas Systems
12 Ships for Carriage of Oil or Dry Cargo in Bulk
13 Requirements Concerning use of Crude Oil or Slops as Fuel for Tanker Boilers
Section 1
General
envisaged, details are to be submitted 1.5 Intact stability of tankers during liquid
accordingly. transfer operations
- Compliance with intact and damage stability 1.5.1 All oil tankers of 5000 tonnes deadweight
requirements of the statutory authorities. and above are to satisfy the requirements of
intact stability during liquid transfer operations
1.3 Materials and material protection given in MARPOL, Annex I, Reg.27, where
applicable. (For conditions of applicability see
1.3.1 Materials used for the construction of hull, Reg.27).
piping and fittings are to be compatible with the
liquids and their vapours. Hatch packing All other tankers to which the MARPOL, Annex
materials should be resistant to the liquids and I, Reg.27 does not apply are to comply with the
their vapours. Synthetic materials for requirements given in 1.5.2 during liquid transfer
components and piping are to be approved in operations which include cargo loading and
each separate case. unloading, lightering, ballasting and
deballasting, ballast water exchange, and tank
1.3.2 Materials used in the inert gas system are cleaning operations. Alternatively, requirements
to be suitable for their intended purpose. In of MARPOL Annex I, Reg.27 could be applied
particular those parts of scrubbers, blowers, as a matter of equivalence.
non-return devices, scrubber effluent and other
drain pipes which may be subjected to corrosive 1.5.2 For any operating draught reflecting
action of the gases and/or liquids are to be actual, partial or full load conditions, including
either constructed of corrosion resistant material the intermediate stages of liquid transfer
or lined with rubber, glass fibre epoxy resin or operations the following intact stability criteria is
other equivalent coating material. to be complied with:
1.3.3 Impressed current systems and a) In port (see note below), the initial
magnesium or magnesium alloy anodes are not metacentric height GMo is not to be less
permitted in oil cargo tanks and in tanks than 0.15 [m]. Positive intact stability is to
adjacent to oil cargo tanks. Where aluminium extend from the initial equilibrium position at
anodes are fitted in oil cargo tanks and in tanks which GMo is calculated over a range of at
adjacent to oil cargo tanks, the installations are least 20 degrees to port and to starboard.
to satisfy the requirements of Pt.3, Ch.2,
Sec.3.4. b) At sea, the intact stability criteria contained
in paragraphs Chapter 3 of IMO Resolution
1.3.4 Aluminium coatings containing greater A.749(18), the Intact Stability Code, or the
than 10 percent aluminium by weight in the dry criteria contained in the national
film are not to be applied in cargo tanks, cargo requirements of the flag administration if the
tank deck area, in pump rooms, cofferdams or national stability requirements provide at
any other spaces where flammable cargo least an equivalent degree of safety are to
vapour may accumulate. be complied with.
1.3.5 Aluminised pipes may be permitted in Note : At some port locations where the
ballast tanks, in inerted cargo tanks and, environmental conditions are similar to those at
provided the pipes are protected from accidental sea, the requirements given in para (b) are to be
impact, in hazardous areas on open deck. applied.
Section 2
Ship Arrangement
2.1 Location and separation of spaces This protection may however be obtained by an
angle bar or a diagonal plate across the corner.
2.1.1 Location and separation of cargo spaces Such cofferdams, if accessible, is to be
from machinery, accommodation, service ventilated and if not accessible, is to be filled
spaces, control stations etc. are to be in with a suitable and compatible compound.
accordance with Pt.6, Ch.2, Sec.1.5.
2.1.6 A cofferdam between the forward cargo
2.1.2 All dry spaces and tanks intended for tank and the forepeak may be dispensed with, if:
water ballast which can remain empty in loaded
condition are to be so arranged that they cannot - direct access is provided to the forepeak
be used for any other purpose. from the open deck,
2.1.3 Slop tanks are to be designed for efficient - the air and sounding pipes to the forepeak
decantation. Positions of inlets, outlets, baffles space are led to the open deck, and
and weirs where fitted, are to be located to
ensure minimum turbulence and entrainment of - portable means are provided for gas
oil or emulsion with water. detection and inerting the forepeak
compartment.
2.1.4 Cargo tanks are to be segregated from
machinery spaces, accommodation spaces and 2.2 Tank arrangement
other spaces of electrical hazard by means of
cofferdams at least 760 [mm] in length and 2.2.1 The disposition of transverse bulkheads
covering the whole area of the end bulkheads of should in general comply with the requirements
cargo tanks. A pump room, oil fuel bunker or of Pt.3, Ch.10, as applicable to ships with
water-ballast tank will be accepted in lieu of a machinery aft.
cofferdam. Oil engines or electrical equipment of
potential fire hazard are not to be sited in these 2.2.2 The arrangement of the spaces within the
pump rooms or cofferdams. cargo region with respect to the following
features are to be in accordance with the
2.1.5 Where a corner-to-corner situation occurs MARPOL 73/78 (as amended), Annex I.
between a safe space and a cargo tank, the
safe space is to be protected by a cofferdam.
Feature Regulation
a) Protection of cargo tank region with double bottom and wing ballast
19
tank/spaces
b) Segregated ballast tank (SBT) 18
c) Protective location of SBT 18
d) Crude oil washing (COW) (Crude carriers only), 33
e) Segregation of fuel oil/ballast water 16
f) Slop tanks and oil/water interface detectors 29
g) Sludge tank for fuel oil 12
h) Minimization of retention of oil on board 30(4) & (5)
i) Tank size limitation / Accidental oil outflow performance 23
j) Subdivision and damage stability Reg.19, Reg.24
and Reg.28
k) Intact stability 27
l) Pump room bottom protection
22
2.2.3 The aggregate capacity of wing tanks, attaching, rigging, suspending or supporting the
double bottom tanks, forepeak tanks and aft portable means of access forms a permanent
peak tanks intended to carry water ballast is not part of the ship’s structure. All portable
to be less than the capacity of segregated equipment is to be capable of being readily
ballast tanks necessary to meet the erected or deployed by ship’s personnel.
requirements of MARPOL Annex I, Regulation
18. 2.3.3 The construction and materials of all
means of access and their attachment to the
2.2.4 Small tankers with single hull ship’s structure are to be approved by IRS.
arrangements will be specially considered.
2.3.4 Access to cofferdams, ballast tanks, cargo
2.3 Arrangement for access in the cargo area tanks and other spaces in the cargo area are to
and forward spaces be direct from the open deck and such as to
ensure their complete inspection. (For typical
2.3.1 Each space is to be provided with a means arrangement See Fig.2.3.4(a) and Fig.2.3.4(b)).
of access to enable, throughout the life of a ship, Access to double bottom or to forward ballast
overall and close-up inspections and thickness spaces may be through a pump room, deep
measurements of the ship’s structures. Such cofferdam, pipe tunnel, double hull space or
means of access are to comply with the similar compartment not intended for the
requirements of the technical provisions for carriage of oil or hazardous cargoes.
means of access for inspections, specified in
2.4. Every double bottom space is to be provided
with separate access without having to pass
The technical provisions do not apply to cargo through other neighbouring double bottom
tanks of combined chemical/ oil tankers space.
complying with Part 5 Ch.3. However, they are
to be applied to ballast tanks in such vessels. 2.3.5 Where a duct keel or pipe tunnel is fitted
and access is normally required for operational
Each space for which close-up inspection is not purposes, access is to be provided at each end
required such as fuel oil tanks and void spaces and at least one other location at approximately
forward of cargo area, may be provided with a mid-length. Access is to be directly from the
means of a access necessary for overall survey exposed deck. There is to be no connection to
intended to report on the overall conditions of engine room. Where an after access is to be
the hull structure. provided from the pump room to the duct keel,
requirements of Pt.6, Ch.2, 1.5.2.4 are to be
2.3.2 Where it is impracticable to fit permanent complied with. Mechanical ventilation is to be
means of access, the provision of movable or provided and such spaces are to be adequately
portable means of access, as specified in 2.4 ventilated prior to entry. A suitable notice is to
may be considered, provided that the means of be posted at the entry stipulating a sufficient
f) instructions for the rigging and use of vertical ladder is not to be skewed by more than
any portable means of access in a safe 2°.
manner;
f) Overhead obstructions means the deck or
g) an inventory of all portable means of stringer structure including stiffeners above the
access; and means of access.
The second part of the Ship Structure Access g) Distance below deck head means the
Manual is to contain a form of record of distance below the plating.
periodical inspections and maintenance, and
change of inventory of portable equipment due 2.4.2 Structural members subject to the close-up
to additions or replacement after construction. inspections and thickness measurements of the
The format of this part is to be approved at the ship’s structure referred to in Pt.1, Ch.2, except
time of construction of the ship. The manual is to those in double bottom spaces are to be
include a re-approval procedure for any changes provided with a permanent means of access to
to the permanent, portable or movable means of the extent as specified in Table 2.4.2a and
access. Table 2.4.2b, as applicable. Approved
alternative methods such as rafting may be used
The Ship Structure Access Manual is to be in combination with the fitted permanent means
approved by IRS and an updated copy including of access, provided that the structure allows for
all revisions / re-approvals is to be kept onboard. its safe and effective use.
2.4 Technical provisions for means of access 2.4.3 Permanent means of access should as far
for inspections as possible be integral to the structure of the
ships, thus ensuring that they are robust and at
2.4.1 Definitions : For the purpose of these the same time contributing to the overall
technical provisions the following definitions strength of the structure of the ship.
apply:
2.4.4 Elevated passageways forming sections of
a) Rung means the step of a vertical ladder or a permanent means of access, where fitted are
step on the vertical surface. to have a minimum clear width of 600 [mm],
except for going around vertical web where the
b) Tread means the step of an inclined ladder minimum clear width may be reduced to 450
or step for the vertical access opening. [mm] and have guard rails over the open side of
their entire length. Sloping structures providing
c) Flight of an inclined ladder means the part of the access that are sloped 5 degrees or
actual stringer length of an inclined ladder. more from the horizontal plane are to be of a
For vertical ladders, it is the distance non-skid construction. Non-skid construction is
between the platforms. to be such that the surface on which the
personnel walks provides sufficient friction to the
d) Stringer means: sole of boots even when the surface is wet and
covered with thin sediment.
i) the frame of a ladder; or
Guard rails are to be atleast 1000 [mm] in height
ii) the stiffened horizontal plating structure fitted and consist of a rail and an intermediate rail.
on the side shell, transverse bulkheads and/or Guard rails are to be fitted on the open side. For
longitudinal bulkheads in the space. For the stand alone passageways guard rails are to be
purpose of ballast tanks of less than 5 [m] width fitted on both sides of these structures.
forming double side spaces, the horizontal Guardrail stanchions are to be attached to the
plating structure is credited as a stringer and a permanent means of access. The distance
longitudinal permanent means of access, if it between the passageway and the intermediate
provides a continuous passage of 600 [mm] or rail and the distance between intermediate rail
more in width past frames or stiffeners on the and the top rail shall not be more than 500 [mm].
side shell or longitudinal bulkhead. Openings in They are to be of substantial construction
stringer plating utilized as permanent means of ensuring adequate design strength as well as
access are to be arranged with guard rails or residual strength during service life. Stanchions
grid covers to provide safe passage on the are to be not more than 3 [m] apart.
stringer or safe access to each transverse web. Discontinuous handrails are allowed provided
the gap does not exceed 50 [mm]. (See
e) Vertical ladder means a ladder of which the Fig.2.4.4). The distance between adjacent
inclined angle is 70° and over upto 90°. A stanchions across the handrail gaps is to be not
more than 350 [mm].
Indian Register of Shipping
Rules and Regulations for the Construction and Classification of Steel Ships - 2014
Page 9 of 44
___________________________________________________________________________________
Durability of passage ways and guard rails are be subject to compatibility with the liquid carried
to be ensured by corrosion protection and in the tank. Fire resistant materials are to be
inspection and maintenance during services. used for all means of access.
Use of alternative materials such as GRP are to
Table 2.4.2a : Means of access for ballast and cargo tanks of oil tankers
Access to the underdeck and vertical structure
Water ballast wing tanks of less than 5 [m] width forming double side spaces and their bilge
hopper sections
Double side spaces above hopper side tank
1. For double side spaces above the upper knuckle point of the bilge hopper sections, permanent
means of access are to be provided in accordance with 1.1 to 1.3:
1.1 where the vertical distance between horizontal uppermost stringer and deck head is 6 [m] or
more, one continuous longitudinal permanent means of access is to be provided for the full length of
the tank with a means to allow passing through transverse webs installed at a minimum of 1.6 [m] to
a maximum of 3 [m] below the deck head with a vertical access ladder at each end of the tank;
1.2 continuous longitudinal permanent means of access, which are integrated in the structure, at a
vertical distance not exceeding 6 [m] apart; (when the permanent means of access is integral with the
structure, the allowable vertical distance may be increased by 10%) and
1.3 plated stringers are as far as possible, be in alignment with horizontal girders of transverse
bulkheads.
Notes:
a) 1.1 above is for access to under deck structures, whereas 1.2 is for access for inspection of
vertical structures (transverse webs) on longitudinal bulkheads.
b) 1.1 to 1.3 above are also applicable to wing tanks designed as void spaces
c) For a tank where the vertical distance between horizontal upper stringer and deck head varies at
different sections item 1.1 is to be applied to such sections which fall under the criteria.
d) The continuous permanent means of access may be a wide longitudinal, which provides access
to critical details on the opposite side by means of platforms as necessary on web frames. In
case the vertical opening of the web frame is located in way of the open part between the wide
longitudinal and the longitudinal on the opposite side, platforms shall be provided on both sides
of the web frames to allow safe passage through the web frame.
e) Where two access hatches are required by clause 2.3.6, access ladders at each end of the tank
are to be led to the deck.
2. For bilge hopper sections of which the vertical distance from the tank bottom to the upper knuckle
point is 6 [m] and over, one longitudinal permanent means of access is to be provided for the full
length of the tank. It is to be accessible by vertical permanent means of access at each end of the
tank.
Notes:
b) The height of a bilge hopper tank located outside of the parallel part of vessel is to be
taken as the maximum of the clear vertical distance measured from the bottom plating to
the hopper plating of the tank.
c) The foremost and aftmost bilge hopper ballast tanks with raised bottom, of which the
height is 6 [m] and over, a combination of transverse and vertical means of access to the
upper knuckle point for each transverse web may be accepted in place of the longitudinal
permanent means of access.
2.1 The longitudinal continuous permanent means of access may be installed at a minimum 1.6 [m] to
maximum 3 [m] from the top of the bilge hopper section. In this case, a platform extending the
longitudinal continuous permanent means of access in way of the web frame may be used to access
the identified structural critical areas.
2.2 Alternatively, the continuous longitudinal permanent means of access may be installed at a
minimum of 1.2 [m] below the top of the clear opening of the web ring allowing a use of portable
means of access to reach identified structural critical areas.
3. Where the vertical distance referred to in 2 is less than 6 [m], alternative means as defined in 2.4.10
or portable means of access may be utilized in lieu of the permanent means of access. To facilitate
the operation of the alternative means of access, in-line openings in horizontal stringers are to be
provided. The openings are to be of an adequate diameter and are to have suitable protective railings.
Table 2.4.2b : Means of access for ballast and cargo tanks of oil tankers
Access to the underdeck and vertical structure
Water ballast tanks, except those specified in Table 2.4.2a and cargo oil tanks
1. For tanks of which the height is 6 [m] and over containing internal structures, permanent means
of access is to be provided in accordance with 1.1 to 1.6:
1.1 continuous athwartship permanent access arranged at each transverse bulkhead on the stiffened
surface, at a minimum of 1.6 [m] to a maximum of 3 [m] below the deck head;
1.2 at least one continuous longitudinal permanent means of access at each side of the tank. One of
these accesses is to be at a minimum of 1.6 [m] to a maximum of 6 [m] below the deck head and the
other is to be at a minimum of 1.6 [m] to a maximum of 3 [m] below the deck head;
(1.2 is applicable also when the deck longitudinals and deck transverses are fitted on deck but the
supporting brackets are fitted under the deck)
1.3 access between the arrangements specified in 1.1 and 1.2 and from the main deck to either 1.1 or
1.2;
1.4 continuous longitudinal permanent means of access which are integrated in the structural member
on the stiffened surface of a longitudinal bulkhead, in alignment, where possible, with horizontal
girders of transverse bulkheads, are to be provided for access to the transverse webs unless
permanent fittings are installed at the upper most platform for use of alternative means, as defined in
2.4.10 for inspection at intermediate heights; (rafting is not acceptable for this purpose)
For water ballast tanks of 5 [m] or more in width, such as on an ore or oil carrier, side shell plating
shall be considered in the same way as “longitudinal bulkhead”.
1.5 for ships having cross-ties which are 6 [m] or more above tank bottom, a transverse permanent
means of access on the cross-ties providing inspection of the tie flaring brackets at both sides of the
tank, with access from one of the longitudinal permanent means of access in 1.4;
1.6 alternative means as defined in 2.4.10 may be provided for small ships as an alternative to 1.4 for
cargo oil tanks of which the height is less than 17 [m].
Notes:
a) 1.1, 1.2 and 1.3 above are for access to underdeck structure, uppermost sections of
transverse webs and connection between these structures
b) 1.4, 1.5 and 1.6 above are meant for access to vertical structures only and are linked to the
presence of transverse webs on longitudinal bulkheads.
c) If there are no underdeck structures (deck longitudinals and deck transverses) but there
are vertical structures in the cargo tank supporting transverse and longitudinal bulkheads,
access in accordance with 1.1 to 1.6 is to be provided for inspection of the upper parts of
vertical structure on transverse and longitudinal bulkheads.
d) If there are no stiffening structures inside the cargo tank, 1.1 to 1.6 are not applicable.
e) The requirements in 1.1 to 1.6 are also to be applied to void spaces of comparable volume in
the cargo area.
f) The vertical distance below the overhead structure is to be measured from the underside of
the main deck plating to the top of the platform of the means of access at a given location
g) The height of the tank is to be measured at each tank. For a tank where the height varies at
different bays, the requirements are to be applied to only such bays of a tank that have height
6 [m] and over.
2. For tanks of which the height is less than 6 [m], alternative means as defined in 2.4.10 or portable
means may be utilized in lieu of the permanent means of access.
3. For fore peak tanks with a depth of 6 [m] or more at the centre line of the collision bulkhead, a
suitable means of access is to be provided for access to critical areas such as the underdeck
structure, stringers, collision bulkhead and side shell structure.
3.1 Stringers of less than 6 [m] in vertical distance from the deck head or a stringer immediately above
are considered to provide suitable access in combination with portable means of access.
3.2 In case the vertical distance between the deck head and stringers, stringers or the lowest stringer
and the tank bottom is 6 [m] or more, alternative means of access as defined in 2.4.10 is to be
provided.
Fig.2.4.4
the passage unless gratings or other foot holds an inclined ladder. However, the vertical
are provided. distance of the upper most section of the vertical
ladder may be reduced to 1.6 [m], if the ladder
The opening of 600 [mm] x 800 [mm] may have lands on a longitudinal or athwartship
corner radii of 300 [mm]. An opening of 600 permanent means of access fitted within that
[mm] in height x 800 [mm] in width may be range. The flights of the inclined ladders are
accepted as access opening in vertical normally to be not more than 6 [m] in vertical
structures where it is not desirable to make large height. The lowermost section of the ladders
opening considering structural strength aspects, may be vertical for a distance not exceeding 2.5
such as in girders and floors in double bottom [m].
tanks.
b) Where vertical ladders are used for access
0
31
620
deck of the vertical ladder providing access to a
850
2.8.2 The arrangements, at all times are to be d) The common link is to be of stud link type
capable of rapid deployment in the absence of grade 2 or 3.
main power on the ship to be towed and easy
connection to the towing ship. At least one of the e) The chafing chain is to be able to withstand a
emergency towing arrangements are to be pre- breaking load not less than twice the SWL. For
rigged, ready for rapid deployment. each type of ETA, the nominal diameter of
common link for chafing chains is to comply with
2.8.3 Towing pennant, chafing gear, fairleads the value indicated in the following table:
and strong points on the ship are to have a
minimum working strength as follows:
2.9 Cargo manifold gutter bars - freeing accordance with Pt.3, Ch.11, Sec.5.4 and
arrangements and intact stability effective closures provided for use during
loading and discharge operations. Attached
2.9.1 Where gutter bars are installed on the closures are to be arranged in such a way that
weather decks of tankers in way of cargo jamming cannot occur while at sea, ensuring
manifolds and are extended aft as far as the that the freeing ports will remain fully effective.
after house front for the purpose of containing
cargo spills on deck during loading and 2.9.3 On ships without deck camber, or where
discharge operations the free surface effects the height of the installed gutter bars exceeds
caused by containment of a cargo spill during the camber, and for tankers having cargo tanks
liquid transfer operations or of boarding seas exceeding 60% of the vessel's maximum beam
while underway require consideration with at midships regardless of gutter bar height, an
respect to the vessel's available margin of assessment of the initial stability (GMo) for
positive initial stability (GMo). compliance with the relevant intact stability
requirement taking into account the free surface
2.9.2 Where the gutter bars installed are greater effect caused by liquids contained by the gutter
than 300 [mm] in height, they are to be treated bars will be required if gutter bars are provided.
as bulwarks according to the Load Line
Convention, with freeing ports arranged in
Section 3
Longitudinal Strength
Section 4
Hull Structure
4.1.2 Inner hull and longitudinal bulkheads are 4.1.4 The minimum thickness requirement of all
to extend beyond the cargo tank region as far structural parts in the cargo tank region is
forward and aft as practicable and are to be
effectively scarfed into the adjoining structure. t = (5.0 + 0.02L) √k + tc [mm]
4.1.3 Primary members are to be so arranged where, k and tc are to be obtained from Pt.3,
as to ensure effective continuity of strength Ch.2.
throughout the tank structure. Abrupt changes in
depth of sections are to be avoided. Vertical 4.1.5 The arrangement and scantlings of all tank
webs on structure are to be arranged in line with boundary panels are to be capable of
the double bottom floors, deck transverses and withstanding the dynamic loads from the liquids
vertical transverses at the longitudinal inside the tanks. Where tanks are intended to be
bulkheads to ensure continuity of transverse partially filled, the scantling calculations together
structure. with the predicted dynamic loadings are to be
submitted.
4.2.3 Longitudinal girders are to be provided at 4.3.4 Brackets are to be provided at the ends of
the crossties to connect to the transverses or
- centreline (or duct keel) girders. Transverses and vertical webs are to be
- under longitudinal bulkhead (or sloping fitted with tripping brackets at the junctions with
plates of bulkhead stool in case of vertically cross ties. Where the width of the face plate of
corrugated longitudinal bulkheads) the cross ties exceeds 150 [mm] on any one
- under sloping plate of hopper side tank side of the web, additional tripping brackets are
where fitted. to be provided to support the face plate.
4.2.4 In way of vertically corrugated transverse 4.3.5 End connections of cross-ties are to
bulkheads supported by stools, additional ensure adequate area of connection and may
longitudinal girders are to be arranged extending require additional bracket thickness. Full
at least to the first plate floor adjacent to the penetration welding may be required particularly
bulkhead stool sloping plates on each side. in way of toes of the end brackets.
These girders are to be spaced not more than
3.6 [m] apart. 4.4 Deck structure
4.2.5 Plate floors are to be arranged in way of 4.4.1 Where small diameter threaded openings
transverse bulkheads and sloping plates of are arranged on the upper decks for staging
bulkhead stools. wires, these are to be located clear of the other
openings and similar areas of stress
4.2.6 The inner bottom plating thickness and concentration. Care is to be taken to ensure a
longitudinals are also to comply with the gradual transition at the thread ends and the
requirements for cargo tank boundaries as given edges of the holes are to be ground smooth.
in Pt.3, Ch.10. The closing arrangements are to be as per
2.3.8.
4.2.7 Transverse continuity of inner bottom is to
be maintained outboard of inner hull. 4.4.2 The scantlings of deck transverses and
girders are to be determined by means of direct
4.3 Side structure calculations.
4.3.1 Where a hopper side tank is fitted, a 4.4.3 A trunk deck, if fitted is to extend over the
transverse is to be arranged in the hopper tank full length of the cargo tanks and is to be
in line with each double bottom plate floor. effectively scarfed into the main hull structure.
Scarfing brackets are to be fitted in the hopper The trunk deck and the sides are to be
in line with the inner bottom on both sides of longitudinally framed and the transverse primary
each transverse to ensure continuity of the inner members are to be aligned with the outboard
bottom plating into the hopper side tank. deck transverses.
Longitudinal knuckles in the hopper tank plating
are to be adequately supported. A horizontal 4.4.4 Where external stiffening is carried in way
girder is to be arranged at the top of the hopper of the trunk deck, appropriate tripping brackets
space and is to be located close to the knuckle are to be fitted in way of the underdeck
between the hopper and the inner hull. Where supporting structure. The arrangement and
additional longitudinal girders are provided to details of the external girders will be specially
satisfy access requirements as per 2.3.7, these considered.
are to be arranged in line with horizontal girders
on the transverse bulkhead and wing tank cross 4.4.5 The thickness of the trunk top and side
ties where fitted. plating as well as the scantlings of the stiffeners
and girders are to be obtained as per Pt.3, Ch.8
& 9 respectively.
4.5.3 Particular attention is to be paid to the 4.6.1 The members are to have adequate end
through thickness properties at the connection fixity, lateral support and web stiffening, and the
to the deck and inner bottom. structure is to be arranged to minimize hard
spots or other sources of stress concentration.
4.5.4 Where longitudinal bulkheads are Openings are to have well rounded corners and
corrugated horizontally, the corrugations are to smooth edges and are to be located having
be aligned, and stiffening arrangements on regard to the stress distribution and buckling
plane members are to be arranged to provide strength of the plate panel.
adequate support in way of flanges of abutting
corrugations. Where both the longitudinal and 4.6.2 To maintain continuity of strength,
transverse bulkheads are horizontally substantial horizontal and vertical brackets are
corrugated, the ends are to be connected to to be fitted to transverses or stringers at the
ensure continuity. ends of the cross ties. Horizontal brackets are to
be aligned with the cross tie face plates, and
4.5.5 Bulkhead stools in way of vertically vertical end brackets are to be aligned with the
corrugated bulkheads where fitted are to be cross tie web.
generally as per Pt.5, Ch.1, Sec.2.9. An efficient
system of reinforcement is to be arranged in line 4.6.3 In a ring system where the end bracket is
with the tank transverse bulkheads or bulkhead integral with the webs of the members, and the
stools at the intersection with the sloped plating face plate is carried continuously along the
of double bottom hopper tanks and topside edges of the members and the bracket, the full
tanks. area of the largest face plate is to be maintained
upto the mid-point of the bracket and then
4.5.6 The arrangement of stools and adjacent gradually tapered to the smaller face plates.
structure common to the cargo tank is to be Butts in face plates are to be kept well clear of
designed to avoid pockets in which gas could the toes of brackets.
collect.
4.6.4 The thickness of separate end brackets is
4.5.7 Non-oil tight wash bulkheads are generally generally to be not less than that of the thicker
to be of plane construction having an area of of the primary member webs being connected,
perforation between 5 to 10 percent of the total but may be required to be locally increased at
area of the bulkhead. Large perforations should the toes. The bracket is to extend to adjacent
not be provided on the top and bottom strakes of tripping brackets, stiffeners or other support
longitudinal bulkheads. The stiffening points. Bracket toes are to be well radiused.
arrangement and the perforations are to be Where the bracket is attached to a corrugated
arranged so as not to impair strength of the bulkhead, the plating at the bracket toe is to be
bulkhead and provide adequate support to the suitably reinforced.
loads from the end connections. Where tanks
are intended to be partially filled, the scantlings 4.6.5 Tripping brackets are generally to be fitted
and arrangement are to be capable of close to the toes of end brackets, in way of
withstanding the dynamic loads. cross ties and generally at every fourth stiffener
elsewhere. Arrangements should also be made
to prevent tripping at the intersection with other 4.6.8 Longitudinals within the range of cargo
primary members. tanks are not permitted to have closely spaced
scallops except in way of ballast pipe suctions.
4.6.6 In way of cross ties and their end Reinforcement in these areas will be specially
connections lightening holes are not to be cut in considered. Small air and drain holes, cut-outs
side and longitudinal bulkhead stringers. at erection butts and similar widely spaced
Lightening holes are also to be avoided on openings are, in general not to be less than 200
vertical webs on longitudinal bulkheads and in [mm] clear of the toes of end brackets,
wing ballast tanks. intersections with primary supporting members
and other areas of high stress. All openings are
4.6.7 Holes cut in primary longitudinal members to be well rounded with smooth edges.
within 0.1D of deck and bottom are, in general to
be reinforced. Where holes are cut in primary 4.6.9 Where holes are cut for heating coils, the
longitudinal members in areas of high stress and lower edge of the hole is to be not less than 100
where primary members are of higher tensile [mm] from the inner bottom. Where large
steel, they are to be elliptical, or equivalent, to notches are cut in the transverses for the
minimise stress concentration. passage of longitudinal framing, adjacent to
openings for heating coils, the notches for
longitudinals are to be collared.
Section 5
5.1.1 Direct strength calculations are required in 5.2.1 The calculations are to be carried out for
cases where simplified formulations are not able the realistic condition which cause most severe
to take into account special stress distributions, loading on the various parts of cargo tank
boundary conditions or structural arrangements structures.
with sufficient accuracy.
5.2.2 For transverse and longitudinal girders in
5.1.2 For those girder systems where such the cargo region following conditions are to be
direct strength calculations are mentioned in the considered:
preceeding sections of this Chapter, scantlings
obtained from simplified formulae may have to - Sea-going conditions:
be increased based on the results obtained. - any cargo tank empty with adjacent
cargo tanks full and the ship on full
5.1.3 The computer programs used are to take draught
into account the effects of bending, shear, axial - any cargo tank filled with adjacent cargo
and torsional deformations. tanks full and the ship at the minimum
sea-going draught
For deep girders, bulkhead panels, bracket - all cargo tanks within a transverse
zones etc. FEM or equivalent methods are to be section of the ship filled, with adjoining
applied. For systems consisting of slender cargo tanks forward and aft empty and
girders, calculations may be based on beam the ship at the minimum sea-going
theory. draught
- In case of tanks of breadth > 0.6B, full
The calculations are to reflect the structural tank with adjacent tanks empty, ship at
response of 2 or 3-dimensional structure the minimum sea-going draught and
considered, with due attention to the boundary heeled at an angle of φ/2 (φ = roll angle
conditions. as per Pt.3, Ch.4, Sec.2).
Section 6
room lower platform and is to be provided with a 6.2.5 Cofferdams, which are required to be
damper capable of being opened or closed from provided at the fore and aft ends of the cargo
the weather deck and lower platform level. An spaces, are to be fitted with suitable drainage
arrangement involving a specific ratio of areas of arrangements, generally, in accordance with
upper emergency and lower main ventilation following:
openings, which can be shown to result in at
least the required number of air changes 6.2.5.1 Where deep cofferdams can be filled up
through the lower inlets, can be accepted with water ballast, a ballast pump in the main
without the use of dampers. When the lower engine room may be used for emptying the after
inlets are sealed off owing to the flooding of the cofferdam. Where fitted, a ballast pump in a
bilges, then at least 75 per cent of the required forward pump room may be used for draining
number of air changes is to be obtainable the forward cofferdam. In each case, the
through the upper inlets. Means are to be suctions are to be led direct to the pump and not
provided to ensure the free flow of gases to a pipe system.
through the upper platform to the duct intakes.
6.2.5.2 Where intended to be dry compartments,
6.1.8 The arrangements and materials of after cofferdam adjacent to the pump room may
mechanical ventilator components are to be be drained as provided in 6.2.4. Forward
designed to prevent the risk of incendive cofferdam may be drained by a bilge/ballast
sparking. Where non-metallic materials are used pump in a forward pump room. Alternatively,
they are to have anti-static properties. cofferdams may be drained by bilge ejectors.
6.1.9 Renewable flame screens are to be 6.2.6 Cofferdams are to have no direct
provided in ventilation ducts, and ventilation connections to cargo tanks or cargo lines.
intakes are to be so arranged as to minimise the
possibility of re-cycling hazardous vapours from 6.2.7 Ballast tanks and void spaces within the
any ventilation discharge openings. Vent exits cargo area are not to be connected to cargo
are to be arranged to discharge upwards. pumps or have any connections to the cargo
system. A separate ballast/bilge pump is to be
6.1.10 Vent exits from pump rooms are to provided for dealing with the contents of these
discharge at least 3 [m] above the deck and spaces. This pump is to be located in the cargo
from the nearest air intakes or openings to pump room or other suitable space within the
accommodation and enclosed working spaces cargo area.
and from possible sources of ignition.
Consideration will be given to connecting double
6.2 Piping systems for bilge, ballast, oil fuel bottom and/or wing tanks, which are in the cargo
etc. area, to pumps in the machinery spaces where
the tanks are completely separated from the
6.2.1 There is to be no connection between cargo tanks by cofferdams, heating ducts, or
piping systems in the cargo area and the piping containment spaces, etc.
systems in the remainder of the vessel, unless
explicitly specified herein. The forepeak tank can be ballasted with the
system serving ballast tanks within the cargo
6.2.2 The oil fuel bunkering system is to be area, provided:
entirely separate from the cargo handling
system. - the forepeak tank is considered as
hazardous area;
6.2.3 The pumping arrangements in the
machinery space and forward end of the ship - the vent pipe openings are located on open
are to comply with the requirements for general deck at an appropriate distance from
cargo ships, in so far as they are applicable. sources of ignition. In this respect, the
hazardous zones distances are to be
6.2.4 Cargo pump rooms are to have a drainage defined in accordance to IEC 60092-502:
system connected to pumps or bilge ejectors. Electrical installations in ships - Tankers –
The cargo pumps may be used for this purpose Special features;
provided each bilge suction pipe is fitted with a
screw-down non-return valve and an additional - means are provided, on the open deck, to
valve/cock is fitted to the pipe connection allow measurement of flammable gas
between the pump and the non-return valve. concentrations within the forepeak tank by a
Pump room suctions are not to enter the engine suitable portable instrument;
room.
b) In case the enclosed space has a 6.2.10 So far as practicable, the air and
common boundary with the cargo tanks sounding pipes required by 6.2.9 are not to pass
and is therefore a hazardous area, the through cargo tanks. Where this cannot be
enclosed space can be well ventilated. avoided e.g. on oil tankers of deadweight less
than 5000 tonnes, where wing ballast tanks or
The hazardous area classification for above is in spaces need not be provided, the sounding and
accordance to IEC 60092-502: Electrical air pipes may pass through the cargo tanks.
installations in ships - Tankers - Special However, the pipes are to be of steel having a
features. wall thickness of not less than 12.5 [mm] and
they are to be in continuous lengths or with
6.2.8 Ballast piping is not to pass through cargo welded joints.
tanks as far as possible and is not to be
connected to cargo oil piping. Provision may, 6.2.11 The requirements for integrated cargo
however, be made for emergency discharge of and ballast systems are given in Sec.7.6.
water ballast by means of a portable spool
connection to a cargo oil pump and where this is 6.3 Steam connection to cargo tanks
arranged, a non-return valve is to be fitted in the
ballast suction to the cargo oil pump. The 6.3.1 Where steaming out and/or fire
portable spool piece is to be mounted in a extinguishing connections are provided for cargo
conspicuous position in the pump room and a tanks or cargo pipe lines, they are to be fitted
permanent notice restricting its use is to be with valves of the screw-down non-return type.
prominently displayed adjacent to it. Shut-off The main supply to these connections is to be
valves shall be provided to shut-off the cargo fitted with a master valve placed in a readily
and ballast lines before the spool piece is accessible position clear of the cargo tanks.
removed.
6.4 Equipment in dangerous spaces
Ballast piping passing through cargo tanks and
cargo oil pipes passing through segregated 6.4.1 Oil engines, or, any other equipment which
ballast tanks, as permitted by MARPOL Annex I could constitute a possible source of ignition,
Reg. 19, are to be of heavy gauge steel of are not to be situated within cargo tanks, pump
minimum wall thickness according to the table rooms, cofferdams or other spaces liable to
hereunder with welded or heavy flanged joints contain explosive vapours or in spaces
the number of which is to be kept to a minimum. immediately adjacent to cargo oil or slop tanks.
Only expansion bends (not glands) are The temperature of steam or other fluid, in pipes
permitted in these lines within cargo tanks for (or heating coils) in these spaces is not to
serving the ballast tanks and within the ballast exceed 220°C.
tanks for serving the cargo tanks.
c) Bulkhead penetrations of sample pipes 6.5.3 Protection screens of not more than 13
between safe and dangerous areas are to [mm] square mesh are to be fitted in the inlet
be of approved type and have same fire and outlet ventilation openings on the open deck
integrity as the division penetrated. A to prevent the entrance of objects into the fan
manual isolating valve is to be fitted in each housing.
of the sampling lines at the bulkhead on the
gas safe side. 6.5.4 The impeller and the housing in way of the
impeller are to be made of alloys which are
approved as being spark proof by appropriate
test.
6.5.7 The following impellers and housings are d) Wafer-style valves with non-conductive
considered as sparking and are not permitted: (e.g. PTFE) gaskets or seals.
a) impellers of an aluminium alloy or 6.6.3 Where bonding straps are required, they
magnesium alloy and a ferrous housing, are to be:
regardless of tip clearance,
a) Clearly visible so that any shortcomings
b) housing made of an aluminium alloy or a can be clearly detected;
magnesium alloy and a ferrous impeller,
regardless of tip clearance, b) Designed and sited so that they are
protected against mechanical damage
c) any combination of ferrous impeller and and that they are not affected by high
housing with less than 13 [mm] design tip resistivity contamination e.g. corrosive
clearance. products or paint;
6.5.8 Type tests on the finished product are to c) Easy to install and replace.
be carried out in accordance with the
Section 7
7.1.4 Cargo tank access hatches and all other 7.2.7 In general, cargo oil pumps are to be
openings to cargo tanks, such as ullage and driven by steam where the prime movers are
tank cleaning openings, sighting ports and installed in the pump rooms. Where the prime
restricted sounding devices, are to be located on movers are not driven by steam, details are to
the weather deck and are not to be arranged in be submitted for special approval.
enclosed compartments.
7.3 Cargo piping systems
7.2 Cargo pumps
7.3.1 The complete cargo piping system is to be
7.2.1 Cargo oil pumps are to be designed so as located within the cargo tank area.
to minimise the risk of sparking and oil leakage
at the stuffing box. 7.3.2 Expansion joints of approved type or
bends are to be provided, where necessary, in
7.2.2 Where cargo pumps are driven by shafting the cargo pipe lines.
which passes through a pump room bulkhead,
shafting is to be provided with flexible couplings 7.3.3 Means for drainage of cargo lines are to
and gastight stuffing boxes are to be fitted to the be provided. Drain lines may be led to a cargo
shaft at the pump room bulkhead. The glands tank or to a separate tank for this purpose.
are to be efficiently lubricated from outside the
pumproom and constructed so as to reduce the 7.3.4 The cargo piping system is not to have any
risk of overheating. The bulkhead shaft glands, connection to permanent ballast tanks.
bearings and pump casings are to be provided
with temperature sensing devices. Alarms are to 7.3.5 Filling lines to cargo tanks are to be so
be initiated in the cargo control room or the arranged that the formation of static electricity is
pump control station. reduced. When cargo is loaded directly into
tanks, the loading pipes are to be led as low as
Parts, which may come in contact, if the seals practicable in the tank.
are misaligned or bearings are damaged, are to
be of materials which will not spark. Where 7.3.6 Terminal pipes, valves and other fittings in
bellows are incorporated in the design, these the cargo loading and discharge lines to which
are to be hydraulically tested to 3.4 bar before shore installation hoses are directly connected,
fitting. are to be of steel or approved ductile material.
They are to be strongly supported. A manually
7.2.3 A stop valve and a relief valve of adequate operated shut-off valve is to be fitted to each
capacity are to be fitted on the delivery side of shore loading/discharging connection.
each pump. Relief valves are to be fitted in
close- circuit, i.e. discharging to the suction side 7.3.7 Where a cargo hose connection is
of the pumps. Relief valve may be omitted in arranged outside the cargo area, the pipe
case of centrifugal pumps, which are so leading to such connection is to be provided with
designed that the discharge pressure cannot means of segregation such as a spectacle
exceed the design pressure. flange or removable spool piece or equivalent
(see MSC Circ.474) located within cargo area.
7.2.4 A pressure gauge is to be fitted on the The space within 3 [m] of the cargo hose
delivery side of each pump. Where the pump is connection flange is to be considered as a
driven by a prime mover, which is installed in a dangerous area with regard to electrical or
space other than the pump room, an additional incendiary equipment.
pressure gauge is to be fitted at a suitable
position visible from the controlling position of 7.3.8 Isolation of piping systems which serve
the prime mover. tanks containing incompatible cargoes are to be
made by means of removable pipe lengths and
7.2.5 Where cargo pumps are driven by blank flanges. Isolating shut off valves, single or
hydraulic motors which are located inside cargo double, or spectacle flanges are not acceptable
tanks, the design is to be such that the as equivalent arrangement.
contamination of the operating media and cargo
oil cannot take place under normal operating 7.3.9 Cargo piping is not to be led through any
conditions. tank containing a cargo which is incompatible
with that contained in the tank served by such
7.2.6 Means are to be provided for stopping the piping, unless it is encased in a pipe tunnel.
cargo oil pumps from a position outside the
pump rooms, as well as at the pumps. 7.3.10 Where cargo suction and/or filling lines
are led through cargo tanks, or through other
spaces situated below the weather deck, the
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connection to each tank is to be provided with a valve actuators in the event of damage to the
valve situated inside the tank, and capable of main hydraulic circuits on deck. In the case of
being operated from the deck. In the case of valves located inside cargo tanks, this could be
cargo tanks which are located adjacent to achieved by ensuring that the supply lines to
below-deck pump rooms, or pipe tunnels, the actuators are led vertically inside the tank from
deck operated valve may be located in these deck, and that connections with necessary
spaces at the bulkhead. In any case, not less isolating valves, are provided on deck for
than two isolating shut off valves are to be coupling to a portable pump carried on board.
provided in the pipelines between the tanks and
cargo pumps. 7.5 Cargo handling controls
7.4.3 All actuators are to be of a type which will 7.5.4 The cargo handling controls and
prevent the valves from opening inadvertently in instrumentation are, so far as possible, to be
the event of the loss of pressure in the operating separate from the propulsion and auxiliary
medium. Indication is to be provided at the machinery controls and instrumentation.
remote control station showing whether the
valve is open or shut. 7.6 Integrated cargo and ballast systems on
tankers
7.4.4 Compressed air is not to be used for
operating actuators inside cargo tanks. The 7.6.1 The following requirements apply to
actuator operating medium in hydraulic systems integrated cargo and ballast systems meaning
is to have a flash point of 60°C or above (Closed any integrated hydraulic and/or electric system
Cup Test) and is to be compatible with the used to drive both cargo and ballast pumps
intended cargoes. (including active control and safety systems, but
excluding passive components, e.g. piping).
7.4.5 The design of the actuator is to be such
that contamination of the operating medium with 7.6.2 Adequate measures are to be taken to
cargo liquid cannot take place under normal prevent cargo and ballast pumps becoming
operating conditions. inoperative simultaneously due to a single
failure in the integrated cargo and ballast
7.4.6 Where the operating medium is oil or other system, including its control and safety systems
fluid, the supply tank is to be located as high as in order to ensure that these systems are
practicable above the level of the top of the available for use even in emergency condition
cargo tanks, and all actuator supply lines are to whilst at sea
enter the tanks through the highest part of the
tanks. Furthermore the supply tank is to be of 7.6.3 The following features are to be ensured:
the closed type with an air pipe led to a safe
space on the open deck and fitted with a - The emergency stop circuits of the cargo
flameproof wire gauge diaphragm at it's open and ballast systems are to be independent
end. This tank is also to be fitted with a high and from the circuits for the control systems. A
low level audible and visual alarm. The single failure in the control system circuits or
requirements of this paragraph need not be the emergency stop circuits are not to
complied with if the actuators and piping are render the integrated cargo and ballast
located external to the cargo tanks. system inoperative;
7.4.7 It is recommended that for remote control - Manual emergency stops of the cargo
valves not arranged for manual operation, pumps are to be arranged in such a way
emergency means be provided for operating the
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Section 8
8.1.8 Pressure/vacuum valves are to be set at a 8.1.13 Vent outlets and pressure/vacuum valve
positive pressure of not more than 0.2 bar above outlets, if used during loading, are to be
atmospheric and a negative pressure of not arranged to discharge the vapour in an upward
more than 0.07 bar below atmospheric unless vertical direction. All outlets are to be arranged
the tank scantlings are specially considered. to prevent the entrance of water into the cargo
tanks.
8.1.9 In no case are shut-off valves to be fitted
either above or in the pipe leading to a 8.1.14 Openings for pressure release required
pressure/vacuum valve. However, bypass by 8.1.4(a) are to :
valves may be fitted or provision may be made
to enable the tank pressure/vacuum valves to be a) have as great a height as is practicable
held in an open position. The arrangements are above the cargo tank deck to obtain
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Chapter 2 Part 5
Page 30 of 44 Oil Tankers
8.1.15 Vent outlets for cargo loading, 8.2 Cargo tank purging and/or gas freeing
discharging and ballasting required by 8.1.4(b)
are to : 8.2.1 Arrangements for purging/and or gas
freeing are to be such as to minimise the
a) permit the free flow of vapour mixtures or hazards due to the dispersal of flammable
alternatively, permit the throttling of the vapours in the atmosphere and to flammable
discharge of the vapour mixtures to achieve mixtures in cargo tank.
a velocity of not less than 30
metres/second. 8.2.2 When the ship is provided with an inert
gas system the cargo tanks are first to be
b) be so arranged that the vapour mixture is purged until the concentration of hydrocarbon
discharged vertically upwards. vapours has been reduced to less than 2 per
cent by volume. Thereafter gas freeing may take
c) where the method is by free flow of vapour place at the cargo tank deck level.
mixtures, be such that the outlet is not less
than 6 [m] above the cargo tank deck or fore 8.2.3 The arrangements for inerting, purging or
and aft gangway if situated within 4 [m] of gas-freeing of empty tanks as required in 8.2.1
gangway and located not less than 10 [m] are to be to the satisfaction of IRS and are to be
measured horizontally from the nearest air such that the accumulation of hydrocarbon
intakes and openings to enclosed spaces vapours in pockets formed by the internal
containing a source of ignition and from structural members in a tank is minimized and
deck machinery, which may include anchor that:
windlass and chain locker openings and
equipment which may constitute an ignition .1 on individual cargo tanks, the gas outlet pipe,
hazard. if fitted, shall be positioned as far as practicable
from the inert gas/air inlet and in accordance
IR-c) Electrical equipment fitted in compliance with 8.1 and Pt.6 Ch.3, 5.6. The inlet of such
with IEC Publication 60092 – “Electrical outlet pipes may be located either at deck level
installations in ships – Part 502 : Tankers or at not more than 1 m above the bottom of the
– Special features” is not considered a tank;
source of ignition or ignition hazard (refer
Pt 4, Ch. 8, Clause 12.9.10.2 for area .2 the cross-sectional area of such gas outlet
classification for electrical equipment pipe referred to in 8.2.3.1 is to be such that an
installation). exit velocity of at least 20 [m/s] can be
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maintained when any three tanks are being tanks entering the double hull spaces
simultaneously supplied with inert gas. Their through the system;
outlets shall extend not less than 2 m above c) where such spaces are not permanently
deck level; and connected to an inert gas distribution
system, appropriate means are to be
.3 each gas outlet referred to in paragraph provided to allow connection to the inert gas
8.2.3.2 is to be fitted with suitable blanking main.
arrangements.
8.3.3 At least two suitable portable instruments
8.2.4 When the ship is not provided with an inert for measuring oxygen and flammable vapour
gas system, the operation is to be such that the concentrations are to be provided. In selecting
flammable vapour is initially discharged either: these instruments, due attention shall be given
to their use in combination with the fixed gas-
a) through the vent outlets as specified in sampling-line systems referred to in paragraph
8.1.15; or 8.3.4.
b) through outlets at least 2 [m] above the
cargo tank deck level with a vertical efflux 8.3.4 Where the atmosphere in double hull
velocity of at least 30 metres/second spaces cannot be reliably measured using
maintained during gas freeing operation; or flexible gas sampling hoses, such spaces are to
c) through outlets at least 2 [m] above the be fitted with permanent gas sampling lines. The
cargo tank deck level with a vertical efflux configuration of such line systems are to be
velocity of at least 20 metres/second and adapted to the design of such spaces.
which are protected by suitable devices to
prevent the passage of flame. 8.3.5 The materials of construction and the
dimensions of gas sampling lines are to be such
8.2.5 When the flammable vapour concentration as to prevent restriction. Where plastic materials
at the outlet has been reduced to 30 per cent of are used, they should be electrically conductive.
the lower flammable limit, gas freeing may
thereafter be continued at the cargo tank deck 8.3.6 Arrangements for fixed hydrocarbon gas
level. detection systems in double-hull and double-
bottom spaces of oil tankers
8.2.6 All tankers are to be equipped with at least
two portable instruments for measuring oxygen 8.3.6.1 In addition to the requirements in 8.3.3 to
and flammable vapour concentrations. Also refer 8.3.5 above, oil tankers of 20,000 tonnes
para 11.8.5 regarding measurement in inert deadweight and above, constructed on or after 1
atmosphere. Suitable means are to be provided January 2012, are to be provided with a fixed
for the calibration of such instruments. hydrocarbon gas detection system complying
with Pt.6, Ch.8 for measuring hydrocarbon gas
8.3 Inerting, ventilation and gas concentrations in all ballast tanks and void
measurement detection of double hull and spaces of double-hull and double-bottom spaces
double bottom spaces adjacent to the cargo tanks, including the
forepeak tank and any other tanks and spaces
8.3.1 Double hull and double bottom spaces are under the bulkhead deck adjacent to cargo
to be fitted with suitable connections for the tanks.
supply of air.
8.3.6.2 Oil tankers provided with constant
8.3.2 On tankers required to be fitted with inert operative inerting systems for such spaces need
gas systems: not be equipped with fixed hydrocarbon gas
detection equipment.
a) double hull spaces are to be fitted with
suitable connections for the supply of inert 8.3.6.3 Notwithstanding the above, cargo pump-
gas; rooms complying with the provisions of 6.4.2 to
b) where hull spaces are connected to a 6.4.5 and IR6.4.5 need not comply with the
permanently fitted inert gas distribution requirements of this paragraph (i.e. 8.3.6).
system, means are to be provided to
prevent hydrocarbon gases from the cargo
Section 9
Section 10
10.1 General other than at the top of the tank, and the main
supply lines are to be run above the weather
10.1.1 Following requirements are to be deck.
complied with for vessels fitted with heating
arrangements for cargoes. 10.1.5 Isolating shut-off valves or cocks are to
be provided at the inlet and outlet connections of
10.1.2 Spectacle flanges or spool pieces are to each tank, and means are to be provided for
be provided in the heating medium supply and regulating the flow.
return pipes to the cargo heating system, in a
suitable position in the cargo area, so that the 10.1.6 Where steam or water is employed in the
lines can be blanked off in circumstances where heating circuits, the returns are to be led to an
the cargo does not require to be heated or observation tank which is to be in a well
where the heating coils have been removed ventilated and well lighted part of the machinery
from the tank. Alternatively, blanking space remote from the boilers.
arrangements may be provided for each tank
heating circuit. 10.1.7 Where a thermal oil is employed in the
heating circuits, the arrangements will be
10.1.3 The heating medium is to be compatible specially considered.
with the cargoes to be heated. Where a
combustible liquid is used as the heating 10.1.8 In any heating system, a higher pressure
medium it is to have a flash point of 60°C or is to be maintained within the heating circuit
above (Closed Cup Test). In general the than the maximum pressure head which can be
temperature of the heating medium is not to exerted by the contents of the cargo tank on the
exceed 220°C. circuit. Alternatively, when the heating circuit is
not in use, it may be drained and blanked.
10.1.4 The heating medium supply and return
lines are not to penetrate the cargo tank plating, 10.1.9 Means are to be provided for measuring
the cargo temperature.
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Section 11
11.1.3 The following plans are to be submitted 11.3.2 The compartment in which any oil fired
for approval. inert gas generator is located is to be treated as
machinery space of category A.
- schematic diagram of inert gas system
including water supply and discharge piping 11.3.3 Two fuel oil pumps are to be fitted to the
inert gas generator. One fuel pump only may be
- piping arrangement for inert gas distribution accepted provided sufficient spares for the fuel
and tank ventilation oil pump and its prime mover are carried on
board to enable any failure of the fuel oil pump
- schematic diagram of automatic control, and its prime mover to be rectified by the ship's
monitoring and indicating systems. crew.
11.1.4 Vessels complying with these 11.3.4 The inert gas system is to be capable of :
requirements will be eligible for the notation NV.
a) inerting empty cargo tanks by reducing the
11.1.5 Any proposal to use an inert gas other oxygen content of the atmosphere in each
than flue gas, e.g. nitrogen, will be specially tank to a level at which combustion cannot
considered. be supported;
11.1.6 Throughout this Section the term 'cargo b) maintaining the atmosphere in any part of
tank' includes 'slop tanks' also. any cargo tank with an oxygen content not
exceeding eight percent by volume and at a
11.2 Materials positive pressure at all times in port and at
sea except when it is necessary for such a
11.2.1 Materials used in inert gas systems are to tank to be gas free;
be suitable for their intended purpose and are to
comply with the requirements specified in Part 2 c) eliminating the need for air to enter a tank
of the Rules. during normal operations except when it is
necessary for such a tank to be gas free;
11.2.2 Materials are to be selected so as to
reduce the probability for corrosion and erosion,
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d) purging empty cargo tanks of hydrocarbon be divided equally between the two blowers and
gas, so that subsequent gas freeing in no case is one blower to have a capacity less
operations will at no time create a than 1/3 of the total capacity required.
flammable atmosphere within the tank.
11.5.2 The inert gas system is to be so designed
11.3.5 The system is to be capable of delivering that the maximum pressure which it can exert on
inert gas to the cargo tanks at a rate of at least any cargo tank will not exceed the test pressure
125 percent of the maximum rate of discharge of any cargo tank. Suitable shut-off
capacity of the ship expressed as a volume. arrangements are to be provided on the suction
and discharge connections of each blower.
11.3.6 The system is to be capable of delivering Arrangements are to be provided to enable the
inert gas with an oxygen content of not more functioning of the inert gas plant to be stabilized
than five per cent by volume in the inert gas before commencing cargo discharge. If the
supply main to the cargo tanks at any required blowers are to be used for gas freeing, their air
rate of flow. inlets are to be provided with blanking
arrangements.
11.3.7 Flue gas isolating valves are to be fitted
in the inert gas supply mains between the boiler 11.5.3 The blowers are to be located aft of all
uptakes and the flue gas scrubber. These valves cargo tanks, cargo pump rooms and cofferdams
are to be provided with indicators to show separating these spaces from machinery spaces
whether they are open or shut and precautions of Category A.
are to be taken to maintain them gastight and
keep the seatings clear of soot. Arrangements 11.6 Gas distribution lines
are to be made to ensure that boiler soot
blowers cannot be operated when the 11.6.1 Special consideration is to be given to the
corresponding flue gas valve is open. design and location of scrubber and blowers
with relevant piping and fittings in order to
11.4 Gas scrubber prevent flue gas leakages into enclosed spaces.
11.4.1 A flue gas scrubber is to be fitted which 11.6.2 To permit safe maintenance, an
will effectively cool the inert gas and remove additional water seal or other effective means of
solids and sulphur combustion products. The preventing flue gas leakage is to be fitted
cooling water arrangements are to be such that between the flue gas isolating valves and
an adequate supply of water will always be scrubber or incorporated in the gas entry to the
available without interfering with any essential scrubber.
services on the ship. Provision is also to be
made for alternative supply of cooling water. 11.6.3 A gas regulating valve is to be fitted in
the inert gas supply main. This valve is to be
11.4.2 Filters or equivalent devices are to be automatically controlled to close as required in
fitted to minimize the amount of water carried 11.8.9 and 11.8.10. It is also to be capable of
over to the inert gas blowers. automatically regulating the flow of inert gas to
the cargo tanks unless means are provided to
11.4.3 The scrubber is to be located aft of all automatically control the speed of the inert gas
cargo tanks, cargo pump rooms and cofferdams blowers required in 11.4.1.
separating these spaces from machinery spaces
of Category A. 11.6.4 The valve referred to in 11.6.3 is to be
located at the forward bulkhead of the
11.5 Gas blowers forwardmost gas safe space through which the
inert gas supply main passes. (A gas-safe space
11.5.1 At least two blowers are to be fitted which is a space in which the entry of hydrocarbon
together are to be capable of delivering to the gases, which would produce hazards with
cargo tanks at least the volume of gas required regard to flammability or toxicity, is avoided.)
by 11.3.4. In the system with gas generators,
one blower only may be accepted if that system 11.6.5 At least two non-return devices, one of
is capable of delivering the total volume of gas which is to be a water seal, are to be fitted in the
required by 11.3.4 to the protected cargo tanks, inert gas supply main. In order to prevent the
provided that sufficient spares for the blower return of hydrocarbon vapour to the machinery
and its prime mover are carried on board to space uptakes or to any gas safe spaces under
enable any failure of the blower and its prime all normal conditions of trim, list and motion of
mover to be rectified by the ship's crew. When the ship. They are to be located between the
two blowers are provided, the total required automatic valve required by 11.6.3 and the
capacity of the inert gas system is preferably to
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aftermost connection to any cargo tank or cargo with either stop valves or equivalent means of
pipeline. control for isolating each tank. Where stop
valves are fitted, they are to be provided with
11.6.6 The devices referred to in 11.6.5 are to locking arrangements, which are to be under the
be located in the cargo area on deck. control of a responsible ship's officer. The
control system for operating these valves is to
11.6.7 The water seal referred to in 11.6.5 is to provide unambiguous information of the
be capable of being supplied by two separate operational status of the valves.
pumps, each of which is to be capable of
maintaining an adequate supply at all times. 11.6.16 In combination carriers, the arrange-
ment to isolate the slop tanks containing oil or oil
11.6.8 The arrangement of the seal and its residues from other tanks is to consist of blank
associated fittings is to be such that it will flanges which will remain in position at all times
prevent backflow of hydrocarbon vapours and other than when cargoes other than oil are being
will ensure the proper functioning of the seal carried except as may be accepted by the
under operating conditions. National Statutory Authority. (Refer to the
relevant section of MSC/Circ.353, as amended
11.6.9 Provision is to be made to ensure that the by MSC/Circ.387).
water seal is protected against freezing in such
a way that the integrity of seal is not impaired by 11.6.17 Means are to be provided to protect
overheating. cargo tanks against the effect of over-pressure
or vacuum caused by thermal variations when
11.6.10 A water loop or other approved the cargo tanks are isolated from the inert gas
arrangement is also to be fitted to each mains.
associated water supply and drain pipe and
each venting or pressure sensing pipe leading to 11.6.18 Piping systems are to be so designed
gas safe spaces. Means are to be provided to as to prevent the accumulation of cargo or water
prevent such loops from being emptied by in the pipelines under all normal conditions.
vacuum.
11.6.19 Suitable arrangements are to be
11.6.11 The deck water seal and all loop provided to enable the inert gas main to be
arrangements are to be capable of preventing connected to an external supply of inert gas.
return of hydrocarbon vapours at a pressure The arrangements are to consist of a 250 [mm]
equal to the test pressure of the cargo tanks. nominal pipe size bolted flange, isolated from
the inert gas main by a valve and located
11.6.12 The second non-return device is to be a forward of the non-return valve referred to in
non-return valve or equivalent capable of 11.6.12. The design of the flange is to conform
preventing the return of vapours or liquids and to the appropriate class in the standards
fitted forward of the deck water seal required in adopted for the design of other external
11.6.5. It is to be provided with positive means connections in the ship's cargo piping system.
of closure. As an alternative to positive means of
closure, an additional valve having such means 11.7 Venting arrangements
of closure may be provided forward of the non-
return valve to isolate the deck water seal from 11.7.1 The arrangements for inerting, purging or
the inert gas main to the cargo tanks. gas freeing of empty tanks as required in 8.2.2
are to be such that the accumulation of
11.6.13 As an additional safeguard against the hydrocarbon vapours in pockets formed by the
possible leakage of hydrocarbon liquids or internal structural members in a tank is
vapours back from the deck main, means are to minimized and that :
be provided to permit this section of the line
between the valve having positive means of a) on individual cargo tanks the gas outlet
closure referred to in 11.6.12 and the valve pipe, if fitted, is to be positioned as far as
referred to in 11.6.3 to be vented in a safe practicable from the inert gas/air inlet and in
manner when the first of these valves is closed. accordance with Sec.9. The inlet of such
outlet pipes may be located either at deck
11.6.14 The inert gas main may be divided into level or at not more than 1 [m] above the
two or more branches forward of the non-return bottom of the tank;
devices required by 11.6.5.
b) the cross sectional area of such gas outlet
11.6.15 The inert gas supply mains are to be pipes referred to in (a) is to be such that an
fitted with branch piping leading to each cargo exit velocity of at least 20 metres/second
tank. Branch piping for inert gas is to be fitted can be maintained when any three tanks are
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a) low water pressure or low water flow rate to 11.8.12 The alarms required in (e), (f) and (h) of
the flue gas scrubber as referred to in 11.8.7 are to be fitted in the machinery space
11.4.1. cargo control room, where provided, but in each
case in such a position that they are
b) high water level in the flue gas scrubber as immediately received by responsible members
referred to in 11.4.1. of the crew.
a) insufficient oil fuel supply; 11.9.1 The inert gas system, including alarms
and safety devices, is to be installed on board
b) failure of the power supply to the generator; and tested under working conditions to the
satisfaction of the Surveyors.
c) failure of the power supply to the automatic
control system for the generator. 11.10 Nitrogen generator systems
11.8.9 Automatic shut-down of the inert gas 11.10.1 The following requirements are specific
blowers and gas regulating valve as well as oil only to the gas generator system and apply
fuel supply to inert gas generators is to be where inert gas is produced by separating air
arranged on predetermined limits being reached into its constituent gases by passing
in respect of (a), (b) and (c) of 11.8.7. compressed air through a bundle of hollow
fibres, semi-permeable membranes or adsorber
11.8.10 Automatic shut-down of the gas materials
regulating valve is to be arranged in respect of
11.8.7(d) and in 11.8.8(b). 11.10.2 Where such systems are provided in
place of the boiler flue gas or oil fired inert gas
11.8.11 In respect of 11.8.7(e), when the oxygen generators in section 11.1 through 11.9, the
content of the inert gas exceeds 8 per cent by relevant requirements of section 11 for the
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piping arrangements, alarms and only from the open deck and the access door is
instrumentation down stream of the gas to open outwards. Permanent ventilation and
generator are to be complied with alarm are to be fitted as required by paragraph
11.10.5.
11.10.3 A nitrogen generator consists of a feed
air treatment system and any number of 11.10.12 The oxygen-enriched air from the
membranes or adsorber modules in parallel nitrogen generator is to be discharged on the
necessary to meet the required capacity which open deck to a safe location which is to be:
is to be at least 125% of the maximum
discharge capacity of the ship expressed as a - outside of the hazardous area(as defined by
volume. IEC 60092-502);
11.10.4 The air compressor and the nitrogen - not within 3 [m] of areas traversed by
generator may be installed in the engine room or personnel; and
in a separate compartment. A separate
compartment is to be treated as one of "other - not within 6 [m] of air intakes for machinery
machinery spaces" with respect to fire (engines and boilers) and all ventilation inlets.
protection.
The nitrogen product enriched gas from the
11.10.5 Where a separate compartment is protective devices of the nitrogen receiver is to
provided, it is to be positioned outside the cargo be discharged on the open deck to a safe
area and is to be fitted with an independent location which is to be:
mechanical extraction ventilation system
providing 6 air changes per hour. A low oxygen - not within 3 [m] of areas traversed by
alarm is to be fitted for this compartment. personnel; and
11.10.6 The compartment is to have no direct - not within 6 [m] of air intakes for machinery
access to accommodation spaces, service (engines and boilers) and all ventilation
spaces and control stations. inlets/outlets.
11.10.7 The nitrogen generator is to be capable 11.10.13 In order to carry out maintenance,
of delivering high purity nitrogen with O2 content means of isolation are to be fitted between the
not exceeding 5% by volume. The system is to generator and the receiver.
be fitted with automatic means to discharge "off-
spec" gas to the atmosphere during start-up and 11.10.14 At least two non-return devices are to
abnormal operation. be fitted in the inert gas supply main, one of
which is to be of the double block and bleed
11.10.8 The system is to be provided with two arrangement given in P5, Ch.3, para 21.1.2. The
air compressors. The total required capacity of second non-return device is to be equipped with
the system is preferably to be divided equally positive means of closure.
between the two compressors, and in no case is
one compressor to have a capacity less than 1/3 11.10.15 Instrumentation is to be provided for
of the total capacity required. continuously monitoring the temperature and
pressure of air at the discharge side of the
11.10.9 Only one air compressor may be compressor and at the inlet to the nitrogen
accepted provided that sufficient spares for the generator.
air compressor and its prime mover are carried
on board to enable their failure to be rectified by 11.10.16 Instrumentation is to be fitted for
the ship's crew. continuously indicating and permanently
recording the oxygen content of the inert gas
11.10.10 A feed air treatment system is to be downstream of the nitrogen generator when
fitted to remove free water, particles and traces inert gas is being supplied.
of oil from the compressed air, and to preserve
the specification temperature. 11.10.17 The instrumentation referred to in
11.10.16 to be placed in the cargo control room
11.10.11 Where fitted, a nitrogen receiver/buffer where provided. But where no cargo control
tank may be installed in a dedicated room is provided, they are to be placed in a
compartment or in the separate compartment position easily accessible to the officer in charge
containing the air compressor and the generator of cargo operations.
or may be located in the cargo area. Where the
nitrogen receiver/buffer tank is installed in an 11.10.18 Audible and visual alarms are to be
enclosed space, the access is to be arranged provided to indicate:
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11.10.20 The alarms required by 11.10.18 a) to
a) low feed air pressure from compressor as f) are to be fitted in the machinery space and
referred to in 11.10.15 cargo control room, where provided, but in each
case in such a position that they are
b) high air temperature as referred to in immediately acknowledged by responsible
11.10.15 members of the crew.
c) high condensate level at automatic drain of 11.11 Nitrogen/inert gas systems fitted for
water separator as referred to in paragraph purposes other than inerting required by
11.10.10 Sec.11-10
d) failure of electrical heater, if fitted 11.11.1 This section applies to systems fitted on
oil tankers of less than 20,000 DWT, gas
e) oxygen content in excess of that required in tankers or chemical tankers.
paragraph 11.10.7
11.11.2 The requirements of section 11.10 apply
f) failure of power supply to the except paragraphs 11.10.1, 11.10.2, 11.10.3
instrumentation as referred to in paragraph and 11.10.8.
11.10.16.
11.11.3 Where the connections to the cargo
11.10.19 Automatic shut-down of the system is tanks, to the hold spaces or to cargo piping are
to be arranged upon alarm conditions as not permanent, the non-return devices required
required by 11.10.18 (a) to (e). by paragraph 11.10.14 may be substituted by
two non-return valves.
Section 12
12.1 General
12.2 Structural arrangement
12.1.1 Ships intended to carry either oil in bulk
with flash point not exceeding 60°C (closed cup 12.2.1 Cargo tanks are to facilitate efficient
test) or alternatively dry bulk cargo are to cleaning. Tank boundaries are to have plane
comply with the additional requirements of this surface, corrugated surface or vertical stiffeners
section. as far as practicable. Horizontal primary
members are to be avoided inside tanks; where
12.1.2 Relevant requirements for bulk carriers primary structural members are unavoidable,
and ore carriers given in Pt.5, Ch.1 are also to attention is to be paid to the cleaning facilities.
be complied with, as applicable.
12.2.2 Openings which may be used for cargo
12.1.3 Dry cargoes and oil (with flash point operations, for example in the bottom of topside
below 60°C) are not be carried simultaneously, tanks, are not permitted in bulkheads and decks
except for oil retained in protected slop tanks separating oil cargo spaces from other spaces
when the ship is carrying dry cargoes. Prior to not designed and equipped for the carriage of oil
employing the ship for the carriage of dry cargoes unless they are equipped with
cargoes, the entire cargo area is to be cleaned, alternative approved means to ensure
gas freed, inerted and isolated in accordance equivalent integrity.
with the requirements of the National or Port
Authorities. 12.2.3 Where transverse bulkheads in wing
tanks have different structural arrangement than
12.1.4 Attention is drawn to the requirements of in way of the holds, arrangements are to be
Pt.6, Ch.2, 1.5.4.2 regarding ventilation and gas made to ensure continuity of transverse strength
freeing of enclosed spaces in combination across the longitudinal bulkheads.
carriers which are to be complied with. In way of
cargo holds for oil, enclosed spaces in which 12.2.4 Suitable arrangements are to be provided
explosive gases may accumulate are to be for gas freeing the double bottom, double hull,
avoided. hopper, side and topside tanks. Similar
arrangements are to be provided for cargo oil
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ducts which are used as pipe tunnels when the the contents of the slop tanks directly over the
ship is carrying dry cargo. open deck when the ship is in the dry cargo
mode. When the transfer system is used for slop
12.3 Hatch covers transfer in the dry cargo mode, it is to have no
connection to other systems. Separation from
12.3.1 The hatch covers and the sealing system other systems by means of removal of spool
are to avoid leakages caused by possible elastic pieces may be accepted.
deformation of the hatchways.
12.4.4 Hatches and tank cleaning openings to
12.3.2 The scantlings and arrangement of hatch slop tanks are to be provided only on the open
covers are to be obtained as per Pt.3, Ch.12. deck and are to be fitted with closing
Where cargo holds are intended to be partially arrangements. Except when they are closed
filled, the hatch covers may require to be watertight by bolted plates, these closing
additionally strengthened. arrangements are to be provided with locking
arrangements, under the control of a
12.4 Slop tanks responsible ship's officer.
12.4.1 These requirements are applicable to 12.4.5 Slop tanks are to be provided with an
combination carriers where oil residues are approved independent venting system, generally
retained in the slop tanks and the ship is in accordance with Sec.8.2.
otherwise gasfree.
12.4.6 At least two portable instruments are to
12.4.2 The slop tanks are to be surrounded by be available on board for gas detection.
cofferdams except where the boundaries are the
hull, main cargo deck, cargo pump-room 12.4.7 Adequate ventilation is to be provided for
bulkhead or oil fuel bunker tank. These spaces surrounding slop tanks.
cofferdams are not to be open to a double
bottom, pipe tunnel, pump room or other 12.4.8 Warning notices are to be erected at
enclosed spaces nor they are to be used for suitable points detailing the precautions to be
cargo or ballast and are not to be connected to observed prior to the ship loading or unloading,
piping systems serving oil cargo or ballast. or when the ship is carrying dry cargo with liquid
Means are to be provided for filling the in the slop tanks.
cofferdams with water and draining them. Where
the boundary of a slop tank is the cargo pump 12.4.9 Attention is drawn to the requirements of
room bulkhead, the pump room should not be certain Flag state/ Port state Authorities
open to the double bottom, pipe tunnel or other whereby an inert gas system is to be provided
enclosed spaces except when they are closed for blanketting the slop tank contents.
gastight by bolted plates.
12.5 Cargo piping
12.4.3 Means are to be provided for isolating the
piping connecting the pump room with the slop 12.5.1 Where cargo wing tanks are provided,
tanks. The means of isolation is to consist of a cargo oil lines below deck are to be installed
valve followed by a spectacle flange or a spool inside these tanks. However, IRS may permit
piece with appropriate blank flanges. This cargo oil lines to be placed in special ducts
arrangement is to be located adjacent to the provided these are capable of being adequately
slop tanks, but where this is unreasonable or cleaned and ventilated to the satisfaction of IRS.
impracticable it may be located within the pump Where cargo wing tanks are not provided, cargo
room directly after the piping penetrates the oil lines below deck are to be placed in special
bulkhead. A separate pumping and piping ducts.
arrangement is to be provided for discharging
Section 13
13.1 In tankers crude oil or slops may be used 13.6 When it is necessary to preheat crude oil or
as fuel for main or auxiliary boilers according to slops, their temperature is to be automatically
the following requirements. For this purpose all controlled and a high temperature alarm is to be
arrangement drawings of a crude oil installation fitted.
with pipeline layout and safety equipment are to
be submitted for approval in each case. 13.7 The piping for crude oil or slops and the
draining pipes for the tray defined in 13.9 are to
13.2 Crude oil or slops may be taken directly have a thickness as follows:
from cargo tanks or from slop tanks or from
other suitable tanks. These tanks are to be fitted External diameter of pipes, de thickness, t
in the cargo tank area and are to be separated
from non-gas-dangerous areas by means of OD [mm] Thickness [mm]
cofferdams with gas-tight bulkheads.
82.5 6.3
13.3 The construction and workmanship of the 88.9 - 108 7.1
boilers and burners are to be proved to be 114.3 > 139.7 8.0
satisfactory in operation with crude oil. The
whole surface of the boilers shall be gas-tight 152.4 8.8
separated from the engine room. The boilers
themselves are to be tested for gas-tightness Their connections (to be reduced to a minimum)
before being used. The whole system of pumps, are to be of the heavy flange type. Within the
strainers, separators and heaters, if any, shall engine room and boiler room these pipes are to
be fitted in the cargo pump room or in another be fitted within a metal duct, which is to be gas-
room, to be considered as dangerous and tight and tightly connected to the fore bulkhead
separated from engine and boiler room by gas- separating the pump room and to the tray. This
tight bulkheads. When crude oil is heated by duct (and the enclosed piping) is to be fitted at a
steam or hot water the outlet of the heating coils distance from the ship's side of at least 20% of
should be led to a separate observation tank the vessel's beam amidships and be at an
installed together with above mentioned inclination rising towards the boiler so that the oil
components. This closed tank is to be fitted with naturally returns towards the pump room in the
a venting pipe led to the atmosphere in a safe case of leakage or failure in delivery pressure. It
position according to the rules for tankers and is to be fitted with inspection openings with gas-
with the outlet fitted with a suitable flame proof tight doors in way of connections of pipes within
wire gauze of corrosion resistant material which it, with an automatic closing drain-trap placed on
is to be easily removable for cleaning. the pump room side, set in such a way as to
discharge leakage of crude oil into the pump
13.4 Electric, internal combustion and steam room. In order to detect leakages, level position
(when the steam temperature is higher than indicators with relevant alarms are to be fitted on
220°C) prime movers of pumps, of separators (if the drainage tank defined in 13.9. Also a vent
any), etc., shall be fitted in the engine room or in pipe is to be fitted at the highest part of the duct
another non-dangerous room. Where drive and is to be led to the open in a safe position.
shafts pass through pump room bulkhead or The outlet is to be fitted with a suitable flame
deck plating, gas-tight glands are to be fitted. proof wire gauze of corrosion resistant material
The glands are to be efficiently lubricated from which is to be easily removable for cleaning.
outside the pump room.
The duct is to be permanently connected to an
13.5 Pumps shall be fitted with a pressure relief approved inert gas system or steam supply in
bypass from delivery to suction side and it shall order to make possible:
be possible to stop them by a remote control
placed in a position near the boiler fronts or - injection of inert gas or steam in the duct in
machinery control room and from outside the case of fire or leakage
engine room.
- purging of the duct before carrying out work Electrical equipment installed in gas dangerous
on the piping in case of leakage. areas or in areas which may become dangerous
(i.e. in the hood or duct in which crude-oil piping
13.8 In way of the bulkhead to which the duct is placed) is to be of certified safe type.
defined in 13.7 is connected, delivery and return
oil pipes are to be fitted on the pump room side, 13.11 When using fuel oil for delivery to and
with shut-off valves remotely controlled from a return from boilers fuel oil burning units in
position near the boiler fronts or from the accordance with the Rules shall be fitted in the
machinery control room. The remote control boiler room. Fuel oil delivery to, and returns
valves should be interlocked with the hood from, burners shall be effected by means of
exhaust fans (defined in 13.10) to ensure that suitable mechanical interlocking devices so that
whenever crude oil is circulating the fans are running on fuel oil automatically excludes
running. running on crude oil or vice versa.
13.9 Boilers shall be fitted with a tray or gutter 13.12 The boiler compartments are to be fitted
way of acceptable height and be placed in such with a mechanical ventilation plant and shall be
a way as to collect any possible oil leakage from designed in such a way as to avoid the
burners, valves and connections. formation of gas pockets.
Such a tray or gutter way shall be fitted with a Ventilation is to be particularly efficient in way of
suitable flame proof wire gauze, made of electrical plants and machinery and other plants
corrosion resistant material and easily which may generate sparks. These plants shall
dismountable for cleaning. Delivery and return be separated from those for service of other
oil pipes shall pass through the tray or gutterway compartments.
by means of a tight penetration and shall then
be connected to the oil supply manifolds. 13.13 A gas detector plant shall be fitted with
intakes in the duct defined in 13.7, in the hood
A quick closing master valve is to be fitted on duct (downstream of the exhaust fans in way of
the oil supply to each boiler manifold. The tray the boilers) and in all zones where ventilation
or gutterway shall be fitted with a draining pipe may be reduced. An optical warning device is to
discharging into a collecting tank in pump room. be installed near the boiler fronts and in the
This tank is to be fitted with a venting pipe led to machinery control room. An acoustical alarm,
the open in a safe position and with the outlet audible in the machinery space and control
fitted with wire gauze made of corrosion room, is to be provided.
resistant material and easily dismountable for
cleaning. The draining pipe is to be fitted with 13.14 Means are to be provided for the boiler to
arrangements to prevent the return of gas to the be automatically purged before firing.
boiler or engine room.
13.15 Independent of the fire extinguishing plant
13.10 Boilers shall be fitted with a suitable hood as required by the Rules, an additional fire
placed in such a way as to enclose as much as extinguishing plant is to be fitted in the engine
possible of the burners, valves and oil pipes, and boiler rooms in such a way that it is possible
without preventing, on the other side, air inlet to for an approved fire extinguishing medium to be
burner register. The hood, if necessary, is to be directed on to the boiler fronts and on to the tray
fitted with suitable doors placed in such a way defined in 13.9. The emission of extinguishing
as to enable inspection of and access to oil medium should automatically stop the exhaust
pipes and valves placed behind it. It is to be fan of the boiler hood.
fitted with a duct leading to the open in a safe
position, the outlet of which is to be fitted with a 13.16 A warning notice must be fitted in an
suitable flame wire gauze, easily dismountable easily visible position near the boiler front. This
for cleaning. At least two mechanically driven notice must specify that when an explosive
exhaust fans having spark proof impellers are to mixture is signalled by the gas detector plant
be fitted so that the pressure inside the hood is defined in 13.13 the watch keepers are to
less than that in the boiler room. The exhaust immediately shut off the remote controlled
fans are to be connected with automatic change valves on the crude oil delivery and return pipes
over in case of stoppage or failure of the one in in the pump room, stop the relative pumps,
operation. The exhaust fan prime movers shall inject inert gas into the duct defined in 13.7 and
be placed outside the duct and a gas-tight turn the boilers to normal running on fuel oil.
bulkhead penetration shall be provided for shaft.
13.17 One pilot burner in addition to the normal
burning control is required.
Appendix A
List of oils*
Asphalt solutions
Gasoline blending stocks
Blending stocks
Roofers flux Alkylates - fuel
Straight run residue Reformaters
Polymer - fuel
Oils
Gasolines
Clarified
Crude oil Casinghead (natural)
Mixtures containing crude oil Automotive
Diesel oil Aviation
Fuel oil no.4 Straight run
Fuel oil no.5 Fuel oil no.1 (kerosene)
Fuel oil no.6 Fuel oil no.1-D
Residual fuel oil Fuel oil no.2
Road oil Fuel oil no.2-D
Transformer oil
Aromatic oil (excluding vegetable oil) Jet fuels
Lubricating oils and blending stocks
Mineral oil JP-1 (kerosene)
Motor oil JP-3
Penetrating oil JP-4
Spindle oil JP-5 (kerosene, heavy)
Turbine oil Turbo fuel
Kerosene
Distillates Mineral spirit
Appendix B
List of cargoes other than oils which can be carried on oil tankers
Note 2 : Some liquid substances are identified as falling into Pollution Category Z and therefore,
subject to certain requirements of Annex II of MARPOL 73/78.
End of Chapter
Chapter 3
Chemical Carriers
Contents
Section
Introduction
Preamble
1 General
2 Ship Survival Capability and Location of Cargo Tanks
3 Ship Arrangements
4 Cargo Containment
5 Cargo Transfer
6 Materials of Construction, Protective Linings and Coatings
7 Cargo Temperature Control
8 Cargo Tank Venting and Gas-freeing Arrangement
9 Environmental Control
10 Electrical Installations
11 Fire Protection and Extinction
12 Mechanical Ventilation in the Cargo Area
13 Instrumentation
14 Personnel Protection
15 Special Requirements
16 Operational Requirements
17 Summary of Minimum Requirements
18 List of Chemicals to which this Chapter does not Apply
19 Index of Products Carried in Bulk
20 Transport of Liquid Chemical Wastes
21 Inert Gas Systems
Introduction
IR 1.3 The Rules incorporate the final text of the IR 2.0 Ship operational requirements
IBC Code in full. For purpose of classification
with Indian Register of Shipping and assignment IR 2.1 The IBC Code contains requirements in
of the notations provided for in IR 4.0, chemical respect of operational matters which are not
tankers are required to comply with these Rules within the scope of classification as defined in
and the relevant provisions of IRS Rules and the Rules for Ships, but are the responsibility of
Regulations for the Classification of Ships. The the National Authority or Administration
paragraphs which are not included in the IMO responsible for issuing the Certificate of Fitness.
code, but have been included in these Rules for
the purpose of classification have been prefixed IR 2.2 Similarly, operational requirements which
with the letters "IR". appear in the IBC Code will not be dealt with by
IRS for classification purposes.
IR 1.4 Ships built prior to the coming-into-force
date of these Rules where the provisions of IR 2.3 Those paragraphs which are considered
these Rules have not been applied will continue to be operational are indicated in Sec.16.
to be dealt with for classification purposes on
the basis of the Rules for Chemical Tankers to IR 3.0 Chemicals to which the Code does not
which these vessels were built. In considering apply
new or additional chemical cargoes for inclusion
in the cargo lists of these ships individual IR 3.1 Sec.18 contains a list of chemicals to
consideration, taking account of the ships' which the IBC Code does not apply. For
arrangements and the nature of the proposed classification purposes the carriage of these
cargoes, will be given. listed products is therefore not restricted to
Chemical Tankers constructed in accordance
with these Rules.
Fig. IR 4.2
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IR 4.4 The assignment of Ship Type will not IR 4.5.4 Chemical tankers will not generally be
imply that the ship is suitable for all cargoes eligible for a reduction of cargo tank scantlings
listed in Sec.17 as requiring that Ship Type. in association with a corrosion control notation.
Those cargoes from Sec.17 and 18 for the
carriage of which the ship has been approved IR 5.0 List of defined Cargoes
will be named on a list of Defined Cargoes
which will be attached to the Classification IR 5.1 The tanks for which each cargo has been
Certificate. approved will be indicated on the list of Defined
Cargoes attached to the Classification
IR 4.5 Additional notations Certificate as provided for in IR 4.4 together with
any specific conditions of carriage.
IR 4.5.1 Additional notations may be given for
the following features:- IR 5.2 Where Chemical Cargoes which are dealt
with in these Rules but which are not on the list
a) Independent tanks, when fitted; of Defined Cargoes for classification purposes
are to be carried, it will be Owner's responsibility
b) Maximum permissible specific gravity for to ensure that particulars are forwarded to IRS
which the scantlings have been approved, for consideration of the classification aspects
where greater than 1.025, e.g. "SG 2.0"; prior to carriage.
11. As from the date of entry into force of the to the Code, whether from the point of view
1983 amendments to the 1974 SOLAS of safety or of marine pollution, must be
Convention (i.e. 1 July 1987) and the date of adopted and brought into force in
implementation of Annex II of MARPOL accordance with the procedures laid down
73/78 (i.e. 6 April 1987), this Code became in Article VIII of SOLAS 74 and Article 16 of
subject to mandatory requirements under MARPOL 73/78 respectively.
these Conventions. Any future amendment
Section 1
General
1.1 Application
IR 1.1.6 Products covered in 1.1.6 will be
IR 1.1.1 The requirements of this Chapter are in specially considered by IRS.
addition to the requirements of Pt.1 to 4 of the
Rules as applicable. 1.1.7 Unless expressly provided otherwise the
Chapter applies to ships the keels of which are
1.1.1 This Chapter applies to ships regardless of at a stage at which:
size, including those of less than 500 tons gross
tonnage, engaged in the carriage of bulk .1 construction identifiable with the ship begins;
cargoes of dangerous or noxious liquid chemical and
substances, other than petroleum or similar
flammable products as follows: .2 assembly has commenced comprising at
least 50 tonnes or 1% of the estimated mass of
.1 products having significant fire hazards in all structural material, whichever is less;
excess of those of petroleum products and
similar flammable products; on or after 1 July 1986.
.2 products having significant hazards in IR 1.1.7 For classification purposes these Rules
addition to or other than flammability. may, but need not be, applied to ships for which
the midship section is approved prior to 1 July
1.1.2 Products that have been reviewed and 1986.
determined not to present safety and pollution
hazards to such an extent as to warrant the 1.1.8 A ship, irrespective of the date of
application of the Code are found in Sec.18. construction, which is converted to a chemical
tanker on or after 1 July 1986, is to be treated as
1.1.3 Liquids covered by the Chapter are those a chemical tanker constructed on the date on
having a vapour pressure not exceeding 0.28 which such conversion commences. This
MPa at a temperature of 37.8°C. conversion provision does not apply to the
modification of a ship referred to in regulation
1.1.4 For the purpose of the 1974 SOLAS 1(12) of Annex II of MARPOL 73/78.
Convention, the Chapter applies to ships which
are engaged in the carriage of products included 1.1.9 Where reference is made in the Chapter to
in Sec.17 on the basis of their safety a paragraph, all the provisions of the
characteristics and identified as such by an subparagraphs of that designation will apply.
entry of S or S/P in column d.
1.2 Hazards
1.1.5 For the purposes of MARPOL 73/78, the
Code applies only to NLS tankers, as defined in Hazards of products covered by this Chapter
regulation 1.16.2 of Annex II thereof, which are include:
engaged in the carriage of Noxious Liquid
Substances identified as such by an entry of X, 1.2.1 Fire hazard defined by flashpoint, boiling
Y or Z in column c of Section 17. point, flammability limits and auto-ignition
temperature of the chemical.
1.1.6 For a product proposed for carriage in
bulk, but not listed in Sec.17 or 18, the 1.2.2 Health hazard defined by:
Administration and port Administrations involved
in such carriage should prescribe the preliminary .1 corrosive effects on the skin in the liquid
suitable conditions for the carriage, having state; or
regard to the criteria for hazard evaluation of
bulk chemicals. The Organization should be .2 acute toxic effect, taking into account
notified of the conditions for consideration for values of
inclusion of the product in the Code. For the
evaluation of the pollution hazard of such a LD50 (oral): a dose which is lethal to
product and assignment of its pollution category, 50% of the test subjects
the procedure specified in regulation 6.3 of when administered orally;
Annex II of MARPOL 73/78 must be followed.
1.3.1 Accommodation spaces are those 1.3.10 Cofferdam is the isolating space
spaces used for public spaces, corridors, between two adjacent steel bulkheads or decks.
lavatories, cabins, offices, hospitals, cinemas, This space may be a void space or a ballast
games and hobbies rooms, barber shops, space.
pantries containing no cooking appliances and
similar spaces. Public spaces are those portions 1.3.11 Control stations are those spaces in
of the accommodation spaces which are used which ship's radio or main navigating equipment
for halls, dining rooms, lounges and similar or the emergency source of power is located or
permanently enclosed spaces. where the fire-recording or fire-control
equipment is centralized. This does not include
1.3.2.1 Administration means the Government special fire-control equipment which can be
of the State whose flag the ship is entitled to fly. most practically located in the cargo area.
1.3.2.2 Port administration means the 1.3.12 Dangerous chemicals means any liquid
appropriate authority of the country in the port chemicals designated as presenting a safety
which the ship is loading or unloading. hazard, based on the safety criteria for
assigning products to chapter 17.
1.3.3 Boiling point is the temperature at which
a product exhibits a vapour pressure equal to 1.3.13 Density is the ratio of the mass to the
the atmospheric pressure. volume of a product, expressed in terms of
kilograms per cubic metre. This applies to ventilation and air-conditioning machinery, and
liquids, gases and vapours. similar spaces, and trunks to such spaces.
1.3.33 Vapour pressure is the equilibrium 1.5.1.1 The survey of ships so far as regards the
pressure of the saturated vapour above the enforcement of the provisions of the regulations
liquid expressed in bars absolute at a specified and granting of exemptions therefrom, should be
temperature. carried out by the officers of the Administration.
The Administration may, however, entrust the
1.3.34 Void space is an enclosed space in the surveys either to Surveyors nominated for the
cargo area external to a cargo tank, other than a purpose or to organisations recognized by it.
hold space, ballast space, oil fuel tank, cargo
pump-room, pump-room, or any space in normal 1.5.1.2 The Administration nominating surveyors
use by personnel. or recognising organizations to conduct surveys
should, as a minimum, empower any nominated
1.4 Equivalents surveyor or recognized organization to:
IR 1.4.1 The construction, equipment, etc. which .1 require repairs to a ship; and
do not comply with the provisions of these Rules
but are considered to be equivalent to these .2 carry out surveys if requested by the port
Rules would be specially considered by IRS. State authority concerned.
1.4.1 Where the Chapter requires that a The Administration should notify the
particular fitting, material, appliance, apparatus, Organization of the specific responsibilities and
item of equipment or type thereof is to be fitted condition of the authority delegated to
or carried in a ship, or that any particular nominated surveyors or recognized organization
provision should be made, or any procedure or for circulation to the Contracting Governments.
arrangement is to be complied with, the
Administration may allow any other fitting, 1.5.1.3 When a nominated surveyor or
material, appliance, apparatus, item of recognized organization determines that the
equipment or type thereof to be fitted or carried, condition of the ship or its equipment does not
or any other provision, procedure or correspond substantially with the particulars of
arrangement to be made in that ship, if it is the certificates or is such that the ship is not fit
satisfied by trial thereof or otherwise that such to proceed to sea without danger to the ship, or
fitting, material, appliance, apparatus, item of persons on board, such surveyor or organization
equipment or type thereof or that any particular should immediately ensure that corrective action
provision, procedure or arrangement is at least is taken and should in due course notify the
as effective as that required by the Chapter. Administration. If such corrective action is not
However, the Administration may not allow taken the relevant certificate should be
operational methods or procedures to be made withdrawn immediately; and, if the ship is in a
an alternative to a particular fitting, material port of another Contracting Government, the
appliance, apparatus, item of equipment, or type
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Port State authority concerned should also be fitness for the Carriage of Dangerous
notified immediately. Chemicals in Bulk.
1.5.1.4 In every case, the Administration should IR.3 Those items which are additional to the
guarantee the completeness and efficiency of requirements of Annual Survey may be
the survey, and should undertake to ensure the examined between the second or third
necessary arrangements to satisfy this annual survey.
obligation.
.4 A mandatory annual survey within 3
1.5.2 Survey requirements months before or after the anniversary of the
International Certificate of Fitness for the
IR 1.5.2.1 The Classification Regulations for Carriage of Dangerous Chemicals in Bulk
New Construction Surveys, the classification of which should include a general examination
ships not built under Survey and Periodical to ensure that the structure, equipment,
Survey Regulations are given in Pt.1 of the fittings, arrangements and materials remain
Rules. The following requirements are also to be in all respects satisfactory for the service for
complied with. which the ship is intended. Such a survey
should be endorsed in the International
1.5.2.1 The structure, equipment, fittings, Certificate of Fitness for the Carriage of
arrangements and material (other than items in Dangerous Chemicals in bulk.
respect of which a Cargo Ship Safety
Construction Certificate, Cargo Ship Safety .5 An additional survey, either general or
Equipment Certificate and Cargo Ship Safety partial according to the circumstances,
Radiotelegraphy Certificate or Cargo Ship should be made when required after an
Safety Radiotelephony Certificate are issued) of investigation prescribed in 1.5.3.3 or
a chemical tanker should be subjected to the whenever any important repairs or renewals
following surveys: are made. Such a survey should ensure that
the necessary repairs or renewals have been
.1 An initial survey before the ship is put in effectively made, that the material and
service or before the International Certificate workmanship of such repairs or renewals are
of Fitness for the Carriage of Dangerous satisfactory; and that the ship is fit to proceed
Chemical in Bulk is issued for the first time, to sea without danger to the ship or persons
which should include a complete examination on board or without presenting unreasonable
of its structure, equipment, fittings, threat of harm to the marine environment.
arrangements and material in so far as the
ship is covered by the Code. This survey 1.5.3 Maintenance of conditions after survey
should be such as to ensure that the
structure, equipment, fittings, arrangements 1.5.3.1 The condition of the ship and its
and material fully comply with the applicable equipment should be maintained to confirm with
provisions of the Code. the provisions of the Code to ensure that the
ship will remain fit to proceed to sea without
.2 A periodical survey at intervals specified danger to the ship or persons on board or
by the Administration, but not exceeding 5 without presenting an unreasonable threat of
years which should be such as to ensure that harm to the marine environment.
the structure, equipment, fittings,
arrangements and material comply with the 1.5.3.2 After any survey of the ship under 1.5.2
applicable provisions of the Code. has been completed, no change should be
made in the structure, equipment, fittings,
.3 A minimum of one intermediate survey arrangements and material covered by the
within 3 months before or after the second survey, without the sanction of the
anniversary date or within 3 months before or Administration, except by direct replacement.
after the third anniversary date of the
certificate, which shall take the place of one 1.5.3.3 Whenever an accident occurs to a ship
of the annual surveys specified in 1.5.2.1.4. or a defect is discovered, either of which affects
Intermediate surveys should be such as to the safety of the ship or the efficiency or
ensure that the safety equipment, and other completeness of its life-saving appliances or
equipment, and associated pump and piping other equipment, the master or owner of the
systems comply with the applicable ship should report at the earliest opportunity to
provisions of the Code and are in good the Administration, the nominated surveyor or
working order. Such surveys should be recognised organization responsible for issuing
endorsed on the International Certificate of the relevant certificate, who should cause
investigations to be initiated to determine
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whether a survey, as required by 1.5.2.1.5 is 1.5.6.2.2 When the renewal survey is completed
necessary. If the ship is in a port of another after the expiry date of the existing certificate,
Contracting Government, the master or owner the new certificate shall be valid from the date of
should also report immediately to the port State completion of the renewal survey to a date not
authority concerned and the nominated surveyor exceeding 5 years from the date of expiry of the
or recognised organization should ascertain that existing certificate.
such a report has been made.
1.5.6.2.3 When the renewal survey is completed
1.5.4 Issue of International certificate of more than 3 months before the expiry date of
fitness the existing certificate, the new certificate shall
be valid from the date of completion of the
1.5.4.1 An International Certificate of Fitness for renewal survey to a date not exceeding 5 years
the Carriage of Dangerous Chemicals in Bulk from the date of completion of the renewal
the model form of which is set out in the survey.
appendix to the Code, should be issued after an
initial or periodical survey to a chemical tanker 1.5.6.3 If a certificate is issued for a period of
engaged in international voyages which less than 5 years, IRS may extend the validity of
complies with the relevant requirements of the the certificate beyond the expiry date to the
Code. maximum period specified in 1.5.6.1, provided
that the surveys referred to in 1.5.2.1.3 and
1.5.4.2 The certificate issued under provisions of 1.5.2.1.4, applicable when a certificate is issued
this Section should be available on board for for a period of 5 years, are carried out as
inspection at all times. appropriate.
1.5.5 Issue or endorsement of International 1.5.6.4 If a renewal survey has been completed
certificate of fitness by another Government and a new certificate cannot be issued or placed
on board the ship before the expiry date of the
1.5.5.1 A Party to the 1974 SOLAS Convention existing certificate, the Surveyor may endorse
and to MARPOL 73/78 may, at the request of the existing certificate. Such a certificate shall
another Party, cause a ship entitled to fly the be accepted as valid for a further period which
flag of the other State to be surveyed and, if shall not exceed 5 months from the expiry date.
satisfied that the requirements of the Code are
complied with, issue or authorise the issue of 1.5.6.5 If a ship, at the time when a certificate
the certificate to the ship, and, where expires, is not in a port in which it is to be
appropriate, endorse or authorise the surveyed, IRS may extend the period of validity
endorsement of the certificate on board the ship of the certificate but this extension shall be
in accordance with the Code. Any certificate so granted only for the purpose of allowing the ship
issued should contain a statement to the effect to complete its voyage to the port in which it is to
that it has been issued at the request of the be surveyed, and then only in cases where it
Government of the State whose flag the ship is appears proper and reasonable.
entitled to fly.
1.5.6.6 A certificate, issued to a ship engaged
1.5.6 Duration and validity of the on short voyages which has not been extended
International certificate of fitness under the foregoing provisions of this section,
may be extended by the Administration for a
1.5.6.1 An International Certificate of Fitness for period of grace of up to one month from the date
the Carriage of Dangerous Chemicals in Bulk of expiry stated on it. When the renewal survey
should be issued for a period specified by the is completed, the new certificate shall be valid to
Administration which should not exceed 5 years. a date not exceeding 5 years from the date of
expiry of the existing certificate before the
1.5.6.2 No extension of the 5 years period of the extension was granted.
certificate should be permitted.
1.5.6.7 In special circumstances, as determined
1.5.6.2.1 Notwithstanding the provisions of by the Administration, a new certificate need not
1.5.6.1, when the renewal survey is completed be dated from the date of expiry of the existing
within 3 months before the expiry date of the certificate as required by 1.5.6.2.2, 1.5.6.5 or
existing certificate, the new certificate shall be 1.5.6.6. In these special circumstances, the new
valid from the date of completion of the renewal certificate shall be valid to a date not exceeding
survey to a date not exceeding 5 years from the 5 years from the date of completion of the
date of expiry of the existing certificate. renewal survey.
1.5.6.8 If an annual or intermediate survey is - ventilating pipes and openings for cargo
completed before the period specified in 1.5.2, tanks, pump rooms and other gas-
then: dangerous spaces.
.1 the anniversary date shown on the certificate - doors, air locks, hatches, ventilating pipes
shall be amended by endorsement to a date and openings, hinged scuttles which can be
which shall not be more than 3 months later opened, and other openings to gas safe
than the date on which the survey was spaces adjacent to the cargo area including
completed; spaces in and below the forecastle.
.2 the subsequent annual or intermediate survey - cargo pipes and gas return pipes over the
required by 1.5.2 shall be completed at the deck with shore-connections including stern
intervals prescribed by that section using the pipes for cargo discharge or gas-freeing of
new anniversary date; and cargo tanks.
.3 the expiry date may remain unchanged - deckplan showing location and type of all
provided one or more annual or intermediate monitoring equipment for cargo handling
surveys, as appropriate, are carried out so that such as, level gauging, overflow control,
the maximum intervals between the surveys temperature read out etc.
prescribed by 1.5.2 are not exceeded.
IR 1.6.2 Plans with the following particulars for
1.5.6.9 The certificate issued under 1.5.4 or the tanks are to be submitted for approval:
1.5.5 should cease to be valid in any of the
following cases: - drawings of cargo tanks including
information on non-destructive testing of
.1 if the relevant surveys are not completed welds and strength and tightness testing of
within the periods specified under 1.5.2; tanks.
- doors, hatches and any other openings to - arrangement and location of underwater
pump rooms and other gas-dangerous discharge outlet(s).
spaces.
IR 1.6.4 Plans showing the following equipment
and systems are to be submitted for approval:
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- arrangement of cargo cooling systems.
- arrangement and capacity of air ducts, fans
and their motors in the cargo area, drawing - arrangement of possible thermal insulation
and material specification of rotating parts and specification of insulation materials.
and casing of the fans.
- drawings showing details of design,
- drawings of portable ventilators and attachment and location of anodes and
drawings showing where and how these are other fittings in tanks and cofferdams.
to be fitted.
IR 1.6.5 Plans of electrical installations giving
- arrangement for gas-freeing of cargo tanks the following particulars are to be submitted for
and cargo lines. Arrangement of cargo tank approval:
venting systems.
- area classification drawings.
- arrangement and specification of all
monitoring systems and devices for liquid - drawings showing location of all electrical
level indication. equipment in gas dangerous area.
- quick-closing arrangements for cargo - single line diagram for intrinsically safe
valves. circuits.
Section 2
2.1 General
.2 A Type 2 ship is a chemical tanker
2.1.1 Ships subject to the requirements of this intended to transport products listed in
Chapter are to survive the normal effects of Sec.17 with appreciably severe
flooding following assumed hull damage caused environmental and safety hazards which
by some external force. In addition, to safeguard require significant preventive measures to
the ship and the environment, the cargo tanks of preclude an escape of such cargo.
certain types of ships are to be protected from
penetration in the case of minor damage to the .3 A Type 3 ship is a chemical tanker
ship resulting, for example, from contact with a intended to transport products listed in
jetty or tug, and given a measure of protection Sec.17 with sufficiently severe environmental
from damage in the case of collision or and safety hazards which require a moderate
stranding, by locating them at specified degree of containment to increase survival
minimum distances inboard from the ship's shell capability in a damaged condition.
plating. Both the damage to be assumed and
the proximity of the cargo tanks to the ship's Thus a Type 1 ship is a chemical tanker
shell is to be dependent upon the degree of intended for the transportation of products
hazard presented by the products to be carried. considered to present the greatest overall
hazard and Type 2 and Type 3 for products of
2.1.2 Ships subject to the requirements of this progressively lesser hazards. Accordingly, a
Chapter are to be designed to one of the Type 1 ship is to survive the most severe
following standards: standard of damage and its cargo tanks are to
be located at the maximum prescribed distance
.1 A Type 1 ship is a chemical tanker inboard from the shell plating.
intended to transport products listed in
Sec.17 with very severe environmental and 2.1.3 The ship type required for individual
safety hazards which require maximum products is indicated in column "e" in the Table
preventive measures to preclude an escape 17.1.1.
of such cargo.
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2.1.4 If a ship is intended to carry more than one 2.3 Shipside discharges below the freeboard
product listed in Sec.17, the standard of damage deck
is to correspond to that product having the most
stringent ship type requirement. The 2.3.1 The provision and control of valves fitted to
requirements for the location of individual cargo discharges led through the shell from spaces
tanks, however, are those for ship types related below the freeboard deck or from within the
to the respective products intended to be superstructures and deckhouses on the
carried. freeboard deck fitted with weathertight doors are
to comply with the requirements of the relevant
2.2 Freeboard and intact stability regulation of the International Convention on
Load Lines in force, except that the choice of
2.2.1 Ships subject to this Chapter may be valves is to be limited to:
assigned the minimum freeboard permitted by
the International Convention on Load Lines in .1 one automatic nonreturn valve with a
force. However, the draught associated with the positive means of closing from above the
assignment is not to be greater than the freeboard deck; or
maximum draught otherwise permitted by this
Chapter. .2 where the vertical distance from the
summer load waterline to the inboard end
2.2.2 The stability of the ship in all seagoing of the discharge pipe exceeds 0.01L, two
conditions is to be to a standard which is automatic non-return valves without
acceptable to the Administration. positive means of closing, provided that the
inboard valve is always accessible for
2.2.3 When calculating the effect of free examination under service conditions.
surfaces of consumable liquids for loading
conditions it is to be assumed that, for each type 2.3.2 For the purpose of this Chapter "summer
of liquid, at least one transverse pair or a single waterline" and "freeboard deck", have the
centre tank has a free surface and the tank or meanings as defined in the International
combination of tanks to be taken in to account is Convention on Load Lines in force.
to be that where the effect of the free surfaces is
the greatest. The free surface effect in 2.3.3 The automatic nonreturn valves referred to
undamaged compartments is to be calculated by in 2.3.1 are to comply with recognized standards
a method acceptable to the Administration. and are to be fully effective in preventing
admission of water into the ship, taking into
2.2.4 Solid ballast is not normally to be used in account the sinkage, trim and heel in survival
double bottom spaces in the cargo area. Where, requirements given in 2.9.
however, because of stability considerations, the
fitting of solid ballast in such spaces becomes 2.4 Conditions of loading
unavoidable, then its disposition is to be
governed by the need to ensure that the impact 2.4.1 Damage survival capability is to be
loads resulting from bottom damage are not investigated on the basis of the loading
directly transmitted to the cargo tank structure. information submitted to IRS for all anticipated
conditions of loading and variations in draught
2.2.5 The master of the ship is to be supplied and trim. Ballast conditions where the chemical
with a loading and stability information booklet. tanker is not carrying products covered by this
This booklet is to contain details of typical Chapter, or is carrying only residues of such
service and ballast conditions, provisions for products, need not be considered.
evaluating other conditions of loading and a
summary of the ship's survival capabilities. In 2.5 Damage assumptions
addition, the booklet is to contain sufficient
information to enable the master to load and 2.5.1 The assumed maximum extent of damage
operate the ship in a safe and seaworthy is to be :
manner.
Side damage
Longitudinal extent 1
3
L2/3 or 14.5 [m], whichever is less
B/5 or 11.5 [m], whichever is less (measured inboard from the ship's side at
Transverse extent
the right angles to the centreline at the level of the summer load line)
upwards without limit (from the moulded line of the bottom shell plating at
Vertical extent
centreline)
Bottom damage
For 0.3L from the forward
Any other part of the ship
perpendicular of the ship
Longitudi-nal extent 1
3
L2/3 or 14.5 [m], whichever is less 1
3
L2/3 or 5 [m], whichever is less
Transver-se extent B/6 or 10 [m], whichever is less B/6 or 5 [m], whichever is less
B/15 or 6 [m], whichever is less. B/15 or 6 [m], whichever is less.
(measured from the moulded line of (measured from the moulded line of
Vertical extent
the bottom shell plating at centreline the bottom shell plating at centreline
(see 2.6.2)) (see 2.6.2))
2.5.2 If any damage of a lesser extent than the suction well of independent tanks below the
maximum damage specified in 2.5.1 would upper limit of bottom damage is not to exceed
result in a more severe condition, such damage 350 [mm]. Suction wells installed in accordance
is to be considered. with this paragraph may be ignored in
determining the compartments affected by
2.6 Location of cargo tanks damage.
2.7.6 Equalization arrangements requiring .4 A Type 3 ship of more than 225 [m] in
mechanical aids such as valves or cross- length is to be assumed to sustain damage
levelling pipes, if fitted, are to be considered for anywhere in its length;
the purpose of reducing an angle of heel or
attaining the minimum range of residual stability .5 A Type 3 ship of 125 [m] in length or
to meet the requirements of 2.9 and sufficient more but not exceeding 225 m in length is
residual stability is to be maintained during all to be assumed to sustain damage
stages where equalization is used. Spaces anywhere in its length except involving
which are linked by ducts of large cross- either of the bulkheads bounding a
sectional area may be considered to be machinery space located aft;
common.
.6 A Type 3 ship below 125 [m] in length is
2.7.7 If pipes, ducts, trunks or tunnels are to be assumed to sustain damage
situated within the assumed extent of damage anywhere in its length except involving
penetration, as defined in 2.5, arrangements are damage to the machinery space when
to be such that progressive flooding cannot located aft. However, the ability to survive
thereby extend to compartments other than the flooding of the machinery spaces would
those assumed to be flooded for each case of be considered by IRS.
damage.
2.8.2 In the case of small Type 2 and Type 3
2.7.8 The buoyancy of any superstructure ships which do not comply in all respects with
directly above the side damage is to be the appropriate requirements of 2.8.1.3 and
disregarded. The unflooded parts of 2.8.1.6, special dispensation may only be
superstructures beyond the extent of damage, considered by the Administration provided that
however, may be taken into consideration alternative measures can be taken which
provided that: maintain the same degree of safety. The nature
of the alternative measures are to be approved
.1 they are separated from the damaged and clearly stated and be available to the Port
space by watertight divisions and the Administration. Any such dispensation is to be
requirements of 2.9.3 in respect of these duly noted on the International Certificate of
intact spaces are complied with; and fitness referred to in 1.5.4.
Section 3
Ship Arrangements
spaces and control stations in relation to cargo 3.3.4 Normal access ladders are not to be fitted
piping and cargo vent systems. vertical and are to incorporate platforms at
suitable intervals.
3.2.3 Entrances, air inlets and openings to
accommodation, service and machinery spaces 3.3.5 Means are to be provided to deal with
and control stations are not to face the cargo drainage and any possible leakage from cargo
area. They are to be located on the end pumps and valves in cargo pump-rooms. The
bulkhead not facing the cargo area and/or on bilge system serving the cargo pump-room is to
the outboard side of the superstructure or be operable from outside the cargo pump-room.
deckhouse at a distance of at least 4% of the One or more slop tanks for storage of
length of the ship but not less than 3 [m] from contaminated bilge water or tank washings are
the end of the superstructure or deckhouse to be provided. A shore-connection with a
facing the cargo area. This distance, however, standard coupling or other facilities are to be
need not exceed 5 [m]. No doors are to be provided for transferring contaminated liquids to
permitted within the limits mentioned above, on-shore reception facilities.
except that doors to those spaces not having
access to accommodation and service spaces 3.3.6 Pump discharge pressure gauges are to
and control stations, such as cargo control be provided outside the cargo pump-room.
stations and store-rooms may be fitted. Where
such doors are fitted, the boundaries of the 3.3.7 Where machinery is driven by shafting
space are to be insulated to "A-60" standard. passing through a bulkhead or deck, gastight
Bolted plates for removal of machinery may be seals with efficient lubrication or other means of
fitted within the limits specified above. ensuring the permanence of the gas seal are to
Wheelhouse doors and wheelhouse windows be fitted in way of the bulkhead or deck.
may be located within the limits specified above
so long as they are so designed that a rapid and 3.4 Access to spaces in the cargo area
efficient gas and vapour tightening of the
wheelhouse can be ensured. Windows and 3.4.1 Access to cofferdams, ballast tanks, cargo
sidescuttles facing the cargo area and on the tanks and other spaces in the cargo area is to
sides of the superstructures and deckhouses be direct from the open deck and such as to
within the limits specified above are to be of the ensure their complete inspection. Access to
fixed (non-opening) type. Such sidescuttles in double bottom spaces may be through a cargo
the first tier on the main deck are to be fitted pump-room, pump-room, deep cofferdam, pipe
with inside covers of steel or equivalent material. tunnel or similar compartments, subject to
consideration of ventilation aspects.
IR3.2.3 Access to forecastle spaces containing
sources of ignition may be permitted through 3.4.2 For access through horizontal openings,
doors facing cargo area provided the doors are hatches or manholes, the dimensions are to be
located outside hazardous areas as defined in sufficient to allow a person wearing a self-
IEC Publication 60092-502. contained air-breathing apparatus and protective
equipment to ascend or descend any ladder
3.3 Cargo pump-rooms without obstruction and also to provide a clear
opening to facilitate the hoisting of an injured
3.3.1 Cargo pump-rooms are to be so arranged person from the bottom of the space. The
as to ensure: minimum clear opening is to be not less than
600 [mm] by 600 [mm].
.1 unrestricted passage at all times from any
ladder platform and from the floor; and 3.4.3 For access through vertical openings, or
manholes providing passage through the length
.2 unrestricted access to all valves necessary and breadth of the space, the minimum clear
for cargo handling for a person wearing the opening is to be not less than 600 [mm] by 800
required personnel protective equipment. [mm] at a height of not more than 600 [mm] from
the bottom shell plating unless gratings or other
3.3.2 Permanent arrangements are to be made footholds are provided.
for hoisting an injured person with a rescue line
while avoiding any projecting obstacles. 3.4.4 Smaller dimensions may be approved by
IRS in special circumstances, if the ability to
3.3.3 Guard railings are to be installed on all traverse such openings or to remove an injured
ladders and platforms. person can be proved to the satisfaction of IRS.
3.6 Pump and pipeline identification 3.7.4 Entrances, air inlets and openings to
accommodation, service and machinery spaces
3.6.1 Provisions are to be made for the and control stations are not to face the cargo
distinctive marking of pumps, valves and shore-connection location of bow or stern
pipelines to identify the service and tanks which loading and unloading arrangements. They are
they serve. to be located on the outboard side of the
superstructure or deckhouse at a distance of at
3.7 Bow or stern loading and unloading least 4% of the length of the ship but not less
arrangements than 3 [m] from the end of the house facing the
cargo shore-connection location of the bow or
3.7.1 Cargo piping may be fitted to permit bow stern loading and unloading arrangements. This
or stern loading and unloading. Portable distance, however, need not exceed 5 [m].
arrangements are not permitted. Sidescuttles facing the shore-connection
location and on the sides of the superstructure
3.7.2 Bow or stern loading and unloading lines or deckhouse within the distance mentioned
are not to be used for the transfer of products above are to be of the fixed (non-opening) type.
required to be carried in type 1 ships. Bow and In addition, during the use of the bow or stern
stern loading and unloading lines are not to be loading and unloading arrangements, all doors,
used for the transfer of cargoes emitting toxic ports and other openings on the corresponding
vapours required to comply with 15.12.1, unless superstructure or deck-house side should be
specifically approved by IRS. closed. Where, in the case of small ships,
compliance with 3.2.3 and this paragraph is not
3.7.3 In addition to the requirements of 5.1 the possible, IRS may approve relaxations from the
following provisions apply : above requirements.
.1 The piping outside the cargo area is to be 3.7.5 Air pipes and other openings to enclosed
fitted at least 760 [mm] inboard on the open spaces not listed in 3.7.4 are to be shielded from
deck. Such piping is to be clearly identified any spray which may come from a burst hose or
and fitted with a shutoff valve at its connection.
connection to the cargo piping system within
the cargo area. At this location, it is also to
Indian Register of Shipping
Chapter 3 Part 5
Page 20 of 81 Chemical Carriers
Section 4
Cargo Containment
Section 5
Cargo Transfer
sag or buckling of pipes due to weight of pipes .1 Bellows in accordance with recognized
and content and to superimposed loads from standards may be specially considered.
supports, ship deflection or other causes, the
wall thickness is to be increased over that .2 Slip joints are not to be used.
required by 5.1.1 or, if this is impracticable or
would cause excessive local stresses, these 5.2.5 Welding, post weld heat treatment and
loads are to be reduced, protected against or non-destructive testing are to be performed in
eliminated by other design methods. accordance with Part 4 of IRS Rules.
5.1.6.3 Flanges, valves and other fittings are to 5.3 Flange connections
be in accordance with recognized standards,
taking into account the design pressure defined 5.3.1 Flanges are to be of the welded neck, slip-
under 5.1.2. on or socket-welded type. However, socket-
welded-type flanges are not to be used in
5.1.6.4 For flanges not complying with a nominal size above 50 [mm].
standard the dimensions of flanges and
associated bolts are to be to the satisfaction of 5.3.2 Flanges are to comply with recognized
IRS. standards as to their type, manufacture and test.
5.2 Piping fabrication and joining details 5.4 Test requirements for piping
5.2.1 The requirements of this Section apply to 5.4.1 The test requirements of this Section apply
piping inside and outside the cargo tanks. to piping inside and outside cargo tanks.
However, relaxations from these requirements However, relaxations from these requirements
may be accepted in accordance with recognized may be accepted in accordance with recognized
standards for open-ended piping and for piping standards for piping inside tanks and open-
inside cargo tanks except for cargo piping ended piping.
serving other cargo tanks.
5.4.2 After assembly, each cargo piping system
5.2.2 Cargo piping is to be joined by welding is to be subject to a hydrostatic test to at least
except: 1.5 times the design pressure. When piping
systems or parts of systems are completely
.1 for approved connections to shutoff valves manufactured and equipped with all fittings, the
and expansion joints; and hydrostatic test may be conducted prior to
installation aboard the ship. Joints welded on
.2 for other exceptional cases specifically board are to be hydrostatically tested to at least
approved by IRS. 1.5 times the design pressure.
5.2.3 The following direct connections of pipe 5.4.3 After assembly on board, each cargo
lengths, without flanges may be considered: piping system is to be tested for leaks to a
pressure depending on the method applied.
.1 Butt welded joints with complete
penetration at the root may be used in all 5.5 Piping arrangements
applications.
5.5.1 Cargo piping is not to be installed under
.2 Slip-on welded joints with sleeves and deck between the outboard side of the cargo-
related welding having dimensions in containment spaces and the skin of the ship
accordance with recognized standards are unless clearances required for damage
only to be used for pipes with an external protection (see 2.6) are maintained; but such
diameter of 50 [mm] or less. This type of joint distances may be reduced where damage to the
is not to be used when crevice corrosion is pipe would not cause release of cargo provided
expected to occur. that the clearance required for inspection
purposes is maintained.
.3 Screwed connections in accordance with
recognized standards are only to be used for 5.5.2 Cargo piping, located below the main
accessory lines and instrumentation lines deck, may run from the tank it serves and
with external diameters of 25 [mm] or less. penetrate tank bulkheads or boundaries
common to longitudinally or transversally
5.2.4 Expansion of piping is normally to be adjacent cargo tanks, ballast tanks, empty
allowed for by the provision of expansion loops tanks, pump-rooms or cargo pump-rooms
or bends in the piping system. provided that inside the tank it serves, it is fitted
with a stop valve operable from the weather
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deck and provided cargo compatibility is .2 one stop valve at each cargo hose
assured in the event of piping failure. As an connection;
exception, where a cargo tank is adjacent to a
cargo pump-room, the stop valve operable from .3 remote shutdown devices for all cargo
the weather deck may be situated on the tank pumps and similar equipment.
bulkhead on the cargo pump-room side,
provided an additional valve is fitted between 5.6.2 The controls necessary during transfer or
the bulkhead valve and the cargo pump. A transport of cargoes covered by this Chapter
totally enclosed hydraulically operated valve other than in cargo pump-rooms which have
located outside the cargo tank may, however, be been dealt with elsewhere in this Chapter are
accepted provided that the valve is: not to be located below the weather deck.
.1 designed to preclude the risk of leakage; 5.6.3 For certain products additional cargo
transfer control requirements are shown in
.2 fitted on the bulkhead of the cargo tank column "o" in Sec.17, Table 17.1.1.
which it serves;
5.7 Ship's cargo hoses
.3 suitably protected against mechanical
damage; 5.7.1 Liquid and vapour hoses used for cargo
transfer are to be compatible with the cargo and
.4 fitted at a distance from the shell, as suitable for the cargo temperature.
required for damage protection; and
5.7.2 Hoses subject to tank pressure or the
.5 operable from the weather deck. discharge pressure of pumps are to be designed
for a bursting pressure not less than 5 times the
5.5.3 In any cargo pump-room where a pump maximum pressure the hose will be subjected to
serves more than one tank, a stop valve is to be during cargo transfer.
fitted in the line to each tank.
5.7.3 Each new type of cargo hose, complete
5.5.4 Cargo piping installed in pipe tunnels is with end fittings, is to be prototype-tested at a
also to comply with the requirements of 5.5.1 normal ambient temperature with 200 pressure
and 5.5.2. Pipe tunnels are to satisfy all tank cycles from zero to at least twice the specified
requirements for construction, location and maximum working pressure. After this cycle
ventilation and electrical hazard requirements. pressure test has been carried out, the
Cargo compatibility is to be assured in the event prototype test is to demonstrate a bursting
of a piping failure. The tunnel is not to have any pressure not less than 5 times its specified
other openings except to the weather deck and maximum working pressure at the intended
cargo pump-room or pump-room. extreme service temperature. Hoses used for
prototype testing are not to be used for cargo
5.5.5 Cargo piping passing through bulkheads is service. Thereafter, before being placed in
to be so arranged as to preclude excessive service, each new length of cargo hose
stresses at the bulkhead and is not to utilize produced is to be hydrostatically tested at
flanges bolted through the bulkhead. ambient temperature to a pressure not less than
1.5 times its specified maximum working
5.6 Cargo transfer control systems pressure but not more than two-fifths of its
bursting pressure. The hose is to be stenciled or
5.6.1 For the purpose of adequately controlling otherwise marked with its specified maximum
the cargo, cargo transfer systems are to be working pressure and, if used in other than
provided with: ambient temperature services, its maximum and
minimum service temperature, as applicable.
.1 one stop valve capable of being manually The specified maximum working pressure is not
operated on each tank filling and discharge to be less than 1 [MPa] gauge.
line, located near the tank penetration; if an
individual deepwell pump is used to IR5.8 Integrated cargo and ballast system
discharge the contents of a cargo tank, a
stop valve is not required on the discharge IR5.8.1 The requirements given in Pt.5, Ch.2,
line of that tank; Sec.7.6 are to be applied.
Section 6
.1 notch ductility at the operating IR 6.5 For use of aluminium coatings onboard
temperature; chemical tankers also see 1.3.4 & 1.3.5 of Ch.2.
Section 7
Section 8
capped or plugged drain cocks are to be 8.3.2 A Controlled tank venting system is a
provided. system in which pressure and vacuum relief
valves or pressure/vacuum valves are fitted to
8.2.3 Provision is to be made to ensure that the each tank to limit the pressure or vacuum in the
liquid head in any tank does not exceed the tank. A controlled venting system may consist of
design head of that tank. Suitable high-level individual vents from each tank or such
alarms, overflow control systems or spill valves, individual vents on the pressure side only as
together with gauging and tank filling procedures may be combined into a common header or
may be accepted for this purpose. Where the headers with due regard to cargo segregation.
means of limiting cargo tank overpressure In no case should shut-off valves be fitted either
includes an automatic closing valve, the valve is above or below pressure or vacuum relief valves
to comply with the appropriate provisions 15.18. or pressure/vacuum valves. Provision may be
made for bypassing a pressure or vacuum valve
8.2.4 Tank venting systems are to be designed or pressure/vacuum valve under certain
and operated so as to ensure that neither operating conditions provided that the
pressure nor vacuum created in the cargo tanks requirements of 8.2.5 is maintained and that
during loading or unloading exceeds tank design there is suitable indication to show whether or
parameters. The main factors to be considered not the valve is bypassed.
in the sizing of a tank venting system are as
follows: IR8.3.2 By-passing of high velocity valves is not
allowed. In other cases by-passing
.1 design loading and unloading rate; pressure/vacuum valves may be allowed during
cargo operations for cargoes which do not
.2 gas evolution during loading; this should require a vapour return system, provided the
be taken account of by multiplying the vent-line outlet is fitted with flame arrestors and
maximum loading rate by a factor of at least is located at a height above deck level as
1.25; required by 8.3.4.1.
.3 density of the cargo vapour mixture; 8.3.3 On ships constructed on or after 1 July
2002, controlled tank venting systems should
.4 pressure less in vent piping and across consist of a primary and a secondary means of
valves and fittings; allowing full flow relief of vapour to prevent over-
pressure or under-pressure in the event of
.5 pressure/vacuum settings of relief devices. failure of one means. Alternatively, the
secondary means may consist of pressure
8.2.5 Tank vent piping connected to cargo tanks sensors fitted in each tank with a monitoring
of corrosion-resistant material, or to tanks which system in the ship's cargo control room or
are lined or coated to handle special cargoes, as position from which cargo operations are
required by this Chapter, is to be similarly lined normally carried out. Such monitoring equipment
or coated, or constructed of corrosion-resistant should also provide an alarm facility which is
material. activated by detection of over-pressure or
under-pressure conditions within a tank.
8.2.6 The master is to be provided with the
maximum permissible loading and unloading 8.3.4 The position of vent outlets of a controlled
rates for each tank or group of tanks consistent tank venting system is to be arranged:
with design of the venting systems.
.1 at a height of not less than 6 [m] above the
8.3 Types of tank venting systems weather deck or above a raised walkway if
fitted within 4 [m] of the raised walkway;
8.3.1 An Open tank venting system is a
system which offers no restriction except for .2 at a distance of at least 10 [m] measured
friction losses to the free flow of cargo vapours horizontally from the nearest air intake or
to and from the cargo tanks during normal opening to accommodation, service and
operations. An open venting system may consist machinery spaces and ignition sources.
of individual vents from each tank, or such
individual vents may be combined into a 8.3.5 The vent outlet height referred to in 8.3.4.1
common header or headers, with due regard to may be reduced to 3 [m] above the deck or a
cargo segregation. In no case should shut-off raised walkway, as applicable, provided that
valves be fitted either to the individual vents or high velocity venting valves of an approved type
to the header. directing the vapour/air mixture upwards in a
unimpeded jet with an exit velocity of at least 30
[m/s] are fitted.
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8.3.6 Controlled tank venting systems fitted to .1 through the vent outlets specified in 8.3.4
tanks to be used for cargoes having a flashpoint and 8.3.5; or
not exceeding 60°C (closed cup test) are to be
provided with devices to prevent the passage of .2 through outlets at least 2 [m] above the
flame into the cargo tanks. The design, testing cargo tank deck level with a vertical efflux
and locating of the devices should contain at velocity of at least 30 [m/s] maintained during
least the standards adopted by the the gas freeing operation; or
Organisation.
.3 through outlets at least 2 [m] above the
8.3.7 In designing venting systems and in the cargo tank deck level with a vertical efflux
selection of devices to prevent the passage of velocity of at least 20 [m/s] which are
flame for incorporation into the tank venting protected by suitable devices to prevent the
system, due attention is to be paid to the passage of flame.
possibility of the blockage of these systems and
fittings by, for example, the freezing of cargo When the flammable vapour concentration at
vapour, polymer build up, atmospheric dust or the outlets has been reduced to 30% of the
icing up in adverse weather conditions. In this lower flammable limit and in the case of a toxic
context it is to be noted that flame arresters and product the vapour concentration does not
flame screens are more susceptible to blockage. present a significant health hazard, gas freeing
Provisions are to be made such that the system may thereafter be continued at cargo tank deck
and fittings may be inspected, operationally level.
checked, cleaned or renewed as applicable.
8.5.2 The outlets referred to in 8.5.1.2 and
8.3.8 Reference in 8.3.1 and 8.3.2 to the use of 8.5.1.3 may be fixed or portable pipes.
shut-off valves in the venting lines are to be
interpreted to extend to all other means of 8.5.3 In designing a gas-freeing system in
stoppage including spectacle blanks and blank conformity with 8.5.1 particularly in order to
flanges. achieve the required exit velocities of 8.5.1.2
and 8.5.1.3, due consideration are to be given to
8.4 Venting requirements for individual the following:
products
.1 materials of construction of system;
8.4.1 Venting requirements for individual
products are shown in column "g" and additional .2 time to gas-free;
requirements in column "o" in Sec.17, Table
17.1.1. .3 flow characteristics of fans to be used;
Section 9
Environmental Control
9.1.2 There are four different types of control for system is not to raise the cargo tank
cargo tanks, as follows: pressure to more than the tank's relief valve
setting.
.1 Inerting by filling the cargo tank and
associated piping systems and, where .3 Where padding is used, similar
specified in Sec.15, the spaces surrounding arrangements for supply of the padding
the cargo tanks, with a gas or vapour which medium is to be made as required for inert
will not support combustion and which will gas in .1 and .2.
not react with the cargo, and maintaining that
condition. .4 Means are to be provided for monitoring
ullage spaces containing a gas blanket to
.2 Padding by filling the cargo tank and ensure that the correct atmosphere is being
associated piping systems with a liquid, gas maintained.
or vapour which separates the cargo from
the air, and maintaining that condition. .5 Inerting or padding arrangements or both,
where used with flammable cargoes, are to
.3 Drying by filling the cargo tank and be such as to minimize the creation of static
associated piping systems with moisture-free electricity during the admission of the inerting
gas or vapour with a dewpoint of -40°C or medium.
below at atmospheric pressure, and
maintaining that condition. 9.1.4 Where drying is used and dry nitrogen is
used as the medium, similar arrangements for
.4 Ventilation forced or natural. supply of the drying agent are to be made to
those required in 9.1.3. Where drying agents are
9.1.3 Where inerting or padding of cargo tanks used as the drying medium on all air inlets to the
is required: tank, sufficient medium is to be carried for the
duration of the voyage, taking into consideration
.1 An adequate supply of inert gas for use in the diurnal temperature range and the expected
filling and discharging the cargo tanks is to humidity.
be carried or is to be manufactured on board
unless a shore supply is available. In 9.2 Environmental control requirements for
addition, sufficient inert gas is to be available individual products
on the ship to compensate for normal losses
during transportation. 9.2.1 The required types of environmental
control for certain products are shown in column
.2 The inert gas system on board the ship is "h" in Sec.17, Table 17.1.1.
to be able to maintain a pressure of at least
0.07 bar gauge within the containment
system at all times. In addition, the inert gas
Section 10
Electrical Installations
Section 11
11.3.9 A monitor and hose connection for a 11.3.15 Where flammable cargoes are to be
foam applicator is to be situated both port and carried all sources of ignition are to be excluded
starboard at the poop front or accommodation from hazardous locations referred to in 10.2.
spaces facing the cargo area.
11.3.16 Ships fitted with bow or stern loading
11.3.10 Applicators are to be provided for and unloading arrangements are to be provided
flexibility of action during fire-fighting operations with one additional foam monitor meeting the
and to cover areas screened from the monitors. requirements of 11.3.7 and one additional
The capacity of any applicator is not to be less applicator meeting the requirements of 11.3.10.
than 400 [l/min] and the applicator throw in still The additional monitor is to be located to protect
air conditions is to be not less than 15 [m]. The the bow or stern loading and unloading
number of foam applicators provided are to be arrangements. The area of the cargo line
not less than four. The number and disposition forward or aft of the cargo area is to be
of foam main outlets are to be such that foam protected by the above-mentioned applicator.
from at least two applicators can be directed to
any part of the cargo tanks deck area. 11.4 Special requirements
Section 12
12.0 For ships to which the Code applies, the 12.1.1 Cargo pump-rooms and other enclosed
requirements of this Section replace the spaces which contain cargo handling equipment
requirements of SOLAS regulation II-2/4.5.2.6 and similar spaces in which work is performed
and 4.5.4. However, for products addressed on the cargo are to be fitted with mechanical
under paragraphs 11.1.2 and 11.1.3, except ventilation systems, capable of being controlled
acids and products for which paragraph 15.16 from outside such spaces.
apply, SOLAS regulation II-2/4.5.2.6 and 4.5.4
may apply in lieu of the provisions of this 12.1.2 Provision is to be made to ventilate such
Section. spaces prior to entering the compartment and
operating the equipment and a warning notice
12.1 Spaces normally entered during cargo requiring the use of such ventilation is to be
handling operation placed outside the compartment.
12.1.3 Mechanical ventilation inlets and outlets Sec.10 are to be of non-sparking construction
are to be arranged to ensure sufficient air whose details are given in Pt.5, Ch.2, Sec.6.5 of
movement through the space to avoid the these Rules.
accumulation of toxic or flammable vapours or
both (taking into account their vapour densities) 12.1.9 Sufficient spare parts are to be carried for
and to ensure sufficient oxygen to provide a safe each type of fan on board, required by this
working environment, but in no case is the Section.
ventilation system to have a capacity of less
than 30 changes of air per hour based upon the 12.2 Pump-rooms and other enclosed spaces
total volume of the space. For certain products, normally entered
increased ventilation rates for cargo pump-
rooms are prescribed in 15.17. Pump-rooms and other enclosed spaces
normally entered, which are not covered by
12.1.4 Ventilation systems are to be permanent 12.1.1, are to be fitted with mechanical
and are normally to be of the extraction type. ventilation systems, capable of being controlled
Extraction from above and below the floor plates from outside such spaces and complying with
is to be possible. In rooms housing motors the requirements of 12.1.3, except that the
driving cargo pumps, the ventilation is to be of capacity is not to be less than 20 changes of air
the positive pressure type. per hour, based upon the total volume of the
space. Provision is to be made to ventilate such
12.1.5 Ventilation exhaust ducts from spaces spaces prior to entering.
within the cargo area is to discharge upwards in
locations at least 10 [m] in the horizontal 12.3 Spaces not normally entered
direction from ventilation intakes and openings
to accommodation, service and machinery Double bottoms, cofferdams, duct keels, pipe
spaces and control stations and other spaces tunnels, hold spaces and other spaces where
outside the cargo area. cargo may accumulate, are to be capable of
being ventilated to ensure a safe environment
12.1.6 Ventilation intakes are to be so arranged when entry into the spaces is necessary. Where
as to minimize the possibility of recycling a permanent ventilation system is not provided
hazardous vapours from any ventilation for such spaces, approved means of portable
discharge opening. mechanical ventilation are to be provided.
Where necessary, owing to the arrangement of
12.1.7 Ventilation ducts are not to be led spaces, for instance hold spaces, essential
through accommodation, service and machinery ducting for such ventilation is to be permanently
spaces or other similar spaces. installed. For permanent installations, the
capacity of eight air changes per hour is to be
12.1.8 Electric motors driving fans are to be provided and for portable systems the capacity
placed outside the ventilation ducts if the of 16 air changes per hour. Fans or blowers are
carriage of flammable products is intended. to be clear of personnel access openings, and
Ventilation fans and fan ducts, in way of fans are to comply with 12.1.8.
only, for hazardous locations referred to in
Section 13
Instrumentation
13.2.1 Ships carrying toxic or flammable 13.2.4 Vapour detection requirements for
products or both are to be equipped with at least individual products are shown in column "k" in
two instruments designed and calibrated for Sec.17, Table 17.1.1.
testing for the specific vapours in question. If
such instruments are not capable of testing for
Section 14
Personnel Protection
14.2.2 One complete set of safety equipment is place near the cargo pump-room. The other sets
to consist of: of safety equipment are also to be kept in
suitable, clearly marked, easily accessible,
.1 one self-contained air-breathing apparatus places.
(not using stored oxygen);
14.2.6 The breathing apparatus is to be
.2 protective clothing, boots, gloves and tight- inspected at least once a month by a
fitting goggles; responsible officer, and the inspection recorded
in the ship's log-book. The equipment is to be
.3 fire proof lifeline with belt resistant to the inspected and tested by an expert at least once
cargoes carried; and a year.
14.2.3 For the safety equipment required in 14.3.1 Ships carrying cargoes, for which ‘Yes’ is
14.2.1, all ships are to carry the following, either: indicated in column ‘n’ of Table 17.1.1 are to be
provided with suitable respiratory and eye
.1 one set of fully charged spare air bottles protection sufficient for every person on board
for each breathing apparatus; for emergency escape purposes, subject to the
following:
.2 a special air compressor suitable for the
supply of high-pressure air of the required .1 filter-type respiratory protection is
purity; unacceptable;
.4 fully charged spare air bottles with a total .3 emergency escape respiratory protection
free air capacity of at least 6,000 l for each is not to be used for fire-fighting or cargo
breathing apparatus on board in excess of handling purposes and is to be marked to
the requirements of SOLAS Regulation II- that effect.
2/10.10.
Individual cargoes to which the provisions of this
14.2.4 A cargo pump-room on ships carrying paragraph apply are indicated in column "n" in
cargoes which are subject to the requirements Sec.17, Table 17.1.1.
of 15.18 or cargoes for which in column "k" in
Sec.17, Table 17.1.1 toxic vapour detection 14.3.2 The ship is to have on board medical
equipment is required but is not available is to first-aid equipment including oxygen
have either: resuscitation equipment and antidotes for
cargoes carried, based on the guidelines
.1 a low-pressure line system with hose developed by the Organisation.
connections suitable for use with the
breathing apparatus required by 14.2.1. This Reference is made to the Medical First Aid
system is to provide sufficient high-pressure Guide for Use in Accidents Involving Dangerous
air capacity to supply, through pressure Goods (MFAG), which provides advice on the
reduction devices, enough low-pressure air treatment of casualties in accordance with the
to enable two men to work in a gas- symptoms exhibited as well as equipment and
dangerous space for at least 1 hour without antidotes that may be appropriate for treating
using the air bottles of the breathing the casualty.
apparatus. Means should be provided for
recharging the fixed air bottles and breathing 14.3.3 A stretcher which is suitable for hoisting
apparatus air bottles from a special air an injured person up from spaces such as the
compressor suitable for the supply of high- cargo pump-room is to be placed in a readily
pressure air of the required purity; or accessible location.
Section 15
Special Requirements
15.2.1 The ammonium nitrate solution is to 15.2.7 Cargo pumps are to be of the centrifugal
contain at least 7% by weight of water. The deepwell type or of the centrifugal type with
acidity (pH) of the cargo when diluted with ten water flushed seals.
parts of water to one part of cargo by weight is
to be between 5.0 and 7.0. The solution is to not 15.2.8 Vent piping is to be fitted with approved
contain more than 10 ppm chloride ions, 10 ppm weatherhoods to prevent clogging. Such
ferric ions, and is to be free of other weatherhoods are to be accessible for
contaminants. inspection and cleaning.
15.2.2 Tanks and equipment for ammonium 15.2.9 Hot work on tanks, piping and equipment
nitrate solution are to independent of tanks and which have been in contact with ammonium
equipment containing other cargoes or nitrate solution is only to be done after all traces
combustible products. Equipment which may, in of ammonium nitrate have been removed, inside
service or when defective, release combustible as well as outside.
products into the cargo, e.g. lubricants, is not to
be used. Tanks are not to be used for seawater 15.3 Carbon disulphide
ballast.
Carbon disulphide may be carried either under a
15.2.3 Except where expressly approved by water pad or under a suitable inert gas pad as
IRS, ammonium nitrate solutions are not to be specified in the following paragraphs:
transported in tanks which have previously
contained other cargoes unless tanks and Carriage under water pad
associated equipment have been cleaned to the
satisfaction of IRS. 15.3.1 Provision is to be made to maintain a
water pad in the cargo tank during loading,
15.2.4 The temperature of the heat exchanging unloading and transit. In addition, a suitable inert
medium in the tank heating system is not to gas pad is to be maintained in the ullage space
exceed 160°C. The heating system is to be during transit.
provided with a control system to keep the cargo
at a bulk mean temperature of 140°C. High- 15.3.2 All openings are to be in the top of the
temperature alarms at 145°C and 150°C and a tank, above the deck.
low-temperature alarm at 125°C are to be
provided. Where the temperature of the heat 15.3.3 Loading lines are to terminate near the
exchanging medium exceeds 160°C an alarm is bottom of the tank.
also to be given. Temperature alarms and
controls are to be located on the navigating 15.3.4 A standard ullage opening is to be
bridge. provided for emergency sounding.
15.2.5 If the bulk mean cargo temperature 15.3.5 Cargo piping and vent lines are to be
reaches 145°C, a cargo sample is to be diluted independent of piping and vent lines used for
with ten parts of distilled or demineralized water other cargo.
to one part of cargo by weight and the acidity
(pH) is to be determined by means of a narrow 15.3.6 Pumps may be used for discharging
range indicator paper or stick. Acidity (pH) cargo, provided they are of the deepwell or
measurements is then to be taken every 24 hydraulically driven submersible types. The
Carriage under suitable inert gas pad 15.3.20 No other cargo handling, tank cleaning
or deballasting is to take place concurrent with
15.3.11 Carbon disulphide is to be carried in loading or discharge of carbon disulphide.
independent tanks with a design pressure of not
less than 0.06 MPa gauge 15.3.21 A water spray system of sufficient
capacity is to be provided to blanket effectively
15.3.12 All openings are to be located on the top the area surrounding the loading manifold, the
of the tank, above the deck. exposed deck piping associated with product
handling and the tank domes. The arrangement
15.3.13 Gaskets used in the containment of piping and nozzles is to be such as to give a
2
system are to be of a material which does not uniform distribution rate of 10 l/m /min. Remote
react with, or dissolve in, carbon disulphide. manual operation is to be arranged such that
remote starting of pumps supplying the water-
15.3.14 Threaded joints are not permitted in the spray system and remote operation of any
cargo containment system, including the vapour normally closed valves in the system can be
lines. carried out from a suitable location outside the
cargo area adjacent to the accommodation
15.3.15 Prior to loading, the tank(s) is to be spaces and readily accessible and operable in
inerted with suitable inert gas until the oxygen the event of fire in the areas protected. The
level is 2% by volume or lower. Means are to be water-spray system is to be capable of both
provided to automatically maintain a positive local and remote manual operation and the
pressure in the tank using suitable inert gas arrangement is to ensure that any spilled cargo
during loading, transport and discharge. The is washed away. Additionally, a water hose with
system is to be able to maintain this positive pressure to the nozzle when atmospheric
pressure between 0.01 and 0.02 MPa and is to temperature permits is to be connected ready
be remotely monitored and fitted with for immediate use during loading and unloading
over/under-pressure alarms. operations.
15.3.16 Hold spaces surrounding an 15.3.22 No cargo tanks are to be more than
independent tank carrying carbon disulphide is 98% liquid-full at the reference temperature (R).
to be inerted by a suitable inert gas until the
oxygen level is 2% or less. Means are to be 15.3.23 The maximum volume (VL) of cargo to
provided to monitor and maintain this condition be loaded in a tank is to be:
throughout the voyage. Means is also to be
provided to sample these spaces for carbon
disulphide vapour.
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ρR
VL = 0.98 V 15.4.3 Inert gas displacement may be used for
ρL discharging cargo from pressure tanks provided
where, the cargo system is designed for the expected
pressure.
V = volume of the tank
15.4.4 In view of the fire hazard, provision is to
ρR = relative density of cargo at the reference be made to avoid any ignition source or heat
temperature (R) generation or both in the cargo area.
ρL = relative density of cargo at the loading 15.4.5 Pumps may be used for discharging
temperature cargo, provided that they are of a type designed
to avoid liquid pressure against the shaft gland
R = reference temperature. or are of a hydraulically operated submerged
type and are suitable for use with the cargo.
15.3.24 The maximum allowable tank filling
limits for each cargo tank is to be indicated for 15.4.6 Provisions are to be made to maintain the
each loading temperature which may be applied inert-gas pad in the cargo tank during loading,
and for the applicable maximum reference unloading and transit.
temperature, on a list approved by the
Administration. A copy of the list is to be 15.5 Hydrogen peroxide solutions
permanently kept on board by the master.
15.5.1 Hydrogen peroxide solutions over 60%
15.3.25 Zones on open deck, or semi-enclosed but not over 70%.
spaces on open deck within three metres of a
tank outlet, gas or vapour outlet, cargo pipe 15.5.1.1 Hydrogen peroxide solutions over 60%
flange or cargo valve of a tank certified to carry but not over 70% is to be carried in dedicated
carbon disulphide, are to comply with the ships only and no other cargoes are to be
electrical equipment requirements specified for carried.
carbon disulphide in column "i", of Section 17.
Also, within the specified zone, no other heat 15.5.1.2 Cargo tanks and associated equipment
sources, like steam piping with surface are to be either pure aluminium (99.5%) or solid
temperatures in excess of 80°C is to be allowed. stainless steel (304L, 316, 316L or 316Ti), and
passivated in accordance with approved
15.3.26 Means are to be provided to ullage and procedures. Aluminium is not to be used for
sample the cargo without opening the tank or piping on deck. All nonmetallic materials of
disturbing the positive suitable inert gas blanket. construction for the containment system are
neither to be attacked by hydrogen peroxide nor
15.3.27 The product is to be transported only in contribute to its decomposition.
accordance with a cargo handling plan that has
been approved by the Administration. Cargo 15.5.1.3 Pump-rooms are not to be used for
handling plans are to show the entire cargo cargo transfer operations.
piping system. A copy of the approved cargo
handling plan is to be made available on board. 15.5.1.4 Cargo tanks are to be separated by
The International Certificate of Fitness for the cofferdams from oil fuel tanks or any other
Carriage of Dangerous Chemicals in Bulk is to space containing flammable or combustible
be endorsed to include reference to the materials.
approved cargo handling plan.
15.5.1.5 Tanks intended for the carriage of
15.4 Diethyl ether hydrogen peroxide are not to be used for
seawater ballast.
15.4.1 Unless inerted, natural ventilation is to be
provided for the voids around the cargo tanks 15.5.1.6 Temperature sensors are to be
while the vessel is under way. If a mechanical installed at the top and bottom of the tank.
ventilation system is installed, all blowers are to Remote temperature readouts and continuous
be of nonsparking construction. Mechanical monitoring are to be located on the navigating
ventilation equipment is not to be located in the bridge. If the temperature in the tanks rises
void spaces surrounding the cargo tanks. above 35°C, visible and audible alarms are to be
activated on the navigation bridge.
15.4.2 Pressure relief valve settings are not to
be less than 0.02 MPa gauge for gravity tanks. 15.5.1.7 Fixed oxygen monitors (or gas-
sampling lines) are to be provided in void
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Chapter 3 Part 5
Page 38 of 81 Chemical Carriers
spaces adjacent to tanks to detect leakage of hydrogen peroxide. He is to certify to the master
the cargo into these spaces. Remote readouts, that the cargo has been loaded in a stable
continuous monitoring (if gas sampling lines are condition.
used, intermittent sampling is satisfactory) and
visible and audible alarms similar to those for 15.5.1.12 Protective clothing that is resistant to
the temperature sensors are also to be located hydrogen peroxide solutions is to be provided
on the navigating bridge. The visible and audible for each crew member involved in cargo transfer
alarms are to be activated if the oxygen operations. Protective clothing is to include non
concentration in these void spaces exceeds flammable coveralls, suitable gloves, boots and
30% by volume. Two portable oxygen monitors eye protection.
are also to be available as back-up systems.
15.5.2 Hydrogen peroxide solutions over 8%
15.5.1.8 As a safeguard against uncontrolled but not over 60% by mass
decomposition, a cargo jettisoning system is to
be installed to discharge the cargo overboard. 15.5.2.1 The ship's shell plating is not to form
The cargo is to be jettisoned if the temperature any boundaries of tanks containing this product.
rise of the cargo exceeds a rate of 2°C per hour
over a 5 hour period or when the temperature in 15.5.2.2 Hydrogen peroxide is to be carried in
the tank exceeds 40°C. tanks thoroughly and effectively cleaned of all
traces of previous cargoes and their vapours or
15.5.1.9 Cargo tank venting system is to have ballast. Procedures for inspection, cleaning,
pressure/vacuum relief valves for normal passivation and loading of tanks are to be in
controlled venting, and rupture discs or a similar accordance with the MSC/Circ.394. A certificate
device for emergency venting, if tank pressure is to be on board the vessel indicating that the
rises rapidly as a result of uncontrolled procedures in the circular have been followed.
decomposition. Rupture discs are to be sized on The passivation requirement may be waived by
the basis of tank design pressure, tank size and an Administration for domestic shipments of
anticipated decomposition rate. short duration. Particular care in this respect is
essential to ensure the safe carriage of
15.5.1.10 A fixed water-spray system is to be hydrogen peroxide.
provided for diluting and washing away any
concentrated hydrogen peroxide solution spilled .1 When hydrogen peroxide is carried no
on deck. The areas covered by the water-spray other cargoes are to be carried
are to include the manifold/hose connections simultaneously.
and the tank tops of those tanks designated for
carrying hydrogen peroxide solutions. The .2 Tanks which have contained hydrogen
minimum application rate is to satisfy the peroxide may be used for other cargoes after
following criteria: cleaning in accordance with the procedures
outlined in MSC/Circ.394.
.1 The product is to be diluted from the
original concentration to 35% by weight .3 Consideration in design is to provide
within 5 minutes of the spill. minimum internal tank structure, free
draining, no entrapment and ease of visual
.2 The rate and estimated size of the spill is inspection.
to be based upon maximum anticipated
loading and discharge rates, the time 15.5.2.3 Cargo tanks and associated equipment
required to stop flow of cargo in the event of is to be either pure aluminium (99.5%) or solid
tank overfill or a piping/hose failure, and the stainless steel of types suitable for use with
time necessary to begin application of hydrogen peroxide (e.g.304, 304L, 316, 316L,
dilution water with actuation at the cargo 316Ti). Aluminium is not to be used for piping on
control location or on the navigating bridge. deck. All nonmetallic materials of construction
for the containment system are neither be
15.5.1.11 Only those hydrogen peroxide attacked by hydrogen peroxide nor contribute to
solutions which have a maximum decomposition its decomposition.
rate of 1% per year at 25°C are to be carried.
Certification from the shipper that the product 15.5.2.4 Cargo tanks are to be separated by a
meets this standard is to be presented to the cofferdam from fuel oil tanks or any other space
master and kept on board. A technical containing materials incompatible with hydrogen
representative of the manufacturer is to be on peroxide.
board to monitor the transfer operations and
have the capability to test the stability of the 15.5.2.5 Temperature sensors are to be
installed at the top and bottom of the tank.
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Remote temperature readouts and continuous necessary to begin application of dilution
monitoring are to be located on the navigating water with actuation at the cargo control
bridge. If the temperature in the tank rises above location or on the navigating bridge.
35°C, visible and audible alarms are to activate
on the navigating bridge. 15.5.2.10 Only those hydrogen peroxide
solutions which have maximum decomposition
15.5.2.6 Fixed oxygen monitors (or gas rate of 1% per year at 25°C are to be carried.
sampling lines) are to be provided in void Certification from the shipper that the product
spaces adjacent to tanks to detect leakage of meets this standards is to be presented to the
the cargo into these spaces. The enhancement master and kept on board. A technical
of flammability by oxygen enrichments is to be representative of the manufacturer is to be on
recognized. Remote readouts, continuous board to monitor the transfer operations and
monitoring (if gas sampling lines are used, have the capability to test the stability of the
intermittent sampling is satisfactory) and visible hydrogen peroxide. He is to certify to the master
and audible alarms similar to those for the that the cargo has been loaded in a stable
temperature sensors are also to be located on condition.
the navigating bridge. The visible and audible
alarms are to activate if the oxygen 15.5.2.11 Protective clothing that is resistant to
concentration in these void spaces exceeds hydrogen peroxide is to be provided for each
30% by volume. Two portable oxygen monitors crew member involved in cargo-transfer
are also to be available as back-up systems. operations. Protective clothing is to include
coveralls that are nonflammable, suitable
15.5.2.7 As a safeguard against uncontrolled gloves, boots and eye protection.
decomposition, a cargo jettisoning system is to
be installed to discharge the cargo overboard. 15.5.2.12 During transfer of hydrogen peroxide
The cargo is to be jettisoned if the temperature the related piping system is to be separated
rise of the cargo exceeds a rate of 2°C per hour from all other systems. Cargo hoses used for
over a 5 hour period or when the temperature in transfer of hydrogen peroxide are to be marked
the tank exceeds 40°C. "For Hydrogen Peroxide Transfer only".
15.5.2.8 Cargo-tank venting systems with 15.5.3 Procedures for inspection, cleaning,
filtration are to have pressure vacuum-relief passivation and loading of tanks for the
valves for normal controlled venting, and a carriage of hydrogen peroxide solutions over
device for emergency venting, if tank pressure 8% but not over 60% by mass, which have
rises rapidly as a result of an uncontrolled contained other cargoes, or for the carriage
decomposition rate, as stipulated in 15.5.20. of other cargoes after the carriage of
These venting systems are to be designed in hydrogen peroxide
such a manner that there is no introduction of
seawater into the cargo tank even under heavy 15.5.3.1 Tanks having contained cargoes other
sea conditions. Emergency venting is to be than hydrogen peroxide are to be inspected,
sized on the basis of tank design pressure and cleaned and passivated before re-use for the
tank size. transport of hydrogen peroxide solutions. The
procedures for inspection and cleaning, as given
15.5.2.9 A fixed water-spray system is to be in paragraphs 15.5.3.2 to 15.5.3.8 below, apply
provided for diluting and washing away any to both stainless steel and pure aluminium tanks
concentrated solution spilled on deck. The areas (see paragraph 15.5.3.2). Procedures for
covered by the water-spray are to include the passivation are given in paragraph 15.5.3.9 for
manifold/hose connections and the tank tops of stainless steel and 15.5.3.10 for aluminium.
those tanks designated for the carriage of Unless otherwise specified, all steps apply to the
hydrogen peroxide solutions. The minimum tanks and to all associated equipment having
application rate is to satisfy the following criteria: been in contact with the other cargo.
.1 The product is to be diluted from the 15.5.3.2 After unloading the previous cargo the
original concentration to 35% by weight tank should be rendered safe and inspected for
within 5 minutes of the spill. any residues, scale and rust.
.2 The rate of estimated size of the spill is to 15.5.3.3 Tanks and associated equipment shall
be based upon maximum anticipated loading be washed with clean filtered water. The water
and discharge rates, the time required to to be used shall at least have the quality of
stop flow of the cargo in the event of tank potable water with a low chlorine content.
overfill or a piping/hose failure, and the time
15.5.3.4 Trace residues and vapours of the depending upon the concentration of
previous cargo shall be removed by steaming of acid, the ambient temperature and other
tank and equipment. factors. During this time a continuous
contact between the surfaces to be
15.5.3.5 Tanks and equipment are washed passivated and the nitric acid shall be
again with clean water (quality as above) and ensured. In the case of large surfaces
dried, using filtered, oil-free air. this may be achieved by recirculating
the acid. Hydrogen gas may be evolved
15.5.3.6 The atmosphere in the tanks shall be in the passivation process, leading to
sampled and investigated for the presence of the presence of an explosive
organic vapours and oxygen concentration. atmosphere in the tanks. Therefore,
appropriate measures must be taken to
15.5.3.7 The tank shall be checked again by avoid the build-up or the ignition of such
visual inspection for residues of the previous an atmosphere.
cargo, scale and rust as well as for any smell of
the previous cargo. .6 After passivation the surfaces shall
be thoroughly washed with clean filtered
15.5.3.8 If inspection or measurements indicate water. The washing process shall be
the presence of residues of the previous cargo repeated until the effluent water has the
or its vapours, actions described in paragraphs same pH value as the incoming water.
15.5.3.3 to 15.5.3.5 shall be repeated.
.7 Surfaces treated according to the
15.5.3.9 Tanks and equipment made from above steps may cause some
stainless steel have contained other cargoes decomposition when coming into
than hydrogen peroxide or which have been contact with hydrogen peroxide for the
under repair shall be cleaned and passivated, first time. This decomposition will cease
regardless of any previous passivation, after a short time (usually within two or
according to the following procedure: three days). Therefore an additional
flushing with hydrogen peroxide for a
.1 New welds and other repaired parts period of at least two days is
shall be cleaned and finished using recommended.
stainless steel wire brush, chisel,
sandpaper or buff. Rough surfaces shall .8 Only degreasing agents and acid
be given a smooth finish. A final cleaning agents which have been
polishing is necessary. recommended for this purpose by the
manufacturer of the hydrogen peroxide
.2 Fatty and oily residues shall be shall be used in the process.
removed by the use of appropriate
organic solvents or detergent solutions 15.5.3.10 Tanks and equipment made from
in water. The use of chlorine-containing aluminium and which have contained cargoes
compounds shall be avoided as they other than hydrogen peroxide, or which have
can seriously interfere with passivation. been under repair, shall be cleaned and
passivated. The following is an example of a
.3 The residues of the degreasing agent recommended procedure:
shall be removed, followed by a
washing with water. .1 The tank shall be washed with a solution
of a sulphonated detergent in hot water,
.4 In the next step, scale and rust shall followed by a washing with water.
be removed by the application of acid
(e.g. a mixture of nitric and hydrofluoric .2 The surface shall then be treated for 15 to
acids), followed again by a washing with 20 min with a solution of sodium hydroxide
clean water. of a concentration of 7% by mass or treated
for a longer period with a less concentrated
.5 All the metal surfaces which can solution (e.g. for 12 h with 0.4 to 0.5%
come into contact with hydrogen sodium hydroxide). To prevent excessive
peroxide shall be passivated by the corrosion at the bottom of the tank when
application of nitric acid of a treating with more concentrated solutions of
concentration between 10 and 35% by sodium hydroxide, water shall be added
mass. The nitric acid must be free from continuously to dilute the sodium hydroxide
heavy metals, other oxidizing agents or solution which collects there.
hydrogen fluoride. The passivation
process shall continue for 8 to 24 h,
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.3 The tank shall be thoroughly washed with apply to the tanks and to all associated
clean, filtered water. As soon as possible equipment having been in contact with hydrogen
after washing, the surface shall be peroxide):
passivated by the application of nitric acid of
a concentration between 30 and 35% by .1 Hydrogen peroxide cargo residue shall be
mass. The passivation process shall drained as completely as possible from
continue for 16 to 24 h. During this time a tanks and equipment.
continuous contact between the surfaces to
be passivated and the nitric acid shall be .2 Tanks and equipment shall be rinsed with
ensured. clean water, and subsequently thoroughly
washed with clean water.
.4 After passivation the surfaces shall be
thoroughly washed with clean, filtered water. .3 The interior of the tanks hall be dried and
The washing process shall be repeated until inspected for any residues.
the effluent water has the same pH value as
the incoming water. Steps .1 to .3, in 15.5.3.16 shall be carried out
under the supervision of the master or the
.5 A visual inspection shall be made to shipper. Step .3) in paragraph 15.5.3.16 shall be
ensure that all surfaces have been treated. carried out by a person familiar with the safety-
It is recommended that an additional relevant properties of the chemical to be
flushing is carried out for a minimum of 24 h transported and of hydrogen peroxide.
with dilute hydrogen peroxide solution of a
concentration approximately 3% by mass. SPECIAL CAUTIONS :
15.5.3.11 The concentration and stability of the 1) Hydrogen peroxide decomposition may
hydrogen peroxide solution to be loaded shall be enrich the atmosphere with oxygen and
determined. appropriate precautions shall be
observed.
15.5.3.12 The hydrogen peroxide is loaded
under intermittent visual supervision of the 2) Hydrogen gas may be evolved in the
interior of the tank from an appropriate opening. passivation processes described in
paragraphs 15.5.3.9, 15.5.3.10 .2) and
15.5.3.13 If substantial bubbling is observed 15.5.3.10 .4), leading to the presence of
which does not disappear within 15 min after the an explosive atmosphere in the tank.
completion of loading, the contents of the tank Therefore, appropriate measures must
shall be unloaded and disposed of in an be taken to avoid the build-up or the
environmentally safe manner. The tank and ignition of such an atmosphere.
equipment shall then be repassivated as
described above. 15.6 Motor fuel anti-knock compounds
(containing lead alkyls)
15.5.3.14 The concentration and stability of the
hydrogen peroxide solution shall be determined 15.6.1 Tanks used for these cargoes are not to
again. If the same values are obtained within the be used for the transportation of any other cargo
limits of error as in paragraph 15.5.3.10, the except those commodities to be used in the
tank is considered to be properly passivated and manufacture of motor fuel anti-knock
the cargo ready for shipment. compounds containing lead alkyls.
15.7.5 All openings are to be at the top of cargo .2 carboxylic acids and anhydrides (e.g.
tanks, and fittings and joints attached thereto formic, acetic);
are to be materials resistant to phosphorus
pentoxide. .3 halogenated carboxylic acids (e.g.
chloroacetic);
15.7.6 Phosphorus is to be loaded at a
temperature not exceeding 60°C. .4 sulphonic acids (e.g. benzene sulphonic);
15.7.7 Tank heating arrangements are to be .5 caustic alkalies (e.g. sodium hydroxide,
external to tanks and have a suitable method of potassium hydroxide);
temperature control to ensure that the
temperature of the phosphorus does not exceed .6 ammonia and ammonia solutions;
60°C. A high-temperature alarm is to be fitted.
.7 amines and amine solutions;
15.7.8 A water drench system acceptable to IRS
is to be installed in all void spaces surrounding .8 oxidizing substances.
the tanks. The system is to operate
automatically in the event of an escape of 15.8.3 Before loading, tanks are to thoroughly
phosphorus. and effectively cleaned, to remove all traces of
previous cargoes from tanks and associated
15.7.9 Void spaces referred to in 15.7.8 are to pipework, except where the immediately prior
be provided with effective means of mechanical cargo has been propylene oxide or ethylene
ventilation which is to be capable of being oxide/propylene oxide mixtures. Particular care
sealed off quickly in an emergency. is to be taken in the case of ammonia in tanks
made of steel other than stainless steel.
15.7.10 Loading and discharge of phosphorus is
to be governed by a central system on the ship 15.8.4 In all cases, the effectiveness of cleaning
which, in addition to incorporating high-level procedures for tanks and associated pipework is
alarms, is to ensure that no overflow of tanks is to checked by suitable testing or inspection, to
possible and that such operations can be ascertain that no traces of acidic or alkaline
materials remain that might create a hazardous
situation in the presence of these products.
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15.8.13 Filling and discharge piping are to
15.8.5 Tanks are to be entered and inspected extend to within 100 [mm] of the bottom of the
prior to each initial loading of these products to tank or any sump pit.
ensure freedom from contamination, heavy rust
deposits and visible structural defects. When 15.8.14.1 The containment system for a tank
cargo tanks are in continuous service for these containing these products is to have a valved
products, such inspections are to be performed vapour-return connection.
at intervals of not more than two years.
15.8.14.2 The products are to be loaded and
15.8.6 Tanks for the carriage of these products discharged in such a manner that venting of the
are to be of steel or stainless steel construction. tanks to atmosphere does not occur. If vapour
return to shore is used during tank loading, the
15.8.7 Tanks for the carriage of these products vapour-return system connected to a
may be used for other cargoes after thorough containment system for the product is to be
cleaning of tanks and associated pipework independent of all other containment systems.
systems by washing or purging.
15.8.14.3 During discharge operations, the
15.8.8 All valves, flanges, fittings and accessory pressure in the cargo tank must be maintained
equipment are to be of a type suitable for use above 0.007 MPa gauge.
with the products and are to be constructed of
steel or stainless steel in accordance with 15.8.15 The cargo may be discharged only by
recognized standards. The chemical deepwell pumps, hydraulically operated
composition of all material used is to be submerged pumps, or inert gas displacement.
submitted to IRS for approval prior to fabrication. Each cargo pump is to be arranged to ensure
Discs or disc faces, seats and other wearing that the product does not heat significantly if the
parts of valves are to be made of stainless steel discharge line from the pump is shut off or
containing not less than 11% chromium. otherwise blocked.
15.8.9 Gaskets are to be constructed of 15.8.16 Tanks carrying these products are to be
materials which do not react with, dissolve in, or vented independently of tanks carrying other
lower the autoignition temperature of, these products. Facilities are to be provided for
products and which are fire-resistant and sampling the tank contents without opening the
possess adequate mechanical behaviour. The tank to atmosphere.
surface presented to the cargo is to be
polytetrafluoroethylene (PTFE), or materials 15.8.17 Cargo hoses used for transfer of these
giving a similar degree of safety by their products are to be marked "FOR ALKYLENE
inertness. Spirally- wound stainless steel, with a OXIDE TRANSFER ONLY".
filler of PTFE or similar fluorinated polymer, may
be accepted. 15.8.18 Cargo tanks, void spaces and other
enclosed spaces, adjacent to an integral gravity
15.8.10 Insulation and packing, if used, is to be cargo tank carrying propylene oxide, are to
of a material which does not react with, dissolve either contain a compatible cargo (those
in, or lower the autoignition temperature of, cargoes specified in 15.8.2 are examples of
these products. substances considered incompatible) or be
inerted by injection of a suitable inert gas. Any
15.8.11 The following materials are generally hold space in which an independent cargo tank
found unsatisfactory for gaskets, packing and is located is to be inerted. Such inerted spaces
similar uses in containment systems for these and tanks are to be monitored for these
products and would require testing before being products and oxygen. The oxygen content of
approved by IRS: these spaces is to be maintained below 2
percent. Portable sampling equipment is
.1 Neoprene or natural rubber, if it comes satisfactory.
into contact with the products.
15.8.19 In no case is air to be allowed to enter
.2 Asbestos, or binders used with asbestos. the cargo pump or piping system while these
products are contained within the system.
.3 Materials containing oxides of magnesium,
such as mineral wools. 15.8.20 Prior to disconnecting shore-lines, the
pressure in liquid and vapour lines are to be
15.8.12 Threaded joints are not permitted in the relieved through suitable valves installed at the
cargo liquid and vapour lines. loading header. Liquid and vapour from these
lines are not to be discharged to atmosphere.
Indian Register of Shipping
Chapter 3 Part 5
Page 44 of 81 Chemical Carriers
ρL = density of cargo at the loading temperature 15.9 Sodium chlorate solution (50% or less
and pressure. by mass)
15.8.26.3 The maximum allowable tank filling 15.9.1 Tanks and associated equipment which
limits for each cargo tank is to be indicated for have contained this product may be used for
each loading temperature which may be applied, other cargoes after thorough cleaning by
and for the applicable maximum reference washing or purging.
temperature, on a list to be approved by IRS. A
copy of the list is to be permanently kept on 15.9.2 In the event of spillage of this product, all
board by the master. spilled liquid is to be thoroughly washed away
without delay. To minimize fire risk, spillage is
15.8.27 The cargo is to be carried under a not to be allowed to dry out.
suitable protective padding of nitrogen gas. An
automatic nitrogen make-up system is to be 15.10 Sulphur liquid (molten)
installed to prevent the tank pressure falling
below 0.07 bar gauge in the event of product 15.10.1 Cargo tank ventilation is to be provided
temperature fall due to ambient conditions or to maintain the concentration of hydrogen
maloperation of refrigeration systems. Sufficient sulphide below one half of its lower explosive
nitrogen is to be available on board to satisfy the limit throughout the cargo-tank vapour space for
demand of the automatic pressure control. all conditions of carriage, i.e. below 1.85% by
Nitrogen of commercially pure quality (99.9% by volume.
volume) is to be used for padding. A battery of
nitrogen bottles connected to the cargo tanks 15.10.2 Where mechanical ventilation systems
through a pressure reduction valve satisfies the are used for maintaining low gas concentrations
intention of the expression "automatic" in this in cargo tanks, an alarm system is to be
context. provided to give warning if the system fails.
15.8.28 The cargo tank vapour space is to be 15.10.3 Ventilation systems are to be so
tested prior to and after loading to ensure that designed and arranged as to preclude
the oxygen content is 2% by volume or less. depositing of sulphur within the system.
elasticity of the lining is not to be less than that and exit velocity of at least 30 [m/s], are
of the supporting boundary plating. fitted.
IR15.11.2 “Lining” (refer clause 15.11.2 above) 15.12.2 Tank venting systems are to be
is an acid-resistant material that is applied to the provided with a connection for a vapour return
tank or piping system in a solid state with a line to the shore installation.
defined elasticity property.
IR15.12.2 Tank venting systems are to be
15.11.3 Unless constructed wholly of corrosion- provided with a stop valve for vapour return to
resistant materials or fitted with an approved shore.
lining, the plating thickness is to take into
account the corrosivity of the cargo. 15.12.3 Products are:
15.11.4 Flanges of the loading and discharge .1 not be to stowed adjacent to oil fuel tanks;
manifold connections are to be provided with
shields, which may be portable, to guard against .2 to have separate piping systems; and
the danger of the cargo being sprayed; and in
addition, drip trays are also to be provided to .3 to have tank vent systems separate from
guard against leakage on to the deck. tanks containing nontoxic products.
15.11.5 Because of the danger of evolution of 15.12.4 Cargo tank relief valve settings are to be
hydrogen when these substances are being a minimum of 0.02 MPa gauge.
carried, the electrical arrangements are to
comply with 10.1.4. The certified safe type 15.13 Cargoes protected by additives
equipment is to be suitable for use in hydrogen-
air mixtures. Other sources of ignition are not to 15.13.1 Certain cargoes, with a reference in
be permitted in such spaces. column "o" in Sec.17, Table 17.1.1, by the
nature of their chemical make-up, tend, to under
15.11.6 Substances subjected to the certain conditions of temperature, exposure to
requirements of this clause are to be segregated air or contact with a catalyst, to undergo
from oil fuel tanks, in addition to the segregation polymerization, decomposition, oxidation or
requirements in 3.1.1. other chemical changes. Mitigation of this
tendency is carried out by introducing small
15.11.7 Provision is to be made for suitable amounts of chemical inhibitors into the liquid
apparatus to detect leakage of cargo into cargo or controlling the cargo-tank environment.
adjacent spaces.
15.13.2 Ships carrying these cargoes are to be
15.11.8 The cargo pump-room bilge pumping so designed as to eliminate from the cargo tanks
and drainage arrangements are to be of and cargo-handling system any material of
corrosion-resistant materials. construction or contaminants which could act as
a catalyst or destroy the inhibitor.
15.12 Toxic products
15.13.3 Care is to be taken to ensure that these
15.12.1 Exhaust openings of tank vent systems cargoes are sufficiently protected to prevent
are to be located: deleterious chemical change at all times during
the voyage. Ships carrying such cargoes are to
.1 at a height of B/3 or 6 m, whichever is be provided with a certificate of protection from
greater, above the weather deck or, in the the manufacturer, and kept during the voyage,
case of a deck tank, the access gangway; specifying:
.2 not less than 6 [m] above the fore-and-aft .1 the name and amount of additive present;
gangway, if fitted with 6 [m] of the gangway;
and .2 whether the additive is oxygen dependent;
.3 15 [m] from any opening or air intake to .3 date additive was put in the product and
any accommodation and service spaces; duration of effectiveness;
.4 the vent height may be reduced to 3 [m] .4 any temperature limitations qualifying the
above the deck or fore-and-aft gangway, as additives' effective lifetime; and
applicable, provided high-velocity vent valves
of an approved type, directing the vapour-air
mixture upwards in an unimpeded jet with
Indian Register of Shipping
Rules and Regulations for the Construction and Classification of Steel Ships - 2014
Page 47 of 81
___________________________________________________________________________________
.5 the action to be taken should the length of voyages of limited duration, IRS may agree to
the voyage exceed the effective lifetime of waive requirements for a refrigeration system. A
the additives. notation of any such agreement, listing
geographic area restrictions and times of the
15.13.4 Ships using the exclusion of air as the year, or voyage duration limitations, would be
method of preventing oxidation of the cargo are included in the conditions of carriage on the
to comply with 9.1.3. International Certificate of Fitness for the
Carriage of Dangerous Chemicals in Bulk.
15.13.5 A product containing an oxygen
dependent additive should be carried without 15.14.4 Connections are to be provided for
inertion (in tanks of a size not greater than 3,000 returning expelled gases to shore during
3
m ). Such cargoes should not be carried in a loading.
tank requiring inertion under the requirements of
SOLAS Chapter II-2. IR15.14.4 Tank venting systems are to be
provided with a stop valve for vapour return to
15.13.6 Venting systems are to be of a design shore.
that eliminates blockage from polymer build-up.
Venting equipment is to be of a type that can be 15.14.5 Each tank is to be provided with a
checked periodically for adequacy of operation. pressure gauge which indicates the pressure in
the vapour space above the cargo.
15.13.7 Crystallization or solidification of
cargoes normally carried in the molten state can 15.14.6 Where the cargo needs to be cooled,
lead to depletion of inhibitor in parts of the tank thermometers are to be provided at the top and
contents. Subsequent remelting can thus yield bottom of each tank.
pockets of uninhibited liquid, with the
accompanying risk of dangerous polymerization. 15.14.7.1 No cargo tanks is to be more than
To prevent this, care is to be taken to ensure 98% liquid-full at the reference temperature (R).
that at no time are such cargoes allowed to
crystallize or solidify, either wholly or partially, in 15.14.7.2 The maximum volume (VL) of cargo to
any part of the tank. Any required heating be loaded in a tank is to be:
arrangements are to be such as to ensure that
in no part of the tank does cargo become ρR
overheated to such an extent that any VL = 0.98V
dangerous polymerization can be initiated. If the ρL
temperature from steam coils would induce where,
overheating, an indirect low-temperature heating
system is to be used. V = volume of the tank
15.14.1 For a cargo referenced in column "o" in ρL = density of cargo at loading temperature
Sec.17, Table 17.1.1 to this clause, a
mechanical refrigeration system is to be R = reference temperature is the temperature at
provided unless the cargo system is designed to which the vapour pressure of the cargo
withstand the vapour pressure of the cargo at corresponds to the set pressure of the pressure-
45°C. Where the cargo system is designed to relief valve.
withstand the vapour-pressure of the cargo at
45°C, and no refrigeration system is provided, a 15.14.7.3 The maximum allowable tank filling
notation would be made in the conditions of limits for each cargo tank is to be indicated for
carriage on the International Certificate of each loading temperature which may be applied,
Fitness for the Carriage of Dangerous and for the applicable maximum reference
Chemicals in Bulk to indicate the required relief temperature, on a list approved by IRS. A copy
valve setting for the tanks. of the list should be permanently kept on board
by the master.
15.14.2 A mechanical refrigeration system is to
maintain the liquid temperature below the boiling 15.15 Cargo contamination
temperature at the cargo-tank design pressure.
15.15.1 Where column "o" in the Sec.17, Table
15.14.3 When ships operate in restricted areas 17.1.1 refers to this Section, water is not to be
and at restricted times of the year, or on allowed to contaminate this cargo. In addition,
the following provisions apply:
Indian Register of Shipping
Chapter 3 Part 5
Page 48 of 81 Chemical Carriers
.1 Air inlets to pressure/vacuum relief valves 15.18.4 Level alarms are to be capable of being
of tanks containing the cargo are to be tested prior to loading.
situated at least 2 [m] above the weather
deck. 15.18.5 The high-level alarm system required
under 15.18.6 are to be independent of the
.2 Water or steam is not to be used as the overflow control system required by 15.18.7 and
heat transfer media in a cargo temperature are to be independent of the equipment required
control system required by Sec.7. by 13.1.
.3 The cargo is not to be carried in cargo 15.18.6 Cargo tanks are to be fitted with a visual
tanks adjacent to permanent ballast or water and audible high-level alarm which complies
tanks unless the tanks are empty and dry. with 15.18.1 to 15.18.5 and which indicates
when the liquid level in the cargo tank
.4 The cargo is not to be carried in tanks approaches the normal full condition.
adjacent to slop tanks or cargo tanks
containing ballast or slops or other cargoes 15.18.7 A tank overflow control system required
containing water which may react in a by this Section is to:
dangerous manner. Pumps, pipes or vent
lines serving such tanks are to be separate .1 come into operation when the normal tank
from similar equipment serving tanks loading procedures fail to stop the tank liquid
containing the cargo. Pipelines from slop level exceeding the normal full condition;
tanks or ballast lines are not to pass through
tanks containing the cargo unless encased in .2 give a visual and audible tank-overflow
a tunnel. alarm to the ship's operator; and
.1 the ranks are sufficiently insulated from Temperature sensors should be used to monitor
fire; and the cargo pump temperature to detect
overheating due to pump failures.
.2 the vessel has a water deluge system for
the tanks such that the cargo temperature is
maintained below 100°C and the
Section 16
Operational Requirements
50 mPa.s at 20°C, the temperature at which the .2 personnel wear breathing apparatus and
cargo has a viscosity of 25 mPa.s is to be other necessary protective equipment, and
specified in the shipping document. the entire operation is under the close
supervision of a responsible officer.
16.2.7 Where column "o" in Sec.17, Table
17.1.1 refers to this paragraph, the cargo's 16.4.3 Personnel are not to enter such spaces
melting point is to be indicated in the shipping when the only hazard is of a purely flammable
document. nature, except under the close supervision of a
responsible officer.
16.3 Personnel training
16.5 Stowage of cargo samples
16.3.1 All personnel are to be adequately
trained in the use of protective equipment and 16.5.1 Samples which have to be kept on board
have basic training in the procedures are to be stowed in a designated spaces
appropriate to their duties, necessary under situated in the cargo area or, exceptionally,
emergency conditions. elsewhere, subject to the approval of IRS.
16.3.2 Personnel involved in cargo operations 16.5.2 The stowage space is to be:
are to be adequately trained in handling
procedures. .1 cell-divided in order to avoid shifting of the
bottles at sea;
16.3.3 Officers are to be trained in emergency .2 made of material fully resistant to the
procedure to deal with conditions of leakage, different liquids intended to be stowed; and
spillage or fire involving the cargo based on the .3 equipped with adequate ventilation
guidelines developed by the Organisation* and a arrangements.
sufficient number of them are to be instructed
and trained in essential first aid for cargoes 16.5.3 Samples which react with each other
carried. dangerously are not to be stowed close to each
other.
(* Refer to the Medical First Aid Guide for use in
Accidents Involving Dangerous Goods (MFAG), 16.5.4 Samples are not to be retained on board
which provides advice on the treatment of longer than necessary.
casualties in accordance with the symptoms
exhibited as well as equipment and antidotes 16.6 Cargoes not to be exposed to excessive
that may be appropriate for treating the casualty heat
and to the relevant provisions of the STCW
Code, parts A and B.) 16.6.1 Where the possibility exists of a
dangerous reaction of a cargo such as
16.4 Opening of and entry into cargo tanks polymerization, decomposition, thermal
instability or evolution of gas, resulting from local
16.4.1 During handling and carriage of cargoes overheating of the cargo in either the tank or
producing flammable or toxic vapours, or both, associated pipelines, such cargo is to be loaded
or when ballasting after the discharge of such and carried adequately segregated from other
cargo, or when loading or unloading cargo, products whose temperature is sufficiently high
cargo tank lids are always to be kept closed. to initiate a reaction of such cargo. (see 7.1.5.4).
With any hazardous cargo, cargo tank lids,
ullage and sighting ports and tank washing 16.6.2 Heating coils in tanks carrying this
access covers are to be open only when product are to be blanked off or secured by
necessary. equivalent means.
16.4.2 Personnel are not to enter cargo tanks, 16.6.3 Heat-sensitive products are not to be
void spaces around such tanks, cargo handling carried in deck tanks which are not insulated.
spaces or other enclosed spaces unless:
16.6.4 In order to avoid elevated temperatures,
.1 the compartment is free of toxic vapours this cargo should not be carried in deck tanks.
and not deficient in oxygen; or
Section 17
15.11.2 to 15.11.4,
Acetic anhydride Z S/P 2 2G Cont. No T2 IIA No R F-T A Yes 15.11.6 to 15.11.8,
15.18.6
15.18.6, 16.2.6,
Acetochlor X P 2 2G Open No Yes O No A No
16.2.7
15.13, 15.12,
Acetone cyanohydrin Y S/P 2 2G Cont. No T1 IIA Yes C T A Yes 15.16 to 15.18,
16.6.1 to 16.6.3
15.12.3, 15.13,
Acrylamide solution (50%
Y S/P 2 2G Open No NF C No No No 15.18.6, 16.6.1,
or less)
16.2.7
15.13, 15.18.6,
Acrylic acid Y S/P 2 2G Cont. No T2 IIA No R F-T A No
16.6.1, 16.2.7
15.12, 15.13,
Acrylonitrile Y S/P 2 2G Cont. No T1 IIB No C F-T A Yes
15.16, 15.18
Acrylonitrile Styrene
copolymer dispersion in Y P 3 2G Open No Yes O No AB No 15.18.6, 16.2.6
polyether polyol
Alcohols (C12-C13),
AB 15.18.6, 16.2.6,
primary, linear and Y S/P 2 2G Open No - - Yes O No No
C 16.2.7
essentially linear
Alcohols (C14-C18),
AB
primary, linear and Y S/P 2 2G Open No - - Yes O No No 15.18.6, 16.2.6
C
essentially linear
a c d e f g h i’ i’’ i’’’ j k l n o
n-Alkanes (C10+) Y P 3 2G Cont. No No R F A No 15.18.6
15.18.6, 16.2.6,
Alkenyl (C11+) amide X P 2 2G Open No - - Yes O No A No
16.2.7
Alkyl acrylate-vinylpyridine
Y P 2 2G Cont. No No R F A No 15.19.6, 16.2.7
copolymer in toluene
Alkylaryl phosphate
mixtures (more than 40%
AB 15.12, 15.16,
Diphenyl tolyl phosphate, X S/P 1 2G Cont. No T1 IIA Yes C T No
C 15.18
less than 0.02% ortho-
isomers)
Alkybenzene, alkylindane,
alkylidine mixture (each Z P 3 2G Open No Yes O No A No 15.18.6
C12-C17)
Alkylbenzene mixtures
AB 15.12, 15.17,
(containing at least 50% of Y S/P 3 2G Cont. No T1 IIA No C F-T No
C 15.19.6
toluence)
BC 15.12, 15.16,
Alkyl(c12+) dimethylamine X S/P 1 2G Cont. No - - Yes C T Yes
D 15.18
Alkyldithiothiadiazole (C6-
Y P 3 2G Open No Yes O No A No 15.18.6, 16.2.6
C24)
15.18.6, 15.19,
Alkyl (C7-C9) nitrates Y S/P 2 2G Open No Yes O No AB No 16.6.1, 16.6.2,
16.6.3
a c d e f g h i’ i’’ i’’’ j k l n o
Alkyl (C8-C10) / (C12-
C14):(50% / 50%)
Y P 3 2G Open No Yes O No No No 16.2.7, 16.2.6
polyglucoside solution
(55% or less)
Alkyl (C12-C14)
polyglucoside solution Y P 3 2G Open No Yes O No No No 15.18.6, 16.2.7
(55% or less)
Alkyl (C8-C10)
polyglucoside solution Y P 3 2G Open No Yes O No No No 16.2.6
(65% or less)
15.12, 15.16,
Allyl alcohol Y S/P 2 2G Cont. No T2 IIB No C F-T A Yes
15.18
15.12, 15.16,
Allyl chloride Y S/P 2 2G Cont. No T2 IIA No C F-T A Yes
15.18
Aluminium sulphate
Y P 2 2G Open No Yes O No A No 15.18.6
solution
Aminoethyldiethanolamine/
Aminoethy lethanolamine Z P 3 2G Open No - - Yes O No A No 16.2.7
solution
2-Amino-2-methyl-1-
Z P 3 2G Open No Yes O No A No
propanol
Ammonium hydrogen
Z P 3 2G Open No Yes O No A No
phosphate solution
Ammonium
Z P 3 2G Open No - - Yes O No A No 16.2.7
lignosulphonate solutions
15.2, 15.11.4,
Ammonium nitrate solution
Z S/P 2 1G Open No NF O No No No 15.11.6, 15.17,
(93% or less)
15.18.6, 16.2.7
Ammonium polyphosphate
Z P 3 2G Open No Yes O No A No
solution
Ammonium sulphate
Z P 3 2G Open No Yes O No A No
solution
15.12, 15.16,
Ammonium sulphide
Y S/P 2 2G Cont. No No C F-T A Yes 15.18, 16.6.1,
solution (45% or less)
16.6.2, 16.6.3
Ammonium thiosulphate
Z P 3 2G Open No NF O No No No 16.2.7
solution (60% or less)
15.12, 15.16,
Aniline Y S/P 2 2G Cont. No T1 IIA Yes C T A No
15.18
15.18.6, 16.2.6,
Aryl polyolefins (C11-C50) Y P 2 2G Open No Yes O No AB No
16.2.7
a c d e f g h i’ i’’ i’’’ j k l n o
Aviation alkylates (C8
paraffins and iso- X P 2 2G Cont. No No R F B No 15.18.6
paraffines B.Pt.95- 120°C)
Benzene sulphonyl
Z S/P 3 2G Cont. No Yes R T AD No 15.18.6, 16.2.7
chloride
Benzenetricarboxylic acid,
Y P 2 2G Open No Yes O No AB No 15.18.6, 16.2.6
triotyl ester
15.12, 15.13,
Benzyl chloride Y S/P 2 2G Cont. No T1 IIA Yes C T AB Yes
15.16, 15.18
15.13, 15.18.6,
Butyl acrylate (all isomers) Y S/P 2 2G Cont. No T2 IIB No R F-T A No
16.6.1, 16.6.2
F- 15.12, 15.16,
Butylamine (all isomers) Y S/P 2 2G Cont. No No R A Yes
T 15.18.6
Butylbenzenes (all
X P 2 2G Cont. No No R F A No 15.18.6
isomers)
15.8.1 to 15.8.7,
15.8.12, 15.8.13,
15.8.16, 15.8.17,
Ine
1,2-Butylene oxide Y S/P 3 2G Cont. T2 IIB No R F AC No 15.8.18, 15.8.19,
rt
15.8.21, 15.8.25,
15.8.27, 15.8.29,
15.18.6
15.13, 15.18.6,
Butyl methacrylate Z S/P 3 2G Cont. No IIA No R F-T AD No
16.6.1, 16.6.2
Butyraldehyde (all
Y S/P 3 2G Cont. No T3 IIA No R F-T A No 15.18.6
isomers)
15.11.2 to 15.11.4,
Butyric acid Y S/P 3 2G Cont. No Yes R No A No 15.11.6 to 15.11.8,
15.18.6
a c d e f g h i’ i’’ i’’’ j k l n o
Calcium hydroxide slurry Z P 3 2G Open No - - Yes O No A No 16.2.7
Calcium hypochlorite
Y S/P 2 2G Cont. No NF R No No No 15.18.6
solution (15% or less)
Calcium hypochlorite
X S/P 1 2G Cont. No NF R No No No 15.18, 16.2.7
solution (more than 15%)
Calcium lignosulphonate
Z P 3 2G Open No - - Yes O No A No 16.2.7
solutions
Calcium nitrate/
Magnesium nitrate/
Z P 3 2G Open No - - Yes O No A No 16.2.7
Potassium chloride
solution
epsilon-Caprolactam
(molten or aqueous Z P 3 2G Open No Yes O No A No
solutions)
15.12, 15.18.6,
Carbolic oil Y S/P 2 2G Cont. No Yes C F-T A No
16.2.7
Pa
d+
Carbon disulphide Y S/P 2 1G Cont. T6 IIC No C F-T C Yes 15.3, 15.12, 15.18
Ine
rt
15.12, 15.16,
Carbon tetrachloride Y S/P 2 2G Cont. No NF C T No Yes
15.18.6
2 AB 15.18.6, 16.2.6,
Castor oil Y P 2G Open No - - Yes O No No
(k) C 16.2.7
15.13, 16.6.1,
Cetyl/Eicosyl methacrylate
Y S/P 2 2G Open No Yes O No AD No 16.6.2, 15.18.6,
mixture
16.2.7
15.11.2, 15.11.4,
Chloroacetic acid (80% or 15.11.6, 15.11.7,
Y S/P 2 2G Cont. No NF C No No No
less) 15.11.8, 15.12.3,
15.18, 16.2.7
4-Chloro-2-
methylphenoxyacetic acid, Y P 2 2G Open No NF O No No No 15.18.6, 16.2.7
dimethylamine salt solution
15.12, 15.16,
AB
o-Chloronitrobenzene Y S/P 2 2G Cont. No Yes C T No 15.17, 15.18,
D
16.2.6, 16.2.7
a c d e f g h i’ i’’ i’’’ j k l n o
15.11.2 to 15.11.4,
2-or3-Chloro-propionic
Z S/P 3 2G Open No Yes O No A No 15.11.6 to 15.11.8,
acid
16.2.7
15.11.2 to 15.11.8,
Chlorosulphonic acid Y S/P 1 2G Cont. No NF C T No Yes 15.12, 15.15.1,
15.18
Chlorotoluenes (mixed
Y S/P 2 2G Cont. No No R F-T AB No 15.18.6
isomers)
15.18.6, 16.2.6,
Coal tar X S/P 2 2G Cont. No T2 IIA Yes R No BD No
16.2.7
Coal tar naphtha solvent Y S/P 2 2G Cont. No T3 IIA No R F-T AD No 15.18.6, 16.2.7
15.18.6, 16.2.6,
Coal tar pitch (molten) X S/P 2 1G Cont. No T2 IIA Yes R No BD No
16.2.7
2 AB 15.19.6, 16.2.6,
Cocoa butter Y S/P 2G Open No - - Yes O No No
(k) C 16.2.7
2 AB 15.18.6, 16.2.6,
Coconut oil Y S/P 2G Open No - - Yes O No No
(k) C 16.2.7
AB 15.18.6, 16.2.6,
Coconut oil fatty acid Y S/P 2 2G Open No - - Yes O No No
C 16.2.7
2 AB 15.18.6, 16.2.6,
Corn Oil Y S/P 2G Open No - - Yes O No No
(k) C 16.2.7
2 AB 15.18.6, 16.2.6,
Cotton seed Oil Y S/P 2G Open No - - Yes O No No
(k) C 16.2.7
15.12.3, 15.12.4,
Creosote (coal tar) X S/P 2 2G Cont. No T2 IIA Yes R T AD No 15.18.6, 16.2.6,
16.2.7
Cresylic acid,
Y S/P 2 2G Open No Yes O No AB No 15.18.6
dephenolized
15.12, 15.17,
Crotonaldehyde Y S/P 2 2G Open No T3 IIB No R F-T A Yes
15.18.6
15.13, 15.18,
1,5,9-Cyclododecatriene X S/P 1 2G Cont. No Yes R T A No
16.6.1, 16.6.2
Cyclohexanone,
Y S/P 3 2G Cont. No Yes R F-T A No 15.18.6
Cyclohexanol mixture
a c d e f g h i’ i’’ i’’’ j k l n o
Cyclopentane Y P 2 2G Cont. No No R F A No 15.18.6
AC 15.13, 15.18,
Decyl acrylate X S/P 1 2G Open No T3 IIA Yes O No No
D 16.6.1, 16.6.2
Decyloxytetrahydrothio-
X S/P 2 2G Cont. No Yes R T A No 15.18.6, 16.2.7
phene dioxide
Dialkykl (C8-C9)
Z P 3 2G Open No Yes O No AB No
diphenylamines
Dialkyl (C7-C13)
X P 2 2G Open No Yes O No AB No 15.18.6, 16.2.6
phthalates
AC
Dibutylamine Y S/P 3 2G Cont. No T2 IIA No R F-T No 15.18.6
D
Dibutyl hydrogen
Y P 3 2G Open No Yes O No A No 15.18.6, 16.2.7
phosphonate
AB
2,6-Di-tert-butylphenol X P 1 2G Open No - - Yes O No No 15.19, 16.2.7
CD
Dichlorobenzenes (all AB
X S/P 2 2G Cont. No T1 IIA Yes R T No 15.18.6
isomers) D
F- AB 15.12.3, 15.16,
3-4 Dichloro-1-butene Y S/P 2 2G Cont. No No C Yes
T C 15.18.6
F-
1-1-Dichloroethane Z S/P 3 2G Cont. No T2 IIA No R A Yes 15.18.6
T
F-
Dichloroethyl ether Y S/P 2 2G Cont. No T2 IIA No R A No 15.18.6
T
15.18.6, 16.2.6,
2,4-Dichlorophenol Y S/P 2 2G Cont. Dry Yes R T A No
16.2.7
2,4-Dichlorophenoxyacetic
acid, diethanolamine salt Y S/P 3 2G Open No NF O No No No 15.18.6, 16.2.7
solution
2,4-Dichlorophenoxyacetic
acid, diethanolamine salt Y S/P 3 2G Open No NF O No No No 15.18.6, 16.2.7
solution (70% or less)
2,4-Dichlorophenoxyacetic
15.18.6, 16.2.6,
acid, triisopropanolamine Y S/P 3 2G Open No NF O No No No
16.2.7
salt solution
F-
1,1-Dichloropropane Y S/P 2 2G Cont. No No R AB No 15.12, 15.18.6
T
F-
1,2-Dichloropropane Y S/P 2 2G Cont. No T1 IIA No R AB No 15.12, 15.18.6
T
F- 15.12, 15.16,
1,3-Dichloropropene X S/P 2 2G Cont. No T2 IIA No C AB Yes
T 15.17, 15.18
a c d e f g h i’ i’’ i’’’ j k l n o
A,
Dichloropropene / F- 15.12, 15.16,
X S/P 2 2G Cont. No No C B, Yes
Dichloropropane mixtures T 15.17, 15.18
D
15.11.2, 15.11.4,
Dr 15.11.6, 15.11.7,
2,2-Dichloropropionic acid Y S/P 3 2G Cont. Yes R No A No
y 15.11.8, 15.19.6,
16.2.7
F-
Diethylamine Y S/P 3 2G Cont. No T2 IIA No R A Yes 15.12, 15.18.6
T
F-
Diethylamino-ethanol Y S/P 2 2G Cont. No T2 IIA No R AC No 15.18.6
T
BC
2,6-Diethy laniline Y S/P 3 2G Open No Yes O No No 15.18.6, 16.2.7
D
Diethylene glycol
Y P 3 2G Open No - - Yes O No A No 15.18.6, 16.2.6
phthalate
Diethylenetriaminepentaa
cetic acid, pentasodium Z P 3 2G Open No - - Yes O No A No
salt solution
Di-(2-ethylhexyl)
Y S/P 2 2G Open No Yes O No AD No 15.18.6
phosphoric acid
Diglycidyl ether of
Y P 2 2G Open No Yes O No A No 15.18.6, 16.2.6
bisphenol F
F- AC
Diisobutylamine Y S/P 2 2G Cont. No No R No 15.12.3, 15.18.6
T D
F-
Diisopropylamine Y S/P 2 2G Cont. No T2 IIA No C A Yes 15.12, 15.18
T
Diisopropylbenzene (all
X P 2 2G Open No Yes O No A No 15.18.6
isomers)
Diisopropylnaphthalene
Y P 2 2G Open No - - Yes O No A No 15.18.6
a c d e f g h i’ i’’ i’’’ j k l n o
AC
N,N-Dimethylacetamide Z S/P 3 2G Cont. No - - Yes C T No 15.12, 15.16
D
N,N-Dimethylacetamide
Z S/P 3 2G Cont. No Yes R T B No 15.12.1, 15.16
solution (40% or less)
Dimethylamine solution F- AC
Y S/P 3 2G Cont. No T2 IIA No R No 15.12, 15.18.6
(45% or less) T D
Dimethylamine solution
F- AC 15.12, 15.16,
(greater than 45% but not Y S/P 2 2G Cont. No No C Yes
T D 15.18
greater than 55%)
Dimethylamine solution
F- AC 15.12, 15.14,
(greater than 55% but not Y S/P 2 2G Cont. No No C Yes
T D 15.16, 15.18
greater than 65%)
F- 15.12.3,
Dimethyl disulphide Y S/P 2 2G Cont. No T3 IIA No R B No
T 15.12.4, 15.18.6
F-
Dimethylethanolamine Y S/P 3 2G Cont. No T3 IIA No R AD No 15.18.6
T
F-
Dimethylformamide Y S/P 3 2G Cont. No T2 IIA No R AD No 15.18.6
T
Dimethyl hydrogen
Y S/P 3 2G Cont. No Yes R T AD No 15.12.1, 15.18.6
phosphite
15.18.6, 16.2.6,
Dimethyl octanoic acid Y P 2 2G Open No Yes O No A No
16.2.7
2,2-Dimethylpropane-1,3-
Z P 3 2G Open No Yes O No AB No 16.2.7
diol (molten or solution)
15.12, 15.16,
15.18, 15.20,
Dinitrololuene (molten) X S/P 2 2G Cont. No Yes C T A No
16.2.6, 16.2.7,
16.6.4
15.12, 15.18,
1,4-Dioxane Y S/P 2 2G Cont. No T2 IIB No C F-T A No
16.2.7
15.18.6, 16.2.6,
Diphenyl X P 2 2G Open No Yes O No B No
16.2.7
15.18.6, 16.2.6,
Diphenylamine (molten) Y P 2 2G Open No - - Yes O No BD No
16.2.7
Diphenylamine, reaction
product with 2,2,4- Y S/P 1 2G Open No Yes O No A No 15.18, 16.2.6
Trimethylpentene
15.18.6, 16.2.6,
Diphenylamines, alkylated Y P 2 2G Open No Yes O No A No
16.2.7
Diphenyl/Diphenyl ether
X P 2 2G Open No Yes O No B No 15.18.6, 16.2.7
mixtures
Diphenyl ether
X P 2 2G Open No Yes O No A No 15.18.6, 16.2.7
a c d e f g h i’ i’’ i’’’ j k l n o
Diphenyl ether/Diphenyl
phenyl ether mixture X P 2 2G Open No Yes O No A No 15.18.6, 16.2.7
AB
15.12, 15.15.2,
Diphenylmethane Dr Yes T C
Y S/P 2 2G Cont. - - C No 15.16, 15.18.6,
diisocyanate y (a) (a) (b)
16.2.6, 16.2.7
D
AB 15.12, 15.16,
Resin oil, distilled Y S/P 2 2G Cont. No T1 II A No C F-T No
C 15.18.6
Dithiocarbamate ester
X P 2 2G Open No Yes O No AD No 15.18.6, 16.2.7
(C7-C35)
15.18.6, 16.2.6,
Diundecyl phthalate Y P 2 2G Open No Yes O No AB No
16.2.7
AB 15.12, 15.16,
tert-Dodecanethiol X S/P 1 2G Cont. No - - Yes C T Yes
D 15.18
Dodecylamine/Tetradecyl
Y S/P 2 2G Cont. No Yes R T AD No 15.18.6, 16.2.7
amine mixture
Dodecyl hydroxypropyl
X P 2 2G Open No Yes O No A No 15.18.6
sulphide
15.13, 15.18.6,
Dodecyl/Octadecyl
Y S/P 3 2G Open No Yes O No A No 16.2.6, 16.6.1,
methacrylate (mixture)
16.6.2
15.12, 15.16,
Epichlorohydrin Y S/P 2 2G Cont. No IIB No C F-T A Yes
15.18
a c d e f g h i’ i’’ i’’’ j k l n o
Ethyl acetoacetate
Z P 3 2G Open No Yes O No A No
15.13, 15.18.6,
Ethyl acrylate Y S/P 2 2G Cont. No T2 IIB No R F-T A Yes
16.6.1, 16.6.2
15.12, 15.14,
Ethylamine Y S/P 2 1G Cont. No T2 IIA No C F-T CD Yes
15.18.6
S-Ethyl
Y P 2 2G Open No Yes O No A No 16.2.7
dipropylthiocarbamate
15.12, 15.16,
Ethylene chlorohydrin Y S/P 2 2G Cont. No T2 IIA No C F-T AD Yes
15.18
Ethylenediaminetetraaceti
c acid, tetrasodium salt Y S/P 3 2G Open No - - Yes O No A No 15.18.6
solution
15.12, 15.18.6,
Ethylene dibromide Y S/P 2 2G Cont. No NF C T No Yes
16.2.7
Ethylene oxide/Propylene
oxide mixture with an
Ine 15.8, 15.12,
ethylene oxide content of Y S/P 2 1G Cont. T2 IIB No C F-T AC No
rt 15.14, 15.18
not more than 30% by
mass
15.13, 15.18.6,
2-Ethylhexyl acrylate Y S/P 3 2G Open No T3 IIB Yes O No A No
16.6.1, 16.6.2
a c d e f g h i’ i’’ i’’’ j k l n o
2-Ethyl-2 (hydroxymethyl)
15.18.6, 16.2.6,
propane-1,3-diol, C8-C10 Y P 2 2G Open No Yes O No AB No
16.2.7
ester
15.13, 15.18.6,
Ethyl methacrylate Y S/P 3 2G Cont. No T2 IIA No R F-T AD No
16.6.1, 16.6.2
Ye 15.12.3, 15.16,
N-Ethylmethylallylame Y S/P 2 2G Cont. No T2 IIB No C F AC
s 15.18
15.12.3,
Fatty acid methyl esters AB 15.12.4,
Y S/P 2 2G Cont. No - - Yes R T No
(m) C 15.18.6, 16.2.6,
16.2.7
15.2.3, 15.12.4,
AB
Fatty acids, 12+ Y S/P 2 2G Cont. No - - Yes R T No 15.18.6, 16.2.6,
C
16.2.7
15.12.3,
AB
Fatty acids, C8-C10 Y S/P 2 2G Cont. No - - Yes R T No 15.12.4, 15.18,
C
16.2.6, 16.2.7
AB
Fatty acids, C16+ Y P 2 2G Open No - - Yes O No No 15.18.6, 16.2.6
C
15.11, 15.18.6,
Ferric chloride solutions Y S/P 3 2G Open No NF O No No No
16.2.7
2 AB 15.18.6, 16.2.6,
Fish oil Y S/P 2G Open No - - Yes O No No
(k) C 16.2.7
Formaldehyde solutions Ye
Y S/P 3 2G Cont. No T2 IIB No R F-T A 15.18.6, 16.2.7
(45% or less) s
15.11.2 to
T Ye 15.11.4, 15.11.6
Formic acid Y S/P 3 2G Cont. No T1 IIA No R A
(g) s to 15.11.8,
15.18.6, 16.2.7
Glucitol/glycerol blend
AB 15.12.3,
propoxylated (containing Z S/P 3 2G Cont. No - - Yes R T No
C 15.12.4, 15.18.6
less than 10% amines)
Glutaraldehyde solutions
Y S/P 3 2G Open No NF O No No No 15.18.6
(50% or less)
15.18.6, 16.2.6,
Glycerol monooleate Y P 2 2G Open No - - Yes O No A No
16.2.7
AB 15.12.3,
Glycerol propoxylated Z S/P 3 2G Cont. No - - Yes R T No
C 15.12.4, 15.18.6
Glycerol, propoxylated AB
Z P 3 2G Open No - - Yes O No No
and ethoxylated C
a c d e f g h i’ i’’ i’’’ j k l n o
Glycerol/sucrose blend
AB
propoxylated and Z P 3 2G Open No - - Yes O No No
C
ethoxylated
15.11.2, 15.11.3
15.11.4,
15.11.6,
Glyoxylic acid solution AC 15.11.7,
Y S/P 3 2G Open No - - Yes O No No
(50% or less) D 15.11.8,
15.18.6, 16.2.7,
16.6.1, 16.6.2,
16.6.3
2 AB 15.18.6, 16.2.6,
Groundnut oil Y P 2G Open No - - Yes O No No
(k) C 16.2.7
1-Hexadecylnaphthalene
/ 1,4-
Y P 2 2G Open No Yes O No AB No 15.18.6, 16.2.6
bis(hexadecyl)naphthalen
e mixture
Hexamethylenediamine
Z P 3 2G Open No Yes O No A No
adipate (50% in water)
15.12, 15.16,
Hexamethylenediamine Ye
Y S/P 2 2G Cont. No Yes C T C 15.17, 15.18.6,
(molten) s
16.2.7
Hexamethylenediamine
Y S/P 3 2G Cont. No Yes R T A No 15.18.6
solution
AC 15.12, 15.16,
Hexamethylene Ye
Y S/P 2 1G Cont. Dry T1 IIB Yes C T (b) 15.15.1, 15.17,
diisocyanate s
D 15.18
15,12,3,
1,6-Hexanediol,
Y P 3 2G Open No - - Yes O No A No 15.12.4,
distillation overheads
15.18.6, 16.2.7
Ye
Hydrochloric acid Z S/P 3 1G Cont. No NF R T No 15.11
s
Hydrogen peroxide
solutions (over 60% but Y S/P 2 2G Cont. No NF C No No No 15.5.1, 15.18.6
not over 70% by mass)
a c d e f g h i’ i’’ i’’’ j k l n o
Hydrogen peroxide
15.5.2, 15.18,
solutions (over 8% but Y S/P 3 2G Cont. No NF C No No No
15.18.6
not over 60% by mass)
15.12, 15.13,
2-Hydroxyethyl acrylate Y S/P 2 2G Cont. No Yes C T A No 15.18.6, 16.6.1,
16.6.2
N-(Hydroxyethyl)
ethylenediaminetriacetic
Y P 3 2G Open No Yes O No A No 15.18.6
acid, trisodium salt
solution
2-Hydroxy-4-(methylthio)
Z P 3 2G Open No Yes O No A No
butanoic acid
2 AB 15.18.6, 16.2.6,
Illipe oil Y P 2G Open No - - Yes O No No
(k) C 16.2.7
15.12, 15.13,
Isobutyl methacrylate Z P 3 2G Cont. No No R F A No 15.16, 15.18,
16.6.1, 16.6.2
AB 15.12, 15.15.1,
Isophorone diisocyanate X S/P 2 2G Cont. Dry Yes C T No
D 15.16, 15.18.6
15.13, 15.14,
Isoprene Y S/P 3 2G Cont. No T3 IIB No R F B No 15.18.6, 16.6.1,
16.6.2
16.2.7, 15.18.6,
Isopropanolamine Y S/P 3 2G Open No T2 IIA Yes O F-T A No
16.2.6
Ye 15.12, 15.14,
Isopropylamine Y S/P 2 2G Cont. No T2 IIA No C F-T CD
s 15.18
15.1, 15.12,
Lactonitrile solution (80% AC Ye 15.16 15.17,
Y S/P 2 1G Cont. No Yes C T
or less) D s 15.18, 16.6.1,
16.6.2, 16.6.3
2 AB 15.18.6, 16.2.6,
Lard Y S/P 2G Open No - - Yes O No No
(k) C 16.2.7
Latex: Carboxylated
styrene-Butadiene
Z P 3 2G Open No - - -Yes O No A No 16.2.7
copolymer; Styrene-
Butadiene rubber
15.18.6, 16.2.6,
Lauric acid X P 2 2G Open No Yes O No A No
16.2.7
Ligninsulphonic acid,
Z P 3 2G Open No - - -Yes O No A No 16.2.7
sodium salt solution
2 AB 15.18.6, 16.2.6,
Linseed oil Y S/P 2G Open No - - Yes O No No
(k) C 16.2.7
Ye 15.12, 15.18.6,
Liquid chemical wastes X S/P 2 2G Cont. No No C F-T A
s 20.5.1
a c d e f g h i’ i’’ i’’’ j k l n o
Long-chain alkaryl 15.18.6, 16.2.6,
Y P 2 2G Open No Yes O No AB No
polyether (C11-C20) 16.2.7
Long-chain alkaryl
Y P 2 2G Open No - - Yes O No A No 15.18.6, 16.2.7
sulphonic acid (C16-C60)
Long-chain
15.18.6, 16.2.6,
alkylphenate/Phenol Y P 2 2G Open No - - Yes O No A No
16.2.7
sulphide mixture
Magnesium chloride
Z P 3 2G Open No Yes O No A No
solution
Magnesium long-chain
15.18.6, 16.2.6,
alkaryl sulphonate (C11- Y P 2 2G Open No - - Yes O No A No
16.2.7
C50)
AC
Maleic anhydride Y S/P 3 2G Cont. No Yes R No No 16.2.7
(f)
2 AB 15.18.6, 16.2.6,
Mango kernel oil Y P 2G Open No - - Yes O No No
(k) C 16.2.7
Mercaptobenzothiazol,
X S/P 2 2G Open No NF O No No No 15.18.6, 16.2.7
sodium salt solution
Methacryclic acid –
alkoxypoly (alkylene
oxide) methacrylate
Z S/P 3 2G Open No - - NF O No AC No 16.2.7
copolymer, sodium salt
aqueous solution (45% or
less)
15.13, 16.6.1,
Methacrylic acid Y S/P 3 2G Cont. No Yes R T A No
15.18.6, 16.2.7
Methacrylic resin in
Y S/P 2 2G Cont. No T2 IIA No R F-T AB No 15.18, 16.2.7
ethylene dichloride
Ye 15.12, 15.14,
Methacrylonitrile Y S/P 2 2G Cont. No No C F-T A
s 15.16, 15.18
3-Methoxy-1-butanol Z P 3 2G Cont. No No R F A No
N-(2-Methoxy-1-methyl
ethyl)-2-ethyl-6-methyl X P 1 2G Open No Yes O No A No 15.18, 16.2.6
chloroacetanilide
Ye 15.13, 15.18.6,
Methyl acrylate Y S/P 2 2G Cont. No T1 IIB No R F-T A
s 16.6.1, 16.6.2
Methylbutynol Z P 3 2G Cont. No No R F A No
a c d e f g h i’ i’’ i’’’ j k l n o
Methyl butyrate Y P 3 2G Cont. No No R F A No 15.18.6
Methylcyclopentadiene
Y P 2 2G Cont. No No R F B No 15.18.6
dimer
Ye 15.12, 15.14,
Methyl formate Z S/P 2 2G Cont. No No R F-T A
s 15.18
2-Methyl-2-hydroxy-3- AB
Z S/P 3 2G Cont. No IIA No R F-T No 15.18.6, 16.2.7
butyne D
15.13, 15.18.6,
Methyl methacrylate Y S/P 2 2G Cont. No T2 IIA No R F-T A No
16.6.1, 16.6.2
3-Methyl-3-
Z P 3 2G Open No Yes O No A No
methoxybutanol
Methylnaphthalene
X S/P 2 2G Cont. No Yes R No AD No 15.18.6
(molten)
15.12.3, 15.18,
4-Methylpyridine Z S/P 2 2G Cont. No No C F-T A No
16.2.7
AD 15.13, 15.18.6,
alpha- Methylstyrene Y S/P 2 2G Cont. No T1 IIB No R F-T No
(j) 16.6.1, 16.6.2
Molybdenum Polysulfide
15.12, 15.17,
Long Chain Alkyl AB Ye
Y S/P 2 2G Cont. No - - Yes C T 15.18, 16.2.6,
Dithiocarbamide C s
16.2.7
Complex
Naphthalenesulphonic
acid-Formaldehyde
Z P 3 2G Open No - - Yes O No A No 16.2.7
copolymer, sodium salt
solution
Nitrilotriacetic acid,
Y P 3 2G Open No Yes O No A No 15.18.6
trisodium salt solution
a c d e f g h i’ i’’ i’’’ j k l n o
15.12, 15.16,
Nitrobenzene Y S/P 2 2G Cont. No T1 IIA Yes C T AD No 15.17, 15.18,
16.2.7
A 15.18.6, 16.6.1,
Nitroethane Y S/P 3 2G Cont. No IIB No R F-T No
(f) 16.6.2, 16.6.4
Nitroethane
A 15.18.6, 16.6.1
(80%)/Nitropro-pane Y S/P 3 2G Cont. No IIB No R F-T No
(f) to 16.6.3
(20%)
15.12, 15.18.6,
o-Nitrophenol (molten) Y S/P 2 2G Cont. No Yes C T AD No
16.2.6, 16.2.7
Nitropropane
A
(60%)/Nitroethane (40%) Y S/P 3 2G Cont. No No R F-T No 15.18.6
(f)
mixture
15.12, 15.17,
o- or p-Nitrotoluenes Y S/P 2 2G Cont. No IIB Yes C T AB No
15.18.6
Nonyl methacrylate
Y P 2 2G Open No Yes O No AB No 15.18.6, 16.2.7
monomer
15.18, 16.2.6,
Nonylphenol X P 1 2G Open No Yes O No A No
16.2.7
Nonylphenol
Y P 2 2G Open No - - Yes O No A No 15.18.6, 16.2.6
poly(4+)ethoxylate
a c d e f g h i’ i’’ i’’’ j k l n o
Octane (all isomers) X P 2 2G Cont. No No R F A No 15.18.6
Olefin-Alkyl ester
15.18.6, 16.2.6,
copolymer (molecular Y P 2 2G Open No Yes O No AB No
16.2.7
weight 2000+)
Alpha-Olefins (C6-C18)
X P 2 2G Cont. No No R F A No 15.18.6, 16.2.7
mixtures
15.11.2 to
15.11.8,
Ye
Oleum Y S/P 2 2G Cont. No NF C T No 15.12.1,
s
15.16.2, 15.16,
15.18, 16.2.6
2 AB 15.18.6, 16.2.6,
Olive oil Y S/P 2G Open No - - Yes O No No
(k) C 16.2.7
Oxygenated aliphatic AB
Z S/P 3 2G Open No - - Yes O No No
hydrocarbon mixtures C
AB 15.18.6, 16.2.6,
Palm acid oil Y S/P 2 2G Open No - - Yes O No No
C 16.2.7
AB 15.18.6, 16.2.6,
Palm fatty acid distillate Y S/P 2 2G Open No - - Yes O No No
C 16.2.7
AB 16.2.7, 15.19.6,
Palm kernel acid oil Y S/P 2 2G Open No Yes O No No
C 16.2.6
2 AB 15.18.6, 16.2.6,
Palm kernel oil Y S/P 2G Open No T3 IIB Yes O No No
(k) C 16.2.7
2 AB 15.19.6, 16.2.6,
Palm kernel olein Y P 2G Open No - - Yes O No No
(k) C 16.2.7
2 AB 15.19.6, 16.2.6,
Palm kernel stearin Y P 2G Open No - - Yes O No No
(k) C 16.2.7
2 AB 15.19.6, 16.2.6,
Palm mid fraction Y P 2G Open No - - Yes O No No
(k) C 16.2.7
2 AB 15.18.6, 16.2.6,
Palm oil Y S/P 2G Open No - - Yes O No No
(k) C 16.2.7
15.12.3,
Non-edible industrial AB 15.12.4,
Y S/P 2 2G Cont. No - - Yes R No No
grade palm oil C 15.19.6, 16.2.6,
16.2.7
2 AB 15.18.6, 16.2.6,
Palmolein Y P 2G Open No - - Yes O No No
(k) C 16.2.7
2 AB 15.18.6, 16.2.6,
Palm stearin Y P 2G Open No - - Yes O No No
(k) C 16.2.7
15.18.6, 16.2.6,
Paraffin wax Y P 2 2G Open No Yes O No AB No
16.2.7
a c d e f g h i’ i’’ i’’’ j k l n o
Paraldehyde-ammonia
Y S/P 2 2G Cont. No No C F-T A No 15.12.3, 15.18
reaction product
15.12, 15.16,
Pentachloroethane Y S/P 2 2G Cont. No NF R T No No
15.18.6
15.13, 15.18.6,
1,3-Pentadiene Y S/P 3 2G Cont. No No R F-T AB No
16.6.1 to 16.6.3
Ye Ye
Pentaethylenehexamine X S/P 2 2G Open No Yes O No B 15.19
s s
15.11.2,
n-Pentanoic acid 15.11.3,
(64%)/2-Methyl butyric Y S/P 2 2G Open No T2 Yes C No AD No 15.11.4, 15.11.6
acid (36%) mixture to 15.11.8,
16.12.3, 15.18
15.12.1,
Perchloroethylene Y S/P 2 2G Cont. No NF R T No No
15.12.2, 15.18.6
15.18.6, 16.2.6,
Petrolatum Y P 2 2G Open No - - Yes O No A No
16.2.7
15.12, 15.18,
Phenol Y S/P 2 2G Cont. No T1 IIA Yes C T A No
16.2.7
15.11.1 to
15.11.4, 15.11.6
Phosphoric acid Z S/P 3 2G Open No NF O No No No
to 15.11.8,
16.2.7
Pad
+
(Ve
Phosphorus, yellow or No Ye 15.7, 15.18,
X S/P 1 1G Cont. nt C No C
white (c) s 16.2.7
or
Iner
t)
Poly(2-8)alkylene glycol
Z P 3 2G Open No - - Yes O No A No
monoalkyl (C1-C6) ether
Poly(2-8)alkylene glycol
monoalkyl (C1-C6) ether Y P 2 2G Open No - - Yes O No A No 15.19.6
acetate
Polyalkyl (C10-C18)
methacrylate/ethylene- 15.18.6, 16.2.6,
Y P 2 2G Open No Yes O No AB No
propylene copolymer 16.2.7
mixture
a c d e f g h i’ i’’ i’’’ j k l n o
Polybutene Y P 2 2G Open No - - Yes O No A No 15.19.6, 16.2.6
15.19.6,
Polybutenyl succinimide Y P 2 2G Open No - - Yes O No A No
16.2.6, 16.2.7
15.18, 16.2.6,
Poly(2+)cyclic aromatics X P 1 2G Cont. No Yes R No AD No
16.2.7
Polyether (molecular
Y P 2 2G Open No - - Yes O No A No 15.19.6, 16.2.6
weight 1350+)
Polyethylene glycol
Z P 3 2G Open No Yes O No A No
dimethyl ether
Polyethylene
polyamines(more than Y S/P 2 2G Open No Yes O No A No 16.2.7, 15.19.6
50% C5-C20 paraffin oil)
Polyferric sulphate
Y S/P 3 2G Open No NF O No No No 15.18.6
solution
Poly(imioethylene)-graft-
N-poly(ethyleneoxy) Z S/P 3 2G Open No - - NF O No AC No 16.2.7
solution (90% or less)
Polyisobutenamine in
aliphatic (C10-C14) Y P 3 2G Open No T3 IIA Yes O No A No 15.18.6
solvent
Polyisobutenyl anhydride
Z P 3 2G Open No Yes O No AB No
adduct
Polyolefin amide
Y P 2 2G Open No Yes O No AB No 15.18.6, 16.2.6
alkeneamine (C17+)
Polyolefin amide
15.18.6,
alkeneamine borate Y P 2 2G Open No Yes O No AB No
16.2.6, 16.2.7
(C28-C250)
Polyolefinamine (C28-
Y P 2 2G Open No Yes O No A No 15.18.6, 16.2.7
C250)
Polyolefinamine in 15.18.6,16.2.6,
Y P 2 2G Cont. No No R F A No
aromatic solvent 16.2.7
Polyolefin aminoester
15.18.6,
salts (molecular weight Y P 2 2G Open No - - Yes O No A No
16.2.6, 16.2.7
2000+)
15.18.6,
Polyolefin anhydride Y P 2 2G Open No Yes O No AB No
16.2.6, 16.2.7
Polyolefin
phosphorosulphide, 15.18.6,
Y P 2 2G Open No Yes O No AB No
barium derivative (C28- 16.2.6, 16.2.7
C250)
Poly(20)oxyethylene 15.18.6,
Y P 2 2G Open No Yes O No A No
sorbitan monooleate 16.2.6, 16.2.7
AB
Polypropylene glycol Z S/P 3 2G Cont. No Yes O No No 15.18.6
C
a c d e f g h i’ i’’ i’’’ j k l n o
Potassium chloride
Z S/P 3 2G Open No - - NF O No A No 16.2.7
solution
Potassium hydroxide
Y S/P 3 2G Open No NF O No No No 15.18.6
solution
15.18.6,
Potassium oleate Y P 2 2G Open No Yes O No A No
16.2.6, 16.2.7
Potassium thiosulphate
Y P 3 2G Open No NF O No No No 15.18.6, 16.2.7
(50% or less)
F-
Propionaldehyde Y S/P 3 2G Cont. No No R A Yes 15.16, 15.18.6
T
15.11.2 to
15.11.4,
Propionic acid Y S/P 3 2G Cont. No T1 IIA No R F A Yes 15.11.6 to
15.11.8,
15.18.6
F- 15.12, 15.16 to
Propionitrile Y S/P 2 1G Cont. No T1 IIB No C AD Yes
T 15.18
Ine F-
n-Propylamine Z S/P 2 2G Cont. T2 IIA No C AD Yes 15.12, 15.18
rt T
Propylbenzene (all
Y P 3 2G Cont. No No R F A No 15.18.6
isomers)
Propylene glycol
Z P 3 2G Cont. No No R F AB No
monoalkyl either
2 AB 15.18.6,
Rapeseed oil Y S/P 2G Open No - - Yes O No No
(k) C 16.2.6, 16.2.7
2 AB 15.18.6,
Rice bran oil Y S/P 2G Open No - - Yes O No No
(k) C 16.2.6, 16.2.7
15.18.6,
Rosin Y P 2 2G Open No Yes O No A No
16.2.6, 16.2.7
2 AB 15.18.6,
Safflower oil Y S/P 2G Open No - - Yes O No No
(k) C 16.2.6, 16.2.7
2 AB 15.18.6,
Shea butter Y S/P 2G Open No - - Yes O No No
(k) C 16.2.6, 16.2.7
Sodium aluminosilicate
Z P 3 2G Open No Yes O No AB No
slurry
a c d e f g h i’ i’’ i’’’ j k l n o
Sodium benzoate Z P 3 2G Open No Yes O No A No
Sodium borohydride
15.18.6,
(15% or less)/Sodium Y S/P 3 2G Open No NF O No No No
16.2.6, 16.2.7
hydroxide solution
Sodium carbonate
Z P 3 2G Open No Yes O No A No
solution
Sodium dichromate
Y S/P 2 2G Open No NF C No No No 15.12.3, 15.18
solution (70% or less)
Sodium hydrogen
sulphide (6% or
Z P 3 2G Open No NF O No No No 15.18.6, 16.2.7
less)/Sodium carbonate
(3% or less) solution
Sodium hydrogen
sulphite solution (45% or Z S/P 3 2G Open No NF O No No No 16.2.7
less)
15.12, 15.14,
Sodium
F- 15.16, 15.18,
hydrosulphide/Ammoniu Y S/P 2 2G Cont. No No C A Yes
T 16.6.1, 16.6.2,
m sulphide solution
16.6.3
Ve
nt
Sodium hydrosulphide or
Z S/P 3 2G Cont. NF R T No No 15.18.6, 16.2.7
solution (45% or less) pad
(ga
s)
Sodium hypochlorite
Y S/P 2 2G Cont. No NF R No No No 15.18.6
solution (15% or less)
15.12.3.1,
Sodium nitrite solution Y S/P 2 2G Open No NF O No No No 15.12.3.2,
15.18, 16.2.7
Sodium petroleum
Y S/P 2 2G Open No Yes O No A No 15.18.6, 16.2.6
sulphonate
Sodium thiocyanate
Y P 3 2G Open No Yes O No No No 15.18.6, 16.2.7
solution (56% or less)
2 AB
Soyabean oil Y S/P 2G Open No - - Yes O No No 15.18.6, 16.2.6
(k) C
15.13, 15.19.6,
Styrene monomer Y S/P 3 2G Cont. No T1 IIA No R F AB No
16.6.1, 16.6.2
Ve
nt
or F-
Sulphur (molten) Z S 3 1G Open T3 Yes O No No 15.10, 16.2.7
pad T
(ga
s)
15.11, 15.15.1,
Sulphuric acid Y S/P 3 2G Open No NF O No No No
15.18.6
a c d e f g h i’ i’’ i’’’ j k l n o
15.11, 15.15.1,
Sulphuric acid, spent Y S/P 3 2G Open No NF O No No No
15.18.6
Sulphurized
polyolefinamide alkene Z P 3 2G Open No - - Yes O No A No
(C28-C250) amine
2 AB 15.18.6,
Sunflower seed oil Y S/P 2G Open No - - Yes O No No
(k) CD 16.2.6, 16.2.7
AB 15.12, 15.16,
Tall oil, crude Y S/P 2 2G Cont. No - - Yes C T Yes
C 15.18, 16.2.6
AB
Tall oil, distilled Y P 2 2G Open No - - Yes O No No 15.18.6, 16.2.6
C
15.12, 15.16,
AB
Tall oil pitch Y S/P 2 2G Cont. No - - Yes C T Yes 15.18, 16.2.6,
C
16.2.7
2 AB 15.18.6,
Tallow Y P 2G Open No - - Yes O No No
(k) C 16.2.6, 16.2.7
15.18.6,
Tallow fatty acid Y P 2 2G Open No - - Yes O No A No
16.2.6, 16.2.7
15.12, 15.16,
Tetrachloroethane Y S/P 2 2G Cont. No NF R T No No
15.18.6
F-
Tetrahydrofuran Z S 3 2G Cont. No T3 IIB No R A No 15.18.6
T
Tetramethylbenzene (all
X P 2 2G Open No Yes O No A No 15.18.6, 16.2.7
isomers)
15.12, 15.16,
Toluenediamine Y S/P 2 2G Cont. No Yes C T AD Yes 15.18, 16.2.6,
16.2.7
AC 15.12, 15.15.1,
F-
Toluene diisocyanate Y S/P 2 2G Cont. Dry T1 IIA Yes C (b) Yes 15.16, 15.18,
T
D 16.2.7
15.12, 15.16,
o-Toluidine Y S/P 2 2G Cont. No Yes C T A No
15.18
15.12, 15.16,
1,2,3-Trichlorobenzene AC
X S/P 1 2G Cont. No Yes C T Yes 15.18, 16.2.7,
(molten) D
16.2.6
15.12.1,
1,1,2-Trichloroethane Y S/P 3 2G Cont. No NF R T No No
15.18.6
15.12, 15.16,
Trichloroethylene Y S/P 2 2G Cont. No T2 IIA Yes R T No No
15.18.6
AB 15.12, 15.16,
1,2,3-Trichloropropane Y S/P 2 2G Cont. No Yes C T No
D 15.18
1,1,2-Trichloro-1,2,2-
Y P 2 2G Open No NF O No No No 15.18.6
Trifluoroethane
a c d e f g h i’ i’’ i’’’ j k l n o
Tricresyl phosphate
15.12.3, 15.18,
(containing l% or more Y S/P 1 2G Cont. No T2 IIA Yes C No AB No
16.2.6
ortho-isomer)
Tricresyl phosphate
(containing less than 1% Y S/P 2 2G Open No Yes O No A No 15.19.6, 16.2.6
ortho-isomer)
15.18.6,
Tridecanoic acid Y P 2 2G Open No Yes O No A No
16.2.6, 16.2.7
F-
Triethylamine Y S/P 2 2G Cont. No T2 IIA No R AC Yes 15.12, 15.18.6
T
F- 15.12.1,
Triethyl phosphite Z S/P 3 2G Cont. No No R AB No
T 15.18.6, 16.2.7
Triisopropylated phenyl
X P 2 2G Open No Yes O No A No 15.18.6, 16.2.6
phosphates
15.11.2 to
15.11.8,
Trimethylacetic acid Y S/P 3 2G Cont. No Yes R No A No
15.18.6,
16.2.6, 16.2.7
Trimethylbenzenes (all
X P 2 2G Cont. No No R F A No 15.18.6
isomers)
Trimethylol propane AB
Z S/P 3 2G Open No - - Yes O No No
propoxylated C
2,2,4-Trimethyl-1,3-
Z P 3 2G Open No Yes O No AB No
pentanediol diisobutyrate
2,2,4-Trimethyl-1,3-
Y P 2 2G Open No Yes O No A No 15.18.6
petanediol-1-isobutyrate
2 AB 15.18.6,
Tung oil Y S/P 2G Open No - - Yes O No No
(k) C 16.2.6, 16.2.7
Urea/Ammonium nitrate
Z P 3 2G Open No Yes O No A No
solution
Urea/Ammonium nitrate
solution (containing less Z S/P 3 2G Cont. No NF R T A No 16.2.7
than 1% free ammonia)
Urea/Ammonium
Y P 2 2G Open No Yes O No A No 15.18.6
phosphate solution
a c d e f g h i’ i’’ i’’’ j k l n o
Valeraldehyde (all Ine F-
Y S/P 3 2G Cont. T3 IIB No R A No 15.4.6, 15.18.6
isomers) rt T
AB 15.18.6,
Vegetable acid oils (m) Y S/P 2 2G Open No - - -Yes O No No
C 16.2.6, 16.2.7
15.13, 15.18.6,
Vinyl acetate Y S/P 3 2G Cont. No T2 IIA No R F A No
16.16.1, 16.6.2
15.4, 15.13,
Ine F-
Vinyl ethyl ether Z S/P 2 1G Cont. T3 IIB No C A Yes 15.14, 15.18,
rt T
16.6.1, 16.6.2
15.13, 15.14,
Ine F-
Vinylidene chloride Y S/P 2 2G Cont. T2 IIA No R B Yes 15.18.6,
rt T
16.6.1, 16.6.2
15.13, 15.18.6,
Vinyl neodecanoate Y S/P 2 2G Open No Yes O No AB No
16.6.1, 16.6.2
15.18.6,
Waxes Y P 2 2G Open No Yes O No AB No
16.2.6, 16.2.7
15.18.6, 16.2.7
Xylenes Y P 2 2G Cont. No No R F A No
(h)
Xylenes/ethylbenzene
Y P 2 2G Cont. No - - No R F A No 15.18.6
(10% or more) mixture
Zinc alkyl
Y P 2 2G Open No Yes O No AB No 15.18.6, 16.2.6
dithiophosphate (C3-C14)
Notes:
a If the product to be carried contains flammable solvents such that the flashpoint does not exceed 60°C then special
electrical systems and a flammable-vapour detector should be provided.
b Although water is suitable for extinguishing open-air fires involving chemicals to which this footnote applies, water should
not be allowed to contaminate closed tanks containing these chemicals because of the risk of hazardous gas generation.
c Phosphorus, yellow or white is carried above its auto-ignition temperature and therefore flashpoint is not appropriate.
Electrical equipment requirements may be similar to those for substances with a flashpoint above 60°C.
d Requirements are based on those isomers having a flashpoint of 60°C, or less; some isomers have a flashpoint greater
than 60°C, and therefore the requirements based on flammability would not apply to such isomers.
g Confined spaces are to be tested for both formic acid vapours and carbon monoxide gas, a decomposition product.
i For mixtures containing no other components with safety hazards and where the pollution category is Y or less.
k Requirements for Ship Type identified in column e might be subject to regulation 4.1.3 of Annex II of MARPOL 73/78.
Section 18
18.1 The following are chemicals which have to certain operational requirements of Annex II
been reviewed for their safety and pollution of MARPOL 73/78.
hazards and determined not to present hazards
to such an extent as to warrant application of 18.4 Liquid mixtures which are assessed or
this Chapter. provisionally assessed under regulation 6.3 of
Annex II of MARPOL as falling into pollution
18.2 Although the chemicals listed in this category Z or OS and which do not present
Section fall outside the scope of the Chapter, it safety hazards, may be carried under the
is to be noted that some safety precautions may appropriate entry in this Section for “Noxious or
be needed for their safe transportation. Non-Noxious Liquid Substances, not otherwise
Accordingly, IRS would prescribe appropriate specified (n.o.s.)”.
safety requirements.
18.5 Explanatory notes to Table 18.1.1 are
18.3 Some chemicals are identified as falling given below:
into pollution category Z and therefore, subject
Product name The product name is to be used in the shipping document for any cargo offered for
bulk shipments. Any additional name may be included in brackets after the product
name. In some cases, the product names are not identical with the names given in
previous issues of the Code.
Pollution The letter Z means the pollution category assigned to each product under Annex II
category of MARPOL 73/78. OS means the product was evaluated and found to fall outside
the categories X, Y or Z.
Table 18.1.1
Section 19
Section 20
20.2.1 "Liquid chemical wastes" are substances, .1 notification has been sent by the
solutions or mixtures, offered for shipment, competent authority of the country of origin,
containing or contaminated with one or more or by the generator or exporter through the
constituents which are subject to the channel of the competent authority of the
requirements of this Chapter and for which no country of origin, to the country of final
direct use is envisaged but which are carried for destination; and
dumping, incineration or other methods of
disposal other than at sea. .2 the competent authority of the country of
origin, having received the written consent of
20.2.2 "Transboundary movement" means the country of final destination stating that
maritime transport of wastes from an area under the wastes will be safely incinerated or
the national jurisdiction of one country to or treated by other methods of disposal, has
through an area under the national jurisdiction of given authorization to the movement.
another country, or to or through an area not
under the national jurisdiction of any country, 20.5 Documentation
provided at least two countries are concerned by
the movement. 20.5.1 In addition to the documentation specified
in 16.2 of this Chapter, ships engaged in
20.3 Applicability transboundary movement of liquid chemical
wastes are to carry on board a waste movement
20.3.1 The requirements of this Section are document issued by the competent authority of
applicable to the transboundary movement of the country of origin.
liquid chemical wastes in bulk by seagoing ships
and are to be considered in conjunction with all
other requirements of this Chapter.
20.7 Carriage and handling of liquid chemical .2 any additional requirements of this
wastes Chapter applicable to the substance or, in
case of a mixture, its constituent presenting
20.7.1 Liquid chemical wastes are to be carried the predominant hazard.
in ships and cargo tanks in accordance with the
Section 21
End of Chapter
Chapter 4
Contents
Section
Introduction
Preamble
1 General
2 Ship Survival Capability and Cargo Tank Location
3 Ship Arrangements
4 Cargo Containment
5 Process Pressure Vessels and Liquid, Vapour and Pressure Piping Systems
6 Materials of Construction
7 Cargo Pressure/Temperature Control
8 Cargo Tank Vent Systems
9 Environmental Control
10 Electrical Arrangements
11 Fire Protection and Fire Extinguishing
12 Mechanical Ventilation in Cargo Area
13 Instrumentation (Gauging, Gas Detection)
14 Personnel Protection
15 Filling Limits for Cargo Tanks
16 Use of Cargo as Fuel
17 Special Requirements
18 Operating Requirements
19 Summary of Minimum Requirements
Introduction
IR1.3 These Rules are considered to IR2.1 The regulations for classification and the
incorporate the final text of the IGC code in full. assignment of class notations are given in Pt.1
The number of various clauses in these Rules of the Rules, to which reference is to be made.
are the same as those appearing in the IMO In general, the class notation to be assigned
code. The numbering of paragraphs which are would be "SUL Liquefied gas carrier" where
not there in the IMO code, but have been the vessel is designed and constructed primarily
included in these Rules for the purpose of for the carriage of liquefied gases in bulk in
classification have been prefixed by the letters integral, membrane or independent tanks.
'IR'.
IR2.2 Additional class notation in respect of
IR1.4 The IGC code contains requirements for following items will be assigned as appropriate:
operational matters which are not within the
scope of classification requirements and IRS - Ship Type, i.e. 1G, 2G, 2PG or 3G;
does not require these to be investigated for the
purpose of classification. However, these - Type of Tanks;
matters are the responsibility of the National
Authority or Administration responsible for - Name(s) of gas(es);
issuing the International Certificate of Fitness.
- Maximum vapour pressure (at sea and
IR1.5 For the purpose for classification the in harbor); minimum and (where
following words in the construction rules of the necessary) maximum cargo
IMO code (not in the survey regulations) have temperature;
been changed as appropriate:
- Design ambient temperatures (when the
ship is suitable for continuous service in
'Organization' to 'IRS' high and/or low temperature climatic
conditions).
'should be' to 'is to be' or 'are to be'
-
Preamble
1. The purpose of this Code is to provide an 5. Requirements for new products and their
international standard for the safe carriage conditions of carriage will be circulated as
by sea in bulk of liquefied gases and certain recommendations, on an interim basis,
other substances listed in chapter 19 of the when adopted by the Maritime Safety
Code, by prescribing the design and Committee of the Organization, prior to the
construction standards of ships involved in entry into force of the appropriate
such carriage and the equipment they amendments, under the terms of article VIII
should carry so as to minimize the risk to the of the International Convention for the
ship, to its crew and to the environment, Safety of Life at Sea, 1974.
having regard to the nature of the products
involved. 6. The Code primarily deals with ship design
and equipment. In order to ensure the safe
2. The basic philosophy is one of ship types transport of the products the total system
related to the hazards of the products must, however, be appraised. Other
covered by the Code. Each of the products important facets of the safe transport of the
may have one or more hazard properties products, such as training, operation, traffic
which include flammability, toxicity, control and handling in port, are being or will
corrosivity and reactivity. A further possible be examined further by the Organization.
hazard may arise due to the products being
transported under cryogenic or pressure 7. The development of the Code has been
conditions. greatly assisted by the work of the
International Association of Classification
3. Severe collisions or strandings could lead to Societies (IACS) and full account has been
cargo tank damage and result in taken of the IACS Unified Requirements for
uncontrolled release of the product. Such Liquefied Gas Tankers in chapter 4, 5 and
release could result in evaporation and 6.
dispersion of the product and, in some
cases, could cause brittle fracture of the 8. The development of sec.10 has been
ship's hull. The requirements in the Code greatly assisted by the relevant work of the
are intended to minimize this risk as far as International Electrotechnical Commission
practicable, based upon present knowledge (IEC).
and technology.
9. Sec.18 of the Code dealing with operation of
4. Throughout the development of the Code it liquefied gas carriers highlights the
was recognized that it must be based upon regulations in other sections that are
sound naval architectural and engineering operational in nature mentions those other
principles and the best understanding important safety features that are peculiar to
available as to the hazards of the various gas carrier operation.
products covered; furthermore that gas
carrier design technology is not only a 10. The layout of the Code is in line with the
complex technology but is rapidly evolving International Code for the Construction and
and that the Code should not remain static. Equipment of Ships Carrying Dangerous
Therefore the Organization will periodically Chemicals in Bulk (IBC Code) adopted by
review the Code taking into account both the Maritime Safety Committee at its forty-
experience and future development. eighth session.
Section 1
General
1.1.4.1 When cargo tanks contain products for .1 those listed exclusively in Sec.19 of this
which the Chapter requires a type 1G ship, Chapter; and
neither flammable liquids having a flashpoint of
60°C (closed cup test) or less nor flammable .2 one or more of the products which are
products listed in Sec.19 are to be carried in listed both in these Rules and in the
tanks located within the protective zones International Bulk Chemical Code. These
described in 2.6.1.1. products are marked with an asterisk (*) in
column "a" in the Table 19.1.1.
1.1.4.2 Similarly, when cargo tanks contain
products for which the Chapter requires a type 1.1.7.2 When a ship is intended exclusively to
2G/2PG ship, the above-mentioned flammable carry one or more of the products noted in
1.3.3.2 "Port Administration" means the 1.3.13 "Control stations" are those spaces in
appropriate authority of the country in the port of which ships' radio or main navigating equipment
which the ship is loading or unloading. or the emergency source of power is located or
where the fire recording or fire control
1.3.4 "Boiling point" is the temperature at equipment is centralized. This does not include
which a product exhibits a vapour pressure special fire control equipment which can be
equal to the atmospheric barometric pressure. most practically located in the cargo area.
1.3.5 "Breadth (B)" means the maximum 1.3.14 "Flammable products" are those
breadth of the ship, measured amidships to the identified by an "F" in column "f" in Sec.19
moulded line of the frame in a ship with metal (Table 19.1.1).
shell and to the outer surface of the hull in a ship
with shell of any other material. The breadth (B) 1.3.15 "Flammability limits" are the conditions
is to measured in metres. defining the state of fuel-oxidant mixture at
which application of an adequately strong
IR 1.3.5 For the determination of scantlings for external ignition source is only just capable of
hull construction, the breadth (B) to be taken is producing flammability in a given test apparatus.
defined in Pt.3 of the Rules.
1.3.16 "Gas carrier" is a cargo ship constructed
or adapted and used for the carriage in bulk of
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.1 a space in the cargo area which is not 1.3.18 "Gas-safe space" is a space not being a
arranged or equipped in an approved gas-dangerous space.
manner to ensure that its atmosphere is at all
times maintained in a gas-safe condition; 1.3.19 "Hold space" is the space enclosed by
the ship's structure in which a cargo
.2 an enclosed space outside the cargo area containment system is situated.
through which any piping containing the
liquid or gaseous products passes, or within 1.3.20 "Independent" means that a piping or
which such piping terminates, unless venting system, for example, is in no way
approved arrangements are installed to connected to another system and there are no
prevent any escape of product vapour into provisions available for the potential connection
the atmosphere of that space; to other systems.
.3 a cargo containment system and cargo 1.3.21 "Insulation space" is the space, which
piping; may or may not be an interbarrier space,
occupied wholly or in part by insulation.
.4.1 a hold space where cargo is carried in a
cargo containment system requiring a 1.3.22 "Interbarrier space" is the space
secondary barrier; between a primary and a secondary barrier,
whether or not completely or partially occupied
.4.2 a hold space where cargo is carried in a by insulation or other material.
cargo containment system not requiring a
secondary barrier; 1.3.23 "Length (L)" means 96 per cent of the
total length on a waterline at 85 per cent of the
.5 a space separated from a hold space, least moulded depth measured from the top of
space where cargo is carried in a cargo the keel, or the length from the foreside of the
containment system requiring a secondary stem to the axis of the rudder stock on that
barrier, by a single gas-tight steel boundary; waterline, if that be greater. In ships designed
with a rake of keel, the waterline on which this
.6 a cargo pump room and cargo compressor length is measured is to be parallel to the
room; designed waterline. The length (L) is to be
measured in metres.
.7 a zone on the open deck, or semi-
enclosed space on the open deck, within 3 IR 1.3.23 For the determination of scantlings for
[m] of any cargo tank outlet; gas or vapour hull construction, the length (L) to be taken is
outlet, cargo pipe flange, cargo valve or of defined in Pt.3 of the Rules.
entrances and ventilation openings to cargo
pump rooms and cargo compressor rooms; 1.3.24 "Machinery spaces of category A" are
those spaces and trunks to such spaces which
.8 the open deck over the cargo area and 3 contain:
[m] forward and aft of the cargo area on the
open deck upto a height of 2.4 [m] above the .1 internal combustion machinery used for
weather deck; main propulsion; or
.9 a zone within 2.4 [m] of the outer surface .2 internal combustion machinery used for
of a cargo containment system where such purposes other than main propulsion where
surface is exposed to the weather; such machinery has in the aggregate a total
power output of not less than 375 [kW]; or
.10 an enclosed or semi-enclosed space in
which pipes containing products are located. .3 any oil-fired boiler or oil fuel unit.
A space which contains gas detection
equipment complying with Cl. 13.6.5 and a 1.3.25 "Machinery spaces" are all machinery
space utilizing boil-off gas as fuel and spaces of category A and all other spaces
complying with Sec.16 are not considered containing propelling machinery, boilers, oil fuel
gas-dangerous spaces in this context; units, steam and internal combustion engines,
generators and major electrical machinery, oil
.11 a compartment for cargo hoses; or filling stations, refrigerating, stabilizing, venti-
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Page 7 of 97
___________________________________________________________________________________
lation and air-conditioning machinery, and
similar spaces; and trunks to such spaces. .1 removing spool pieces or valves and
blanking the pipe ends;
1.3.26 "MARVS" means the maximum allowable
relief valve setting of a cargo tank. .2 arrangement of two spectacle flanges in
series with provisions for detecting leakage
1.3.27 "Oil fuel unit" is the equipment used for into the pipe between the two spectacle
the preparation of oil fuel for delivery to an oil- flanges.
fired boiler, or equipment used for the
preparation for delivery of heated oil to an 1.3.33 "Service spaces" are those spaces used
internal combustion engine, and includes any oil for galleys, pantries containing cooking
pressure pumps, filters and heaters dealing with appliances, lockers, mail and specie rooms,
oil at a pressure of more than 1.8 bar gauge. store-rooms, workshops other than those
forming part of the machinery spaces and
1.3.28 "Organization" is the International similar spaces and trunks to such spaces.
Maritime Organization (IMO).
1.3.34 "SOLAS " means the International
1.3.29 "Permeability of a space" means the Convention for the Safety of Life at Sea, 1974,
ratio of the volume within that space which is as amended.
assumed to be occupied by water to the total
volume of that space. 1.3.35 "1983 SOLAS amendments" means
amendments to the 1974 SOLAS Convention
1.3.30.1 "Primary barrier" is the inner element adopted by the Maritime Safety Committee of
designed to contain the cargo when the cargo the Organization at its forty-eight session on 17
containment system includes two boundaries. June 1983 by resolution MSC.6(48).
1.3.30.2 "Secondary barrier" is the liquid- 1.3.36 "Tank cover" is the protective structure
resisting outer element of a cargo containment intended to protect the cargo containment
system designed to afford temporary system against damage where it protrudes
containment of any envisaged leakage of liquid through the weather deck and/or to ensure the
cargo through the primary barrier and to prevent continuity and integrity of the deck structure.
the lowering of the temperature of the ship's
structure to an unsafe level. Types of secondary 1.3.37 "Tank dome" is the upward extension of
barrier are more fully defined in Sec.4. a portion of the cargo tank. For below-deck
cargo containment systems the tank dome
1.3.30.3 "Recognized standards" are protrudes through the weather deck or through a
applicable international or national standards tank cover.
acceptable to the Administration or standards
laid down and maintained by an organization 1.3.38 "Toxic products" are identified by a "T"
which complies with the standards adopted by in column "f" in Sec.19 (Table 19.1.1).
the organization* which is recognized by the
Administration. 1.3.39 "Vapour pressure" is the absolute
equilibrium pressure of the saturated vapour
* (Refer to the minimum standards for above the liquid expressed in bars absolute at a
recognized organizations acting on behalf of the specified temperature.
Administration set out in Appendix 1 to the
Guidelines for the Authorization of Organizations 1.3.40 "Void space" is the enclosed space in
acting on behalf of the Administration, adopted the cargo area external to a cargo containment
by the organization by Resolution A.739(18). system, not being a hold space, ballast space,
fuel oil tank, cargo pump or compressor room,
1.3.31 "Relative density" is the ratio of the or any space in normal use by personnel.
mass of a volume of a product to the mass of an
equal volume of fresh water. 1.4 Equivalents
1.3.32 "Separate" means that a cargo piping 1.4.1 Where the Code requires that a particular
system or cargo vent system, for example, is not fitting, material, appliance, apparatus, item of
connected to another cargo piping or cargo vent equipment or type thereof is to be fitted or
system. This separation may be achieved by the carried in a ship, or that any particular provision
use of design or operational methods. is to be made, or any procedure or arrangement
Operational methods should not be used within is to be complied with, the Administration may
a cargo tank and should consist of one of the allow any other fitting, material, appliance,
following types: apparatus, item of equipment or type thereof to
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Page 8 of 97 Liquefied Gas Carriers
.4 An annual survey within 3 months before 1.5.4 Issue and endorsement of certificate
or after the anniversary date of the
International Certificate of Fitness for the 1.5.4.1 A certificate called an International
Carriage of Liquefied Gases in Bulk which Certificate of Fitness for the Carriage of
should include a general examination to Liquefied Gases in Bulk, the model form of
ensure that the structure, equipment, fittings, which is set out in the appendix to the Code,
arrangements and materials remain in all should be issued after an initial or renewal
respects satisfactory for the service for which survey to a gas carrier which complies with the
the ship is intended. Such a survey should relevant requirements of the Code.
be endorsed in the International Certificate of
Fitness for the Carriage of Liquefied Gases 1.5.4.2 The certificate issued under the
in Bulk. provisions of this clause should be available on
board for inspection at all times.
.5 An additional survey, either general or
partial according to the circumstances, 1.5.4.3 When a ship is designed and
should be made when required after an constructed under the provisions of 1.1.5,
investigation prescribed in 1.5.3.3, or International Certificates of Fitness should be
whenever any important repairs or renewals issued in accordance with the requirements of
are made. Such a survey should ensure that this clause and with the requirements of section
the necessary repairs or renewals have been 1.5 of the International Bulk Chemical Code.
effectively made, that the material and
workmanship of such repairs or renewals are 1.5.5 Issue or endorsement of certificate by
satisfactory; and that the ship is fit to proceed another Government
to sea without danger to the ship or persons
on board or without presenting unreasonable 1.5.5.1 A contracting Government may, at the
threat or harm to the marine environment. request of another Government cause a ship
entitled to fly the flag of the other state to be
1.5.3 Maintenance of conditions after survey surveyed and if satisfied that the requirements
of the Code are complied with, issue or
1.5.3.1 The condition of the ship and its authorize the issue of the certificate to the ship
equipment should be maintained to conform with and where appropriate endorse or authorize the
the provisions of the Chapter to ensure that the endorsement of the certificate on board the ship
ship will remain fit to proceed to sea without in accordance with the Code. Any certificate so
danger to the ship or persons on board or issued should contain a statement to the effect
without presenting unreasonable threat or harm that it has been issued at the request of the
to the marine environment. Government of the State whose flag the ship is
entitled to fly.
1.5.3.2 After any survey of the ship under 1.5.2
has been completed, no change should be 1.5.6 Duration and validity of the certificate
made in the structure, equipment, fittings,
arrangements and material covered by the 1.5.6.1 An International Certificate of Fitness for
survey, without the sanction of IRS, except by the Carriage of Liquefied Gases in Bulk should
direct replacement. be issued for a period specified by the
Administration which should not exceed 5 years.
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Page 10 of 97 Liquefied Gas Carriers
1.5.6.3 If a certificate is issued for a period of .1 the anniversary date shown on the certificate
less than 5 years, IRS may extend the validity of shall be amended by endorsement to a date
the certificate beyond the expiry date to the which is not more than 3 months later than the
maximum period specified in 1.5.6.1, provided date on which the survey was completed;
that the surveys referred to in regulation
1.5.2.1.3 and 1.5.2.1.4, applicable when a .2 the subsequent annual or intermediate survey
certificate is issued for a period of 5 years, are required by 1.5.2 shall be completed at the
carried out as appropriate. intervals prescribed by that section using the
new anniversary date;
1.5.6.4 If a renewal survey has been completed
and a new certificate cannot be issued or placed .3 the expiry date may remain unchanged
on board the ship before the expiry date of the provided one or more annual or intermediate
existing certificate, IRS may endorse the surveys, as appropriate, are carried out so that
existing certificate as valid fro a further period the maximum intervals between the surveys
which would not exceed 5 months from the prescribed by 1.5.2 are not exceeded.
expiry date.
1.5.6.9 The certificate should cease to be valid:
1.5.6.5 If a ship, at the time when a certificate
expires, is not in a port in which it is to be .1 If the surveys are not carried out within the
surveyed, IRS may extend the period of validity period specified by 1.5.2;
of the certificate but this extension shall be
granted only for the purpose of allowing the ship .2 Upon transfer of the ship to the flag of
to complete its voyage to the port in which it is to another State. A new certificate should only
be surveyed and then only in cases where it be issued when the Government issuing the
appears proper and reasonable to do so. No new certificate is fully satisfied that the ship
certificate will be extended for a period longer is in compliance with the requirements of
than 3 months and a ship to which an extension 1.5.3.1 and 1.5.3.2. Where a transfer occurs
is granted should not, on its arrival in the port in between Contracting Governments, the
which it is to be surveyed, be entitled by virtue of Government of the State whose flag the ship
such extension to leave that port without having was formerly entitled to fly should, if
a new certificate. When the renewal survey is requested within 3 months after the transfer
completed, the new certificate shall be valid to a has taken place, as soon as possible
date not exceeding 5 years from the date of transmit to the Administration copies of the
expiry of the existing certificate before the certificates carried by the ship before the
extension was granted. transfer and, if available, copies of the
relevant survey reports.
- cargo pump and compressor rooms; - detailed analytical calculation of hull and
tank system for independent tanks, Type B;
- cargo control rooms;
- specification of cooling-down procedure for
- cargo piping with shore connections cargo tanks;
including stern loading/discharge
arrangements and emergency cargo - arrangement and specifications of
dumping arrangement, if fitted; secondary barriers, including method for
periodically checking of tightness;
- cargo hatches, vent pipes and any other
openings to the cargo tanks; - documentation of model tests of primary
and secondary barriers of membrane tanks;
- ventilating pipes, doors and openings to
cargo pump rooms, cargo compressor - drawings and specifications of tank
rooms and other gas-dangerous spaces; insulation; and
- doors, air locks, hatches, ventilating pipes - drawing of marking plate for independent
and openings, hinged scuttles which can be tanks.
opened, and other openings to gas-safe
spaces within and adjacent to the cargo IR 1.6.4 Plans of the following piping systems
area including spaces in and below the are to be submitted for approval:
forecastle;
- drawings and specifications of cargo and
- entrances, air inlets and openings to process piping including vapour piping and
accommodation, service and control station vent lines of safety relief valves or similar
spaces; and piping, and relief valves discharging liquid
cargo from the cargo piping system;
- gas-safe spaces and zones and gas-
dangerous spaces and zones to be clearly - drawings and specifications of offsets,
identified. loops, bends and mechanical expansion
joints, such as bellows, slip joints (only
IR 1.6.3 Plans of the cargo containment system inside tank) or similar means in the cargo
with the following particulars are to be submitted piping;
for approval:
- drawings and specifications of flanges,
- drawing of cargo tanks including information valves and other fittings in the cargo piping
on non-destructive testing of welds and system. For valves intended for piping
strength and tightness testing of tanks; systems with a design temperature below -
55°C, documentation for leak test and
- drawings of support structure of functional test at design temperature (type
independent tanks; test) is required;
Indian Register of Shipping
Chapter 4 Part 5
Page 12 of 97 Liquefied Gas Carriers
- documentation of type tests for expansion - specification of tightness test of hold spaces
components in the cargo piping system; for membrane tank system;
- program for functional tests of all piping - drawings of gastight bulkhead stuffing
systems including valves, fittings and boxes;
associated equipment for handling cargo
(liquid or vapour); - arrangements and specifications of
mechanical ventilation systems for spaces
- specifications of control system for all quick- in the cargo area, giving capacity and
closing shut-off valves; location of fans and their motors. Drawings
and material specifications of rotating parts
- drawings and specifications and insulation and casings for fans and portable
for low temperature piping where such ventilators;
insulation is installed;
- drawings and specifications of protection of
- specification of electrical bonding of piping; hull steel beneath liquid piping where liquid
and leakage may be anticipated, such as at
shore connections and at pump seals;
- specification of means for removal of liquid
contents from cargo loading and discharging - arrangement and specifications of piping
crossover headers and/or cargo hoses prior system for gas freeing and purging of cargo
to disconnecting the shore connection. tanks;
IR 1.6.5 The following plans and particulars for - arrangement of piping for inerting of
the safety relief valves are to be submitted for interbarrier and hold spaces (not required
approval: for independent tanks Type C);
- drawings and specifications for safety relief - specifications of equipment for provision of
valves and pressure/vacuum relief valves dry inert gas (dry air in hold spaces
and associated vent piping; containing independent tanks Type C) for
the maintenance of an inert atmosphere in
- calculation of required cargo tank relief interbarrier and hold spaces;
valve capacity; and
- specification of instruments for
- specification of procedures for changing of measurement of oxygen content in inert
set pressures of cargo tank safety relief atmospheres;
valves if such arrangements are
contemplated. - arrangement and specifications of all
monitoring systems and devices for
IR 1.6.6 Plans of the following equipment and indicating liquid level, vapour pressure and
systems with particulars are to be submitted: temperature in the cargo tanks, interbarrier
and hold spaces;
- construction and specifications of pressure
relief systems for hold spaces, interbarrier - specifications of liquid level alarms;
spaces and cargo piping if such systems are
required; - arrangement of automatic shut-down of
cargo pump and compressors;
- bilge and drainage arrangements in cargo - drawing(s) showing location of all electrical
pump rooms, cargo compressor rooms, equipment in gas dangerous area;
cofferdams, pipe tunnels, hold spaces and
interbarrier spaces; - single line diagram for intrinsically safe
circuits; and
- drawings and specifications of inert gas
pla