Requirements Concerning. Survey and Sertification
Requirements Concerning. Survey and Sertification
Requirements Concerning. Survey and Sertification
Requirements
concerning
SURVEY
AND CERTIFICATION
CONTENTS
Z1 Annual survey of all cargo vessels and intermediate survey of tankers Rev.2 1999
covering class matters in IMO Resolution A. 413 (X1)
Z3 Periodic survey of the outside of the ship's bottom and related items Rev. 1 1996
Z8 Corrosion protection coating for salt water ballast spaces Rev. 1 1995
Z9 Corrosion protection coatings for cargo hold spaces on bulk carriers Rev. 2 1996
Z11 Mandatory ship type and Enhanced Survey Programme (ESP) notations Rev.2 2000
Z15 Hull, Structure, Equipment and Machinery Surveys of Mobile Offshore Drilling Units 1999
Z16 Periodical Surveys of Cargo Installations on ships carrying liquefied gases in bulk 1999
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2 Annual Survey
2.3 Machinery and electrical items - Paragraphs 6.2.2.7 through 6.2.2.25, except for 6.2.2.17.
2.4 Firefighting equipment - Paragraphs 5.2.2.1 through 5.2.2.9 (where requirements pertaining to
firefighting equipment are included in the Society’s Rules).
2.5 Oil tanker additional items (Deck foam and inert gas systems; steering gear; hull, machinery and
equipment) - Paragraphs 5.2.3 and 6.2.3.
2.6 Chemical tanker additional items (Steering gear, structure, equipment, fittings, arrangements, and
materials) - Paragraphs 6.2.4.1 and 12.2.2.1 through 12.2.2.18.
2.7 Gas carrier additional items (Steering gear, structure, equipment, fittings, arrangements, and
materials) - Paragraphs 6.2.4.1 and 13.2.2.1 through 13.2.2.29, except for 13.2.2.25 (fireman’s
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outfit).
3 Intermediate Survey - The Intermediate Survey is to consist of the Annual Survey items
specified above plus the following items.
3.2 Oil tanker additional items (Piping systems and cargo tanks) - Paragraphs 6.3.3.1 through 6.3.3.3.
3.3 Chemical tanker additional items (Steering gear, structure, equipment, fittings, arrangements, and
materials) - Paragraphs 6.3.4 abd 12.3.2.2 through 12.3.2.6.
3.4 Gas carrier additional items (Steering gear, structure, equipment, fittings, arrangements, and
materials) - Paragraphs 6.3.4 and 13.3.2.2 through 13.3.2.5.
Note:
UR Z1 Rev.2, May 1999 is a complete rewrite of the former versions of this UR, i.e. UR Z1(1992) and
its revision in 1994 owing to IMO Assembly Resolution A.746(18) superseding A.413(XI).
Consequently the title of UR Z1 in its original version reading as "Annual Survey of all cargo vessels and
intermediate survey of tankers covering class matters in IMCO Resolution A.413(XI)" has also been
reworded.
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Z3.1 General
Z3.1.1 The Owner should notify the Classification Society whenever the outside of ship's bottom and
related items can be examined in drydock or on a slipway.
Z3.1.2 The outside of ship's bottom and related items are to be examined on two occasions in any five
year period, but with a period not exceeding three years between examinations. Consideration may be
given at the discretion of the Classification Society to any special circumstances justifying an extension
of these intervals.
Z3.1.3 The interval between examinations of the outside of ship's bottom and related items for ships
operating in fresh water and for certain harbour or non-self-propelled craft may be greater than that given
in Z3.1.2.
Z3.1.4 The examination of the outside of ship's bottom and related items of ships may be carried out
while the ship is afloat as an In-water Survey, subject to the provisions of Z3.3, provided the interval
between two examinations in drydock or on a slipway does not exceed five years. Special consideration
should be given to ships of 15 years or over before being permitted to have such inspections.
Z3.1.5 Attention is to be given to the requirements of SOLAS, especially when shorter intervals
between examination of the ship's bottom for certain types of ships are required.
Z3.1.6 For Oil Tankers, Combination Carriers, Bulk Carriers and Chemical Tankers reference should
also be made to Z10.1, Z10.2 and Z10.3 as applicable.
Z3.2.1 When a ship is in drydock or on a slipway, it is to be placed on blocks of sufficient height and
with the necessary staging to permit the examination of elements such as shell plating including bottom
and bow plating, stern frame and rudder, sea chests and valves, propeller, etc.
Z3.2.2 The shell plating is to be examined for excessive corrosion, or deterioration due to chafing or
contact with the ground and for any undue unfairness or buckling. Special attention is to be paid to bilge
keels. Important plate unfairness or other deterioration which do not necessitate immediate repairs are to
be recorded.
Z3.2.3 Sea chests and their gratings, sea connections and overboard discharge valves and cocks and
their fastenings to the hull or sea chests are to be examined. Valves and cocks need not be opened up
more than once in a period of five years unless considered necessary by the Surveyor.
Z3.2.4 Visible parts of rudder, rudder pintles, rudder shafts and couplings and stern frame are to be
examined. If considered necessary by the Surveyor, the rudder is to be lifted or the inspection plates
removed for the examination of pintles. The clearance in the rudder bearings is to be ascertained and
recorded.
Z3.2.5 Visible parts of propeller and stern bush, are to be examined. The clearance in the stern bush
and the efficiency of the oil gland, if fitted, are to be ascertained and recorded. For controllable pitch
propellers, the Surveyor is to be satisfied with the fastenings and tightness of hub and blade sealing.
Dismantling need not to be carried out unless considered necessary by the Surveyor.
Note: IACS agreed for uniform implementation date of Rev. 1 1996 from 1 July 1996.
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Z3-1
Z3.3.2 The In-water Survey is to be carried out with the ship at light draught in sheltered water; the in-
water visibility is to be good and the hull below waterline is to be sufficiently clean to permit meaningful
examination. The Classification Society is to be satisfied with the methods of localisation of the divers
on the plating, which should make use where necessary of permanent markings on the plating at selected
points.
Z3.3.3 The In-water Survey is to be carried out by a Surveyor who is a skilled diver and trained to
carry out In-water Survey, or a qualified diver under surveillance of a Surveyor. The diver has to be
employed by a firm acceptable to the Classification Society.
Z3.3.4 When professional divers are employed, the Surveyor shall be satisfied with the method of
pictorial representation, and a good two-way communication between the Surveyor and divers is to be
provided.
Z3.3.5 If the In-water Survey reveals damage or deterioration that requires early attention, the
Surveyor may require that the ship be drydocked in order that a detailed survey can be undertaken and
the necessary repairs carried out.
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Z3-2
The scope of annual surveys of hatch covers and the specific requirements to be satisfied are listed
under Z4.4.
Z4.3 Special Surveys [*] at maximum intervals of five years. They will normally be performed as part
of the hull Special Survey and/or renewal load line survey.
The scope of Special Survey [*] of hatch covers and the specific requirements to be satisfied are
listed under Z4.5.
1. General
Checking that no unapproved changes have been made to the hatch covers, hatch coamings and
their securing and sealing devices since the last survey.
2.1 Where mechanically operated steel covers are fitted, checking the satisfactory condition of:
- hatch covers;
- tightness devices of longitudinal, transverse and intermediate cross junctions
(gaskets, gaskets lips, compression bars, drainage channels);
- clamping devices, retaining bars, cleating;
- chain or rope pulleys;
- guides;
- guide rails and track wheels;
- stoppers, etc.;
- wires, chains, gypsies, tensioning devices;
- hydraulic system essential to closing and securing;
- safety locks and retaining devices.
2.2 Where portable covers, wooden or steel pontoons are fitted, checking the satisfactory condition
of:
- wooden covers and portable beams, carriers or sockets for the portable beams, and their securing
devices;
- steel pontoons;
- tarpaulins;
- cleats, battens and wedges;
- hatch securing bars and their securing devices;
- loading pads/bars and the side plate edge
- guide plates and chocks;
- compression bars, drainage channels and drain pipes (if any)
2.3 Checking the satisfactory condition of hatch coamings plating and their stiffeners.
Note 1:
* Some member Societies use the term “Special Periodical Survey”, others use the term “Class
Renewal Survey” instead of the term “Special Survey”.
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Z4-1
Z4 2.4 Random checking of the satisfactory operation of mechanically operated hatch covers:
cont'd - stowage and securing in open condition;
- operational testing of hydraulic and power components, wires, chains, and link drives.
operational testing of hydraulic and power components, wires, chains, and link drives;
- checking the effectiveness of sealing arrangements of all hatch covers by hose testing or
equivalent as necessary;
- checking the residual thickness of coamings, steel pontoon or hatch cover plating and
Note 2: The entire text of UR Z4 is reproduced and contained in Annex of Recommendation No. 15.
Any subsequent changes to UR Z4 need to be reflected with a corresponding change to the Annex of
Recommendation No. 15.
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Z4-2
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Z5-1
Z6.3 During each survey cycle, all items are to be surveyed (and tested, where required) in regular
rotation, as far as practicable, with uniform annual share within the five-years class period.
Z6.4 The owner is entitled to fix the sequence in which the individual items of the hull are intended
to be surveyed. However, the sequence in each survey cycle shall be linked with that of the previous one
in such a way that the interval between consecutive (in two cycles) examinations of each item should not
generally exceed five years.
Z6.5 The surveyor may extend the inspection at his discretion, to other items if the inspections
carried out revealed any defects.
Z.6.6 The agreement for surveys to be carried out on a Continuous Survey System basis may be
withdrawn at discretion of the Society concerned.
NOTE: 1. Some member Societies use the term “Hull Special Periodical Survey”, others the term
“Hull Class Renewal Survey” instead of the term “Hull Special Survey”.
NOTE: 2. Ships on the Continuous Survey System are not exempt from other periodical surveys.
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Z6-1
4. Intermediate Survey
4.1 Schedule
4.2 Scope
TABLE 1
TABLE 2
Note:
1. Changes introduced in Rev.7 are to be applied by all Members and Associates from 1 July
2001.
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Z7-1
IACS Req. 1992/Rev. 7 2000
Z7
1. General
Z7 1.1 Application
cont'd
1.1.1 These requirements apply to all self-propelled vessels after construction.
1.1.3 For additional requirements for hull structure, piping systems and ballast tanks applicable to
tankers, bulk carriers and chemical tankers, refer to Z10.1, Z10.2 and Z.10.3 respectively.
1.1.4 For additional requirements applicable to cargo installations on ships carrying liquefied gases in
bulk, refer to Z16.
1.2 Definitions
1.2.1 A Ballast Tank is a tank which is being used primarily for salt water ballast.
1.2.3 A Transverse Section includes all longitudinal members such as plating, longitudinals and girders
at the deck, side, bottom, inner bottom, and longitudinal bulkhead. For transversely framed vessels, a
transverse section includes adjacent frames and their end connections in way of transverse sections.
1.2.4 Representative Spaces are those which are expected to reflect the conditions of other spaces of
similar type and service and with similar corrosion protection systems. When selecting representative
spaces, account is to be taken of the service and repair history on board and identifiable critical and/or
Suspect Areas.
1.2.5 Suspect Areas are locations showing Substantial Corrosion and/or are considered by the Surveyor
to be prone to rapid wastage.
1.2.6 Substantial Corrosion is an extent of corrosion such that assessment of corrosion pattern indicates a
wastage in excess of 75% of allowable margins, but within acceptable limits.
1.2.7 Protective Coatings are to usually be epoxy coating or equivalent. Other coating systems may be
considered acceptable as alternatives provided that they are applied and maintained in compliance with
the manufacturer’s specification.
1.2.9 A Prompt and Thorough Repair is a permanent repair completed at the time of survey to the
satisfaction of the Surveyor, therein removing the need for the imposition of any associated condition of
classification.
1.3 Repairs
1.3.1 Any damage in association with wastage over the allowable limits (including buckling, grooving,
detachment or fracture), or extensive areas of wastage over the allowable limits, which affects or, in the
opinion of the Surveyor, will affect the vessel’s structural, watertight or weathertight integrity, is to be
promptly and thoroughly (see 1.2.9) repaired. Areas to be considered include:
Z7-2
For locations where adequate repair facilities are not available, consideration may be given to allow the
Z7 vessel to proceed directly to a repair facility. This may require discharging the cargo and/or temporary
cont'd repairs for the intended voyage.
1.3.2 Additionally, when a survey results in the identification of substantial corrosion or structural
defects, either of which, in the opinion of the Surveyor, will impair the vessel’s fitness for continued
service, remedial measures are to be implemented before the ship continues in service.
2. Special Survey
2.1 Schedule
2.1.1 Special Surveys are to be carried out at 5 year intervals to renew the class certificates.
2.1.2 The first Special Survey is to be completed within 5 years from the date of initial classification
survey and thereafter within 5 years from the due date of the previous Special Survey. However, an
extension of class of 3 months maximum beyond the 5th year can be granted in exceptional
circumstances. In this case the next period of class will start from the expiry date of the Special Survey
before the extension was granted.
2.1.3 For surveys completed within 3 months before the expiry date of the Special Survey, the next
period of class will start form the expiry date of the Special Survey. For surveys completed more than 3
months before the expiry date of the Special Survey, the period of class will start from the survey
completion date.
2.1.4 The Special Survey may be commenced at the 4th Annual Survey and be progressed with a view to
completion by the 5th anniversary date. When the Special Survey is commenced prior to the 4th Annual
Survey, the entire survey is to be completed within 15 months if such work is to be credited to the
Special Survey.
2.1.5 As part of the preparation for the Special Survey, the thickness determination is to be dealt with, so
far as practicable, in connection with the 4th Annual Survey.
2.2 Scope
2.2.1 The Special Survey is to include, in addition to the requirements of the Annual Survey,
examination, tests and checks of sufficient extent to ensure that the hull, equipment and related piping are
in satisfactory condition and that the ship is fit for its intended purpose for the next five (5) year class
period, subject to proper maintenance and operation and the periodical surveys being carried out at the
due dates.
2.2.2 The examinations of the hull are to be supplemented by thickness measurements and testing as
deemed necessary, to ensure that the structural integrity remains effective and is to be sufficient to
discover Substantial Corrosion, significant deformation, fractures, damages or other structural
deterioration.
2.2.3 The Special Survey is to include examination of underwater parts per Z3.
2.2.4 The anchors and chain cables are to be ranged, examined and the required complement and
condition verified. The chain locker, holdfasts, hawse pipes and chain stoppers are to be examined and
pumping arrangements of the chain locker tested. At Special Survey No. 2 and subsequent Special
Surveys, chain cables are to gauged and renewed in cases where their mean diameter is worn below the
limits allowed by the Society.
2.2.5 All spaces including holds and their ‘tween decks where fitted; double bottom, deep, ballast, peak
and cargo tanks; pumprooms, pipe tunnels, duct keels, machinery spaces, dry spaces, cofferdams and
voids are to be internally examined including the plating and framing, bilges and drain wells, sounding,
venting, pumping and drainage arrangements. Internal examination of fuel oil, lube oil and fresh water
tanks may be specially considered.
2.2.6 Engine room structure is to be examined. Particular attention is to be given to tank tops, shell
plating in way of tank tops, brackets connecting side shell frames and tank tops, and engine room
bulkheads in way of tank top and bilge wells. Where wastage is evident or suspect, thickness
measurements are to be carried out, and renewals or repairs made when wastage exceeds allowable
limits.
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Z7-3
IACS Req. 1992/Rev. 7 2000
Z7
2.2.7 For spaces used for salt water ballast, excluding double bottom tanks, if there is no protective
Z7 coating, soft coating, or POOR protective coating condition and it is not renewed, maintenance of class is
to be subject to the spaces in question being internally examined at annual intervals. Waiver of internal
cont'd
examination at annual intervals for tanks of 12 m3 or less in size, with soft coating, may be considered.
2.2.8 When such conditions are found in salt water ballast double bottom tanks, maintenance of class
may be subject to the spaces in question being internally examined at annual intervals.
2.2.9 Boundaries of double-bottom, deep, ballast, peak, and other tanks, including holds adapted for the
carriage of salt water ballast, are to be tested with a head of liquid to the top of hatches for ballast/cargo
holds or top of air pipes for ballast or fuel oil tanks. Special consideration may be given to limit testing
of fuel oil, lube oil and fresh water tanks to representative tanks.
2.2.10 Hatch covers and coamings are to be examined to verify that no unapproved changes have been
made, that hatch covers are structurally sound and weathertight, and where mechanically operated steel
covers are fitted, satisfactory operation is to be verified.
2.2.11 Thickness measurements are to be carried out in accordance with Table 1. Additionally, any part
of the vessel where wastage is evident or suspect, the Surveyor may require thickness measurements in
order to ascertain the actual thickness of the material.
2.2.12 When thickness measurements indicate Substantial Corrosion, the number of thickness
measurements is to be increased to determine the extent of Substantial Corrosion. Table 2 may be used
as guidance for additional thickness measurements.
3. Annual Surveys
3.1 Schedule
Annual Surveys are to be held within 3 months before or after each anniversary date of the date of the
initial classification survey or the completion of the last Special Survey.
3.2 Scope
3.2.1 The survey consists of an examination for the purpose of ensuring, as far as practicable, that the
hull, equipment and related piping are maintained in a satisfactory condition.
3.2.3 Suspect Areas identified at previous Special Surveys are to be examined. Areas of substantial
corrosion identified at previous special or intermediate survey are to have thickness measurements taken.
3.2.4 In addition, where required by 2.2.7, 2.2.8, 4.2.3, or 4.2.4, internal examination of applicable salt-
water ballast spaces is to be carried out.
Thickness measurements are to be taken as considered necessary by the Surveyor.
4. Intermediate Survey
4.1 Schedule
The Intermediate Survey is to be carried out either at or between the second and third Annual Survey.
4.2 Scope
4.2.1 The scope of the second or third Annual Survey is to be extended to include the following:
4.2.1.1 For vessels over 5 years of age, a general, internal examination of representative spaces used for
salt water ballast is to be carried out. If there is no protective coating, soft coating, or POOR coating
condition, the examination is to be extended to other ballast spaces of the same type.
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Z7-4
Z7 4.2.1.2 For vessels over 10 years of age, a general, internal examination of all spaces used for salt water
ballast is to be carried out.
cont'd
4.2.2 If such examinations reveal no visible structural defects, the examination may be limited to a
verification that the protective coating remains effective.
4.2.3 For spaces used for salt water ballast, excluding double bottom tanks, if there is no protective
coating, soft coating, or POOR protective coating condition and it is not renewed, maintenance of class is
to be subject to the spaces in question being internally examined at annual intervals. Waiver of internal
examination at annual intervals for tanks of 12m3 or less in size, with soft coating, may be considered.
4.2.4 When such conditions are found in salt water ballast double bottom tanks, maintenance of class
may be subject to the spaces in question being internally examined at annual intervals.
4.2.5 In the case of dry cargo ships over 15 years old, other than bulk carriers subject to Z10.2, an
internal examination of selected cargo holds is to be carried out.
Z7-5
Z7 TABLE 1
cont'd
MINIMUM REQUIREMENTS FOR THICKNESS MEASUREMENTS
AT SPECIAL SURVEYS
Special Survey No. 1 Special Survey No. 2 Special Survey No. 3 Subsequent Special Surveys
6) Representative exposed
superstructure deck plating
(poop, bridge, and
forecastle deck).
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 modified at the discretion of the Surveyor if the protective coating
is in GOOD condition.
3. For vessels less than 100 meters in length, the number of transverse sections required at Special Survey No. 3
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 vessels more than 100 meters in length, at Special Survey No. 3, thickness measurements of exposed deck
plating within amidship 0.5 L may be required.
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Z7-6
Z7 TABLE 2
cont'd
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Z7-7
At the time of new construction, all salt water ballast spaces having boundaries formed by the hull
envelope shall have an efficient protective coating, epoxy or equivalent, applied in accordance with the
manufacturer's recommendations.
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For existing bulk carriers, where Owners may elect to coat or recoat cargo holds as noted above,
consideration may be given to the extent of the close-up and thickness measurement surveys. Prior to the
coating of cargo holds of existing vessels, scantlings are to be ascertained in the presence of a Surveyor.
Note: Revision 2, 1996 of Unified Requirements Z9 has been approved by Council for application to
new ships for which the request for class is received on or after 1 July 1998.
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Notes: 1. Revision 4, 1996 of Unified Requirements Z10.1 have been approved by Council for uniform
application from 1 January 1997.
2. Changes introduced in Rev.6 to UR Z10.1 are to be applied by all Member Societies and
Associates from 1 September 1999.
3. Changes introduced in Rev.6.1 to UR Z10.1, i.e. 2.2.1.3 are to be applied by all Member
Societies and Associates from 1 July 2000.
4. Changes introduced in Rev.7 to UR Z10.1 are to be applied by all Member Societies and
Associates from 1 July 2001.
5. Changes introduced in Rev.8 and Rev.8.1 to UR Z10.1 are to be applied by all Member Societies
and Associates from 1 July 2001.
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Z10.1
Z10.1 ENCLOSURES
Table I: Minimum requirements to Close-up Surveys at Special Survey of Oil Tankers, Ore/Oil Ships
cont'd
and etc. Z10.1-10
Table II: Minimum requirements to thickness measurements at Special Survey of Oil Tankers, Ore/Oil
Ships and etc. Z10.1-11
Table III: Minimum requirements to tank testing at Special Survey of Oil Tankers, Ore/Oil Ships etc.
Z10.1-12
Table IV: Requirements for extent of thickness measurements at those areas of substantial corrosion.
Z10.1-13-Z10.1-16
Table VII: Procedures for Certification of Firms Engaged in Thickness Gauging of Hull Structures
Z10.1-19
Annex I: Guidelines for Technical Assessment in conjunction with planning for Enhanced Surveys
of Oil Tankers Special Survey - Hull Z10.1I-1-Z10.1I-5
Annex II: Recommended Procedures for Thickness Measurements of Oil Tankers Ore/Oil
Ships and etc. Z10.1II-1-Z10.1II-24
Annex III: Criteria for Longitudinal Strength of Hull Girder for Oil Tankers
Appendix 1: Calculation criteria of section modulus of midship section of hull girder
Appendix II: Diminution limit of minimum longitudinal strength of ships in service
6. Changes introduced in Rev.9 to UR Z10.1, which come from Res MSC.105(73) and MSC.108(73), i.e.
4.2.4.3(dry-dock in intermediate survey for ships over 15 years), 8(evaluation of longitudinal strength),
Table VIII, Table IX(ii), Table (IX(v) and Annex III, are to be applied by all Member Societies and
Associates from 1 July 2002.
Changes introduced in Rev.9 to UR Z10.1, other than the above, are to be implemented by all Member
Societies and Associates within one year of the adoption by Council.
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Z10.1
1. GENERAL
Z10.1
cont'd 1.1 Application
1.1.1 The requirements apply to all self-propelled Oil Tankers after construction.
1.1.2 The requirements apply to surveys of hull structure and piping systems in way of cargo tanks,
pump rooms, cofferdams, pipe tunnels, void spaces within the cargo area and all ballast tanks. The
requirements are additional to the classification requirements applicable to the remainder of the ship.
1.1.3 The requirements contain the minimum extent of examination, thickness measurements and tank
testing. The survey is to be extended when Substantial Corrosion and/or structural defects are found and
include additional Close-up Survey when necessary.
1.2 Definitions
1.2.1 An Oil Tanker is a ship which is constructed primarily to carry oil in bulk and includes ship types
such as combination carriers (Ore/Oil ships etc.).
1.2.2 A Ballast Tank is a tank which is being used solely for water ballast or a tank which is used for
both cargo and ballast will be treated as a Ballast Tank when substantial corrosion has been found in that
tank.
1.2.3 An Overall Survey is a survey intended to report on the overall condition of the hull structure and
determine the extent of additional Close-up Surveys.
1.2.4 A Close-up Survey is a survey where the details of structural components are within the close
visual inspection range of the surveyor, i.e. normally within reach of hand.
1.2.5 A Transverse Section includes all longitudinal members such as plating, longitudinals and girders
at the deck, side, bottom, inner bottom and longitudinal bulkheads.
1.2.6 Representative Tanks are those which are expected to reflect the condition of other tanks of
similar type and service and with similar corrosion protection systems. When selecting Representative
Tanks account is to be taken of the service and repair history onboard and identifiable Critical Areas
and/or Suspect Areas.
1.2.7 Suspect Areas are locations showing Substantial Corrosion and/or are considered by the Surveyor
to be prone to rapid wastage.
1.2.8 Substantial Corrosion is an extent of corrosion such that assessment of corrosion pattern indicate
a wastage in excess of 75% of allowable margins, but within acceptable limits.
Protective Coating is to usually be epoxy coating or equivalent. Other coating systems may be
considered acceptable as alternatives provided that they are applied and maintained in compliance with
the manufacturer’s specification.
Where Soft Coatings have been applied, safe access is to be provided for the surveyor to verify the
effectiveness of the coating and to carry out an assessment of the conditions of internal structures which
may include spot removal of the coating. When safe access cannot be provided, the soft coating is to be
removed.
Note: Original 1.2.11 definition regarding “Critical Structural Areas” relocated to Annex 1.
Z10.1
1.2.11 Cargo Area is that part of the ship that contains cargo tanks, slop tanks and cargo/ballast pump-
Z10.1 rooms, cofferdams, ballast tanks and void spaces adjacent to cargo tanks and also deck areas throughout
cont'd the entire length and breadth of the part of the ship over the above mentioned spaces.
1.2.12 A Prompt and Thorough Repair is a permanent repair completed at the time of survey to the
satisfaction of the Surveyor, therein removing the need for the imposition of any associated condition of
classification.
1.3 Repairs
1.3.1 Any damage in association with wastage over the allowable limits (including buckling, grooving,
detachment or fracture), or extensive areas of wastage over the allowable limits, which affects or, in the
opinion of the Surveyor, will affect the vessel’s structural, watertight or weathertight integrity, is to be
promptly and thoroughly (see 1.2.12) repaired. Areas to be considered include:
Where adequate repair facilities are not available, consideration may be given to allow the vessel to
proceed directly to a repair facility. This may require discharging the cargo and/or temporary repairs for
the intended voyage.
1.3.2 Additionally, when a survey results in the identification of substantial corrosion or structural
defects, either of which, in the poinion of the Surveyor, will impair the vessel’s fitness for continued
service, remedial measures are to be implemented before the ship continues in service.
2. SPECIAL SURVEY 1
2.1 Schedule
2.1.1 Special Surveys are to be carried out at 5 years intervals to renew the Class Certificate.
2.1.2 The first Special Survey is to be completed within 5 years from the date of the initial classification
survey and thereafter 5 years from the credited date of the pervious Special Survey. However, an
extension of class of 3 months maximum beyond the 5th year can be granted in exceptional
circumstances.
In this case, the next period of class will start from the expiry date of the Special Survey before the
extension was granted.
2.1.3 For surveys completed within 3 months before the expiry date of the Special Survey, the next
period of class will start from the expiry date of the Special Survey. For surveys completed more than 3
months before the expiry date of the Special Survey, the period of class will start from the survey
completion date.
2.1.4 The Special Survey may be commenced at the 4th Annual Survey and be progressed with a view
to completion by the 5th anniversary date. When the Special Survey is commenced prior to the 4th
Annual Survey, the entire survey is to be completed within 15 months if such work is to be credited to
the Special Survey.
2.1.5 (void)
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1
Some member Societies use the term “Special Periodical Survey” others use the term “Class Renewal
Survey” instead of the term “Special Survey”.
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Z10.1-2
IACS Req. 1992/Rev. 9 2002
Z10.1
2.2.1.1 The Special Survey is to include, in addition to the requirements of the Annual Survey,
examination, tests and checks of sufficient extent to ensure that the hull and related piping, as required in
2.2.1.3, is in a satisfactory condition and is fit for its intended purpose for the new period of class of 5
years to be assigned, subject to proper maintenance and operation and to periodical surveys being carried
out at the due dates.
2.2.1.2 All cargo tanks, salt water Ballast Tanks including double bottom tanks, pumprooms, pipe
tunnels, cofferdams and void spaces bounding cargo tanks, decks and outer hull are to be examined, and
this examination is to be supplemented by thickness measurement and testing as deemed necessary, to
ensure that the structural integrity remains effective. The examination is to be sufficient to discover
Substantial Corrosion, significant deformation, fractures, damages or other structural deterioration.
2.2.1.3 Cargo piping on deck, including Crude Oil Washing (COW) piping, and Cargo and Ballast
piping within the above tanks and spaces are to be examined and operationally tested to working pressure
to attending Surveyor’s satisfaction to ensure that tightness and condition remain satisfactory. Special
attention is to be given to any ballast piping in cargo tanks and cargo piping in ballast tanks and void
spaces, and Surveyors are to be advised on all occasions when this piping, including valves and fittings
are open during repair periods and can be examined internally.
2.2.1.4 The survey extent of combined ballast/cargo tanks is to be evaluated based on the records of
ballast history, extent of corrosion protection system provided, and the extent of corrosion found.
2.2.2.1 A survey in dry dock is to be a part of the Special Survey. The overall and close-up surveys and
thickness measurements, as applicable, of the lower portions of the cargo tanks and water ballast tanks
are to be surveyed in accordance with the applicable requirements for special surveys, if not already
surveyed.
Where provided, the condition of the corrosion prevention system of cargo tanks is to be examined. A
ballast tank where a protective coating is found in POOR condition and it is not renewed or where soft
coating has been applied, or where a protective coating has not been applied from the time of
construction, the tank in question is to be examined at annual intervals. Thickness measurements are to
be carried out as deemed necessary by the surveyor.
2.3.1 An Overall Survey of all tanks and spaces, excluding fuel oil, lube oil and fresh water tanks, is to
be carried out at each Special Survey.
2.3.2 The minimum requirements for Close-up Surveys at Special Survey are given in Table I.
2.3.3 The Surveyor may extend the Close-up Survey as deemed necessary taking into account the
maintenance of the tanks under survey, the condition of the corrosion protection system and also in the
following cases:
a) In particular, tanks having structural arrangements or details which have suffered defects in
similar tanks or on similar ships according to available information.
b) In tanks which have structures approved with reduced scantlings due to an approved corrosion
control system.
2.3.4 For areas in tanks where coatings are found to be in a GOOD condition as defined in 1.2.10, the
extent of Close-up Surveys according to Table I may be specially considered by the Classification
Society.
2.4.1 The minimum requirements for thickness measurements at Special Survey are given in Table II.
2.4.2 Provisions for extended measurements for areas with Substantial Corrosion as defined in
1.2.8, are given in Table IV, and as may be additionally specified in the Survey Programme as required
by 5.1.
▲ ▲
Z10.1-3
Z10.1
Z10.1 2.4.3 The Surveyor may further extend the thickness measurements as deemed necessary.
cont'd
2.4.4 For areas in tanks where coating are found to be in a GOOD condition as defined in 1.2.10, the
extent of thickness measurements according to Table II may be specially considered, by the
Classification Society.
2.4.5 Transverse sections are to be chosen where the largest reductions are suspected to occur or are
revealed from deck plating measurements.
2.4.6 In cases where two or three sections are to be measured, at least one is to include a Ballast Tank
within 0.5L amidships.
2.5.1 The minimum requirements for tank testing at Special Survey are given in Table III.
2.5.2 The Surveyor may extend the tank testing as deemed necessary.
2.5.3 Tanks to be tested with a head of liquid to the top of access hatches for cargo tanks, or top of air
pipes for Ballast Tanks, if this gives a higher pressure.
3. ANNUAL SURVEY
3.1 Schedule
3.1.1 Annual Surveys are to be held within 3 months before or after anniversary date from the date of
the initial classification survey or of the date credited for the last Special Survey.
3.2 Scope
3.2.1 General
3.2.1.1 The survey is to consist of an examination for the purpose of ensuring, as far as practicable, that
the hull and piping are maintained in a satisfactory condition.
3.2.2.1 Examination of the hull plating and its closing appliances as far as can be seen.
3.2.3.1 Examination of cargo tank openings including gaskets, covers, coamings and flame screens.
3.2.3.3 Examination of flame screens on vents to all bunker, oily ballast and oily slop tanks.
3.2.3.4 Examination of cargo, crude oil washing, bunker and vent piping systems, including vent masts
and headers.
3.2.4.1 Examination of all pumproom bulkheads for signs of oil leakage or fractures and, in particular,
the sealing arrangements of all penetrations of pumproom bulkheads.
3.2.5.1 Examination of Ballast Tanks when required as a consequence of the results of the Special
▲
Z10.1-4
Survey and Intermediate Survey. When considered necessary by the surveyor, thickness measurement is
Z10.1 to be carried out and if the results of these thickness measurements indicate that Substantial Corrosion is
cont'd found, the extent of thickness measurements is to be increased in accordance with Table IV.
3.2.5.2 Oil Tankers exceeding 15 years of Age: All Ballast Tanks adjacent to (i.e. with a common plane
boundary) a cargo tank with any means of heating are to be examined internally. When considered
necessary by the surveyor, thickness measurements are to be carried out and if the results of these
thickness measurements indicate that Substantial Corrosion is found, the extent of thickness
measurements is to be increased in accordance with Table IV. Tanks or areas where coating was found
to be in GOOD condition at the previous intermediate or special survey may be specially considered by
the Classification Society.
▲
4. INTERMEDIATE SURVEY
4.1 Schedule
4.1.1 The Intermediate Survey is to be held at or between either the 2nd or 3rd Annual Survey.
4.1.2 Those items which are additional to the requirements of the Annual Surveys may be surveyed
either at or between the 2nd and 3rd Annual Survey.
4.2 Scope
4.2.1 General
4.2.1.1 The survey extent of cargo and ballast tanks dependent on the age of the vessel is specified in
4.2.2 to 4.2.4.
4.2.1.2 For weather decks, an examination as far as applicable of cargo, crude oil washing, bunker,
ballast, steam and vent piping systems as well as vent masts and headers is to be carried out. If upon
examination there is any doubt as to the condition of the piping, the piping may be required to be
pressure tested, thickness measured or both.
4.2.2.2 For tanks used for salt water ballast, an Overall Survey of Representative Tanks selected by the
Surveyor is to be carried out. If such inspections reveal no visible structural defects, the examination may
be limited to a verification that the Protective Coating remains efficient.
4.2.2.3 Where POOR Coating Condition, corrosion or other defects are found in salt water Ballast Tanks
or where a Protective Coating was not applied from the time of construction, the examination is to be
extended to other Ballast Tanks of the same type.
4.2.2.4 In salt water Ballast Tanks where a Protective Coating is found in POOR condition as defined in
1.2.10, and it is not renewed, where soft coating has been applied, or where a Protective Coating was not
applied from the time of construction, maintenance of class is to be subject to the tanks in question being
examined and thickness measurements carried out as considered necessary at annual intervals.
4.2.3.2 An Overall Survey of at least two Representative cargo Tanks is to be carried out.
4.2.3.3 For tanks used for salt water ballast including combined cargo/ballast tanks, an Overall Survey of
▲
Z10.1-5
Z10.1
Z10.1 all such tanks is to be carried out. If such survey reveal no visible structural defects, the Survey may be
limited to a verification that the Protective Coatings remain efficient.
cont'd
4.2.3.4 Extent of Close-up Survey:
For areas in tanks where coatings are found to be in GOOD condition as defined by 1.2.10, the extent of
the Close-up surveys may be specially considered by the Classification Society.
The minimum requirements for thickness measurements at the Intermediate Survey are areas found to be
Suspect Areas according to 1.2.7 at the previous Special Survey. Where substantial corrosion as defined
in 1.2.8 is found, the extent of the thickness measurements is to be increased in accordance with the
requirements of Table IV.
4.2.4.1 The requirements of the Intermediate Survey shall be to the same extent as the previous Special
Survey as required in 2 and 5.1. However, pressure testing of cargo and ballast tanks is not required
unless deemed necessary by the attending surveyor.
4.2.4.2 In application of 4.2.4.1, the intermediate survey may be commenced at the second annual
survey and be progressed during the succeeding year with a view to completion at the third annual survey
in lieu of the application of 2.1.4.
4.2.4.3 In application of 4.2.4.1, a survey in dry dock is to be part of the intermediate survey. The
overall and close-up surveys and thickness measurements, as applicable, of the lower portions of the
cargo tanks and water ballast tanks are to be surveyed in accordance with the applicable requirements for
intermediate surveys, if not already surveyed.
5.1.1 A specific Survey Programme is to be worked out in advance of the Special Survey by the Owner
in cooperation with the Classification Society. The Survey Programme is to be in a written format.
5.1.2 In developing the Survey Programme, the following documentation is to be collected and
consulted with a view to selecting tanks, areas, and structural elements to be examined:
5.1.3 The submitted Survey Programme is to account for and comply, as a minimum, with the
requirements of Tables I, II and 2.5 for close-up survey, thickness measurement and tank testing,
respectively, and is to include relevant information including at least:
▲ ▲
Z10.1-6
Z10.1
5.1.4 The Classification Society will advise the Owner of the maximum acceptable structural corrosion
diminution levels applicable to the vessel.
5.1.5 Use may also be made of the Guidelines for Technical Assessment in Conjunction with Planning
for Enhanced Surveys of Oil Tankers Special Survey - Hull, contained in Annex I. These guidelines are
a recommended tool which may be invoked at the discretion of the IACS Member Society, when
considered necessary and appropriate, in conjunction with the preparation of the required Survey
Programme.
5.2.1 The Owner is to provide the necessary facilities for a safe execution of the survey.
5.2.2 Tanks and spaces are to be safe for access, i.e. gas freed, ventilated, and illuminated.
5.2.3 Tanks and spaces are to be sufficiently clean and free from water, scale, dirt, oil residues, etc. to
reveal corrosion, deformation, fractures, damages or other structural deterioration. In particular this
applies to areas which are subject to thickness measurement.
5.3.1 For Overall Survey, means are to be provided to enable the surveyor to examine the hull structure
in a safe and practical way.
5.3.2 For Close-up Survey, one or more of the following means for access, acceptable to the Surveyor,
is to be provided:
5.4.1 Thickness measurement is normally to be carried out by means of ultrasonic test equipment. The
accuracy of the equipment is to be proven to the Surveyor as required.
5.4.2 One or more of the following fracture detection procedures may be required if deemed necessary
by the Surveyor:
– radiographic equipment
– ultrasonic equipment
– magnetic particle equipment
– dye penetrant.
5.5.1 Survey at sea or at anchorage may be accepted provided the Surveyor is given the necessary
assistance from the personnel onboard. Necessary precautions and procedures for carrying out the survey
▲ ▲
Z10.1-7
Z10.1
5.5.3 Explosimeter, oxygen-meter, breathing apparatus, life line and whistles are to be at hand during
the survey. When boats or rafts are used, appropriate life jackets are to be available for all participants.
Boats or rafts are to have satisfactory residual buoyancy and stability even if one chamber is ruptured.
A safety check-list is to be provided.
5.5.4 Surveys of tanks by means of boats or rafts may only be undertaken at the sole discretion of the
Surveyor, who is to take into account the safety arrangements provided, including weather forecasting
and ship response in reasonable sea conditions.
6. DOCUMENTATION ON BOARD
6.1 General
6.1.1 The owner is to supply and maintain on board documentation as specified in 6.2 and 6.3, which is
to be readily available for the surveyor.
6.1.2 The documentation is to be kept on board for the life time of the ship.
6.2.2 The Survey Report File is to be available also in the Owner's and the Classification Society's
management offices.
6.4.1 Prior to inspection, the Surveyor is to examine the completeness of the documentation onboard,
and its contents as a basis for the survey.
▲ ▲
Z10.1-8
Z10.1
7.1.1 The required thickness measurements, if not carried out by the Society itself, are to be witnessed
by a surveyor of the Society. The surveyor is to be on board to the extent necessary to control the
process.
7.1.2 The thickness measurement company is to be part of the survey planning meeting to be held prior
to commencing the survey.
7.2.1 The thickness measurements are to be carried out by a qualified company certified by the
Classification Society according to principles stated in Table VII.
7.3 Reporting
7.3.1 A thickness measurement report is to be prepared. The report is to give the location of
measurements, the thickness measured as well as corresponding original thickness. Furthermore, the
report is to give the date when the measurements were carried out, type of measurement equipment,
names of personnel and their qualifications and has to be signed by the operator. The thickness
measurement report is to follow the principles as specified in the Recommended Procedures for
Thickness Measurements for Oil Tankers, Ore/Oil Ships and etc., contained in Annex II.
7.3.2 The Surveyor is to verify and countersign the thickness measurements report.
8.1.1 The data and information on the structural condition of the vessel collected during the survey is to
be evaluated for acceptability and continued structural integrity of the vessel.
8.1.1.1 In case of oil tankers of 130 m in length and upwards (as defined in the International Convention
on Load Lines in force), the ship’s longitudinal strength is to be evaluated by using the thickness of
structural members measured, renewed and reinforced, as appropriate, during the special survey carried
out after the ship reached 10 years of age in accordance with the criteria for longitudinal strength of the
ship’s hull girder for oil tankers specified in Annex III.
8.1.1.2 The final result of evaluation of the ship’s longitudinal strength required in 8.1.1.1, after renewal
or reinforcement work of structural members, if carried out as a result of initial evaluation, is to be
reported as a part of the Executive Hull Summary.
8.2 Reporting
8.2.2 An Executive Hull Summary of the survey and results is to be issued to the Owner as shown in
Table IX and placed on board the vessel for reference at future surveys. The Executive Hull Summary is
to be endorsed by the Classification Society's head office or regional managerial office.
▲ ▲
Z10.1-9
cont'd
Z10.1
Z10.1
TABLE I
Table of minimum requirements to Close-up Surveys at Special Survey
of Oil Tankers, Ore/Oil Ships and etc.
SPECIAL SURVEY NO. 1 SPECIAL SURVEY NO. 2 SPECIAL SURVEY NO. 3 SPECIAL SURVEY NO. 4
AGE ≤ 5 5 < AGE ≤ 10 10 < AGE ≤ 15 AND SUBSEQUENT
AGE > 15
A) ONE WEB FRAME RING- A) ALL WEB FRAME RINGS- in a A) ALL WEB FRAME RINGS- As special survey No. 3
in a ballast wing tank, if any, ballast wing tank, if any, or a in all ballast tanks
or a cargo wing tank used cargo wing tank, used primarily
primarily for water ballast for water ballast
B) ONE DECK TRANSVERSE- B) ONE DECK TRANSVERSE- in A) ALL WEB FRAME RINGS- Additional transverses included as
in a cargo oil tank each of the remaining ballast in a cargo wing tank deemed necessary by the
tanks, if any Classification Society
D) ONE TRANSVERSE B) ONE DECK TRANSVERSE- A) ONE WEB FRAME RING- in
BULKHEAD- in a ballast tank in a cargo wing tank each remaining cargo wing tank
D) ONE TRANSVERSE B) ONE DECK TRANSVERSE- C) ALL TRANSVERSE BULKHEADS
Z10.1-10
BULKHEAD- in a cargo oil in two cargo centre tanks in all cargo and ballast tanks
wing tank
D) ONE TRANSVERSE C) BOTH TRANSVERSE E) ONE DECK AND BOTTOM
BULKHEAD- in a cargo oil BULKHEADS- in a wing ballast TRANSVERSE- in each cargo
centre tank tank, if any, or a cargo wing tank centre tank
used primarily for water ballast
D) ONE TRANSVERSE BULKHEAD- F) As considered necessary by the
in each remaining ballast tank surveyor
D) ONE TRANSVERSE BULKHEAD-
in a cargo oil wing tank
D) ONE TRANSVERSE BULKHEAD-
in two cargo centre tanks
A) Complete transverse web frame ring B) Deck transverse including C) Transverse bulkhead complete - including
including adjacent structural members. adjacent deck structural members girder system and adjacent members
D) Transverse bulkhead lower part - including E) Deck and bottom transverse including F) Additional complete transverse web frame
▲ girder system and adjacent structural members adjacent structural members ring
1. One section of deck plating 1. Within the cargo area: 1. Within the cargo area: 1. Within the cargo area:
for the full beam of the ship
within the cargo area
(in way of a ballast tank, if .1 Each deck plate .1 Each deck plate .1 Each deck plate
any, or a cargo tank used
primarily for water ballast) .2 One Transverse section .2 Two Transverse sections .2 Three Transverse sections
Z10.1-11
survey according to Table I, survey according to Table I, survey according to Table I, survey according to Table I,
for general assessment and for general assessment and for general assessment and for general assessment and
recording of corrosion pattern recording of corrosion pattern recording of corrosion pattern recording of corrosion pattern
4. Selected wind and water strakes 4. Selected wind and water strakes 4. Selected wind and water strakes
outside the cargo area outside the cargo area outside the cargo area
5. All wind and water strakes 5. All wind and water strakes
within the cargo area within the cargo area
Z10.1
▲
cont'd
Z10.1
Z10.1
TABLE III
Table of minimum requirements to tank testing
at Special Survey of Oil Tankers, Ore/Oil Ships and etc.
1. All ballast tank boundaries 1. All ballast tank boundaries 1. All ballast tank boundaries 1. All ballast tank boundaries
2. Cargo tank boundaries facing 2. Cargo tank boundaries facing 2. Cargo tank boundaries facing 2. Cargo tank boundaries facing
ballast tanks, void spaces, pipe ballast tanks, void spaces, pipe ballast tanks, void spaces, pipe ballast tanks, void spaces, pipe
tunnels, representative fuel oil tunnels, representative fuel oil tunnels, representative fuel oil tunnels, representative fuel oil
tanks, pump-rooms or tanks, pump-rooms or cofferdams tanks, pump-rooms or cofferdams tanks, pump-rooms or
cofferdams cofferdams
3. All cargo tank bulkheads which 3. All remaining cargo tank 3. All remaining cargo tank
form the boundaries of segregated bulkheads bulkheads
Z10.1-12
cargoes
▲
Z10.1
TABLE IV
Z10.1 Sheet 1
cont'd
Requirements for extent of thickness measurement at those areas of substantial corrosion. Special
Survey of Oil Tankers, Ore/Oil ships and etc. within the cargo tank length
BOTTOM STRUCTURE
1. Bottom plating Minimum of 3 bays across tank 5 point pattern for each panel
including aft bay. between longitudinals and webs
Measurements around and under
all bell mouths.
3. Bottom girders and At fore and aft transverse Vertical line of single
brackets bulkhead bracket toes and in measurements on web plating
centre of tanks with one measurement between
each panel stiffener, or a
minimum of three measurements.
Two measurements across face
flat. 5 point pattern on girder/
bhd brackets
4. Bottom transverse webs 3 webs in bays where bottom 5 points pattern over 2 square
plating measured, with metre area. Single measurements
measurements at both ends and on face flat.
middle.
Z10.1-13
Z10.1
Z10.1 TABLE IV
Sheet 2
cont'd
Requirements for extent of thickness measurement at those areas of substantial corrosion. Special
Survey of Oil Tankers, Ore/Oil Ships and etc. within the cargo tank length.
DECK STRUCTURE
3. Deck girders and brackets At fore and aft transverse Vertical line of single measure-
bulkhead, bracket toes and in ments on web plating with one
centre of tanks measurement between each panel
stiffener, or a minimum of three
measurements. Two
measurements across face flat.
5 point pattern on girder/bhd
brackets.
4. Deck transverse webs Minimum of two webs with 5 points pattern over about 2
measurements at middle and square metre areas. Single
both ends of span measurements on face flat
Z10.1-14
Z10.1
TABLE IV
Z10.1 Sheet 3
cont'd
Requirements for extent of thickness measurement at those areas of substantial corrosion. Special
Survey of Oil Tankers, Ore/Oil Ships etc. within the cargo tank length.
2. All other strakes Plating between every 3rd pair Single measurement
of longitudinals in same 3 bays
5. Longitudinals - bracket Minimum of three at top middle 5 point pattern over area of
and bottom of tank in same 3 bays bracket
6. Web frames and cross 3 webs with minimum of three 5 point pattern over about 2
ties locations on each web, square metre area, plus single
including in way of cross tie measurements on web frame
connections and cross tie face flats
▲
Z10.1-15
Z10.1
TABLE IV
Z10.1 Sheet 4
cont'd
Requirements for extent of thickness measurement at those areas of substantial corrosion. Special
Survey of Oil Tankers, Ore/Oil Ships and etc. within the cargo tank length.
3. Strakes in corrugated Plating for each change of 5 point pattern over about 1
bulkheads scantling at centre of panel square metre of plating
and at flange or fabricated
connection
6. Deep webs and girders Measurements at toe of bracket For web, 5 point pattern over
and at centre of span about 1 square metre.
3 measurements across face
flat.
7. Stringer platforms All stringers with measurements 5 point pattern over 1 square
at both ends and middle metre of area plus single
measurements near bracket
toes and on face flats
▲
Z10.1-16
Z10.1
Z10.1 TABLE V
cont'd
Ship Name:
Deck:
Bottom:
Side:
Long.
Bulkheads:
Transv.
Bulkheads:
Overdue Surveys:
Comments:
Date of Inspection:
Inspected by:
Signature:
▲
Z10.1-17
Z10.1
Z10.1 TABLE VI
cont'd
Note: Table VI is superseded by Annex I : Guidelines for Technical Assessment in conjunction with
planning for Enhanced Surveys of Oil Tankers Special Survey - Hull.
Z10.1-18
Z10.1
TABLE VII
Z10.1
cont'd
PROCEDURES FOR CERTIFICATION OF FIRMS ENGAGED IN THICKNESS
MEASUREMENT OF HULL STRUCTURES
1. Application
This guidance applies for certification of the firms which intend to engage in the thickness
measurement of hull structures of the vessels.
3. Certification
(1) Upon satisfactory results of both the audit of the firm in 2(2) and the demonstration tests in 2(3)
above, the Society will issue a Certificate of Approval as well as a notice to the effect that the
thickness measurement operation system of the firm has been certified by the Society.
In case where any alteration to the certified thickness measurement operation system of the firm is
made, such an alteration is to be immediately informed to the Society. Re-audit is made where
deemed necessary by the Society.
5. Cancellation of Approval
(2) Where the Society's surveyor found any deficiencies in the approved thickness measurement
operation systems of the firm.
(3) Where the firm failed to inform of any alteration in 4 above to the Society.
▲
Z10.1-19
Z10.1
Reporting forms are to be worked out individually by the respective Classification Societies. As a
principle the following content of reports for tanker structures is to be included as applicable for the
survey:
1.0 Type of Survey (Special Survey, Intermediate Survey, Annual Survey, Other)
3.1 Coating condition of each tank (if applicable). Identify tanks with anodes.
3.2 Structural condition of each tank:
* Identified tank found in satisfactory condition.
Otherwise identify findings which are to be corrected or recorded, such as:
* Corrosion: – Structure members
– Type of corrosion (Pitting, General)
– Extent
* Cracks (location)
* Buckling (location)
* Indents (location)
The narrative report may be supplemented by sketched/photos of damages/repairs.
3.3 Thickness measurement report endorsed by the attending class surveyor.
3.4 Evaluation result of the ship’s longitudinal strength (for oil tankers of 130m in length and upwards
and of over 10 years of age).
The structure of the reporting content may be different, depending on the report system for the respective
Societies.
▲
Z10.1-20
Z10.1
GENERAL PARTICULARS
TYPE OF CONVERSION:
a) The survey reports and documents listed below have been reviewed by the undersigned and
found to be satisfactory
c) The hull special survey has been completed in accordance with the Regulations on [date]
OFFICE DATE
OFFICE DATE
1)
2)
3)
4)
▲
5)
6)
Z10.1-21
Z10.1
- Examined
- Operationally tested
E) Thickness
measurements: – Reference to Thickness Measurement report
– Summary of where measured
– Separate form indicating the tanks/areas with Substantial
Corrosion, and corresponding
* Thickness diminution
* Corrosion pattern
H) Condition of Class/Recommendations:
j) Evaluation results of the ship’s longitudinal strength (for oil tankers of 130 m in length and
upwards and of over 10 years of age)
Z10.1-22
Z10.1
TABLE IX(iii)
Z10.1
cont'd EXTRACT OF THICKNESS MEASUREMENTS
1) Positions of 2)
substantially corroded Thickness Corrosion Remarks:
Tanks/Areas or Areas diminution [%] pattern e.g. Ref. attached
with deep pitting sketches
Remarks
1) Substantial corrosion, i.e. 75 – 100% of acceptable margins wasted
2) P = Pitting
C = Corrosion in General
Any bottom plating with a pitting intensity of 20% or more, with wastage in the substantial
corrosion range or having an average depth of pitting of 1/3 or more of actual plate thickness is to
be noted.
▲
Z10.1-23
Z10.1
1) 2) 3)
Remarks:
1)
All segregated ballast tanks and combined cargo/ballast tanks to be listed.
2)
C = Coating A = Anodes NP = No Protection
3)
Coating condition according to the following standard
If coating condition "POOR" is given, extended annual surveys are to be introduced. This is to be noted
in part G) of the Executive Hull Summary.
▲
Z10.1-24
Z10.1
1 This section applies to ships regardless of the date of construction: Transverse sectional areas of
deck flange (deck plating and deck longitudinals) and bottom flange (bottom shell plating and bottom
longitudinals) of the ship’s hull girder have been calculated by using the thickness measured, renewed or
reinforced, as appropriate, during the special survey most recently conducted after the ship reached 10
years of age, and found that the diminution of the transverse sectional area does not exceed 10% of the
as-built area, as shown in the following table:
2 This section applies to ships constructed on or after 1 July 2002: Section moduli of transverse
section of the ship’s hull girder have been calculated by using the thickness of structural members
measured, renewed or reinforced, as appropriate, during the special survey most recently conducted after
the ship reached 10 years of age in accordance with the provisions of paragraph 2.2.1.1 of Annex III, and
are found to be within their diminution limits determined by the Classification Society *, as shown in the
following table:
* The actual transverse section modulus of the hull girder of oil tankers calculated under paragraph
2.2.1.1 of Annex III to UR Z10.1 is not to be less than 90% of the required section modulus for
new buildings specified in IACS Unified Requirements S7* or S11, whichever is the greater.
Z10.1-25
Notes
Z10.1
cont'd *1 Zact means the actual section moduli of the transverse section of the ship's hull girder
calculated by using the thickness of structural members measured, renewed or
reinforced, as appropriate, during the special survey, in accordance with
the provisions of paragraph 2.2.1.1 of Annex III.
*2 Zreq means diminution limit of the longitudinal bending strength of ships, as calculated
in accordance with the provisions of paragraph 2.2.1.1 of Annex III.
3 This section applies to ships constructed before 1 July 2002: Section moduli of transverse section
of the ship’s hull girder have been calculated by using the thickness of structural members measured,
renewed or reinforced, as appropriate, during the special survey most recently conducted after the ship
reached 10 years of age in accordance with the provisions of paragraph 2.2.1.2 of Annex III, and found to
meet the criteria required by the Classification Society and that Zact is not less than Zmc (defined in *2
below) as specified in appendix 2 to Annex III, as shown in the following table:
Describe the criteria for acceptance of the minimum section moduli of the ship's hull girder for
ships in service required by the Classification Society.
Notes:
*2 Zmc means the diminution limit of minimum section modulus calculated in accordance with
provisions of paragraph 2.2.1.2 of Annex III.
▲
Z10.1-26
Z10.1 Annex I
Z10.1 ANNEX I
cont'd
GUIDELINES FOR TECHNICAL ASSESSMENT IN CONJUNCTION WITH
PLANNING FOR ENHANCED SURVEYS OF OIL TANKERS
SPECIAL SURVEY - HULL
Contents:
1. INTRODUCTION
2. PURPOSE AND PRINCIPLES
2.1 Purpose
2.2 Minimum Requirements
2.3 Timing
2.4 Aspects to be Considered
3. TECHNICAL ASSESSMENT
3.1 General
3.2 Methods
3.2.1 Design Details
3.2.2 Corrosion
3.2.3 Locations for Close-up Survey and Thickness Measurement
REFERENCES
1. IACS Unified Requirement Z10.1, "Hull Surveys of Oil Tankers."
2.TSCF, "Guidance Manual for the Inspection and Condition Assessment of Tanker Structures, 1986."
3.TSCF, "Condition Evaluation and Maintenance of Tanker Structures, 1992."
1.0 INTRODUCTION
These guidelines contain information and suggestions concerning technical assessments which may be of
use in conjunction with the planning of enhanced special surveys of oil tankers. As indicated in section
5.1.5 of IACS Unified Requirement Z10.1, "Hull Surveys of Oil Tankers," (Ref. 1), the guidelines are a
recommended tool which may be invoked at the discretion of an IACS Member Society, when
considered necessary and appropriate, in conjunction with the preparation of the required Survey
Programme.
2.1 Purpose
The purpose of the technical assessments described in these guidelines is to assist in identifying critical
structural areas, nominating suspect areas and in focusing attention on structural elements or areas of
structural elements which may be particularly susceptible to, or evidence a history of, wastage or
damage. This information may be useful in nominating locations, areas and tanks for thickness
measurement, close-up survey and tank testing.
Critical Structural Areas are locations which have been identified from calculations to require monitoring
or from the service history of the subject ship or from similar or sister ships (if available) to be sensitive
to cracking, buckling or corrosion which would impair the structural integrity of the ship.
2.3 Timing
As with other aspects of survey planning, the technical assessments described in these guidelines are to
be worked out by the Owner or operator in cooperation with the Classification Society well in advance of
the commencement of the Special Survey, i.e., prior to commencing the survey and normally at least 12
to 15 months before the survey's completion due date.
▲
Z10.1I-1
Z10.1 Annex I
3.1 General
There are three basic types of possible failure which may be the subject of technical assessment in
connection with planning of surveys; corrosion, cracks and buckling. Contact damages are not normally
covered by the survey plan since indents are usually noted in memoranda and assumed to be dealt with as
a normal routine by Surveyors.
Technical assessments performed in conjunction with the survey planning process are, in principle to be
as shown schematically in Figure 1 depicts, schematically, how technical assessments can be carried out
in conjunction with the survey planning process.
The approach is basically an evaluation of the risk based on the knowledge and experience related to
design and corrosion.
The design is to be considered with respect to structural details which may be susceptible to buckling or
cracking as a result of vibration, high stress levels or fatigue.
Corrosion is related to the ageing process, and is closely connected with the quality of corrosion
protection at newbuilding, and subsequent maintenance during the service life. Corrosion may also lead
to cracking and/or buckling.
3.2 Methods
This information may be found in the survey reports and/or the Owner's files, including the results of the
Owner's own inspections. The defects should be analyzed, noted and marked on sketches.
In addition, general experience is to be utilized. For example, reference should be made to TSCF's
"Guidance Manual for the Inspection and Condition Assessment of Tanker Structures," (Ref. 2), which
contains a catalogue of typical damages and proposed repair methods for various tanker structural details.
Such figures are to be used together with a review of the main drawings, in order to compare with the
actual structure and search for similar details which may be susceptible to damage. An example is shown
in Figure 2.
The review of the main structural drawings, in addition to using the above mentioned figures, should
include checking for typical design details where cracking has been experienced. The factors
contributing to damage are to be carefully considered.
The use of high tensile steel (HTS) is an important factor. Details showing good service experience
where ordinary, mild steel has been used may be more susceptible to damage when HTS, and its higher
associated stresses, are utilized. There is extensive and, in general, good experience, with the use of HTS
for longitudinal material in deck and bottom structures. Experience in other locations, where the
dynamic stresses may be higher, is less favorable, e.g. side structures.
▲
Z10.1I-2
Z10.1 Annex I
Z10.1 In this respect, stress calculations of typical and important components and details, in accordance with
the latest Rules or other relevant methods, may prove useful and are to be considered.
cont'd The selected areas of the structure identified during this process are to be recorded and marked on the
structural drawings to be included in the Survey Programme.
3.2.2 Corrosion
In order to evaluate relative corrosion risks, the following information is generally to be considered:
- Usage of Tanks and Spaces
- Condition of Coatings
- Condition of Anodes
- Cleaning Procedures
- Previous Corrosion Damage
- Ballast use and time for Cargo Tanks
- Corrosion Risk Scheme (See Ref. 3, Table 3.1)
- Location of Heated Tanks
Ref. 3 gives definitive examples which can be used for judging and describing coating condition, using
typical pictures of conditions.
The evaluation of corrosion risks is to be based on information in Ref. 3, together with relevant
information on the anticipated condition of the ship as derived from the information collected in order to
prepare the Survey Programme and the age of the ship.
The various tanks and spaces are to be listed with the corrosion risks nominated accordingly.
On the basis of the table of corrosion risks and the evaluation of design experience, the locations for
initial close-up survey and thickness measurement (sections) may be nominated.
The sections subject to thickness measurement are to normally be nominated in tanks and spaces where
corrosion risk is judged to be the highest.
The nomination of tanks and spaces for close-up survey should, initially, be based on highest corrosion
risk, and should always include ballast tanks. The principle for the selection is to be that the extent is
increased by age or where information is insufficient or unreliable.
Z10.1I-3
Z10.1 Annex I
Input:
Z10.1 Drawings, Reports, Coating Condition
cont'd Acceptable Corrosion Collection of Information Anode Condition
Allowance Usage of Tanks
Analyse Hull
Damage for Corrosion Damage
Similar Ships This Ship
Where Available
Corrosion Damage
Hull Damage : Similar Ship where
General Experience Available
Survey Programme
Acceptance by
Class & Owner
Survey
Z10.1I-4
Z10.1 Annex I
SHELL PLATING
OR LONGITUDINAL FLAT BAR
BULKHEAD STIFFENER
A A A A
FRACTURED
WELD/WEB ★
FRACTURE
LUG
★
FRACTURE
X
1. Asymmetrical connection of flat bar stiffener resulting in high peak stresses at the heel of
the stiffener under fatigue loading.
2. Insufficient area of connection of longitudinal to web plate.
4. High localised corrosion at areas of stress concentration such as flat bar stiffener connections,
corners of cut-out for the longitudinal and connection of web to shell at cut-outs.
Z10.1I-5
IACS Req. 1994, Rev. 9 2002
Z10.1 Annex II
Z10.1
cont'd
ANNEX II
Z10.1II-1
Z10.1 Annex II
Z10.1 CONTENTS
cont'd
Sheet 1 - Contents
Sheet 2 - Instructions
REPORTS
Sheet 4 - Report TM1-T for recording the thickness measurements of all deck plating, all
bottom shell plating and side shell plating
Sheet 5 - Report TM2-T (i) for recording the thickness measurement of shell and deck
plating at transverse sections - strength deck and sheerstrake plating
Sheet 6 - Report TM2-T (ii) for recording the thickness measurement of shell and deck
plating at transverse sections - shell plating
Sheet 7 - Report TM3-T for recording the thickness measurement of longitudinal members
at transverse sections
Sheet 9 - Report TM5-T for recording the thickness measurement of W.T./O.T. transverse
bulkheads
GUIDANCE
Sheet 11 - Oil tanker typical transverse sections. The diagram includes details of the items
to be measured and the report forms to be used.
Sheet 12 - Ore/Oil ship typical transverse section. The diagram included details of the items
to be measured and the report forms to be used.
Sheet 13 - Transverse section outline. The diagram may be used for those ships where the
diagrams on sheet 11 and sheet 12 are not suitable
Sheet 14 - Oil tank and Ore/Oil Ship, diagrams showing the typical longitudinal members in
a transverse section
Sheet 15 - Transverse sections of oil tankers and ore/oil ships showing typical areas for
thickness measurement in association with close-up survey requirements
Z10.1II-2
Z10.1 Annex II
Z10.1 INSTRUCTIONS
cont'd
3. The remaining sheets 11-15 are guidance diagrams and notes relating
to the reporting forma and the procedure for the thickness
measurements.
Z10.1II-3
Z10.1 Annex II
IMO Number:-
Port of registry:-
Gross tons:-
Deadweight:-
Date of build:-
Classification society:-
____________________________________________________________________________________
Certificate No.
Place of measurement
Qualification of operator:-
____________________________________________________________________________________
* Delete as appropriate
Z10.1II-4
cont'd
Z10.1
TM1–T Report on THICKNESS MEASUREMENT of ALL DECK PLATING, ALL BOTTOM SHELL PLATING or SIDE SHELL PLATING*
( * – delete as appropriate)
Ship's name.................................................... Class Identity No. ................................................................ Report No. .........................................................
STRAKE
POSITION
No. Org. Forward Reading Aft Reading Mean Diminution Maximum
Allowable
PLATE or Thk. Gauged Diminution P Diminution S Gauged Diminution P Diminution S % Diminution
POSITION
Letter mm P S mm % mm % P S mm % mm % P S mm
12th forward
11th
10th
9th
8th
7th
6th
5th
4th
3rd
2nd
Z10.1II-5
1st
Amidships
1st aft
2nd
3rd
4th
5th
6th
7th
8th
9th
10th
11th
12th
Z10.1 NOTES
cont'd
B- All keel, bottom shell plating and bilge plating within the cargo area.
C- Side shell plating including selected wind and water strakes outside cargo area.
2.1 For strength deck indicate the number of the strake of plating inboard from the stringer
plate.
2.2 For bottom plating indicate the number of the strake of plating outboard from the keel
plate.
2.3 For side shell plating give number of the strake of plating below sheerstrake and letter
as shown on shell expansion.
3. For oil tankers all deck plating strakes are to be recorded, for ore/oil ships only the deck plating
strakes outside line of openings are to be recorded.
4. Measurements are to be taken at the forward and aft areas of all and where plates cross
ballast/cargo tank boundaries separate measurements for the area of plating in way of each type of
tank are to be recorded.
5. The single measurements recorded are to represent the average of multiple measurements.
Z10.1II-6
cont'd
Z10.1
TM2–T (i) Report on THICKNESS MEASUREMENT OF SHELL AND DECK PLATING (one, two or three transverse sections)
FIRST TRANSVERSE SECTION AT FRAME SECOND TRANSVERSE SECTION AT FRAME THIRD TRANSVERSE SECTION AT FRAME
NUMBER NUMBER NUMBER
Org. Max. Diminution Diminution Org. Max. Diminution Diminution Org. Max. Diminution Diminution
No. Thk. Alwb. Gauged P S No. Thk. Alwb. Gauged No. Thk. Alwb. Gauged P S
STRAKE Dim. P S Dim.
or Dim. or or
POSITION
Letter mm mm
P S mm % mm % Letter mm mm S mm % mm % Letter mm mm P S mm % mm %
P
Stringer Plate
1st strake inboard
2nd
3rd
4th
5th
Z10.1II-7
6th
7th
8th
9th
10th
11th
12th
13th
14th
centre strake
sheer strake
TOPSIDE
TOTAL
Z10.1
cont'd NOTES
One, two or three sections within the cargo area comprising of the structural items (1), (2) and
(3) as shown on the diagrams of typical transverse sections.
2 For oil tankers all deck plating strakes are to be recorded and for ore/oil ships only the deck
plating strakes outside the line of openings are to be recorded.
3. The topside area comprises deck plating, stringer plate and sheerstrake (including rounded
gunwales).
5. The single measurements recorded are to represent the average of multiple measurements.
Z10.1II-8
cont'd
Z10.1
TM2–T (ii) Report on THICKNESS MEASUREMENT OF SHELL AND DECK PLATING (one, two or three transverse sections)
SHELL PLATING
FIRST TRANSVERSE SECTION AT FRAME SECOND TRANSVERSE SECTION AT FRAME THIRD TRANSVERSE SECTION AT FRAME
NUMBER NUMBER NUMBER
Org. Max. Diminution Diminution Org. Max. Diminution Diminution Org. Max. Diminution Diminution
No. Thk. Alwb. Gauged P S No. Thk. Alwb. Gauged No. Thk. Alwb. Gauged P S
STRAKE Dim. P S Dim.
or Dim. or or
POSITION
Letter mm mm
P S mm % mm % Letter mm mm S mm % mm % Letter mm mm P S mm % mm %
P
1st below sheer strake
2nd
3rd
4th
5th
6th
7th
8th
Z10.1II-9
9th
10th
11th
12th
13th
14th
15th
16th
17th
18th
19th
20th
keel strake
BOTTOM TOTAL
Z10.1 NOTES
cont'd
One, two or three sections within the cargo area comprising of the structural items (4), (5) and
(6) and (7) as shown on the diagrams of typical transverse sections.
4. The single measurements recorded are to represent the average of multiple measurements.
Z10.1II-10
cont'd
Z10.1
TM3-T Report on THICKNESS MEASUREMENT OF LONGITUDINAL MEMBERS (one, two or three transverse sections)
FIRST TRANSVERSE SECTION AT FRAME SECOND TRANSVERSE SECTION AT FRAME THIRD TRANSVERSE SECTION AT FRAME
NUMBER NUMBER NUMBER
Org. Max. Diminution Diminution Org. Max. Diminution Diminution Org. Max. Diminution Diminution
Item Thk. Alwb. Gauged P S Item Thk. Alwb. Gauged Item Thk. Alwb. Gauged P S
STRUCTURAL Dim. P S Dim.
No. Dim. No. No.
MEMBER
mm mm P S mm % mm % mm mm P S mm % mm % mm mm P S mm % mm %
Z10.1II-11
Operators Signature...................................................................... Surveyors Signature .................................................................................... NOTES – See Reverse
NOTES
Z10.1
cont'd
One, two or three sections within the cargo area comprising of the appropriate structural items
(8) to (20) as shown on the diagrams of typical transverse sections.
3. The single measurements recorded are to represent the average of multiple measurements.
Z10.1II-12
cont'd
Z10.1
Report on THICKNESS MEASUREMENT OF TRANSVERSE STRUCTURAL MEMBERS
TM4–T In the cargo oil and water ballast tanks within the cargo tank length
TANK DESCRIPTION:
LOCATION OF STRUCTURE:
Max.
Original Diminution Diminution
Alwb. Gauged
STRUCTURAL MEMBER ITEM Thickness Dim.
P S
mm mm P S mm % mm %
Z10.1II-13
Operators Signature.............................................................. Surveyors Signature .......................................................................... NOTES – See Reverse
Z10.1 Annex II - Sheet 8
Z10.1 Annex II
Z10.1 NOTES
cont'd
1. This report is to be used for recording the thickness measurements of transverse structural
members, comprising of the appropriate structural items (25) to (33) as shown on diagrams of
typical transverse section.
3. The single measurements recorded are to represent the average of multiple measurements.
Z10.1II-14
cont'd
Z10.1
TM5-T Report on THICKNESS OF W.T./O.T TRANSVERSE BULKHEADS
within the cargo tank or cargo hold spaces
TANK/HOLD DESCRIPTION:
Z10.1II-15
Operators Signature.............................................................. Surveyors Signature .......................................................................... NOTES – See Reverse
Z10.1 Annex II - Sheet 9
Z10.1 Annex II
Z10.1 NOTES
cont'd
1. This report is to be used for recording the thickness measurement of W.T./O.T. transverse
bulkheads.
3. The single measurements recorded are to represent the average of multiple measurements.
Z10.1II-16
cont'd
Z10.1
Report on THICKNESS MEASUREMENT OF MISCELLANEOUS STRUCTURAL MEMBERS
LOCATION OF STRUCTURE:
Z10.1II-17
Operators Signature.............................................................. Surveyors Signature .......................................................................... NOTES – See Reverse
Z10.1 Annex II - Sheet 10
Z10.1 Annex II
Z10.1 NOTES
cont'd
1. This report is to be used for recording the thickness measurement of miscellaneous structural
members including the structural items (36), (37) and (38).
2. The single measurements recorded are to represent the average of multiple measurements.
Z10.1II-18
Z10.1 Annex II - Sheet 11
Z10.1
cont'd
Oil tanker - Typical transverse section indication longitudinal and transverse members
9
1 8
9
8 9
2
3
25
27
10
11
29 29
32
31
17
32
4
16 17
32
29 29
18
32 15
14 13 13
13
30 26
5 7
12
12 6
Z10.1II-19
Z10.1 Annex II - Sheet 12
Oil/Ore Ship - Typical transverse section indication longitudinal and transverse members
Z10.1
cont'd
1
2 8
9 36
3
9
10 25
11
27
29
28
32
4 32
18
31
32 17
16
32
28
19
30 29 15 20
14
13
33
7
12
12
Z10.1II-20
Z10.1 Annex II - Sheet 13
Z10.1II-21
Z10.1 Annex II - Sheet 14
Oil Tanker
Ore/oil Ship
Z10.1II-22
Z10.1 Annex II - Sheet 15
C C
B B
Girder
E Girder
Girder
A D
D
D
Lower stool
Z10.1II-23
Z10.1 Annex III
Z10.1
cont'd
ANNEX III
Z10.1 III-1
Z10.1 Annex III
1 General
1.1 These criteria are to be used for the evaluation of longitudinal strength of the ship's hull girder as
required by section 8.1.1.1.
1.2 In order that ship’s longitudinal strength to be evaluated can be recognized as valid, fillet welding
between longitudinal internal members and hull envelopes are to be in sound condition so as to keep
integrity of longitudinal internal members with hull envelopes.
On oil tankers of 130 m in length and upwards and of over 10 years of age, the longitudinal strength of
the ship's hull girder is to be evaluated in compliance with the requirements of this annex on the basis of
the thickness measured, renewed or reinforced, as appropriate, during the special survey.
2.1 Calculation of transverse sectional areas of deck and bottom flanges of hull girder
2.1.1 The transverse sectional areas of deck flange (deck plating and deck longitudinals) and bottom
flange (bottom shell plating and bottom longitudinals) of the ship’s hull girder are to be calculated by
using the thickness measured, renewed or reinforced, as appropriate, during the special survey.
2.1.2 If the diminution of sectional areas of either deck or bottom flange exceeds 10 % of their
respective as-built area (i.e. original sectional area when the ship was built), either one of the following
measures is to be taken:
.1 to renew or reinforce the deck or bottom flanges so that the actual sectional area is not
less than 90% of the as-built area; or
.2 to calculate the actual section moduli (Zact) of transverse section of the ship’s hull
girder by applying the calculation method specified in appendix 1, by using the
thickness measured, renewed or reinforced, as appropriate, during the
special survey.
2.2.1 The actual section moduli of transverse section of the ship’s hull girder calculated in accordance
with the foregoing paragraph 2.1.2.2 is to satisfy either of the following provisions, as applicable:
.1 for ships constructed on or after 1 July 2002, the actual section moduli (Zact) of the
transverse section of the ship's hull girder calculated in accordance with the
requirements of the foregoing paragraph 2.1.2.2 is not to be less than the
diminution limits determined by the Classification Society *; or
.2 for ships constructed before 1 July 2002, the actual section moduli (Zact) of the
transverse section of the ship's hull girder calculated in accordance with the
requirements of the foregoing paragraph 2.1.2.2 is to meet the criteria for
minimum section modulus for ships in service required by the Classification Society,
provided that in no case Zact is to be less than the diminution limit of the
minimum section modulus (Zmc) as specified in appendix 2.
* The actual transverse section modulus of the hull girder of oil tankers calculated under paragraph
2.2.1.1 of Annex III to UR Z10.1 is not to be less than 90% of the required section modulus for
new buildings specified in IACS Unified Requirements S7* or S11, whichever is the greater.
Z10.1 III-2
Z10.1 Annex III
APPENDIX 1
1 When calculating the transverse section modulus of the ship's hull girder, the sectional area of all
continuous longitudinal strength members is to be taken into account.
2 Large openings, i.e. openings exceeding 2.5m in length or 1.2m in breadth and scallops, where
scallop welding is applied, are always to be deducted from the sectional areas used in the section
modulus calculation.
3 Smaller openings (manholes, lightening holes, single scallops in way of seams, etc.) need not be
deducted provided that the sum of their breadths or shadow area breadths in one transverse section does
not reduce the section modulus at deck or bottom by more than 3% and provided that the height of
lightening holes, draining holes and single scallops in longitudinals or longitudinal girders does not
exceed 25% of the web depth, for scallops maximum 75mm.
4 A deduction-free sum of smaller opening breadths in one transverse section in the bottom or deck
area of 0.06(B - ∑b) (where B = breadth of ship, ∑b = total breadth of large openings) may be considered
equivalent to the above reduction in sectional modulus.
5 The shadow area will be obtained by drawing two tangent lines with an opening angle of 30˚.
8 Continuous trunks and longitudinal hatch coamings are to be included in the longitudinal sectional
area provided they are effectively supported by longitudinal bulkheads or deep girders. The deck
modulus is then to be calculated by dividing the moment of inertia by the following distance, provided
this is greater than the distance to the deck line at side:
yt = y 0.9 + 0.2
x
B
where:
Z10.1 III-3
Z10.1 Annex III
Z10.1 APPENDIX 2
cont'd DIMINUTION LIMIT OF MINIMUM LONGITUDINAL STRENGTH
OF SHIPS IN SERVICE
1 The diminution limit of the minimum section modulus ( Zmc) of oil tankers in service is given by
the following formula:
2 3
Zmc = cL B ( Cb + 0.7)k (cm )
where
L = Length of ships. L is the distance, in meters, on the summer load waterline from the
fore side of stem to the after side of the rudder post, or the centre of the rudder stock if
there is no rudder post. L is not to be less than 96%, and need not be greater than 97%,
of the extreme length on the summer load waterline. In ships with unusual stern and
bow arrangement the length L may be specially considered.
c = 0.9 cn
L - 300
1.5
L - 350
1.5
k = 1.0 for mild steel with yield stress of 235N/mm2 and over;
k = 0.78 for high tensile steel with yield stress of 315N/mm2 and over,
k = 0.72 for high tensile steel with yield stress of 355N/mm2 and over.
2 Scantlings of all continuous longitudinal members of the ship's hull girder based on the section
modulus requirement in 1 above are to be maintained within 0.4 L amidships. However, in special cases,
based on consideration of type of ship, hull form and loading conditions, the scantlings may be gradually
reduced towards the end of 0.4 L part, bearing in mind the desire not to inhibit the ship’s loading
flexibility.
3 However, the above standard may not be applicable to ships of unusual type or design, e.g. for
ships of unusual main proportions and/or weight distributions.
-----
▲
▲
Z10.1 III-4
IACS Req. /Rev. 9 2002
Z10.2
4. Intermediate Survey
4.1 Schedule
4.2 Scope
4.2.1 General
4.2.2 Bulk Carriers 5-10 Years of Age
4.2.3 Bulk Carriers 10-15 Years of Age
4.2.4 Bulk Carriers exceeding 15 Years of Age
6. (void)
7. Documentation On Board
7.1 General
7.2 Survey Report File
7.3 Supporting Documents
7.4 Review of Documentation
Notes:
1 .Revisions 4, 5 & 6 1996 of Unified Requirements Z10.2 have been approved by Council for
application as soon as possible but not later than 1 January 1997.
2. Changes introduced in Revision 8, 1998 of UR Z10.2, i.e. 1.1.4 and 2.4.1 and columns for Special
Surveys Nos. 3 and 4 of Table II as well as Annex III should be applied by all Member societies
and Associates not later than 1 July 1998.
▲
Z10.2 ENCLOSURES:
cont'd Table I: Minimum Requirement for Close-up Survey at Special Hull Surveys
of Bulk Carriers
Annex I: IACS Guidelines for Technical Assessment in conjunction with planning for
Enhanced Survey for Bulk Carriers
Annex III: Guidelines for the Gauging of the Vertically Corrugated Transverse Watertight Bulkhead
between Holds Nos. 1 and 2
Annex IV: Additional annual survey requirements for the foremost cargo hold of ships subject to
SOLAS XII/9.1
Notes:
3. Changes introduced in Rev.9 to UR Z10.2 are to be applied by all Member Societies and Associates
from 1 September 1999.
4. Changes introduced in Rev.10 to UR Z10.2 are to be applied by all Member Societies and
Associates from 1 July 2001.
6. Changes introduced in Rev.11 & Rev.11.1 to UR Z10.2 are to be applied by all Member Societies
▲
1. GENERAL
Z10.2
cont'd 1.1 Application
1.1.1 The requirements apply to all self-propelled Bulk Carriers after construction.
1.1.2 The Requirements apply to surveys of hull structure and piping systems in way of the cargo holds,
cofferdams, pipe tunnels, void spaces within the cargo area and all ballast tanks. The requirements are
additional to the classification requirements applicable to the remainder of the ship.
1.1.3 The requirements contain the minimum extent of examination, thickness measurement and tank
testing. The survey is to be extended when Substantial Corrosion and/or structural defects are found and
include additional Close-Up Survey when necessary.
1.1.4 Ships which are required to comply with UR S19 are subject to the additional thickness
measurement guidance contained in Annex III with respect to the vertically corrugated transverse
watertight bulkhead between cargo holds Nos. 1 and 2 for purposes of determining compliance with UR
S19 prior to the relevant compliance deadline stipulated in UR S23 and at subsequent special surveys for
purposes of verifying continuing compliance with UR S19.
1.2 Definitions
1.2.1 A Bulk Carrier is a ship which is constructed generally with single deck, topside tanks and hopper
side tanks in cargo spaces, and it intended primarily to carry dry cargo in bulk and includes such types as
ore carriers and combination carriers1.
1.2.2 A Ballast Tank is a tank which is being used primarily for salt water ballast.
1.2.4 An Overall Survey is a survey intended to report on the overall conditions of the hull structure
and determine the extent of additional Close-Up Surveys.
1.2.5 A Close-Up Survey is a survey where the details of structural components are within the close
visual inspection range of the surveyor i.e. normally within reach of hand.
1.2.6 A Transverse Section includes all longitudinal members such as plating, longitudinals and girders
at the deck, side, bottom; inner bottom and hopper side plating, longitudinal bulkhead and bottom plating
in top wing tanks.
1.2.7 Representative Spaces are those which are expected to reflect the condition of other Spaces
of similar type and service and with similar corrosion protection systems. When selecting
Representative Spaces account is to be taken of the service and repair history on board and identifiable
Critical and/or Suspect Areas.
1.2.8 Suspect Areas are locations showing Substantial Corrosion and/or are considered by the Surveyor
to be prone to rapid wastage.
1.2.9 Substantial Corrosion is an extent of corrosion such that assessment of corrosion pattern indicates
a wastage in excess of 75% of allowable margins, but within acceptable limits.
Protective coating is to usually be epoxy coating or equivalent. Other coating systems may be considered acceptable as
alternatives provided that they are applied and maintained in compliance with the manufacturer’s specifications.
Where soft coatings have been applied, safe access is to be provided for the surveyor to verify the effectiveness of the
coating and to carry out and to out an assessment of the conditions of internal structures which may include spot
removal of the coating. When safe access cannot be provided, the soft coating is to be removed.
1. For combination carrier additional requirements are specified Unified Requirements for Enhanced Surveys
▲
of Oil Tankers.
Z10.2-1
IACS Req. 1992/Rev. 11 2000
Z10.2
1.2.12 Cargo Length Area is that part of the ship which includes all cargo holds and adjacent areas
including fuel tanks, cofferdams, ballast tanks and void spaces.
1.2.13 Special consideration as used in this document is taken to mean as a minimum, that sufficient close-
up inspection and thickness measurements are taken to confirm the actual average condition of the
structure under the coating.
1.2.14 A Prompt and Thorough Repair is a permanent repair completed at the time of survey to the
satisfaction of the Surveyor, therein removing the need for the imposition of any associated condition of
classification.
1.3 Repairs
1.3.1 Any damage in association with wastage over the allowable limits (including buckling, grooving,
detachment or fracture), or extensive areas of wastage over the allowable limits, which affects or, in the
opinion of the Surveyor, will affect the vessel’s structural, watertight or weathertight integrity, is to be
promptly and thoroughly (see 1.2.14) repaired. Areas to be considered include:
For locations where adequate repair facilities are not available, consideration may be given to allow the
vessel to proceed directly to a repair facility. This may require discharging the cargo and/or temporary
repairs for the intended voyage.
1.3.2 Additionally, when a survey results in the identification of substantial corrosion or structural defects,
either of which, in the poinion of the Surveyor, will impair the vessel’s fitness for continued service,
remedial measures are to be implemented before the ship continues in service.
2. SPECIAL SURVEY2
2.1 Schedule
2.1.1 Special Surveys are to be carried out at a 5 year intervals to renew the class certificate.
2.1.2 The first Special Survey is to be completed with 5 years from the date of the initial classification
survey and thereafter within 5 years from the credited date of the previous Special Survey. However, an
extension of class of 3 months maximum beyond the 5th year can be granted in exceptional circumstances.
In this case, the next period of class will start from the expiry date of the Special Survey before the
extension was granted.
2.1.3 For surveys completed within 3 months before the expiry date of the Special Survey, the next
period of class will start from the expiry date of the Special Survey. For surveys completed more than 3
months before the expiry date of the Special Survey, the period of class will start from the survey
completion date.
2 Some member Societies use the term "Special Periodical Survey" other the term "Class Renewal
Survey" instead of the term "Special Survey".
▲
Z10.2-2
IACS Req. 1992/Rev. 11 2000
Z10.2
2.1.4 The Special Survey may be commenced at the 4th Annual Survey and be progressed with a view
Z10.2 to completion by the 5th anniversary date.
cont'd
2.1.5 As part of the preparation for the Special Survey, the thickness measurement and Survey
Programme are to be dealt with in advance of the Special Survey. The thickness measurement is not to
be held before the 4th Annual Survey.
2.2 Scope
2.2.1 General
2.2.1.1 The Special Survey is to include, in addition to the requirements of Annual Surveys,
examination, tests, and checks of sufficient extent to ensure that the hull and related piping are in a
satisfactory condition and that the ship is fit for its intended purpose for the new period of class of 5
years to be assigned subject to proper maintenance and operation and to periodical surveys being carried
out at the due dates.
2.2.1.2 All cargo holds, salt water Ballast Tanks, including double bottom tanks, pipe tunnels,
cofferdams and void spaces bounding cargo holds, decks and outer hull are to be examined, and this
examination is to be supplemented by thickness measurement and testing as deemed necessary, to ensure
that the structural integrity remains effective.
2.2.1.3 All piping systems within the above Spaces are to be examined and tested under working
conditions to ensure that the condition remains satisfactory.
2.2.1.4 The survey extent of combined ballast cargo holds is to be evaluated based on the records of
ballast history, the extent of corrosion protection system provided, and extent of corrosion found.
2.2.1.5 The survey extent of ballast tanks converted to void spaces is to be specially considered in
relation to the requirements for ballast tanks.
2.2.3.1 Where provided, the condition of corrosion prevention system of Ballast Tanks is to be
examined. For tanks used for salt water ballast, excluding double bottom tanks, where a Protective
Coating is found in POOR condition as defined in 1.2.11, and it is not renewed, where soft coating has
been applied, or where a Protective Coating was not applied from the time of construction, maintenance
of class is to be made subject to the tanks in question being examined at annual intervals.
When such breakdown of coating is found in salt water ballast double bottom tanks and it is not renewed,
where a soft coating has been applied, or where a protective coating was not applied from the time of
construction, maintenance of class may be subject to the tanks in question being examined at annual
intervals. When considered necessary by the surveyor, or where extensive corrosion exists, thickness
measurements are to be carried out.
2.2.3.2 Where the protective coating in cargo holds, as defined by Z9 is found to be in GOOD
condition, the extent of close-up surveys and thickness measurements may be specially considered.
Z10.2-3
2.2.4.2 Checking of the satisfactory operation of all mechanically operated hatch covers is to be made,
Z10.2 including:
cont'd
- stowage and securing in open condition;
- proper fit and efficiency of sealing in closed condition;
- operational testing of hydraulic and power components, wires, chains, and link drives.
2.2.4.3 Checking the effectiveness of sealing arrangements of all hatch covers by hose testing or
equivalent.
2.2.4.4 Thickness measurement of the hatch cover and coaming plating and stiffeners is to be carried
out as given in Table II.
2.3.1 An Overall Survey of all tanks and spaces, excluding fuel oil, lube and fresh water tanks, is to be
carried out at each Special Survey.
2.3.2 Each Special Survey is to include a close-up examination of sufficient extent to establish the
condition of the shell frames and their end attachments in all cargo holds and salt water ballast tanks as
indicated in Table I.
2.4.1 The minimum requirements for thickness measurement at Special Survey are given in Table II.
See 1.1.4 and Annex III for additional thickness measurement guidelines applicable to the vertically
corrugated transverse watertight bulkhead between cargo hold Nos. 1 and 2 on ships subject to
compliance with URs S19 and S23.
2.4.2 Representative thickness measurement to determine both general and local levels of corrosion in
the shell frames and their end attachments in all cargo holds and salt water ballast tanks is to be carried
out. Thickness measurement is also to be carried out to determine the corrosion levels on the transverse
bulkhead plating. The thickness measurements may be dispensed with provided the surveyor is satisfied
by the close-up examination, that there is no structural diminution, and the Protective Coating where
applied remains efficient.
2.4.3 The Surveyor may extend the thickness measurement as deemed necessary. Provisions for
extended measurements for areas with Substantial Corrosion as defined in 1.2.9 are given in Table VIII
and as may be additionally specified in the Survey Programme as required by 5.1.
2.4.4 For areas in Spaces where coatings are found to be in a GOOD condition as defined in 1.2.11, the
extent of thickness measurement according to Table II may be specially considered, by the Classification
Society. Refer also to 2.2.3.2
2.4.5 Transverse sections are to be chosen where largest reductions are suspected to occur or are
revealed from deck plating measurements.
2.5.1 All boundaries of salt water ballast tanks, deep tanks and cargo holds used for salt water ballast
within the cargo area length are to pressure tested For Fuel Oil Tanks, only the representative tanks are to
be pressure tested.
2.5.2 The Surveyor may extend the tank testing as deemed necessary
2.5.3 Tanks to be tested with a head of liquid to the top of the hatches for ballast/cargo holds or top of
air pipes for Ballast Tanks or fuel tanks, if this gives a higher pressure.
3. ANNUAL SURVEY
3.1 Schedule
3.1.1 Annual Surveys are to be held within 3 months before or after anniversary date from the date of
the initial classification survey or of the date credited for the last Special Survey.
▲
Z10.2-4
3.2 Scope
Z10.2
cont'd 3.2.1 General
3.2.1.1 The survey is to consist of an examination for the purpose of ensuring, as far as practicable, that
the hull, hatch covers, coamings and piping are maintained in a satisfactory condition.
3.2.2.1 Examination of the hull plating and its closing appliances as far as can be seen.
3.2.3.1 Checking that no unapproved changes have been made to the hatch covers, hatch coamings and
their securing and sealing devices since that last survey.
3.2.3.2 Where mechanically operated steel covers are fitted, checking the satisfactory condition of:-
Where portable covers, wooden or steel pontoons are fitted, checking the satisfactory condition of:
- wooden covers and portable beams, carriers or sockets for the portable beam, and their securing
devices;
- steel pontoons, including close-up survey of hatchcover plating.
- tarpaulins;
- cleats, battens and wedges;
- hatch securing bars and their securing devices;
- loading pads/bars and the side plate edge;
- guide plates and chocks;
- compression bars, drainage channels and drain pipes (if any).
3.2.3.3 Checking the satisfactory condition of hatch coaming plating and their stiffeners including
close-up survey.
3.2.3.4 Random checking of the satisfactory operation of mechanically operated hatch covers is to be
made, including :
stowage and securing in open condition;
proper fit and efficiency of sealing in closed condition;
operational testing of hydraulic and power components, wires, chains, and link drives;
a) Overall Survey of all cargo holds. Where the protective coating in cargo holds, as defined by Z.9
is found to be in GOOD condition, the extent of close-up surveys and thickness measurements may be
specially considered.
b) Close-up examination of sufficient extent, minimum 25% of frames, to establish the condition of
the lower region of the shell frames including approx. lower one third length of side frame at side shell
and side frame end attachment and the adjacent shell plating in the forward cargo hold. Where this level
of survey reveals the need for remedial measures, the survey is to be extended to include a Close-up
Survey of all of the shell frames and adjacent shell plating of that cargo hold as well as a Close-up survey
of sufficient extent of all remaining cargo holds.
▲
Z10.2-5
IACS Req. 1992/Rev. 11 2000
Z10.2
Z10.2 c) When considered necessary by the surveyor, or where extensive corrosion exists, thickness
measurement is to be carried out. If the results of these thickness measurements indicate that Substantial
cont'd Corrosion is found, the extent of thickness measurements is to be increased in accordance with Table
VIII.
a) Overall Survey of all cargo holds. Where the protective coating in cargo holds, as defined by Z.9
is found to be in GOOD condition, the extent of close-up surveys and thickness measurements may be
specially considered.
b) Close-up examination of sufficient extent, minimum 25% of frames, to establish the condition of
the lower region of the shell frames including approx. lower one third length of side frame at side
shell and side frame end attachment and the adjacent shell plating in the forward cargo hold and one
other selected cargo hold. Where this level of survey reveals the need for remedial measures, the survey
is to be extended to include a Close -up Survey of all of the shell frames and adjacent shell plating of that
cargo hold as well as a Close-up Survey of sufficient extent of all remaining cargo holds.
c) When considered necessary by the surveyor, or where extensive corrosion exists, thickness
measurement is to be carried out. If the results of these thickness measurements indicate that Substantial
Corrosion is found, the extent of thickness measurements is to be increased in accordance with Table
VIII.
d) All piping and penetrations in cargo holds, including overboard piping, are to be examined.
3.2.5.1 Examination of Ballast Tanks when required as a consequence of the results of the Special
Survey and Intermediate Survey. When considered necessary by the surveyor, or where extensive
corrosion exists, thickness measurement is to be carried out. If the results of these thickness
measurements indicate that Substantial Corrosion is found, the extent of thickness measurements is to be
increased in accordance with Table VIII.
3.3 Additional annual survey requirements for the foremost cargo hold of ships subject to
SOLAS XII/9.1
3.3.1 Ships subject to SOLAS XII/9.1 are those meeting all the following conditions:
- Bulk Carriers of 150m in length and upwards of single side skin construction,
- carrying solid bulk cargoes having a density of 1780 kg/m3 and above,
- contracted for construction before 1 July 1999, and
- constructed with an insufficient number of transverse watertight bulkheads to enable them to
withstand flooding of the foremost cargo hold in all loading conditions and remain afloat in a
satisfactory condition of equilibrium as specified in SOLAS XII/4.3.
3.3.2 In accordance with SOLAS XII/9.1, for the foremost cargo hold of such ships, the additional
survey requirements listed in Annex IV shall apply.
4. INTERMEDIATE SURVEY
4.1 Schedule
4.1.1 The intermediate Survey is to be held at or between either the 2nd or 3rd Annual Survey.
4.1.2 Those items which are additional to the requirements of the Annual Surveys may be surveyed
either at or between the 2nd and 3rd Annual Survey.
4.2 Scope
4.2.1 General
▲
Z10.2-6
4.2.1.1 The extent of survey is dependent on the age of the vessel as specified in 4.2.2 to 4.2.4.
Z10.2
cont'd 4.2.2 Bulk Carriers 5 -10 Years of Age, the following is to apply:
a) For Spaces used for salt water ballast, an Overall Survey of Representative Spaces selected by
the surveyor is to be carried out. If such inspections reveal no visible structural defects, the
examination may be limited to a verification that the Protective Coating remains efficient.
b) Where POOR Coating Condition (as defined in 1.2.11), corrosion or other defects are
found in salt water Ballast Spaces or where Protective Coating was not applied from the time of
construction, the examination is to be extended to other Ballast Spaces of the same type.
c) In salt water ballast Spaces other than double bottom tanks, where a Protective Coating is found
in POOR condition as defined in 1.2.11, and it is not renewed, where soft coating has been
applied, or where a Protective Coating was not applied from the time of construction,
maintenance of class is to be subject to the tanks in question being examined and thickness
measurements carried out as considered necessary at annual intervals. When such breakdown of
coating is found in salt water ballast double bottom tanks, where a soft coating has been
applied,
or where a coating has not been applied, maintenance of class may be subject to the tanks in
question being examined at annual intervals. When considered necessary by the surveyor, or
where extensive corrosion exists, thickness measurements should be carried out.
d) In addition to the requirements above, areas found suspect according to 1.2.8 at the previous
Special Survey are to be overall and close-up surveyed.
a) An Overall Survey of all cargo holds, including Close-Up Survey of sufficient extent, minimum
25 % of frames, is to be carried out to establish the condition of:
- Shell frames including their upper and lower end attachments, adjacent shell plating,
and transverse bulkheads in the forward cargo hold and one other selected cargo hold.
b) Where considered necessary by the surveyor as a result of the Overall and Close-up Survey as
described in 4.2.2.2a, the survey is to be extended to include a Close-up Survey of all of the
shell frames and adjacent shell plating of that cargo hold as well as a Close-up Survey of
sufficient extent of all remaining cargo holds.
a) Thickness measurement is to be carried out to an extent sufficient to determine both general and
local corrosion levels at areas subject to Close-up Survey as described in 4.2.2.2a. The
minimum requirement for thickness measurements at the Intermediate Survey are areas found
to be Suspect Areas according to 1.2.8 at the previous Special Survey.
c) The thickness measurement may be dispensed with provided the surveyor is satisfied by the
Close-up Survey, that there is no structural diminution and the Protective Coating where fitted
remains effective.
Z10.2-7
IACS Req. 1992/Rev. 11 2000
Z10.2
- All salt water ballast tanks are to be examined. If such inspections reveal no visible
Z10.2 structural defects, the examination may be limited to a verification that the Protective
cont'd Coating remains efficient.
a) An Overall Survey of all cargo holds, including Close-up Survey of sufficient extent, minimum
25 % of frames, is to be carried out to establish the condition of:
- Shell frames including their upper and lower end attachments, adjacent shell plating,
and transverse bulkheads of all cargo holds
b) Where considered necessary by the surveyor as a result of the Overall and Close-up Survey as
described in 4.2.3.2a, the survey is to be extended to include a Close-up Survey of all of the
shell frames and adjacent plating of all cargo holds.
a) Thickness measurement is to be carried out to an extent sufficient to determine both general and
local corrosion levels at areas subject to Close-up Survey as described in 4.2.3.2a. The
minimum requirement for thickness measurements at the intermediate Survey are areas found to
be Suspect Areas according to chapter 1.2.8 at the previous Special Survey.
4.2.4.1 The requirements of the Intermediate Survey shall be to the same extent as the previous Special
Survey as required in 2 and 5.1. However, testing of cargo and ballast tanks is not required
unless deemed necessary by the attending surveyor.
4.2.4.2 In lieu of the requirements of 2.2.2, an under water survey may be considered as
equivalent.
5.1.1 A specific Survey Programme is to be worked out in advance of the Special Survey by the Owner
in cooperation with the Classification Society. The Survey Programme is to be in a written format.
5.1.2 In developing the Survey Programme, the following documentation is to be collected and
consulted with a view to selecting tanks, holds, areas, and structural elements to be examined:
Z10.2-8
- Relevant previous survey and inspection reports from both Classification Society and the Owner,
Z10.2 - Information regarding the use of the ship’s holds and tanks, typical cargoes and other relevant
cont'd data,
- Information regarding corrosion protection level on the newbuilding,
- Information regarding the relevant maintenance level during operation.
5.1.3 The submitted Survey Programme is to account for and comply, as a minimum, with the
requirements of Tables I, II and paragraph 2.5 for close-up survey, thickness measurement and tank
testing, respectively, and is to include relevant information including at least :
5.1.4 The Classification Society will advise the Owner of the maximum acceptable structural corrosion
diminution levels applicable to the vessel.
5.1.5 Use may also be made of the IACS Guidelines for Technical Assessment in Conjunction with
Planning for Enhanced Surveys of Bulk Carriers Special Survey - Hull, contained in Annex I. These
guidelines are a recommended tool which may be invoked at the discretion of the IACS Member Society,
when considered necessary and appropriate, in conjunction with the preparation of the required Survey
Programme.
5.2.1 The owner is to provide the necessary facilities for a safe execution of the survey.
5.2.2 Tanks and Spaces are to be safe for access, i.e. gas freed, ventilated, illuminated, etc.
5.2.3 Tanks and Spaces are to be sufficiently clean and free from water, scale, dirt, oil residues, etc. to
reveal significant corrosion, deformation, fractures, damages or other structural deterioration. In
particular this applies to areas which are subject to thickness measurement.
5.3.1 For Overall Survey, means are to be provided to enable the surveyor to examine the hull structure
in a safe and practical way.
5.3.2 For Close-Up Surveys in a cargo hold and salt water ballast tanks, one or more of the following
means for access, acceptable to the Surveyor, is to be provided:
Z10.2-9
5.4.2 One or more of the following fracture detection procedures may be required if deemed necessary
by the Surveyor:
- radiographic equipment
- ultrasonic equipment
- magnetic particle equipment
- dye penetrant
5.5.1 Voyage surveys may be accepted provided the Surveyor is given the necessary assistance from the
personnel on board. Necessary precautions and procedures for carrying out the survey are to be in
accordance with 5.1, 5.2, 5.3, and 5.4.
5.5.2 A communication system is to be arranged between the survey party in the spaces under
examination and the responsible officer on deck.
6. (void)
7. DOCUMENTATION ON BOARD
7.1 General
7.1.1 The Owners are to supply and maintain on board documentation as specified in 7.2, which is to be
readily available for the surveyor.
7.1.2 The documentation is to be kept on board for the life time of the ship.
7.2.2 The Survey Report File is to be available also in the Owners and the Classification Society's
management offices.
7.4.1 Prior to inspection, the Surveyor is to examine the completeness of the documentation on board,
and its contents as a basis for the survey.
▲
▲
Z10.2-10
8.1.1 Thickness measurements required, if not carried out by the Society itself or by a company
subcontracted directly by the Society, are to be witnessed by a surveyor on board to the extent necessary
to control the process.
The thickness measurement operator is to be part of the survey planning meeting to be held prior to
commencing the survey.
8.2.1 The thickness measurement is to be carried out by a qualified company certified by the
Classification Society according to principles stated in table V.
8.3 Reporting
8.3.1 A thickness measurement report is to be prepared. The report is to give the location of
measurement, the thickness measured as well as corresponding original thickness. Furthermore, the
report is to give the date when the measurement was carried out, type of measuring equipment, names of
personnel and their qualifications and has to be signed by the operator.
The thickness measurement report is to follow the principles as specified in the Recommended
Procedures for Thickness Measurement of Bulk Carriers, contained in Annex II.
8.3.2 The surveyor is to verify and countersign the thickness measurement report.
9.1.1 The data and information on the structural condition of the vessel collected during the survey is to
be evaluated for acceptability and continued structural integrity of the vessel.
9.2 Reporting
9.2.2 An Executive Hull Summary of the survey and results is to be issued to the Owner as shown in
table VII and placed on board the vessel for reference at future surveys. The Executive Hull Summary is
to be endorsed by the Classification Society's head office or regional managerial office.
Z10.2-11
TABLE I
Z10.2 TABLE OF MINIMUM REQUIREMENT FOR CLOSE-UP SURVEY
cont'd AT SPECIAL HULL SURVEYS OF BULK CARRIERS
Special Survey No. 1 Special Survey No. 2 Special Survey No. 3 Special Survey No. 4
Age < 5 5 < Age < 10 10 < Age < 15 and Subsequent
Age > 15
(A) - 25% of shell frames (A) - 25% of shell frames (A) - All shell frames in (A) - All shell frames in
in the forward cargo in all cargo holds the forward cargo all cargo holds
hold at representative including upper and hold and 25% of including upper and
positions. lower end attach- frames in each of the lower end attach-
ments and adjacent remaining cargo ments and adjacent
shell plating. holds, including upper shell plating.
and lower end attach-
(A) - Selected frames in ments and adjacent
remaining cargo shell plating. Areas (B) - (E) as for
holds. Special Survey No. 3
(A) - Cargo hold transverse frames (B) - Transverse web frame or watertight (C) - Cargo hold transverse
transverse bulkhead in water ballast bulkheads plating,
tanks stiffeners and girders
(D) - Cargo hold hatch covers and (E) - Deck plating inside line of hatch
coamings openings between cargo hold hatches
See sketches of sheet 14 for the areas corresponding to (A), (B), (C), (D) and (E)
Z10.2-12
IACS Req. 1992/Rev 11 2000
Z10.2
Z10.2 TABLE II
cont'd TABLE OF MINIMUM REQUIREMENT FOR THE THICKNESS
MEASUREMENT AT SPECIAL HULL SURVEYS OF BULK CARRIERS
Special Survey No. 1 Special Survey No. 2 Special Survey No. 3 Special Survey No. 4
Age ≤ 5 5 < Age ≤ 10 10 < Age ≤ 15 and Subsequent
Age > 15
1. Suspect Areas 1. Suspect Areas 1. Suspect Areas 1. Suspect Areas
2. Within the cargo length: 2. Within the cargo length: 2. Within the cargo length:
a) Two transverse section a) Each deck plate out- a) Each deck plate out-
of deck plating outside side line of cargo side line of cargo
line of cargo opening. hatch openings. hatch openings.
Z10.2-13
Deck:
Bottom:
Side:
Long.
Bulkheads:
Transv.
Bulkheads:
Overdue Surveys:
Comments:
Date of Inspection:
Inspected by:
Signature:
▲
Z10.2-14
TABLE IV
Z10.2
cont'd PRINCIPLES FOR PLANNING DOCUMENT
Note: Table IV is superseded by Annex I: Guidelines for Technical Assessment in conjunction with
planning for Enhanced Surveys of Bulk Carriers Special Survey - Hull.
Z10.2-15
Z10.2 TABLE V
cont'd
PROCEDURES FOR CERTIFICATION OF FIRMS ENGAGED IN THICKNESS
MEASUREMENT OF HULL STRUCTURES
1. Application
This guidance applies for certification of the firms which intend to engage in the thickness
measurement of hull structures of the vessels.
3. Certification
(1) Upon satisfactory results of both the audit of the firm in 2(2) and the demonstration tests in 2(3)
above, the Society will issue a Certificate of Approval as well as a notice to the effect that the
thickness measurement operation system of the firm has been certified by the Society.
In case where any alteration to the certified thickness measurement operation system of the firm is
made, such an alteration is to be immediately informed to the Society. Re-audit is made where
deemed necessary by the Society.
5. Cancellation of Approval
(2) Where the Society's surveyor found any deficiencies in the approved thickness measurement
operation systems of the firm.
(3) Where the firm failed to inform of any alteration in 4 above to the Society
Z10.2-16
Z10.2 TABLE VI
cont'd REPORTING PRINCIPLES
Reporting forms are to be worked out individually by the respective Classification Societies. As a
principle the following content of reports for Bulk Carrier structures is to be included as applicable for
the survey:
1.0 Type of Survey (Special Survey, Intermediate Survey, Annual Survey, Other)
The structure of the reporting content may be different, depending on the report system for the respective
Societies.
Z10.2-17
GENERAL PARTICULARS
TYPE OF CONVERSION:
a) The survey reports and documents listed below have been reviewed by the undersigned and
found to be satisfactory
c) The hull special survey has been completed in accordance with the Regulations on [date]
OFFICE DATE
OFFICE DATE
1)
2)
3)
4)
5)
6)
Z10.2-18
TABLE VII(ii)
Z10.2
cont'd
EXECUTIVE HULL SUMMARY
D) Thickness
measurements: – Reference to Thickness Measurement report
– Summary of where measured
– Separate form indicating the tanks/areas with Substantial
Corrosion, and corresponding
* Thickness diminution
* Corrosion pattern
G) Condition of Class/Recommendations:
Z10.2-19
1) 2)
Remarks
1) Substantial corrosion, i.e. 75 – 100% of acceptable margins wasted
2) P = Pitting
C = Corrosion in General
Any bottom plating with a pitting intensity of 20% or more, with wastage in the substantial
corrosion range or having an average depth of pitting of 1/3 or more of actual plate thickness is
to be noted.
Z10.2-20
1) 2) 3)
Remarks:
1)
All ballast tanks and cargo holds to be listed.
2)
C = Coating A = Anodes NP = No Protection
3)
Coating condition according to the following standard
If coating condition "POOR" is given, extended annual surveys are to be introduced. This is to be noted
in part G) of the Executive Hull Summary.
▲ ▲
Z10.2-21
Z10.2 Requirements for extent of thickness measurement at those areas of Substantial Corrosion.
Special Survey of Bulk Carriers within the cargo area.
cont'd
TABLE VIII
Sheet 1
SHELL STRUCTURES
1. Bottom and Side Shell a. Suspect plate, plus four adjacent a. 5 point pattern for each panel
plating plates between longitudinals
Z10.2-22
Z10.2 Requirements for extent of thickness measurement at those areas of Substantial Corrosion.
Special Survey of Bulk Carriers within the cargo area.
cont'd
TABLE VIII
Sheet 2
1. Lower Stool a. Transverse band within 25mm a. 5 point between stiffeners over
of welded connection to inner- 1 metre length
bottom
Z10.2-23
Requirements for extent of thickness measurement at those areas of Substantial Corrosion. Special
Z10.2 Survey of Bulk Carriers within the cargo area.
cont'd
TABLE VIII
Sheet 3
1. Cross Deck Strip plating Suspect cross deck strip plating a. 5 point pattern between
underdeck stiffeners over 1
metre length
3. Hatch Covers a. Side and end skirts, a. 5 point pattern at each location
each 3 locations
4. Hatch Coamings Each side and end of coaming, one 5 point measurement each band i.e.
band lower 1/3, one band upper 2/3 end or side coaming
of coaming
b. 2 representative swash
transverse bulkheads
i. lower 1/3 of bulkhead i. 5 point pattern over 1 sq. metre
of plating
ii. upper 2/3 of bulkhead ii. 5 point pattern over 1 sq. metre
of plating
iii. stiffeners iii. 5 point pattern over 1 metre
length
c. 3 representative bays of
slope plating
i. lower 1/3 of tank i. 5 point pattern over 1 sq. metre
of plating
ii. upper 2/3 of tank ii. 5 point pattern over 1 sq. metre
of plating
Z10.2-24
6. Main Deck Plating Suspect plates and adjacent (4) 5 point pattern over 1 sq. metre
of plating
7. Main Deck Longitudinals Minimum of 3 longitudinals where 5 point pattern on both web and
plating measured flange over 1 metre length
Z10.2-25
TABLE VIII
Sheet 4
1. Inner/Double Bottom Plating Suspect plate plus all adjacent plates 5 point pattern for each panel
between longitudinals over 1 metre
length
2. Inner/Double Bottom Three longitudinals where plates +3 measurements in line across web
Longitudinals measured and 3 measurements on flange
4. Watertight Bulkheads a. lower 1/3 of tank a. 5 point pattern over 1 sq. metre of
(WT Floors) plating
b. upper 2/3 of tank b. 5 point pattern alternate plates
over 1 sq. metre of plating
Z10.2-26
Z10.2 Requirements for extent of thickness measurement at those areas of Substantial Corrosion.
Special Survey of Bulk Carriers within the cargo area.
cont'd
TABLE VIII
Sheet 5
CARGO HOLDS
1. Side Shell frames Suspect frame and each adjacent a. At each end and mid span:
5 point pattern of both web and
flange
Z10.2-27
Z10.2 ANNEX I
cont'd
GUIDELINES FOR TECHNICAL ASSESSMENT IN CONJUNCTION WITH
PLANNING FOR ENHANCED SURVEYS OF BULK CARRIERS
SPECIAL SURVEY - HULL
Contents:
1. INTRODUCTION
2. PURPOSE AND PRINCIPLES
2.1 Purpose
2.2 Minimum Requirements
2.3 Timing
2.4 Aspects to be Considered
3. TECHNICAL ASSESSMENT
3.1 General
3.2 Methods
3.2.1 Design Details
3.2.2 Corrosion
3.2.3 Locations for Close-up Survey and Thickness Measurement
REFERENCES
1. IACS Unified Requirement Z10.2, "Hull Surveys of Bulk Carriers."
2.TSCF, "Guidance Manual for the Inspection and Condition Assessment of Tanker Structures, 1986."
3.TSCF, "Condition Evaluation and Maintenance of Tanker Structures, 1992."
4. IACS, "Bulk Carriers: Guidelines for Surveys, Assessment and Repair of Hull Structures, 1994."
1.0 INTRODUCTION
These guidelines contain information and suggestions concerning technical assessments which may be of
use in conjunction with the planning of enhanced special surveys of bulk carriers. As indicated in section
5.1.5 of IACS Unified Requirement Z10.2, "Hull Surveys of Bulk Carriers," (Ref. 1), the guidelines are a
recommended tool which may be invoked at the discretion of an IACS Member Society, when
considered necessary and appropriate, in conjunction with the preparation of the required Survey
Programme.
2.1 Purpose
The purpose of the technical assessments described in these guidelines is to assist in identifying critical
structural areas, nominating suspect areas and in focusing attention on structural elements or areas of
structural elements which may be particularly susceptible to, or evidence a history of, wastage or
damage. This information may be useful in nominating locations, areas, holds and tanks for thickness
measurement, close-up survey and tank testing.
Critical Structural Areas are locations which have been identified from calculations to require monitoring
or from the service of the subject ship or from similar or sister ships (if available) to be sensitive to
cracking, buckling or corrosion which would impair the structural integrity of the ship.
2.3 Timing
As with other aspects of survey planning, the technical assessments described in these guidelines should
be worked out by the Owner or operator in cooperation with the Classification Society well in advance of
the commencement of the Special Survey, i.e., prior to commencing the survey and normally at least 12
to 15 months before the survey's completion due date.
▲ ▲
Page I-1
*Design features such as stress levels on various structural elements, design details and extent of
use of high tensile steel.
*Former history with respect to corrosion, cracking, buckling, indents and repairs for the
particular ship as well as similar vessels, where available.
*Information with respect to types of cargo carried, protection of tanks, and condition of coating,
if any, of holds and tanks.
3.1 General
There are three basic types of possible failure which may be the subject of technical assessment in
connection with planning of surveys; corrosion, cracks and buckling. Contact damages are not normally
covered by the survey plan since indents are usually noted in memoranda and assumed to be dealt with as
a normal routine by Surveyors.
Technical assessments performed in conjunction with the survey planning process are, in principle, to be
as shown schematically in Figure 1 depicts, schematically, how technical assessments can be carried out
in conjunction with the survey planning process. The approach is basically an evaluation of the risk in
the following aspects based on the knowledge and experience related to:
- Design
- Corrosion
The design is to be considered with respect to structural details which may be susceptible to buckling or
cracking as a result of vibration, high stress levels or fatigue.
Corrosion is related to the ageing process, and is closely connected with the quality of corrosion
protection at newbuilding, and subsequent maintenance during the service life. Corrosion may also lead
to cracking and/or buckling.
3.2 Methods
Damage experience related to the ship in question and similar ships, where available, is the main source
of information to be used in the process of planning. In addition, a selection of structural details from the
design drawings is to be included.
This information may be found in the survey reports and/or the Owner's files, including the results of the
Owner's own inspections. The defects are to be analyzed, noted and marked on sketches.
In addition, general experience is to be utilized. For example, Figure 2 shows typical locations in bulk
carriers which experience has shown may be susceptible to structrual damage. Also, reference is to be
made to IACS's "Bulk Carriers: Guidelines for Survey, Assessment and Repair," (Ref. 4) which contains
a catalogue of typical damages and proposed repair methods for various bulk carrier structural details.
▲
Page I-2
Z10.2 Such figures are to be used together with a review of the main drawings, in order to compare with the
actual structure and search for similar details which may be susceptible to damage. An example is shown
cont'd in Figure 3.
The review of the main structural drawings, in addition to using the above mentioned figures, is to
include checking for typical design details where cracking has been experienced. The factors
contributing to damage are to be carefully considered.
The use of high tensile steel (HTS) is an important factor. Details showing good service experience
where ordinary, mild steel has been used may be more susceptible to damage when HTS, and its higher
associated stresses are utilized. There is extensive and, in general, good experience, with the use of HTS
for longitudinal material in deck and bottom structures. Experience in other locations, where the
dynamic stresses may be higher, is less favorable, e.g. side structures.
In this respect, stress calculations of typical and important components and details, in accordance with
the latest Rules or other relevant methods, may prove useful and are to be considered.
The selected areas of the structure identified during this process are to be recorded and marked on the
structural drawings to be included in the Survey Programme.
3.2.2 Corrosion
In order to evaluate relative corrosion risks, the following information is generally to be considered:
- Usage of Tanks, Holds and Spaces
- Condition of Coatings
- Condition of Anodes
- Cleaning Procedures
- Previous Corrosion Damage
- Ballast use and time for Cargo Holds
- Risk of Corrosion in Cargo Holds and Ballast Tanks
- Location of Ballast Tanks Adjacent to Heated Fuel Oil Tanks
Ref. 3 gives definitive examples which can be used for judging and describing coating condition, using
typical pictures of conditions.
For bulk carriers, Ref. 4 is to be used as the basis for the evaluation, together with relevant information
on the anticipated condition of the ship as derived from the information collected in order to prepare the
Survey Programme and the age of the ship.
The various tanks, holds and spaces are to be listed with the corrosion risks nominated accordingly.
On the basis of the table of corrosion risks and the evaluation of design experience, the locations for
initial close-up survey and thickness measurement (sections) may be nominated.
The sections subject to thickness measurement are to normally be nominated in tanks, holds and spaces
where corrosion risk is judged to be the highest.
The nomination of tanks, holds and spaces for close-up survey is to, initially, be based on highest
corrosion risk, and is to always include ballast tanks. The principle for the selection should be that the
extent is increased by age or where information is insufficient or unreliable.
▲
Page I-3
Input:
Z10.2 Drawings, Reports, Coating Condition
cont'd Acceptable Corrosion Collection of Information Anode Condition
Allowance Usage of Tanks
Corrosion Damage
Hull Damage : Similar Ship where
General Experience Available
Survey Programme
Acceptance by
Class &Owner
Survey
Page I-4
Z10.2
cont'd
Page I-5
Z10.2
cont'd Side shell frames and end brackets
AREA 1 Structural item (separate bracket configuration)
EXAMPLE 1
;;
;;
Sketch of damage Sketch of repair
Topside
Topside tank tank
S
X Snipe x
frame
;
S 0,3x
Modified
Side brackets
Side
Fractures shell
shell 0,3Y
S
Y Y
Snipe
frame
Hopper S
Hopper
tank tank
Separate Bracket
Configuration 3276/04
S = Sniped end
Page I-6
Z10.2 Annex II
Annex
cont'd
IACS Recommended Procedures for
Thickness Measurements of Bulk Carriers
Page II-1
1. This document is to be used for recording thickness measurements as required by the IACS
Z10.2 Unified Requirement Z10.2.
Annex
cont'd 2. Reporting forms TM1-BC, TM2-BC, TM3-BC, TM4-BC, TM5-BC, TM6-BC and TM7-BC
(sheets 4-11) are to be used for recording thickness measurements and the minimum allowable
diminution is to be stated.
The minimum allowable diminution could be stated in an attached document.
3. The remaining sheets 12-14 are guidance diagrams and notes relating to the reporting forms and
the IACS Unified Requirements for thickness measurement.
Page II-2
Z10.2 CONTENTS
Annex
cont'd
REPORTS
Sheet 4 - Report TM1-BC for recording the thickness measurement of all deck plating, all
bottom shell plating and side shell plating.
Sheet 5 - Report TM2-BC (i) for recording the thickness measurement of shell and deck plating at
transverse sections - strength deck and sheerstrake plating.
Sheet 6 - Report TM2-BC (ii) for recording the thickness measurement of shell and deck plating
at transverse sections - shell plating.
Sheet 7 - Report TM3-BC for recording the thickness measurement of longitudinal members at
transverse sections.
Sheet 8 - Report TM4-BC for recording the thickness measurement of transverse structural
members.
Sheet 9 - Report TM5-BC for recording the thickness measurement of cargo hold transverse
bulkheads.
Sheet 10 - Report TM6-BC for recording the thickness measurement of miscellaneous structural
members.
Sheet 11 - Report TM7-BC for recording the thickness measurement of cargo hold transverse frames.
GUIDANCE
Sheet 12 - Bulk Carrier typical transverse section. The diagram includes details of the items to be
measured and the report forms to be used.
Sheet 13 - Transverse section outline. This diagram may be used for those ships where the
diagram on sheet 12 is not suitable.
Sheet 14 - Sketches of bulk carrier showing typical areas for thickness measurement of cargo hold
frames, structural members and transverse bulkheads in association with close-up survey
requirements.
Sheet 15 - Thickness Measurement - Ore Carriers Typical transverse section indicating longitudinal
and transverse members
Page II-3
IMO number:-
Port of registry:-
Gross tons:-
Deadweight:-
Date of build:-
Classification Society:-
Certificate No:-
Place of measurement:-
Qualification of operators:-
Page II-4
STRAKE
POSITION
No. Org. Forward Reading Aft Reading Mean Diminution Maximum
Allowable
PLATE or Thk. Gauged Diminution P Diminution S Gauged Diminution P Diminution S % Diminution
POSITION
Letter mm P S mm % mm % P S mm % mm % P S mm
12th forward
11th
10th
9th
8th
7th
6th
5th
4th
3rd
2nd
Page II-5
1st
Amidships
1st aft
2nd
3rd
4th
5th
6th
7th
8th
9th
10th
11th
12th
Z10.2 NOTES
Annex
cont'd 1. This report is to be used for recording the thickness measurement of:-
B- Keel, bottom shell plating and bilge plating within the cargo length area.
C- Side shell plating that is all wind and water strakes within the cargo length area.
D- Side shell plating that is selected wind and water strakes outside the cargo length area.
2.1 For strength deck indicate the number of the strake of plating inboard from the stringer
plate.
2.2 For bottom plating indicate the number of the strake of plating outboard from the keel
plate.
2.3 For side shell plating give number of the strake of plating sheerstrake and letter as shown
on shell expansion.
3. Only the deck plating strakes outside line of openings are to be recorded.
4. Measurements are to be taken at the forward and aft areas of all plates and the single
measurements recorded are to represent the average of multiple measurements.
Page II-6
FIRST TRANSVERSE SECTION AT FRAME SECOND TRANSVERSE SECTION AT FRAME THIRD TRANSVERSE SECTION AT FRAME
NUMBER NUMBER NUMBER
Org. Max. Diminution Diminution Org. Max. Diminution Diminution Org. Max. Diminution Diminution
No. Thk. Alwb. Gauged P S No. Thk. Alwb. Gauged No. Thk. Alwb. Gauged P S
STRAKE Dim. P S Dim.
or Dim. or or
POSITION
Letter mm mm
P S mm % mm % Letter mm mm S mm % mm % Letter mm mm P S mm % mm %
P
Stringer Plate
1st strake inboard
2nd
3rd
4th
5th
6th
Page II-7
7th
8th
9th
10th
11th
12th
13th
14th
centre strake
sheer strake
TOPSIDE
TOTAL
NOTES
Z10.2 1. This report is to be used for recording the thickness measurement of:-
Annex
cont'd Strength deck plating and sheerstrake plating transverse sections:-
Two or three section within the cargo length area, comprising of the structural items (1),
(2) and (3) as shown on the diagram of typical transverse section.
2. Only the deck plating strakes outside the line of openings are to be recorded.
3. The topside area comprises deck plating, stringer plate and sheerstrake (including rounded
gunwales).
5. The single measurements recorded are to represent the average of multiple measurements.
Page II-8
SHELL PLATING
FIRST TRANSVERSE SECTION AT FRAME SECOND TRANSVERSE SECTION AT FRAME THIRD TRANSVERSE SECTION AT FRAME
NUMBER NUMBER NUMBER
Org. Max. Diminution Diminution Org. Max. Diminution Diminution Org. Max. Diminution Diminution
No. Thk. Alwb. Gauged P S No. Thk. Alwb. Gauged No. Thk. Alwb. Gauged P S
STRAKE Dim. P S Dim.
or Dim. or or
POSITION
Letter mm mm
P S mm % mm % Letter mm mm S mm % mm % Letter mm mm P S mm % mm %
P
1st below sheer strake
2nd
3rd
4th
5th
6th
7th
8th
Page II-9
9th
10th
11th
12th
13th
14th
15th
16th
17th
18th
19th
20th
keel strake
BOTTOM TOTAL
Z10.2 NOTES
Annex
cont'd 1. This report is to be used for recording the thickness measurement of:-
Two or three sections within cargo length area comprising of the structural (4), (5), (6) and
(7) as shown on the diagram of typical transverse section.
4. The single measurements recorded are to represent the average of multiple measurements.
Page II-10
FIRST TRANSVERSE SECTION AT FRAME SECOND TRANSVERSE SECTION AT FRAME THIRD TRANSVERSE SECTION AT FRAME
NUMBER NUMBER NUMBER
Org. Max. Diminution Diminution Org. Max. Diminution Diminution Org. Max. Diminution Diminution
Item Thk. Alwb. Gauged P S Item Thk. Alwb. Gauged Item Thk. Alwb. Gauged P S
STRUCTURAL Dim. P S Dim.
No. Dim. No. No.
MEMBER
mm mm P S mm % mm % mm mm P S mm % mm % mm mm P S mm % mm %
Page II-11
▲ Operators Signature...................................................................... Surveyors Signature .................................................................................... NOTES – See Reverse
Z10.2 NOTES
Annex
cont'd 1. This report is to be used used for recording the thickness measurement of:-
Two, or three sections within the cargo length area, comprising of the appropriate
structural items (8) to (20) as shown on diagram of typical transverse section.
3. The single measurements recorded are to represent the average of multiple measurements.
Page II-12
TANK DESCRIPTION:
LOCATION OF STRUCTURE:
Max.
Original Diminution Diminution
Alwb. Gauged
STRUCTURAL MEMBER ITEM Thickness Dim.
P S
mm mm P S mm % mm %
Page II-13
Operators Signature.............................................................. Surveyors Signature .......................................................................... NOTES – See Reverse
Z10.2 NOTES
Annex 1. This report is to be used for recording the thickness measurement of transverse structural
cont'd members, comprising of the appropriate structural items (23) to (25) as shown on diagram of
typical transverse section, sheet 12 of this document.
2. Guidance for areas if measurement is indicated on the diagrams shown on sheet 14 of this
document.
3. The single measurements recorded are to represent the average of multiple measurements.
Page II-14
Page II-15
Operators Signature.............................................................. Surveyors Signature .......................................................................... NOTES – See Reverse
Z10.2 NOTES
Annex
cont'd 1. This report form is to be used for recording the thickness measurement of cargo hold transverse
bulkheads.
3. The single measurements recorded are to represent the average of multiple measurements.
Page II-16
LOCATION OF STRUCTURE:
Page II-17
Operators Signature.............................................................. Surveyors Signature .......................................................................... NOTES – See Reverse
Z10.2 NOTES
Annex
cont'd 1. This report is to be used for recording the thickness measurement of miscellaneous structural
members including the structural items (28), (29), (30) and (31) as shown on diagram of typical
transverse section, sheet 12 of this document.
3. The single measurements recorded are to represent the average of multiple measurements.
Page II-18
Page II-19
Operators Signature.......................................................................... Surveyors Signature ...................................................................................... NOTES – See Reverse
Z10.2 NOTES
Annex
cont'd 1. This report is to be used for recording the thickness measurement of:-
Structural item number 34 as shown on the diagram of typical transverse section, sheet 12 of this
document.
2. Guidance for areas of measurement is indicated on the diagrams shown on sheet 14 of this
document.
The single measurement recorded are to represent the average of multiple measurements.
3. The location and pattern of measurements is to be indicated on the sketches of hold frames shown
below.
Upper part
Mid part
Lower part
Page II-20
9
10
24
11
9
16
12
34
19
16
20
17
18 14
14 14 15
23 25
5
13
7
6
Page II-21
Page II-22
IACS Req. 1992, Rev 11 2000
Z10.2 Annex II - Sheet 14
Area C
Lower stool
Hopper
side
Double bottom tank tank
Area E
E E
Hatch Hatch Hatch
opening opening opening
Page II-23
IACS Req. 1992, Rev 11 2000
Z10.2 Annex II - Sheet 15
Page II-24
IACS Req. 1992, Rev 11 2000
Z10.2 Annex II - Sheet 16
D
Lower stool
Page II-25
IACS Req. 1992, Rev 11 2000
Z10.2 ANNEX III
cont'd
Guidelines for the Gauging of the Vertically Corrugated
Transverse Watertight Bulkhead
between Holds Nos. 1 and 2
1. Gauging is necessary to determine the general condition of the structure and to define the extent
of possible repairs and/or reinforcements of the vertically corrugated transverse watertight
bulkhead for verification of the compliance with UR S19.
2. Taking into account the buckling model applied in UR S19 in the evaluation of strength of the
bulkhead, it is essential to determine the thickness diminution at the critical levels shown in
Figures 1 and 2.
3. The gauging is to be carried out at the levels as described below. 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 below are to be gauged.
Locations:
• The mid-breadth of the corrugation flanges at approximately 200 mm above the line of shedder
plates;
• The middle of gusset plates between corrugation flanges, where fitted;
• The middle of the shedder plates;
• The mid-breadth of the corrugation webs at approximately 200 mm above the line of shedder
plates.
Locations:
• The mid-breadth of the corrugation flanges at approximately 200 mm above the line of shedder
plates;
• The middle of gusset plates between corrugation flanges, where fitted;
• The middle of the shedder plates;
• The mid-breadth of the corrugation webs at approximately 200 mm above the line of shedder
plates.
Level (c) Ships with or without lower stool (see Figures 1 and 2):
Locations:
• The mid-breadth of the corrugation flanges and webs at about the mid-height of the corrugation.
4. Where the thickness changes within the horizontal levels, the thinner plate is to be gauged.
III-1
Z10.2
cont'd
lev el c
lev e l a
F ig u re 1
lev el c
le v e l b
F ig u re 2
▲
▲
III-2
Z10.2 Annex IV
Z10.2 ANNEX IV
cont'd Additional annual survey reqiuirements for the foremost cargo hold of ships subject to
SOLAS XII/9.1
1 General
1.1 In the case of Bulk Carrier over 5 years of age, the Annual Survey is to include, in addition to the
requirements of the Annual Surveys prescribed in chapter 3, an examination of the following items:
a) An Overall Survey of the foremost cargo hold, including Close-up Survey of sufficient extent,
minimum 25% of frames, is to be carried out to establish the condition of:
- Shell frames including their upper and lower end attachments, adjacent shell plating, and
transverse bulkheads.
- Areas found suspect according to chapter 1.2.8 at the previous Special Survey.
b) Where considered necessary by the surveyor as a result of the Overall and Close-up Survey as
described in a) above, the survey is to be extended to include a Close-up Survey of all of the shell frames
and adjacent shell plating of the cargo hold.
a) An Overall Survey of the foremost cargo hold, including Close-up Survey is to be carried out to
establish the condition of :
- All shell frames including their upper and lower end attachments, adjacent shell plating, and
transverse bulkheads.
- Areas found suspect according to chapter 1.2.8 at the previous Special Survey.
1.3.1 Thickness measurement is to be carried out to an extent sufficient to determine both general and
local corrosion levels at areas subject to Close-up Survey, as described in 1.2.1 a) and 1.2.2. a) above.
The minimum requirement for thickness measurements are areas found to be Suspect Areas according to
chapter 1.2.8 at the previous Special Survey.
Where Substantial Corrosion as defined in chapter 1.2.9 is found, the extent of thickness measurements
should be increased with the requirements of Table VIII.
1.3.2 The thickness measurement may be dispensed with provided the surveyor is satisfied by the
Close-up Survey, that there is no structural diminution and the Protective Coating where fitted remains
effective.
1.4.1 Where the protective coating in the foremost cargo hold, as defined by Z.9 is found to be in
GOOD condition, the extent of close-up surveys and thickness measurements may be specially
considered.
▲
▲
IV-1
IACS Req. 1992, Rev 11 2000
Z10.3
3. Annual Survey
3.1 Schedule
3.2 Scope
3.2.1 General
3.2.2 Examination of the Hull
3.2.3 Examination of Weather decks
3.2.4 Examination of Cargo pump rooms
3.2.5 Examination of Ballast Tanks
4. Intermediate Survey
4.1 Schedule
4.2 Scope
4.2.1 General
4.2.2 Chemical Tankers 5 - l0 years of Age
4.2.3 Chemical Tankers l0 - 15 years of Age
4.2.4 Chemical Tankers Exceeding 15 years of Age
6. Documentation On Board
6.1 General
6.2 Survey Report File
6.3 Supporting Documents
6.4 Review of Documentation On Board
Notes: 1. This UR Z10.3 is applicable from the first Annual, Intermediate or Special Survey
commencing on or after 1 July 1997.
2. Changes introduced in Rev.2 to UR Z10.3 are to be applied by all Member Societies and
Associates from 1 September 1999.
3. Changes introduced in Rev.3 to UR Z10.3 are to be applied by all Member Societies and
Associates from 1 July 2001.
4. Changes introduced in Rev.4 and Rev.4.1 to UR Z10.3 are to be applied by all Member
Societies and Associates from 1 July 2001.
5. Paragraph 4.2.4.3 is newly introduced in Rev.5 in accordance with Res MSC.105(73) and is to
be implemented from 1 July 2002.
The other changes introduced in Rev.5 are to be implemented within one year of the adoption
▲ ▲
by Council.
ENCLOSURES
Z10.3
cont'd Table I: Minimum requirements to Close-up Surveys at Special Survey of Chemical Tankers
Table III: Minimum requirements to tank testing at Special Survey of Chemical Tankers
Table IV: Requirements for extent of thickness measurements at those areas of substantial
corrosion.
Table VII: Procedures for certification of Firms Engaged in Thickness Gauging of Hull Structures
Annex I: Guidelines for Technical Assessment in conjunction with planning for Enhanced
Surveys of Chemical Tankers Special Survey - Hull.
Z10.3 1. GENERAL
cont'd 1.1 Application
1.1.1 The requirements apply to surveys after construction of all self-propelled Chemical Tankers with
integral tanks i.e. vessels with IMO certificate of fitness for the carriage of dangerous chemicals in bulk.
If a chemical tanker is constructed with both integral and independent tanks, these requirements are
applicable only to that portion of the cargo length containing integral tanks. Combined gas
carriers/chemical tankers with independent tanks within the hull, are to be surveyed as gas carriers.
1.1.2 The requirements apply to surveys of hull structure and piping systems in way of cargo tanks,
pump rooms, cofferdams, pipe tunnels, void spaces within the cargo area and all Ballast Tanks. The
requirements are additional to the classification requirements applicable to the remainder of the ship.
The requirements are not applicable for independent tanks on deck.
1.1.3 The requirements contain the minimum extent of examination, thickness measurements and tank
testing. The survey is to be extended when Substantial Corrosion and/or structural defects are found and
include additional Close-up Survey when necessary.
1.2 Definitions
1.2.1 A Chemical Tanker is a ship constructed or adapted and used for the carriage in bulk of any liquid
product listed in Chapter 17 of the International Code For The Construction And Equipment Of Ships
Carrying Dangerous Chemicals In Bulk, IBC Code.
1.2.2 A Ballast Tank is a tank which is being used solely for water ballast or a tank which is used for
both cargo and ballast will be treated as a Ballast Tank when Substantial Corrosion has been found in
that tank.
1.2.3 An Overall Survey is a survey intended to report on the overall condition of the hull structure and
determine the extent of additional Close-up Surveys.
1.2.4 A Close-up Survey is a survey where the details of structural components are within the close
visual inspection range of the surveyor, i.e. normally within reach of hand.
1.2.5 A Transverse Section includes all longitudinal members such as plating, longitudinals and girders
at the deck, side, bottom, inner bottom and longitudinal bulkheads.
1.2.6 Representative Tanks are those which are expected to reflect the condition of other tanks of similar
type and service and with similar corrosion protection systems. When selecting Representative Tanks
account is to be taken of the service and repair history onboard and identifiable Critical Areas and/or
Suspect Areas.
1.2.7 Suspect Areas are locations showing Substantial Corrosion and/or are considered by the Surveyor
to be prone to rapid wastage.
1.2.8 Substantial Corrosion is an extent of corrosion such that assessment of corrosion pattern indicate a
wastage in excess of 75% of allowable margins, but within acceptable limits.
1.2.9 Protective Coating is to usually be hard coating. In tanks and spaces other than Cargo Tanks, other
coating systems may be considered acceptable as alternatives provided that they are applied in
compliance with the manufacturer's specifications and properly maintained.
Soft Coatings. Where Soft Coatings have been applied, safe access is to be provided for the surveyor to
verify the effectiveness of the coating and to carry out an assessment of the conditions of internal
structures which may include spot removal of the coating. When safe access cannot be provided, the soft
coating is to be removed.
Z10.3-1
IACS Req. 1996/Rev 5, 2002
Z10.3
Z10.3 1.2.11 A Prompt and Thorough repair is a permanent repair completed at the time of survey to the
satisfaction of the Surveyor, therein removing the need for the imposition of any associated condition of
cont'd classification.
1.3 Repairs
1.3.1 Any damage in association with wastage over the allowable limits (including buckling, grooving,
detachment or fracture), or extensive areas of wastage over the allowable limits, which affects or, in the
opinion of the Surveyor, will affect the vessel’s structural, watertight or weathertight integrity, is to be
promptly and thoroughly (see 1.2.11) repaired. Areas to be considered include:
Where adequate repair facilities are not available, consideration may be given to allow the vessel to
proceed directly to a repair facility. This may require discharging the cargo and/or temporary repairs for
the intended voyage.
1.3.2 Additionally, when a survey results in the identification of substantial corrosion or structural
defects, either of which, in the opinion of the Surveyor, will impair the vessel’s fitness for continued
service, remedial measures are to be implemented before the ship continues in service.
2. SPECIAL SURVEY 1
2.1 Schedule
2.1.1 Special Surveys are to be carried out at 5 years intervals to renew the Class Certificate.
2.1.2 The first Special Survey is to be completed within 5 years from the date of the initial classification
survey and thereafter 5 years from the credited date of the previous Special Survey. However, an
extension of class of 3 months maximum beyond the 5th year can be granted in exceptional
circumstances. In this case, the next period of class will start from the expiry date of the Special Survey
before the extension was granted.
2.1.3 For surveys completed within 3 months before the expiry date of the Special Survey, the next
period of class will start from the expiry date of the Special Survey. For surveys completed more than 3
months before the expiry date of the Special Survey, the period of class will start from the survey
completion date.
2.1.4 The Special Survey may be commenced at the 4th Annual Survey and be progressed with a view to
completion by the 5th anniversary date. When the Special Survey is commenced prior to the 4th Annual
Survey, the entire survey is to be completed within 15 months if such work is to be credited to the
Special Survey.
2.1.5 (void)
2.2 Scope
2.2.1 General
2.2.1.1 The Special Survey is to include, in addition to the requirements of the Annual Survey,
examination, tests and checks of sufficient extent to ensure that the hull and related piping, as required in
2.2.1.3, is in a satisfactory condition and is fit for its intended purpose for the new period of class of 5
years to be assigned, subject to proper maintenance and operation and to periodical surveys being carried
out at the due dates.
2.2.1.2 All cargo tanks, salt water Ballast Tanks including double bottom tanks, pumprooms, pipe
tunnels, cofferdams and void spaces bounding cargo tanks, decks and outer hull are to be examined, and
this examination is to be supplemented by thickness measurement and testing as deemed necessary, to
ensure that the structural integrity remains effective. The examination is to be sufficient to discover
Substantial Corrosion, significant deformation, fractures, damages or other structural deterioration.
1 Some member Societies use the term “Special Periodical Survey” others use the term “Class
Renewal Survey” instead of the term “Special Survey”.
▲
Z10.3-2
IACS Req. 1996/Rev 5, 2002
Z10.3
2.2.1.3 Cargo piping on deck and cargo and ballast piping within the above tanks and spaces are to be
Z10.3 examined and operationally tested under working pressure to attending Surveyor’s satisfaction to ensure
cont'd that tightness and condition remain satisfactory. Special attention is to be given to any ballast piping in
cargo tanks and cargo piping in ballast tanks and void spaces, and Surveyors are to be advised on all
cases when the piping, including valves and fittings are open during repair periods and can be examined
internally.
2.2.1.4 The survey extent of combined ballast/cargo tanks is to be evaluated based on the records of
ballast history, extent of corrosion protection system provided, and the extent of corrosion found.
2.2.2.1 A survey in dry dock is to be a part of the Special Survey. The overall and close-up surveys and
thickness measurements, as applicable, of the lower portions of the cargo tanks and water ballast tanks
are to be surveyed in accordance with the applicable requirements for special surveys, if not already
surveyed.
2.2.3.1 Where provided, the condition of the corrosion prevention system of cargo tanks is to be
examined. A ballast tank where a protective coating is found in POOR condition and it is not renewed or
where soft coating has been applied, or where a protective coating has not been applied from the time of
construction, the tank in question is to be examined at annual intervals. Thickness measurements are to
be carried out as considered deemed necessary by the surveyor.
2.3.1 An Overall Survey of all tanks and spaces, excluding fuel oil, lube oil and fresh water tanks, is to
be carried out at each Special Survey. The survey of stainless steel tanks may be carried out as an overall
survey supplemented by Close-up Survey as deemed necessary by the surveyor.
2.3.2 The minimum requirements for Close-up Surveys at Special Survey are given in Table I.
2.3.3 The Surveyor may extend the Close-up Survey as deemed necessary taking into account the
maintenance of the tanks under survey, the condition of the corrosion protection system and also in the
following cases:
a) In particular, tanks having structural arrangements or details which have suffered defects in similar
tanks or on similar ships according to available information.
b) In tanks which have structures approved with reduced scantlings due to an approved corrosion control
system.
2.3.4 For areas in tanks where coatings are found to be in a GOOD condition as defined in 1.2.10, the
extent of Close-up Surveys according to Table I may be specially considered by the Classification
Society.
2.4.1 The minimum requirements for thickness measurements at Special Survey are given in Table II.
Thickness measurement of stainless steel hull structure and piping may be waived by the Classification
Society, except for clad steel plating.
2.4.2 Provisions for extended measurements for areas with Substantial Corrosion as defined in 1.2.8, are
given in Table IV, and as may be additionally specified in the Survey Programme as required by 5.1.
2.4.3 The Surveyor may further extend the thickness measurements as deemed necessary.
2.4.4 For areas in tanks where coating are found to be in a GOOD condition as defined in 1.2.10, the
extent of thickness measurements according to Table II may be specially considered, by the
Classification Society.
2.4.5 Transverse sections are to be chosen where the largest reductions are suspected to occur or are
revealed from deck plating measurements.
2.4.6 In cases where two or three sections are to be measured, at least one is to include a Ballast Tank
▲
Z10.3-3
IACS Req. 1996/Rev 5, 2002
Z10.3
2.5.2 The Surveyor may extend the tank testing as deemed necessary.
2.5.3 Tanks are to be tested with a head of liquid to the top of access hatches for cargo tanks, or top of
air pipes for Ballast Tanks, if this gives a higher pressure.
2.6.1 Selected steel cargo pipes outside cargo tanks and ballast pipes passing through cargo tanks are to
be:
- Thickness measured at random or selected pipe lengths to be opened for internal inspection
- Pressure tested to the maximum working pressure.
Special attention is to be given to cargo/slop discharge piping through Ballast Tanks and void spaces.
3. ANNUAL SURVEY
3.1 Schedule
3.1.1 Annual Surveys are to be held within 3 months before or after anniversary date from the date of the
initial classification survey or of the date credited for the last Special Survey.
3.2 Scope
3.2.1 General
3.2.1.1 The survey is to consist of an examination for the purpose of ensuring, as far as practicable, that
the hull and piping are maintained in a satisfactory condition.
3.2.2.1 Examination of the hull plating and its closing appliances as far as can be seen.
3.2.3.1 Examination of cargo tank openings including gaskets, covers, coamings and flame screens.
3.2.3.3 Examination of flame screens on vents to all bunker, oily ballast and oily slop tanks.
3.2.3.4 Examination of cargo, bunker and vent piping systems, including vent masts and headers.
3.2.5.1 Examination of Ballast Tanks when required as a consequence of the results of the Special
Survey and Intermediate Survey. When considered necessary by the surveyor, thickness measurement is
to be carried out and if the results of these thickness measurements indicate that Substantial Corrosion is
found, the extent of thickness measurements is to be increased in accordance with Table IV.
3.2.5.2 Chemical Tankers exceeding 15 years of Age: All Ballast Tanks adjacent to (i.e. with a
▲ ▲
Z10.3-4
common plane boundary) a cargo tank with any means of heating are to be examined internally. When
Z10.3 considered necessary by the surveyor, thickness measurements are to be carried out and if the results of
these thickness measurements indicate that Substantial Corrosion is found, the extent of thickness
cont'd
measurements is to be increased in accordance with Table IV. Tanks or areas in tanks where coating was
found to be in GOOD condition at the previous Intermediate or Special survey may be specially
considered by the Classification Society.
4. INTERMEDIATE SURVEY
4.1 Schedule
4.1.1 The Intermediate Survey is to be held at or between either the 2nd or 3rd Annual Survey.
4.1.2 Those items which are additional to the requirements of the Annual Surveys may be surveyed
either at or between the 2nd and 3rd Annual Survey.
4.2 Scope
4.2.1 General
4.2.1.1 The survey extent of cargo and ballast tanks dependent on the age of the vessel is specified in Ch
4.2.2 to 4.2.4
4.2.1.2 For weather decks, an examination as far as applicable of cargo, bunker, ballast, steam and vent
piping systems as well as vent masts and headers is to be carried out. If upon examination there is any
doubt as to the condition of the piping, the piping may be required to be pressure tested, thickness
measured or both.
4.2.2.2 For tanks used for salt water ballast, an Overall Survey of Representative Tanks selected by the
Surveyor is to be carried out. If such inspections reveal no visible structural defects, the examination
may be limited to a verification that the Protective Coating remains efficient
4.2.2.3 Where POOR Coating Condition, corrosion or other defects are found in salt water Ballast Tanks
or where a Protective Coating was not applied from time of construction, the examination is to be
extended to other Ballast Tanks of the same type.
4.2.2.4 In salt water Ballast Tanks, where a Protective Coating is found in POOR condition as defined in
1.2.10, and it is not renewed, where soft coating has been applied, or where a Protective Coating was not
applied from time of construction, maintenance of class is to be subject to the tanks in question being
examined and thickness measurements carried out as considered necessary at annual intervals.
4.2.3.2 An Overall Survey of at least two Representative Cargo Tanks is to be carried out. In addition to
the structure, fittings such as valves and instrumentation is to be subject to general examination.
4.2.3.3 For tanks used for salt water ballast including combined cargo/ballast tanks, an Overall Survey of
all such tanks is to be carried out. If such survey reveal no visible structural defects, the Survey may be
limited to a verification that the Protective Coatings remain efficient.
Ballast Tanks: To the same extent as previous Special Survey after second Special Survey.
Cargo Tanks: Two combined cargo/ballast tanks. The extent of survey is to be based
on the record of the previous Special Survey, and repair history of the tanks.
For areas in tanks where coating are found to be in GOOD condition as defined by 1.2.10, the
▲
Z10.3-5
IACS Req. 1996/Rev 5, 2002
Z10.3
extent of the Close-up surveys may be specially considered by the Classification Society.
Z10.3
cont'd 4.2.3.5 Extent of Thickness Measurement:
The minimum requirement for thickness measurements at the Intermediate Survey are areas found to be
Suspect Areas according to 1.2.7 at the previous Special Survey. Where substantial corrosion as defined
in 1.2.8 is found, the extent of thickness measurements is to be increased in accordance with the
requirements of Table IV.
4.2.4 Chemical Tankers Exceeding 15 years of Age, the following shall apply:
4.2.4.1The requirements of the Intermediate Survey are to be to the same extent as the previous Special
Survey as required in 2 and 5.1. However, pressure testing of cargo and ballast tanks is not required
unless deemed necessary by the attending surveyor.
4.2.4.2 In application of 4.2.4.1, the intermediate survey may be commenced at the second annual
survey and be progressed during the succeeding year with a view to completion at the third annual survey
in lieu of the application of 2.1.4.
4.2.4.3 In application of 4.2.4.1, a survey in dry dock is to be part of the intermediate survey. The
overall and close-up surveys and thickness measurements, as applicable, of the lower portions of the
cargo tanks and water ballast tanks are to be survyed in accordance with the applicable requirements for
intermediate surveys, if not already survyed.
5.1.1 A specific Survey Programme is to be worked out in advance of the Special Survey by the Owner
in cooperation with the Classification Society. The Survey Programme is to be in a written format.
5.1.2 In developing the Survey Programme, the following documentation is to be collected and
consulted with a view to selecting tanks, areas, and structural elements to be examined:
5.1.3 The submitted Survey Programme is to account for and comply, as a minimum, with the
requirements of Tables I, II and paragraph 2.5 for close-up survey, thickness measurement and tank
testing, respectively, and is to include relevant information including at least:
5.1.4 The Classification Society will advise the Owner of the maximum acceptable structural corrosion
diminution levels applicable to the vessel.
▲
Z10.3-6
Z10.3 5.1.5 Use may also be made of the Guidelines for Technical Assessment in Conjunction with Planning
cont'd for Enhanced Surveys of Chemical Tankers Special Survey - Hull, contained in Annex I. These
guidelines are a recommended tool which may be invoked at the discretion of the IACS Member Society,
when considered necessary and appropriate, in conjunction with the preparation of the required Survey
Programme.
5.2.1 The Owner is to provide the necessary facilities for a safe execution of the survey.
5.2.2 Tanks and spaces are to be safe for access, i.e. gas freed, ventilated, and illuminated.
5.2.3 Tanks and spaces are to be sufficiently clean and free from water, scale, dirt, oil residues, etc. to
reveal significant corrosion, deformation, fractures, damages or other structural deterioration. In
particular this applies to areas which are subject to thickness measurement.
5.3.1 For Overall Survey, means are to be provided to enable the surveyor to examine the hull structure
in a safe and practical way.
5.3.2 For Close-up Survey, one or more of the following means for access, acceptable to the Surveyor, is
to be provided:
5.4.1 Thickness measurement is normally to be carried out by means of ultrasonic test equipment. The
accuracy of the equipment is to be proven to the Surveyor as required.
5.4.2 One or more of the following fracture detection procedures may be required if deemed necessary
by the Surveyor:
- radiographic equipment
- ultrasonic equipment
- magnetic particle equipment
- dye penetrant
5.5.1 Survey at sea or at anchorage may be accepted provided the Surveyor is given the necessary
assistance from the personnel onboard. Necessary precautions and procedures for carrying out the survey
are to be in accordance with 5.1, 5.2, 5.3 and 5.4.
5.5.2 A communication system is to be arranged between the survey party in the tank and the
responsible officer on deck. This system is to also include the personnel in charge of Ballast pump
handling if boats or rafts are used.
5.5.3 Explosimeter, oxygen-meter, breathing apparatus, life line and whistles are to be at hand during the
survey. When boats or rafts are used, appropriate life jackets are to be available for all participants. Boats
or rafts are to have satisfactory residual buoyancy and stability even if one chamber is ruptured. A safety
check-list is to be provided.
5.5.4 Surveys of tanks by means of boats or rafts may only be undertaken at the sole discretion of the
Surveyor, who is to take into account the safety arrangements provided, including weather forecasting
▲
▲
Z10.3-7
6.1 General
6.1.1 The owner is to supply and maintain on board documentation as specified in 6.2 and 6.3, which
should be readily available for the surveyor.
6.1.2 The documentation is to be kept on board for the life time of the ship.
6.2.2 The Survey Report File is to be available also in the Owner's and the Classification Society's
management offices.
6.4.1 Prior to inspection, the Surveyor is to examine the completeness of the documentation onboard,
and its contents as a basis for the survey.
7.1 General
7.1.1 The required thickness measurements, if not carried out by the Society itself, are to be witnessed
by a surveyor of the Society. The surveyor is to be on board to the extent necessary to control the
process.
7.1.2 The thickness measurement company is to be part of the survey planning meeting to be held prior
to commencing the survey.
▲ ▲
Z10.3-8
7.3 Reporting
7.3.1 A thickness measurement report is to be prepared. The report is to give the location of
measurements, the thickness measured as well as corresponding original thickness. Furthermore, the
report is to give the date when the measurements were carried out, type of measurement equipment,
names of personnel and their qualifications and has to be signed by the operator. The thickness
measurement report is to follow the principles as specified in the Recommended Procedures for
Thickness Measurements of Chemical Tankers, contained in Annex II.
7.3.2 The Surveyor is to verify and countersign the thickness measurements report.
8.1.1 The data and information on the structural condition of the vessel collected during the survey is to
be evaluated for acceptability and continued structural integrity of the vessel.
8.2 Reporting
8.2.2 An Executive Hull Summary of the survey and results is to be issued to the Owner as shown in
Table IX and placed on board the vessel for reference at future surveys. The Executive Hull Summary is
to be endorsed by the Classification Society's head office or regional managerial office.
▲ ▲
Z10.3-9
Z10.3
TABLE I
Table of minimum requirements to Close-up Surveys at Special Survey
of Chemical Tankers,
Special survey No.1 Special survey No. 2 Special survey No. 3 Special survey No.4
A ONE TRANSVERSE SECTION E ALL PLATING AND INTERNAL E ALL PLATING AND INTERNAL As special survey No.3
in a ballast wing tank or ballast double STRUCTURE - in a ballast wing tank or STRUCTURE - in all ballast tanks
hull tank 1) ballast doublehull tank 1)
B ONE DECK TRANSVERSE in B ONE DECK TRANSVERSE - in each E ALL PLATING AND INTERNAL
in a cargo tank or on deck remaining ballast tank or on deck. STRUCTURE - in a cargo wing tank
Z10.3-10
D ONE TRANSVERSE C BOTH TRANSVERSE BULKHEAD
BULKHEAD - in a cargo centre tank - in a ballast wing tank or ballast double hull tank1)
1) Double hull tank - including double bottom and side tank even though these tanks are separate.
A) Complete transverse web frame ring B) Deck transverse including C) Transverse bulkhead complete - including
▲ including adjacent structural members. adjacent deck structural members girder system and adjacent members
D) Transverse bulkhead lower part - including E) Complete tank - including all tank boundaries
girder system and adjacent structural members and internal structure, and external structure
on deck in way of the tank.
cont'd
Z10.3
TABLE II
Table of minimum requirements to thickness measurements
at Special Survey of Chemical Tankers
1. One section of deck plating 1. Within the cargo area: 1. Within the cargo area: 1. Within the cargo area:
for the full beam of the ship
within the cargo area
(in way of a ballast tank, if .1 Each deck plate .1 Each deck plate .1 Each deck plate
any, or a cargo tank used
primarily for water ballast) .2 One Transverse section .2 Two Transverse sections .2 Three Transverse sections
Z10.3-11
members subject to close-up members subject to close-up members subject to close-up members subject to close-up
survey according to Table I, survey according to Table I, survey according to Table I, survey according to Table I,
for general assessment and for general assessment and for general assessment and for general assessment and
recording of corrosion pattern recording of corrosion pattern recording of corrosion pattern recording of corrosion pattern
4. Selected wind and water strakes 4. Selected wind and water strakes 4. Selected wind and water strakes
outside the cargo area outside the cargo area outside the cargo area
5. All wind and water strakes 5. All wind and water strakes
within the cargo area within the cargo area
▲
Z10.3
cont'd
Z10.3
Z10.3
TABLE III
Table of minimum requirements to tank testing
at Special Survey of Chemical Tankers
1. All ballast tank boundaries 1. All ballast tank boundaries 1. All ballast tank boundaries 1. All ballast tank boundaries
2. Cargo tank boundaries facing 2. Cargo tank boundaries facing 2. Cargo tank boundaries facing 2. Cargo tank boundaries facing
ballast tanks, void spaces, pipe ballast tanks, void spaces, pipe ballast tanks, void spaces, pipe ballast tanks, void spaces, pipe
tunnels, representative fuel oil tunnels, representative fuel oil tunnels, representative fuel oil tunnels, representative fuel oil
tanks, pump-rooms or tanks, pump-rooms or cofferdams tanks, pump-rooms or cofferdams tanks, pump-rooms or
cofferdams cofferdams
3. All cargo tank bulkheads which 3. All remaining cargo tank 3. All remaining cargo tank
form the boundaries of segregated bulkheads bulkheads
Z10.3-12
cargoes
▲
Z10.3
TABLE IV
Z10.3 Sheet 1
cont'd
Requirements for extent of thickness measurement at those areas of substantial corrosion. Special
Survey of Chemical Tankers within the cargo tank length
1. Inner Bottom and Suspect plate plus adjacent plates. 5 point pattern for each panel
Bottom plating Measurements around and under between longitudinals over 1
all bell mouths and pump wells metre length
2. Inner Bottom and Three longitudinals where plates 3 measurements in line across
Bottom Longitudinals measured flange and 3 measurements on
vertically web
Z10.3-13
Z10.3 TABLE IV
Sheet 2
cont'd
Requirements for extent of thickness measurement at those areas of substantial corrosion. Special
Survey of Chemical Tankers within the cargo tank length.
DECK STRUCTURE
3. Deck girders and brackets At fore and aft transverse Vertical line of single measure-
bulkhead, bracket toes and in ments on web plating with one
centre of tanks measurement between each panel
stiffener, or a minimum of three
measurements. Two
measurements across face flat.
5 point pattern on girder/bhd
brackets.
4. Deck transverse webs Minimum of two webs with 5 points pattern over about 2
measurements at middle and square metre areas. Single
both ends of span measurements on face flat
NOTE: For tanks where substantial corrosion covers more than 20% of the deck surface, the whole
deck structure including longitudinal and web frames above the tank is to be thickness measured in
accordance with above.
▲
Z10.3-14
TABLE IV
Z10.3 Sheet 3
cont'd
Requirements for extent of thickness measurement at those areas of substantial corrosion. Special
Survey of Chemical Tankers within the cargo tank length.
2. All other strakes Plating between every 3rd pair Single measurement
of longitudinals in same 3 bays
5. Longitudinals - bracket Minimum of three at top middle 5 point pattern over area of
and bottom of tank in same 3 bays bracket
6. Web frames and cross 3 webs with minimum of three 5 point pattern over about 2
ties locations on each web, square metre area, plus single
including in way of cross tie measurements on web frame
connections and cross tie face flats
▲
Z10.3-15
Z10.3 TABLE IV
Sheet 4
cont'd
Requirements for extent of thickness measurement at those areas of substantial corrosion. Special
Survey of Chemical Tankers within the cargo tank length.
3. Strakes in corrugated Plating for each change of 5 point pattern over about 1
bulkheads scantling at centre of panel square metre of plating
and at flange or fabricated
connection
6. Deep webs and girders Measurements at toe of bracket For web, 5 point pattern over
and at centre of span about 1 square metre.
3 measurements across face
flat.
7. Stringer platforms All stringers with measurements 5 point pattern over 1 square
at both ends and middle metre of area plus single
measurements near bracket
toes and on face flats
▲
Z10.3-16
Table V
Z10.3
cont'd Ship Name:
Deck:
Bottom:
Side:
Long.
Bulkheads:
Transv.
Bulkheads:
Overdue Surveys:
Comments:
Date of Inspection:
Inspected by:
Signature:
▲
Z10.3-17
TABLE VII
Z10.3
cont'd
PROCEDURES FOR CERTIFICATION OF FIRMS ENGAGED IN THICKNESS
MEASUREMENT OF HULL STRUCTURES
1. Application
This guidance applies for certification of the firms which intend to engage in the thickness
measurement of hull structures of the vessels.
3. Certification
(1) Upon satisfactory results of both the audit of the firm in 2(2) and the demonstration tests in 2(3)
above, the Society will issue a Certificate of Approval as well as a notice to the effect that the
thickness measurement operation system of the firm has been certified by the Society.
In case where any alteration to the certified thickness measurement operation system of the firm is
made, such an alteration is to be immediately informed to the Society. Re-audit is made where
deemed necessary by the Society.
5. Cancellation of Approval
(2) Where the Society's surveyor found any deficiencies in the approved thickness measurement
operation systems of the firm.
(3) Where the firm failed to inform of any alteration in 4 above to the Society.
▲
Z10.3-18
TABLE VIII
Z10.3
cont'd
REPORTING PRINCIPLES
Reporting forms are to be worked out individually by the respective Classification Societies. As a
principle the following content of reports for tanker structures is to be included as applicable for the
survey:
1.0 Type of Survey (Special Survey, Intermediate Survey, Annual Survey, Other)
The structure of the reporting content may be different, depending on the report system for the respective
Societies.
▲
Z10.3-19
GENERAL PARTICULARS
TYPE OF CONVERSION:
a) The survey reports and documents listed below have been reviewed by the undersigned and
found to be satisfactory
c) The hull special survey has been completed in accordance with the Regulations on [date]
OFFICE DATE
OFFICE DATE
1)
2)
3)
4)
5)
6)
▲
Z10.3-20
TABLE IX(ii)
Z10.3
cont'd
EXECUTIVE HULL SUMMARY
E) Thickness
measurements: – Reference to Thickness Measurement report
– Summary of where measured
– Separate form indicating the tanks/areas with Substantial
Corrosion, and corresponding
* Thickness diminution
* Corrosion pattern
H) Condition of Class/Recommendations:
Z10.3-21
1) 2)
Remarks
1) Substantial corrosion, i.e. 75 – 100% of acceptable margins wasted
2) P = Pitting
C = Corrosion in General
Any bottom plating with a pitting intensity of 20% or more, with wastage in the substantial
corrosion range or having an average depth of pitting of 1/3 or more of actual plate thickness is to
be noted.
▲
Z10.3-22
TABLE IX (iv)
Z10.3
cont'd
TANK PROTECTION
1) 2) 3)
Remarks:
1)
All segregated ballast tanks and combined cargo/ballast tanks to be listed.
2)
C = Coating A = Anodes NP = No Protection
3)
Coating condition according to the following standard
If coating condition "POOR" is given, extended annual surveys are to be introduced. This is to be
noted in part G) of the Executive Hull Summary.
▲
Z10.3-23
Z10.3 ANNEX I
cont'd
GUIDELINES FOR TECHNICAL ASSESSMENT IN CONJUNCTION WITH
PLANNING FOR ENHANCED SURVEYS OF CHEMICAL TANKERS
SPECIAL SURVEY - HULL
Contents:
1. INTRODUCTION
2. PURPOSE AND PRINCIPLES
2.1 Purpose
2.2 Minimum Requirements
2.3 Timing
2.4 Aspects to be Considered
3. TECHNICAL ASSESSMENT
3.1 General
3.2 Methods
3.2.1 Design Details
3.2.2 Corrosion
3.2.3 Locations for Close-up Survey and Thickness Measurement
REFERENCES
1.0 INTRODUCTION
These guidelines contain information and suggestions concerning technical assessments which may be of
use in conjunction with the planning of enhanced special surveys of chemical tankers. As indicated in
section 5.1.5 of IACS Unified Requirement Z10.3, "Hull Surveys of Chemical Tankers," (Ref. 1), the
guidelines are a recommended tool which may be invoked at the discretion of an IACS Member Society,
when considered necessary and appropriate, in conjunction with the preparation of the required Survey
Programme.
2.1 Purpose
The purpose of the technical assessments described in these guidelines is to assist in identifying critical
structural areas, nominating suspect areas and in focusing attention on structural elements or areas of
structural elements which may be particularly susceptible to, or evidence a history of, wastage or
damage. This information may be useful in nominating locations, areas and tanks for thickness
measurement, close-up survey and tank testing.
Critical Structural Areas are locations which have been identified from calculations to require monitoring
or from the service history of the subject ship or from similar or sister ships (if available) to be sensitive
to cracking, buckling or corrosion which would impair the structural integrity of the ship.
2.3 Timing
As with other aspects of survey planning, the technical assessments described in these guidelines should
be worked out by the Owner or operator in cooperation with the Classification Society well in advance of
the commencement of the Special Survey, i.e., prior to commencing the survey and normally at least 12
to 15 months before the survey's completion due date.
▲
Z10.3-24
3.1 General
There are three basic types of possible failure which may be the subject of technical assessment in
connection with planning of surveys; corrosion, cracks and buckling. Contact damages are not normally
covered by the survey plan since indents are usually noted in memoranda and assumed to be dealt with as
a normal routine by Surveyors.
Technical assessments performed in conjunction with the survey planning process are, in principle, to be
as shown schematically in Figure 1 depicts, schematically, how technical assessments can be carried out
in conjunction with the survey planning process. The approach is basically an evaluation of the risk in
the following aspects based on the knowledge and experience related to:
- Design
- Corrosion
The approach is basically an evaluation of the risk based on the knowledge and experience related to
design and corrosion.
The design is to be considered with respect to structural details which may be susceptible to buckling or
cracking as a result of vibration, high stress levels or fatigue.
Corrosion is related to the ageing process, and is closely connected with the quality of corrosion
protection at newbuilding, and subsequent maintenance during the service life. Corrosion may also lead
to cracking and/or buckling.
3.2 Methods
This information may be found in the survey reports and/or the Owner's files, including the results of the
Owner's own inspections. The defects are to be analyzed, noted and marked on sketches.
In addition, general experience is to be utilized. For example, reference should be made to TSCF's
"Guidance Manual for the Inspection and Condition Assessment of Tanker Structures," (Ref. 2), which
contains a catalogue of typical damages and proposed repair methods for various tanker structural details.
Such figures should be used together with a review of the main drawings, in order to compare with the
actual structure and search for similar details which may be susceptible to damage. An example is shown
in Figure 2.
The review of the main structural drawings, in addition to using the above mentioned figures, is to
include checking for typical design details where cracking has been experienced. The factors
contributing to damage are to be carefully considered.
▲
Z10.3-25
Z10.3 The use of high tensile steel (HTS) is an important factor. Details showing good service experience
where ordinary, mild steel has been used may be more susceptible to damage when HTS, and its higher
cont'd associated stresses, are utilized. There is extensive and, in general, good experience, with the use of HTS
for longitudinal material in deck and bottom structures. Experience in other locations, where the
dynamic stresses may be higher, is less favourable, e.g. side structures.
In this respect, stress calculations of typical and important components and details, in accordance with
the latest Rules or other relevant methods, may prove useful and are to be considered.
The selected areas of the structure identified during this process are to be recorded and marked on the
structural drawings to be included in the Survey Programme.
3.2.2 Corrosion
In order to evaluate relative corrosion risks, the following information is generally to be considered:
Ref. 3 gives definitive examples which can be used for judging and describing coating condition, using
typical pictures of conditions.
The evaluation of corrosion risks is to be based on information in Ref. 3, together with relevant
information on the anticipated condition of the ship as derived from the information collected in order to
prepare the Survey Programme and the age of the ship.
The various tanks and spaces are to be listed with the corrosion risks nominated accordingly.
Z10.3-26
Input:
Z10.3 Drawings, Reports, Coating Condition
cont'd Acceptable Corrosion Collection of Information Anode Condition
Allowance Usage of Tanks
Analyse Hull
Damage for Corrosion Damage
Similar Ships This Ship
Where Available
Corrosion Damage
Hull Damage : Similar Ship where
General Experience Available
Survey Programme
Acceptance by
Class & Owner
Survey
Z10.3-27
SHELL PLATING
OR LONGITUDINAL FLAT BAR
BULKHEAD STIFFENER
A A A A
FRACTURED
WELD/WEB ★
FRACTURE
LUG
★
FRACTURE
X
1. Asymmetrical connection of flat bar stiffener resulting in high peak stresses at the heel of
the stiffener under fatigue loading.
2. Insufficient area of connection of longitudinal to web plate.
3. Defective weld at return around the plate thickness.
4. High localised corrosion at areas of stress concentration such as flat bar stiffener connections,
corners of cut-out for the longitudinal and connection of web to shell at cut-outs.
5 High stress in the web of the transverse.
Z10.3-28
Z10.3
cont'd
ANNEX II
Recommended Procedures
for Thickness Measurements of
Chemical Tankers
Z10.3-29
Z10.3 CONTENTS
cont'd
Sheet 1 - Contents
Sheet 2 - Instructions
REPORTS
Sheet 4 - Report TM1-T for recording the thickness measurements of all deck plating, all
bottom shell plating and side shell plating
Sheet 5 - Report TM2-T (i) for recording the thickness measurement of shell and deck
plating at transverse sections - strength deck and sheerstrake plating
Sheet 6 - Report TM2-T (ii) for recording the thickness measurement of shell and deck
plating at transverse sections - shell plating
Sheet 7 - Report TM3-T for recording the thickness measurement of longitudinal members
at transverse sections
Sheet 9 - Report TM5-T for recording the thickness measurement of W.T./O.T. transverse
bulkheads
GUIDANCE
Sheet 11 - Chemical tanker typical transverse sections. The diagram includes details of the items
to be measured and the report forms to be used.
Sheet 12 - Transverse section outline. The diagram may be used for those ships where the
diagram on sheet 11 is not suitable
Z10.3-30
Z10.3
cont'd
INSTRUCTIONS
Z10.3-31
Z10.3
cont'd
GENERAL PARTICULARS
Ships name:-
IMO Number:-
Port of registry:-
Gross tons:-
Deadweight:-
Date of build:-
Classification society:-
____________________________________________________________________________________
Certificate No.
Place of measurement
Qualification of operator:-
____________________________________________________________________________________
Z10.3-32
STRAKE
Z10.3-33
2nd
1st
Amidships
1st aft
2nd
3rd
4th
5th
6th
7th
8th
9th
10th
11th
12th
Z10.3 NOTES
cont'd
B- All keel, bottom shell plating and bilge plating within the cargo area.
C- Side shell plating including selected wind and water strakes outside cargo area
2.1 For strength deck indicate the number of the strake of plating inboard from the stringer
plate.
2.2 For bottom plating indicate the number of the strake of plating outboard from the keel
plate.
2.3 For side shell plating give number of the strake of plating below sheerstrake and letter
as shown on shell expansion.
4. Measurements are to be taken at the forward and aft areas of all and where plates cross
ballast/cargo tank boundaries separate measurements for the area of plating in way of each type of
tank are to be recorded.
5. The single measurements recorded are to represent the average of multiple measurements.
Z10.3-34
FIRST TRANSVERSE SECTION AT FRAME SECOND TRANSVERSE SECTION AT FRAME THIRD TRANSVERSE SECTION AT FRAME
NUMBER NUMBER NUMBER
Org. Max. Diminution Diminution Org. Max. Diminution Diminution Org. Max. Diminution Diminution
No. Thk. Alwb. Gauged P S No. Thk. Alwb. Gauged No. Thk. Alwb. Gauged P S
STRAKE Dim. P S Dim.
or Dim. or or
POSITION
Letter mm mm
P S mm % mm % Letter mm mm S mm % mm % Letter mm mm P S mm % mm %
P
Stringer Plate
1st strake inboard
2nd
3rd
4th
5th
Z10.3-35
6th
7th
8th
9th
10th
11th
12th
13th
14th
centre strake
sheer strake
TOPSIDE
TOTAL
Z10.3 NOTES
cont'd
One, two or three sections within the cargo area comprising of the structural items (1), (2) and
(3) as shown on the diagrams of typical transverse sections.
3. The topside area comprises deck plating, stringer plate and sheerstrake (including rounded
gunwales).
5. The single measurements recorded are to represent the average of multiple measurements.
Z10.3-36
SHELL PLATING
Z10.3-37
8th
9th
10th
11th
12th
13th
14th
15th
16th
17th
18th
19th
20th
keel strake
BOTTOM TOTAL
Z10.3 NOTES
cont'd
One, two or three sections within the cargo area comprising of the structural items (4), (5) and
(6) and (7) as shown on the diagrams of typical transverse sections.
4. The single measurements recorded are to represent the average of multiple measurements.
Z10.3-38
Org. Max. Diminution Diminution Org. Max. Diminution Diminution Org. Max. Diminution Diminution
Item Thk. Allow. Gauged P S Item Thk. Allow. Gauged Item Thk. Allow. Gauged P S
STRUCTURAL Dim. P S Dim.
No. Dim. No. No.
MEMBER
mm mm P S mm % mm % mm mm P S mm % mm % mm mm P S mm % mm %
Z10.3-39
Operators Signature...................................................................... Surveyors Signature .................................................................................... NOTES – See Reverse
Z10.3 Annex II - Sheet 7
Z10.3 Annex II
Z10.3 NOTES
cont'd
One, two or three sections within the cargo area comprising of the appropriate structural items
(8) to (20) as shown on the diagrams of typical transverse sections.
3. The single measurements recorded are to represent the average of multiple measurements.
Z10.3-40
LOCATION OF STRUCTURE:
Max.
Original Diminution Diminution
Alwb. Gauged
STRUCTURAL MEMBER ITEM Thickness Dim.
P S
mm mm P S mm % mm %
Z10.3-41
Operators Signature.............................................................. Surveyors Signature .......................................................................... NOTES – See Reverse
Z10.3 Annex II - Sheet 8
Z10.3 Annex II
Z10.3 NOTES
cont'd
1. This report is to be used for recording the thickness measurements of transverse structural
members, comprising of the appropriate structural items (25) to (33) as shown on diagrams of
typical transverse section.
3. The single measurements recorded are to represent the average of multiple measurements.
Z10.3-42
Z10.3-43
Operators Signature.............................................................. Surveyors Signature .......................................................................... NOTES – See Reverse
Z10.3 Annex II - Sheet 9
Z10.3 Annex II
Z10.3 NOTES
cont'd
1. This report is to be used for recording the thickness measurement of W.T./O.T. transverse
bulkheads.
3. The single measurements recorded are to represent the average of multiple measurements.
Z10.3-44
LOCATION OF STRUCTURE:
Z10.3-45
Operators Signature.............................................................. Surveyors Signature .......................................................................... NOTES – See Reverse
Z10.3 Annex II - Sheet 10
Z10.3 Annex II
Z10.3 NOTES
cont'd
1. This report is to be used for recording the thickness measurement of miscellaneous structural
members.
2. The single measurements recorded are to represent the average of multiple measurements.
Z10.3-46
cont'd Tanker - Typical transverse section indicating longitudinal and transverse members
9
1 8
9
9
2 8
3
25
27
10
11
29 29
32
31
17
32
4
16 17
32
29 29
18
32 15
14 13 13
13
30 26
5 7
12
12 6
Z10.3-47
Z10.3-48
cont'd
Close-up Survey Requirements
C C
B B
Girder
E
Girder
Girder
A
D D
D
Lower stool
Z10.3-49
2. SPECIAL SURVEY 3
2.1 SCHEDULE 3
2.2 SCOPE 4
3. ANNUAL SURVEY 6
3.1 SCHEDULE 6
3.2 SCOPE 6
4. INTERMEDIATE SURVEY 7
4.1 SCHEDULE 7
4.2 SCOPE 8
6. DOCUMENTATION ON BOARD 12
6.1 GENERAL 12
6.2 SURVEY REPORT FILE 12
6.3 SUPPORTING DOCUMENTS 13
6.4 REVIEW OF DOCUMENTATION ON BOARD 13
7.1 GENERAL 13
7.2 CERTIFICATION OF THICKNESS MEASUREMENTS COMPANY 14
7.3 REPORTING 14
ENCLOSURES
Z10.4
cont’d Table I: Minimum requirements for Close-up Surveys at Special Survey of Double Hull Oil Tankers
Z10.4-15
Table II: Minimum requirements for thickness measurements at Special Survey of Double Hull Oil
Tankers Z10.4-16
Table III: Minimum requirements for tank testing at Special Survey of Double Hull Oil Tankers
Z10.4-17
Table IV: Requirements for extent of thickness measurements at those areas of substantial
corrosion. Z10.4-18-Z10.4-22
Table V: Minimum requirements for overall and close-up survey and thickness measurements at
intermediate survey of double hull oil tankers Z10.4-23
Table VII: Procedures for Certification of Firms Engaged in Thickness Gauging of Hull Structures
Z10.4-27
Table VIII: Reporting Principles Z10.4-28
Annex I: Guidelines for Technical Assessment in conjunction with planning for Enhanced Surveys
of Double Hull Oil Tankers Special Survey - Hull Z10.4I-1-Z10.4I-5
Annex II: Recommended Procedures for Thickness Measurements of Double Hull Oil Tankers
Z10.4II-1-Z10.4II-22
Annex III: Criteria for Longitudinal Strength of Hull Girder for Oil Tankers
Appendix 1: Calculation criteria of section modulus of midship section of hull girder
Appendix II: Diminution limit of minimum longitudinal strength of ships in service
▲
Z10.4
Z10.4 1. GENERAL
cont’d
1.1 Application
1.1.1
The requirements apply to all self-propelled Double Hull Oil Tankers after construction.
1.1.2
The requirements apply to surveys of hull structure and piping systems in way of cargo tanks,
pump rooms, cofferdams, pipe tunnels, void spaces within the cargo area and all ballast tanks.
The requirements are additional to the classification requirements applicable to the remainder of
the ship.
1.1.3
The requirements contain the minimum extent of examination, thickness measurements and tank
testing. The survey is to be extended when Substantial Corrosion and/or structural defects are
found and include additional Close-up Survey when necessary.
1.2 Definitions
A Double Hull Oil Tanker is a ship which is constructed primarily for the carriage of oil1) in
bulk, which have the cargo tanks protected by a double hull which extends for the entire length
of the cargo area, consisting of double sides and double bottom spaces for the carriage of water
ballast or void spaces.
A Ballast Tank is a tank which is being used solely for water ballast or, where applicable, a tank
which is used for both cargo and ballast will be treated as a Ballast Tank when substantial
corrosion has been found in that tank.
Z10.4-1
A Transverse Section includes all longitudinal members such as plating, longitudinals and
girders at the deck, sides, bottom, inner bottom and longitudinal bulkheads.
Representative Tanks are those which are expected to reflect the condition of other tanks of
similar type and service and with similar corrosion protection systems. When selecting
Representative Tanks account is to be taken of the service and repair history onboard and
identifiable Critical Structural Areas and/or Suspect Areas.
Suspect Areas are locations showing Substantial Corrosion and/or are considered by the
Surveyor to be prone to rapid wastage.
Protective Coating is to usually be epoxy coating or equivalent. Other coating systems may be
considered acceptable as alternatives provided that they are applied and maintained in
compliance with the manufacturer’s specification. Where Soft Coatings have been applied,
safe access is to be provided for the surveyor to verify the effectiveness of the coating and to
carry out an assessment of the conditions of internal structures which may include spot
removal of the coating. When safe access cannot be provided, the soft coating is to be
removed.
Z10.4-2
IACS Req. 2001
Z10.4
A Prompt and Thorough Repair is a permanent repair completed at the time of survey to the
satisfaction of the Surveyor, therein removing the need for the imposition of any associated
condition of classification.
1.3 Repairs
1.3.1
Any damage in association with wastage over the allowable limits (including buckling,
grooving, detachment or fracture), or extensive areas of wastage over the allowable limits,
which affects or, in the opinion of the Surveyor, will affect the vessel’s structural, watertight or
weathertight integrity, is to be promptly and thoroughly (see 1.2.12) repaired. Areas to be
considered include:
For locations where adequate repair facilities are not available, consideration may be given to
allow the vessel to proceed directly to a repair facility. This may require discharging the cargo
and/or temporary repairs for the intended voyage.
1.3.2
2. SPECIAL SURVEY(2)
2.1 Schedule
2.1.1
Special Surveys are to be carried out at 5 years intervals to renew the Class Certificate.
Note: 2) Some member Societies use the term "Special Periodical Survey" others use the term
"Class Renewal Survey" instead of the term "Special Survey".
▲
Z10.4-3
IACS Req. 2001
Z10.4
2.1.2
Z10.4
cont'd The first Special Survey is to be completed within 5 years from the date of the initial
classification survey and thereafter 5 years from the credited date of the pervious Special
Survey. However, an extension of class of 3 months maximum beyond the 5th year can be
granted in exceptional circumstances.
In this case, the next period of class will start from the expiry date of the Special Survey before
the extension was granted.
2.1.3
For surveys completed within 3 months before the expiry date of the Special Survey, the next
period of class will start from the expiry date of the Special Survey. For surveys completed
more than 3 months before the expiry date of the Special Survey, the period of class will start
from the survey completion date.
2.1.4
The Special Survey may be commenced at the 4th Annual Survey and be progressed with a
view to completion by the 5th anniversary date.
2.1.5
As part of the preparation for the Special Survey, the thickness measurement and Survey
Programme is to be dealt with, in advance of the Special Survey. The thickness measurement is
not to be held before the 4th Annual Survey.
2.2 Scope
2.2.1 General
2.2.1.1
The Special Survey is to include, in addition to the requirements of the Annual Survey,
examination, tests and checks of sufficient extent to ensure that the hull and related piping, as
required in 2.2.1.3, is in a satisfactory condition and is fit for its intended purpose for the new
period of class of 5 years to be assigned, subject to proper maintenance and operation and to
periodical surveys being carried out at the due dates.
2.2.1.2
All cargo tanks, all salt water Ballast Tanks, pump rooms, pipe tunnels, cofferdams and void
spaces bounding cargo tanks, decks and outer hull are to be examined, and this examination is
to be supplemented by thickness measurement and testing as deemed necessary, to ensure that
the structural integrity remains effective. The examination is to be sufficient to discover
Substantial Corrosion, significant deformation, fractures, damages or other structural
deterioration.
2.2.1.3
Cargo piping on deck, including Crude Oil Washing (COW) piping, Cargo and Ballast piping
within the above tanks and spaces are to be examined and operationally tested to working
pressure to attending Surveyor’s satisfaction to ensure that tightness and condition remain
satisfactory. Where provided, special attention is to be given to any ballast piping in cargo tanks
and any cargo piping in ballast tanks and void spaces, and Surveyors are to be advised on all
occasions when this piping, including valves and fittings are open during repair periods and can
be examined internally.
2.2.2.1
A survey in dry dock is to be a part of the Special Survey.
▲
Z10.4-4
2.2.3.2
For tanks used for salt water ballast, where a Protective Coating is found in POOR condition as
defined in 1.2.10 and it is not renewed, where soft coating has been applied, or where a
Protective Coating was not applied from the time of construction, maintenance of class is to be
made subject to the tanks in question being examined at annual intervals. Thickness
measurement is to be carried out as considered necessary.
2.2.4.1
An Overall Survey of all tanks and spaces, excluding fuel oil, lube oil and fresh water tanks, is
to be carried out at each Special Survey.
2.2.4.2
The minimum requirements for Close-up Surveys at Special Survey are given in Table I.
2.2.4.3
The Surveyor may extend the Close-up Survey as deemed necessary taking into account the
maintenance of the tanks under survey, the condition of the corrosion protection system and
also in the following cases:
a) in particular, tanks having structural arrangements or details which have suffered defects in
similar tanks or on similar ships according to available information,
b) In tanks which have structures approved with reduced scantlings due to an approved
corrosion control system.
2.2.4.4
For areas in tanks where coatings are found to be in a GOOD condition as defined in 1.2.10, the
extent of Close-up Surveys according to Table I may be specially considered by the
Classification Society.
2.2.5.1
The minimum requirements for thickness measurements at Special Survey are given in Table II.
2.2.5.2
Provisions for extended measurements for areas with Substantial Corrosion as defined in. 1.2.8,
are given in Table IV, and as may be additionally specified in the Survey Programme as
required. in 5.1.
2.2.5.3
The Surveyor may further extend the thickness measurements as deemed necessary.
2.2.5.4
For areas in tanks where coating are found to be in a GOOD condition as defined in 1.2.10, the
extent of thickness measurements according to Table II may be specially considered, by the
Classification Society.
2.2.5.5
Transverse sections are to be chosen where the largest reductions are suspected to occur or are
▲
Z10.4-5
IACS Req. 2001
Z10.4
2.2.6.1
The minimum requirements for tank testing at Special Survey are given in Table III.
2.2.6.2
The Surveyor may extend the tank testing as deemed necessary.
2.2.6.3
Tanks are to be tested with a head of liquid to the top of access hatches for cargo tanks, or top
of air pipes for Ballast Tanks, if this gives a higher pressure.
3. ANNUAL SURVEY
3.1 Schedule
3.1.1
Annual Surveys are to be held within 3 months before or after anniversary date from the date of
the initial classification survey or of the date credited for the last Special Survey.
3.2 Scope
3.2.1 General
3.2.1.1
The survey is to consist of an examination for the purpose of ensuring, as far as practicable, that
the hull and piping are maintained in a satisfactory condition.
3.2.2.1
Examination of the hull plating and its closing appliances as far as can be seen.
3.2.2.2
Examination of watertight penetrations as far as practicable.
3.2.3.1
Examination of cargo tank openings including gaskets, covers, coamings and flame screens.
3.2.3.2
Examination of cargo tanks pressure/vacuum valves and flame screens.
▲
Z10.4-6
3.2.3.3
Z10.4 Examination of flame screens on vents to all bunker, oily ballast and oily slop tanks.
cont’d
3.2.3.4
Examination of cargo, crude oil washing, bunker and vent piping systems, including vent masts
and headers.
3.2.4.1
Examination of all pump room bulkheads for signs of oil leakage or fractures and, in particular,
the sealing arrangements of all penetrations of pump room bulkheads.
3.2.4.2
Examination of the condition of all piping systems.
3.2.5.1
Examination of Ballast Tanks when required as a consequence of the results of the Special
Survey and Intermediate Survey. When considered necessary by the surveyor, thickness
measurement is to be carried out and if the results of these thickness measurements indicate that
Substantial Corrosion is found, the extent of thickness measurements should be increased in
accordance with Table IV.
4. INTERMEDIATE SURVEY
4.1 Schedule
4.1.1
The Intermediate Survey is to be held at or between either the 2nd or 3rd Annual Survey.
4.1.2
Those items, which are additional to the requirements of the Annual Surveys, may be surveyed
either at or between the 2nd and 3rd Annual Survey.
▲
Z10.4-7
4.2 Scope
Z10.4
cont’d 4.2.1 General
4.2.1.1
The survey extent of cargo and ballast tanks dependent on the age of the vessel is specified in.
4.2.2 to 4.2.4 and shown in Table V.
4.2.1.2
For weather decks, an examination as far as applicable of cargo, crude oil washing, bunker,
ballast, steam and vent piping systems as well as vent masts and headers is to be carried out. If
upon examination there is any doubt as to the condition of the piping, the piping may be
required to be pressure-tested, thickness measured or both.
4.2.2 Double Hull Oil Tankers between 5 and 10 years of age. The following is toapply:
4.2.2.2
For tanks used for salt-water ballast, an Overall Survey of Representative Tanks selected by the
Surveyor is to be carried out.
If the overall survey of salt-water ballast tanks reveals no visible structural defects, the
examination may be limited to verification that the Protective Coatings remain efficient.
4.2.2.3
Where POOR Coating Condition, corrosion or other defects are found in salt water Ballast
Tanks or where a Protective Coating was not applied from the time of construction, the
examination is to be extended to other Ballast Tanks of the same type.
4.2.2.4
In salt-water Ballast Tanks where a Protective Coating is found in POOR condition as defined
in 1.2.10, and it is not renewed, where soft coating has been applied, or where a Protective
Coating was not applied from the time of construction, maintenance of class is to be subject to
the tanks in question being examined and thickness measurements carried out as considered
necessary at annual intervals.
4.2.3 Double Hull Oil Tankers between 10 and 15 years of age. The following is to apply:
4.2.3.2 An Overall Survey of at least two Representative Cargo Tanks is to be carried out.
4.2.3.3
For tanks used for salt-water ballast including combined cargo/ballast tanks, where fitted, an
Overall Survey of all such tanks is to be carried out. If such survey reveals no visible structural
defects, the Survey may be limited to verification that the Protective Coatings remain efficient.
Ballast tanks: to be the same as that at the previous Special Survey after second
Special Survey;
Cargo tanks: the extent of survey is to be based on the record of the previous Special
Survey and repair history of the tanks, and be applied to two cargo
tanks after second Special Survey.
▲
Z10.4-8
4.2.4 Double Hull Oil Tankers exceeding 15 years of age. The following is to apply:
4.2.4.1
The requirements of the Intermediate Survey are to be to the same extent as the previous
Special Survey as required in 2 and 5.1. However, pressure testing of cargo and ballast tanks is
not required unless deemed necessary by the attending surveyor.
4.2.4.2
A survey in dry dock is to be part of the intermediate survey. The overall and close-up surveys
and thickness measurements, as applicable, of the lower portions of the cargo tanks and water
ballast tanks are to be surveyed in accordance with the applicable requirements for intermediate
surveys, if not already surveyed.
Z10.4-9
5.1.1
A specific Survey Programme is to be worked out in advance of the Special Survey by the
Owner in co-operation with the Classification Society. The Survey Programme is to be in a
written format.
5.1.2
5.1.3
The submitted Survey Programme is to account for and comply, as a minimum, with the
requirements of Tables I, II, III and paragraph 2.2.6 for close-up survey, thickness measurement
and tank testing, respectively, and is to include relevant information including at least:
5.1.4
The Classification Society will advise the Owner of the maximum acceptable structural
corrosion diminution levels applicable to the vessel.
5.1.5
Use may also be made of the Guidelines for Technical Assessment in Conjunction with
Planning for Enhanced Surveys of Double Hull Oil Tankers Special Survey - Hull, contained in
Annex I. These guidelines are a recommended tool which may be invoked at the discretion of
the IACS Member Society, when considered necessary and appropriate, in conjunction with the
preparation of the required Survey Programme.
▲
Z10.4-10
IACS Req. 2001
Z10.4
The Owner is to provide the necessary facilities for a safe execution of the survey.
5.2.2
Tanks and spaces are to be safe for access, i.e. gas freed, ventilated, illuminated, etc.
5.2.3
Tanks and spaces are to be sufficiently clean and free from water, scale, dirt, oil residues, etc. to
reveal significant corrosion, deformation, fractures, damages or other structural deterioration. In
particular this applies to areas which are subject to thickness measurement.
5.2.4
5.3.1
For Overall Survey, means are to be provided to enable the surveyor to examine the hull
structure in a safe and practical way.
5.3.2
For Close-up Survey, one or more of the following means for access, acceptable to the
Surveyor, is to be provided:
5.4.1
5.4.2
One or more of the following fracture detection procedures may be required if deemed
necessary by the Surveyor:
• radiographic equipment;
• ultrasonic equipment;
• magnetic particle equipment;
• dye penetrant.
▲
Z10.4-11
Z10.4
cont’d
5.5 Survey at sea or at anchorage
5.5.1
Survey at sea or at anchorage may be accepted provided the Surveyor is given the necessary
assistance from the personnel onboard. Necessary precautions and procedures for carrying out
the survey are to be in accordance with 5.1, 5.2, 5.3 and 5.4.
5.5.2
A communication system is to be arranged between the survey party in the tank and the
responsible officer on deck. This system must also include the personnel in charge of ballast
pump handling if boats or rafts are used.
5.5.3
Explosimeter, oxygen-meter, breathing apparatus, life line and whistles are to be at hand during
the survey. When boats or rafts are used, appropriate life jackets are to be available for all
participants. Boats or rafts are to have satisfactory residual buoyancy and stability even if one
chamber is ruptured. A safety checklist is to be provided.
5.5.4
Surveys of tanks by means of boats or rafts may only be undertaken at the sole discretion of the
Surveyor, who is to take into account the safety arrangements provided, including weather
forecasting and ship response in reasonable sea conditions.
5.5.5
Rafting will only be allowed for the under deck areas for tanks when the coating of the under
deck structure is in good condition and there is no evidence of wastage. The only exception to
this would be if the depths of the webs are 1.5 meters or less.
Alternatively, rafting may be used if a permanent means of access is provided in each day to
allow safe entry and exit. This means of access is to be direct from deck via a vertical ladder
and small platform fitted approximately 2 meters below deck.
If the above conditons are not met, then the under deck area will have to be staged for survey.
6. DOCUMENTATION ON BOARD
6.1 General
6.1.1
The owner is to supply and maintain on board documentation as specified in Ch. 6.2 and 6.3,
which should be readily available for the surveyor.
6.1.2
Z10.4-12
6.2.1
Z10.4 A Survey Report File is to be a part of the documentation on board consisting of:
cont’d
• reports of structural surveys;
• executive hull summary;
• thickness measurement reports.
6.2.2
The Survey Report File is to be available also in the Owner's and the Classification Society's
management offices.
6.3.1
6.4.1
Prior to inspection, the Surveyor is to examine the completeness of the documentation onboard,
and its contents as a basis for the survey.
7.1 General
7.1.1
Thickness measurements required, if not carried out by the Society itself, are to be witnessed by
a surveyor on board to the extent necessary to control the process.
The thickness measurement operator is to be part of the survey planning meeting to be held
prior to commencing the survey.
▲
Z10.4-13
The thickness measurements are to be carried out by a qualified company certified by the
Classification Society according to principles stated in Table VII.
7.3 Reporting
7.3.1
7.3.2
8.1.1
The data and information on the structural condition of the vessel collected during the survey is
to be evaluated for acceptability and continued structural integrity of the vessel.
8.1.1.1 In case of oil tankers of 130 m in length and upwards (as defined in the International
Convention on Load Lines in force), the ship’s longitudinal strength is to be evaluated by using
the thickness of structural members measured, renewed and reinforced, as appropriate, during
the special survey carried out after the ship reached 10 years of age in accordance with the
criteria for longitudinal strength of the ship’s hull girder for oil tankers specified in Annex III.
8.1.1.2 The final result of evaluation of the ship’s longitudinal strength required in 8.1.1.1,
after renewal or reinforcement work of structural members, if carried out as a result of initial
evaluation, is to be reported as a part of the Executive Hull Summary.
8.2 Reporting
8.2.1
8.2.2
An Executive Hull Summary of the survey and results is to be issued to the Owner as shown in
Table IX and placed on board the vessel for reference at future surveys. The Executive Hull
Summary is to be endorsed by the Classification Society's head office or regional managerial
office.
▲
Z10.4-14
IACS Req. 2001
Z10.4
Table I - Minimum Requirements for Close-Up Survey at Special Survey
of Double Hull Oil Tankers
Z10.4
cont’d Age of ship (in years at time of special survey due date)
age ≤ 5 5 < age ≤ 10 10 < age ≤ 15 age > 15
One web frame (1), in a All web frames (1), in a All web frames (1), in all As for Special Survey for
complete ballast tank complete ballast tank ballast tanks age from 10 to 15 years
(see Note 1) (see Note 1)
The knuckle area and the Additional transverse
upper part (5 metres areas as deemed necessary
approximately) of one by the Society
web frame in each
remaining ballast tank
(6)
One deck transverse, in a One deck transverse, in All web frames (7), including
cargo oil tank (2) two cargo oil tanks (2) deck transverse and cross ties,
if fitted. in a cargo oil tank
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
▲
Z10.4-15
Z10.4
cont’d
Z10.4-16
Z10.4 Table III - Minimum Requirements for Tank Testing at Special Survey
of Double Hull Oil Tankers
cont’d
Z10.4-17
Z10.4-18
DECK STRUCTURE
Structural member Extent of measurement Pattern of measurement
Deck plating Two transverse bands across Minimum of three
tank measurements per plate per
band
Deck longitudinals Every third longitudinal in Three measurements in line
each of two bands with a vertically on webs and two
minimum of one measurements on flange (if
longitudinal fitted)
Deck girders and brackets At fore and aft transverse Vertical line of single
(usually in cargo tanks bulkhead, bracket toes and measurements on web
only) in centre of tanks plating with one
measurement between each
panel stiffener, or a
minimum of three
measurements.
Two measurements across
flange. 5-point pattern on
girder/bulkhead brackets
Deck transverse webs Minimum of two webs, with 5-point pattern over one
measurements at both ends square metre area.
and middle of span Single measurements on
flange
Vertical web and transverse Minimum of two webs, and 5-point pattern over one
bulkhead in wing ballast both transverse bulkheads square metre area
tank (two metres from deck)
Panel stiffening Where applicable Single measurements
▲
Z10.4-19
Z10.4-20
Z10.4-21
Z10.4-22
Z10.4-23
IACS Req. 2001
Z10.4
Z10.4 Figure 1 - Close-up Survey Requirements for Double Hull Oil Tankers
cont’d Areas (1) to (5)
Close-up Survey
Area
Z10.4-24
IACS Req. 2001
Z10.4
Z10.4 Figure 2 - Close-up Survey Requirements for Double Hull Oil Tankers
Areas (6) and (7)
cont’d
Close-up Survey
Area
Z10.4-25
TABLE VI
Z10.4
cont’d
Z10.4-26
TABLE VII
Z10.4
cont’d
PROCEDURES FOR CERTIFICATION OF FIRMS ENGAGED IN THICKNESS
MEASUREMENT OF HULL STRUCTURES
1. Application
This guidance applies for certification of the firms which intend to engage in the thickness
measurement of hull structures of the vessels.
3. Certification
(1) Upon satisfactory results of both the audit of the firm in 2(2) and the demonstration tests in 2(3)
above, the Society will issue a Certificate of Approval as well as a notice to the effect that the
thickness measurement operation system of the firm has been certified by the Society.
In case where any alteration to the certified thickness measurement operation system of the firm is
made, such an alteration is to be immediately informed to the Society. Re-audit is made where
deemed necessary by the Society.
5. Cancellation of Approval
(2) Where the Society's surveyor found any deficiencies in the approved thickness measurement
operation systems of the firm.
(3) Where the firm failed to inform of any alteration in 4 above to the Society.
▲
Z10.4-27
Reporting forms are to be worked out individually by the respective Classification Societies. As a
principle the following content of reports for tanker structures is to be included as applicable for the
survey:
1.0 Type of Survey (Special Survey, Intermediate Survey, Annual Survey, Other)
The structure of the reporting content may be different, depending on the report system for the respective
Societies.
▲
Z10.4-28
Z10.4
cont'd
TABLE IX(i)
GENERAL PARTICULARS
TYPE OF CONVERSION:
a) The survey reports and documents listed below have been reviewed by the undersigned and
found to be satisfactory
OFFICE DATE
OFFICE DATE
c) The hull special survey has been completed in accordance with the Regulations on [date]
1)
2)
3)
4)
5)
6)
▲
Z10.4-29
- Examined
- Operationally tested
E) Thickness
measurements: – Reference to Thickness Measurement report
– Summary of where measured
– Separate form indicating the tanks/areas with Substantial
Corrosion, and corresponding
* Thickness diminution
* Corrosion pattern
H) Condition of Class/Recommendations:
J) Evaluation results of the ship’s longitudinal strength (for oil tankers of 130 m in length and
upwards and of over 10 years of age)
Z10.4-30
IACS Req. 2001
Z10.4
1) Positions of 2)
substantially corroded Thickness Corrosion Remarks:
Tanks/Areas or Areas diminution [%] pattern e.g. Ref. attached
with deep pitting sketches
Remarks
1) Substantial corrosion, i.e. 75 – 100% of acceptable margins wasted
2) P = Pitting
C = Corrosion in General
Any bottom plating with a pitting intensity of 20% or more, with wastage in the substantial
corrosion range or having an average depth of pitting of 1/3 or more of actual plate thickness is to
be noted.
▲
Z10.4-31
1) 2) 3)
Remarks:
1)
All segregated ballast tanks and combined cargo/ballast tanks to be listed.
2)
C = Coating A = Anodes NP = No Protection
3)
Coating condition according to the following standard
If coating condition "POOR" is given, extended annual surveys are to be introduced. This is to be noted
in part G) of the Executive Hull Summary.
▲
Z10.4-32
2 This section applies to ships constructed on or after 1 July 2002: Section moduli of transverse
section of the ship’s hull girder have been calculated by using the thickness of structural members
measured, renewed or reinforced, as appropriate, during the special survey most recently conducted after
the ship reached 10 years of age in accordance with the provisions of paragraph 2.2.1.1 of Annex III, and
are found to be within their diminution limits determined by the Classification Society *, as shown in the
following table:
* The actual transverse section modulus of the hull girder of oil tankers calculated under paragraph
2.2.1.1 of Annex III to UR Z10.4 is not to be less than 90% of the required section modulus for
new buildings specified in IACS Unified Requirements S7* or S11, whichever is the greater.
Z10.4-33
IACS Req. 2001
Z10.4
Notes
Z10.4
cont'd *1 Zact means the actual section moduli of the transverse section of the ship's hull girder
calculated by using the thickness of structural members measured, renewed or
reinforced, as appropriate, during the special survey, in accordance with the
provisions of paragraph 2.2.1.1 of Annex III.
*2 Zreq means diminution limit of the longitudinal bending strength of ships, as calculated
in accordance with the provisions of paragraph 2.2.1.1 of Annex III.
3 This section applies to ships constructed before 1 July 2002: Section moduli of transverse section
of the ship’s hull girder have been calculated by using the thickness of structural members measured,
renewed or reinforced, as appropriate, during the special survey most recently conducted after the ship
reached 10 years of age in accordance with the provisions of paragraph 2.2.1.2 of Annex III, and found to
meet the criteria required by the Classification Society and that Zact is not less than Zmc (defined in *2
below) as specified in appendix 2 to Annex III, as shown in the following table:
Describe the criteria for acceptance of the minimum section moduli of the ship's hull girder for
ships in service required by the Classification Society.
Notes:
*2 Zmc means the diminution limit of minimum section modulus calculated in accordance with
provisions of paragraph 2.2.1.2 of Annex III.
▲
Z10.4-34
IACS Req. 2001
Z10.4 Annex I
Z10.4 ANNEX I
cont'd
GUIDELINES FOR TECHNICAL ASSESSMENT IN CONJUNCTION WITH
PLANNING FOR ENHANCED SURVEYS OF DOUBLE HULL OIL TANKERS
SPECIAL SURVEY - HULL
Contents:
1. INTRODUCTION
2. PURPOSE AND PRINCIPLES
2.1 Purpose
2.2 Minimum Requirements
2.3 Timing
2.4 Aspects to be Considered
3. TECHNICAL ASSESSMENT
3.1 General
3.2 Methods
3.2.1 Design Details
3.2.2 Corrosion
3.2.3 Locations for Close-up Survey and Thickness Measurement
REFERENCES
1. IACS Unified Requirement Z10.4, "Hull Surveys of Double Hull Oil Tankers."
2.TSCF, "Guidelines for the Inspection and Maintenance of Double Hull Tanker Structures, 1995."
3.TSCF, "Guidance Manual for Tanker Structures, 1997."
1.0 INTRODUCTION
These guidelines contain information and suggestions concerning technical assessments which may be of
use in conjunction with the planning of enhanced special surveys of double hull oil tankers. As indicated
in 5.1.5 of IACS Unified Requirement Z10.4, "Hull Surveys of Double Hull Oil Tankers," (Ref. 1), the
guidelines are a recommended tool which may be invoked at the discretion of an IACS Member Society,
when considered necessary and appropriate, in conjunction with the preparation of the required Survey
Programme.
2.1 Purpose
The purpose of the technical assessments described in these guidelines is to assist in identifying critical
structural areas, nominating suspect areas and in focusing attention on structural elements or areas of
structural elements which may be particularly susceptible to, or evidence a history of, wastage or
damage. This information may be useful in nominating locations, areas and tanks for thickness
measurement, close-up survey and tank testing.
Critical Structural Areas are locations which have been identified from calculations to require monitoring
or from the service history of the subject ship or from similar or sister ships (if available) to be sensitive
to cracking, buckling or corrosion which would impair the structural integrity of the ship.
2.3 Timing
As with other aspects of survey planning, the technical assessments described in these guidelines are to
be worked out by the Owner or operator in cooperation with the Classification Society well in advance of
the commencement of the Special Survey, i.e., prior to commencing the survey and normally at least 12
to 15 months before the survey's completion due date.
▲
Z10.4I-1
3.1 General
There are three basic types of possible failure which may be the subject of technical assessment in
connection with planning of surveys; corrosion, cracks and buckling. Contact damages are not normally
covered by the survey plan since indents are usually noted in memoranda and assumed to be dealt with as
a normal routine by Surveyors.
Technical assessments performed in conjunction with the survey planning process are, in principle to be
as shown schematically in Figure 1, which depicts how technical assessments can be carried out in
conjunction with the survey planning process. The approach is basically an evaluation of the risk based
on the knowledge and experience related to design and corrosion.
The design is to be considered with respect to structural details which may be susceptible to buckling or
cracking as a result of vibration, high stress levels or fatigue.
Corrosion is related to the ageing process, and is closely connected with the quality of corrosion
protection at newbuilding, and subsequent maintenance during the service life. Corrosion may also lead
to cracking and/or buckling.
3.2 Methods
This information may be found in the survey reports and/or the Owner's files, including the results of the
Owner's own inspections. The defects should be analyzed, noted and marked on sketches.
In addition, general experience is to be utilized. For example, reference is to be be made to the two
TSCF’s publications mentioned in Ref.2 and Ref.3, which contain a catalogue of typical damages and
proposed repair methods for various tanker structural details.
Such figures are to be used together with a review of the main drawings, in order to compare with the
actual structure and search for similar details which may be susceptible to damage. An example is shown
in Figure 2. In particular, Chapter 3 of Ref.2 deals with various aspects specific to double hull tankers,
such as stress concentration locations, misalignment during construction, corrosion trends, fatigue
considerations and areas requiring special attention, which are to be considered in working out the survey
planning.
The review of the main structural drawings, in addition to using the above mentioned figures, should
include checking for typical design details where cracking has been experienced. The factors
contributing to damage are to be carefully considered.
The use of high tensile steel (HTS) is an important factor. Details showing good service experience
where ordinary, mild steel has been used may be more susceptible to damage when HTS, and its higher
associated stresses, are utilized. There is extensive and, in general, good experience, with the use of HTS
for longitudinal material in deck and bottom structures. Experience in other locations, where the
dynamic stresses may be higher, is less favorable, e.g. side structures.
▲
Z10.4I-2
IACS Req. 2001
Z10.4 Annex I
Z10.4 In this respect, stress calculations of typical and important components and details, in accordance with
the latest Rules or other relevant methods, may prove useful and are to be considered.
cont'd
The selected areas of the structure identified during this process are to be recorded and marked on the
structural drawings to be included in the Survey Programme.
3.2.2 Corrosion
In order to evaluate relative corrosion risks, the following information is generally to be considered:
- Usage of Tanks and Spaces
- Condition of Coatings
- Condition of Anodes
- Cleaning Procedures
- Previous Corrosion Damage
- Ballast use and time for Cargo Tanks
- Corrosion Risk Scheme (See Ref. 3, Table 2.1)
- Location of Heated Tanks
Ref. 3 gives definitive examples which can be used for judging and describing coating condition, using
typical pictures of conditions.
The evaluation of corrosion risks is to be based on information in Ref. 3, together with relevant
information on the anticipated condition of the ship as derived from the information collected in order to
prepare the Survey Programme and the age of the ship.
The various tanks and spaces are to be listed with the corrosion risks nominated accordingly.
Special attention is to be given to the areas where the double hull tanker is particularly exposed to
corrosion. To do this end, the specific aspects addressing corrosion in double hull tankers indicated in 3.4
(Corrosion trends) of Ref.2 are to be taken into account.
On the basis of the table of corrosion risks and the evaluation of design experience, the locations for
initial close-up survey and thickness measurement (areas and sections) may be nominated.
The sections subject to thickness measurement are to normally be nominated in tanks and spaces where
corrosion risk is judged to be the highest.
The nomination of tanks and spaces for close-up survey should, initially, be based on highest corrosion
risk, and should always include ballast tanks. The principle for the selection is to be that the extent is
increased by age or where information is insufficient or unreliable.
▲
Z10.4I-3
Input:
Z10.1 Drawings, Reports, Coating Condition
cont'd Acceptable Corrosion Collection of Information Anode Condition
Allowance Usage of Tanks
Analyse Hull
Damage for Corrosion Damage
Similar Ships This Ship
Where Available
Corrosion Damage
Hull Damage : Similar Ship where
General Experience Available
Survey Programme
Acceptance by
Class & Owner
Survey
Z10.4I-4
SHELL PLATING
OR LONGITUDINAL FLAT BAR
BULKHEAD STIFFENER
A A A A
FRACTURED
WELD/WEB ★
FRACTURE
LUG
★
FRACTURE
X
1. Asymmetrical connection of flat bar stiffener resulting in high peak stresses at the heel of
the stiffener under fatigue loading.
2. Insufficient area of connection of longitudinal to web plate.
4. High localised corrosion at areas of stress concentration such as flat bar stiffener connections,
corners of cut-out for the longitudinal and connection of web to shell at cut-outs.
Z10.4I-5
IACS Req. 2001
Z10.4 Annex II
Z10.4
cont'd
ANNEX II
Z10.4II-1
CONTENTS
REPORTS
Sheet 4 - Report TM1-DHT for recording the thickness measurements of all deck plating, all
bottom shell plating and side shell plating
Sheet 5 - Report TM2-DHT (i) for recording the thickness measurement of shell and deck
plating at transverse sections - strength deck and sheerstrake plating
Sheet 6 - Report TM2-DHT (ii) for recording the thickness measurement of shell and deck
plating at transverse sections - shell plating
Sheet 7 - Report TM3-DHT for recording the thickness measurement of longitudinal members
at transverse sections (including double hull plating)
Sheet 8 - Report TM4-DHT for recording the thickness measurement of transverse structural
members
Sheet 9 - Report TM5-DHT for recording the thickness measurement of W.T./O.T. transverse
bulkheads
GUIDANCE
Sheet 11 - Typical transverse section of a double hull oil tanker (up to 150,000 dwt). The diagram
includes details of the items to be measured and the report forms to be used.
Sheet 12 - Typical transverse section of a double hull oil tanker (above 150,000 dwt). The
diagram included details of the items to be measured and the report forms to be used.
Sheet 13 - Transverse section outline. The diagram may be used for those ships where the
diagrams on sheet 11 and sheet 12 are not suitable
Sheet 14 - Transverse section and transverse bulkheads of a double hull oil tanker showing typical
areas for thickiness measurement in association with close-up survey requirements,
areas (1) to (5) as defined in Table I of the UR Z10.4.
Sheet 15 - Transverse section of a double hull oil tanker showing typical areas for thickiness
measurement in association with close-up survey requirements, areas (6) to (7) as
defined in Table I of the UR Z10.4.
▲
Z10.4II-2
Z10.4 INSTRUCTIONS
cont'd
3. The remaining sheets 11-15 are guidance diagrams and notes relating
to the reporting forma and the procedure for the thickness
measurements. ▲
Z10.4II-3
GENERAL PARTICULARS
Z10.4
cont'd
Ships name:-
IMO Number:-
Port of registry:-
Gross tons:-
Deadweight:-
Date of build:-
Classification society:-
____________________________________________________________________________________
Certificate No.
Place of measurement
Qualification of operator:-
____________________________________________________________________________________
* Delete as appropriate
▲
Z10.4II-4
Sheet 3
IACS Req. 2001
cont'd
Z10.4
TM1–DHT Report on THICKNESS MEASUREMENT of ALL DECK PLATING, ALL BOTTOM SHELL PLATING or SIDE SHELL PLATING*
( * – delete as appropriate)
Ship's name.................................................... Class Identity No. ................................................................ Report No. .........................................................
STRAKE
POSITION
No. Org. Forward Reading Aft Reading
PLATE or Thk. Gauged Diminution P Diminution S Gauged Diminution P Diminution S %
POSITION
Letter mm P S mm % mm % P S mm % mm % P S mm
12th forward
11th
10th
9th
8th
7th
6th
5th
4th
3rd
2nd
Z10.4II-5
1st
Amidships
1st aft
2nd
3rd
4th
5th
6th
7th
8th
9th
10th
11th
12th
1.2 All keel, bottom shell plating and bilge plating within the cargo area.
1.3 Side shell plating including selected wind and water strakes outside cargo area.
2.1 For strength deck indicate the number of the strake of plating inboard from the stringer
plate.
2.2 For bottom plating indicate the number of the strake of plating outboard from the keel
plate.
2.3 For side shell plating give number of the strake of plating below sheerstrake and letter
as shown on shell expansion.
3. Measurements are to be taken at the forward and aft areas of all and where plates cross
ballast/cargo tank boundaries separate measurements for the area of plating in way of each type of
tank are to be recorded.
4. The single measurements recorded are to represent the average of multiple measurements.
Z10.4II-6
FIRST TRANSVERSE SECTION AT FRAME SECOND TRANSVERSE SECTION AT FRAME THIRD TRANSVERSE SECTION AT FRAME
NUMBER NUMBER NUMBER
Org. Max. Diminution Diminution Org. Max. Diminution Diminution Org. Max. Diminution Diminution
No. Thk. Alwb. Gauged P S No. Thk. Alwb. Gauged No. Thk. Alwb. Gauged P S
STRAKE Dim. P S Dim.
or Dim. or or
POSITION
Letter mm mm
P S mm % mm % Letter mm mm S mm % mm % Letter mm mm P S mm % mm %
P
Stringer Plate
1st strake inboard
2nd
3rd
4th
5th
Z10.4II-7
6th
7th
8th
9th
10th
11th
12th
13th
14th
centre strake
sheer strake
TOPSIDE
TOTAL
▲
Z10.4 Annex II
Z10.4
cont'd NOTES TO THE REPORT TM2-DHT (i)
One, two or three sections within the cargo area comprising of the structural items (0), (1) and
(2) as shown on the diagrams of typical transverse sections illustrated on sheets 11 and 12 of
this document.
2. The topside area comprises deck plating, stringer plate and sheerstrake (including rounded
gunwales).
4. The single measurements recorded are to represent the average of multiple measurements.
Z10.4II-8
SHELL PLATING
FIRST TRANSVERSE SECTION AT FRAME SECOND TRANSVERSE SECTION AT FRAME THIRD TRANSVERSE SECTION AT FRAME
NUMBER NUMBER NUMBER
Org. Max. Diminution Diminution Org. Max. Diminution Diminution Org. Max. Diminution Diminution
No. Thk. Alwb. Gauged P S No. Thk. Alwb. Gauged No. Thk. Alwb. Gauged P S
STRAKE Dim. P S Dim.
or Dim. or or
POSITION
Letter mm mm
P S mm % mm % Letter mm mm S mm % mm % Letter mm mm P S mm % mm %
P
1st below sheer strake
2nd
3rd
4th
5th
6th
7th
8th
Z10.4II-9
9th
10th
11th
12th
13th
14th
15th
16th
17th
18th
19th
20th
keel strake
BOTTOM TOTAL
▲
Z10.4 Annex II
One, two or three sections within the cargo area comprising of the structural items (3), (4) and
(5) and (6) as shown on the diagrams of typical transverse sections illustrated on sheets 11 and
12 of this document.
4. The single measurements recorded are to represent the average of multiple measurements.
Z10.4II-10
FIRST TRANSVERSE SECTION AT FRAME SECOND TRANSVERSE SECTION AT FRAME THIRD TRANSVERSE SECTION AT FRAME
NUMBER NUMBER NUMBER
Org. Max. Diminution Diminution Org. Max. Diminution Diminution Org. Max. Diminution Diminution
Item Thk. Alwb. Gauged P S Item Thk. Alwb. Gauged Item Thk. Alwb. Gauged P S
STRUCTURAL Dim. P S Dim.
No. Dim. No. No.
MEMBER
mm mm P S mm % mm % mm mm P S mm % mm % mm mm P S mm % mm %
Z10.4II-11
Operators Signature...................................................................... Surveyors Signature .................................................................................... NOTES – See Reverse
▲
Z10.4 Annex II
One, two or three sections within the cargo area comprising of the appropriate structural items
(10) to (29) as shown on the diagrams of typical transverse sections illustrated on sheets 11 and
12 of this document.
3. The single measurements recorded are to represent the average of multiple measurements.
Z10.4II-12
TANK DESCRIPTION:
LOCATION OF STRUCTURE:
Max.
Original Diminution Diminution
Alwb. Gauged
STRUCTURAL MEMBER ITEM Thickness Dim.
P S
mm mm P S mm % mm %
Z10.4II-13
Operators Signature.............................................................. Surveyors Signature .......................................................................... NOTES – See Reverse
Z10.4 Annex II - Sheet 8
Transverse structural members, comprising of the appropriate structural items (30) to (36) as
shown on diagrams of typical transverse sections illustrated on sheets 11 and 12 od this document.
The single measurements recorded are to represent the average of multiple measurements.
Z10.4II-14
TANK/HOLD DESCRIPTION:
Z10.4II-15
Operators Signature.............................................................. Surveyors Signature .......................................................................... NOTES – See Reverse
▲
Z10.4 Annex II
3. The single measurements recorded are to represent the average of multiple measurements.
Z10.4II-16
LOCATION OF STRUCTURE:
Z10.4II-17
Operators Signature.............................................................. Surveyors Signature .......................................................................... NOTES – See Reverse
Z10.4 Annex II - Sheet 10
2. The single measurements recorded are to represent the average of multiple measurements.
Z10.4II-18
0. Strength deck plating 10. Deck longitudinals 20. Longitudinal bulkhead 30. Deck transverse —
plating (remainder) centre tank
1. Stringer plate 11. Sheerstrake longitudinals 21. Longitudinal bulkhead 31. Deck transverse —wing
longitudinals tank
2. Sheerstrake 12. Side shell longitudinals 22. Inner side plating 32. Vertical web in wing
ballast tank
3. Side shell plating 13. Bilge longitudinals 23. Inner side longitudinals 33. Double bottom floor —
wing tank
4. Bilge plating 14. Bottom longitudinals 24. Hopper plating 34. Double bottom floor —
centre tank
5. Bottom shell plating 15. Deck girders 25. Hopper longitudinals 35. Longitudinal bulkhead
vertical web
6. Keel plate 16. Horizontal girders in 26. Inner bottom plating 36. Cross ties
wing ballast tanks
17. Bottom girders 27. Inner bottom
longitudinals
18. Longitudinal bulkhead 28. Topside tank plating
top strake
19. Longitudinal bulkhead 29. Topside tank
bottom strake longitudinals
▲
Z10.4II-19
0. Strength deck plating 10. Deck longitudinals 20. Longitudinal bulkhead 30. Deck transverse —
plating (remainder) centre tank
1. Stringer plate 11. Sheerstrake longitudinals 21. Longitudinal bulkhead 31. Deck transverse —wing
longitudinals tank
2. Sheerstrake 12. Side shell longitudinals 22. Inner side plating 32. Vertical web in wing
ballast tank
3. Side shell plating 13. Bilge longitudinals 23. Inner side longitudinals 33. Double bottom floor —
wing tank
4. Bilge plating 14. Bottom longitudinals 24. Hopper plating 34. Double bottom floor —
centre tank
5. Bottom shell plating 15. Deck girders 25. Hopper longitudinals 35. Longitudinal bulkhead
vertical web
6. Keel plate 16. Horizontal girders in 26. Inner bottom plating 36. Cross ties
wing ballast tanks
Z10.4II-20
The diagram may be used for those ships where the diagrams on sheet 11 and sheet 12 are not suitable.
0. Strength deck plating 10. Deck longitudinals 20. Longitudinal bulkhead 30. Deck transverse —
plating (remainder) centre tank
1. Stringer plate 11. Sheerstrake longitudinals 21. Longitudinal bulkhead 31. Deck transverse —wing
longitudinals tank
2. Sheerstrake 12. Side shell longitudinals 22. Inner side plating 32. Vertical web in wing
ballast tank
3. Side shell plating 13. Bilge longitudinals 23. Inner side longitudinals 33. Double bottom floor —
wing tank
4. Bilge plating 14. Bottom longitudinals 24. Hopper plating 34. Double bottom floor —
centre tank
5. Bottom shell plating 15. Deck girders 25. Hopper longitudinals 35. Longitudinal bulkhead
vertical web
6. Keel plate 16. Horizontal girders in 26. Inner bottom plating 36. Cross ties
wing ballast tanks
17. Bottom girders 27. Inner bottom
longitudinals
18. Longitudinal bulkhead 28. Topside tank plating
top strake
19. Longitudinal bulkhead 29. Topside tank
bottom strake longitudinals
▲
Z10.4II-21
Close-up Survey
Area
Z10.4II-22
Close-up Survey
Area
Z10.4II-23
Z10.4
cont'd
ANNEX III
Z10.4 III-1
1 General
1.1 These criteria is to be used for the evaluation of longitudinal strength of the ship's hull girder as
required by section 8.1.1.1.
1.2 In order that ship’s longitudinal strength to be evaluated can be recognized as valid, fillet welding
between longitudinal internal members and hull envelopes is to be in sound condition so as to keep
integrity of longitudinal internal members with hull envelopes.
On oil tankers of 130 m in length and upwards and of over 10 years of age, the longitudinal strength of
the ship's hull girder is to be evaluated in compliance with the requirements of this annex on the basis of
the thickness measured, renewed or reinforced, as appropriate, during the special survey.
2.1 Calculation of transverse sectional areas of deck and bottom flanges of hull girder
2.1.1 The transverse sectional areas of deck flange (deck plating and deck longitudinals) and bottom
flange (bottom shell plating and bottom longitudinals) of the ship’s hull girder is to be calculated by
using the thickness measured, renewed or reinforced, as appropriate, during the special survey.
2.1.2 If the diminution of sectional areas of either deck or bottom flange exceeds 10 % of their
respective as-built area (i.e. original sectional area when the ship was built), either one of the following
measures is to be taken:
.1 to renew or reinforce the deck or bottom flanges so that the actual sectional area is not
less than 90% of the as-built area; or
.2 to calculate the actual section moduli (Zact) of transverse section of the ship’s hull
girder by applying the calculation method specified in appendix 1, by using the
thickness measured, renewed or reinforced, as appropriate, during the special survey.
2.2.1 The actual section moduli of transverse section of the ship’s hull girder calculated in accordance
with the foregoing paragraph 2.1.2.2 is to satisfy either of the following provisions, as applicable:
.1 for ships constructed on or after 1 July 2002, the actual section moduli (Zact) of the
transverse section of the ship's hull girder calculated in accordance with the
requirements of the foregoing paragraph 2.1.2.2 should is not to be less than the
diminution limits determined by the Classification Society * ; or
.2 for ships constructed before 1 July 2002, the actual section moduli (Zact) of the
transverse section of the ship's hull girder calculated in accordance with the
requirements of the foregoing paragraph 2.1.2.2 is to meet the criteria for
minimum section modulus for ships in service required by the Classification Society,
provided that in no case Zact is to be less than the diminution limit of the minimum
section modulus (Zmc) as specified in appendix 2.
* The actual transverse section modulus of the hull girder of oil tankers calculated under paragraph
2.2.1.1 of Annex III to UR Z10.1 is not to be less than 90% of the required section modulus for
new buildings specified in IACS Unified Requirements S7* or S11, whichever is the greater.
Z10.4 III-2
Z10.4 APPENDIX 1
cont'd
CALCULATION CRITERIA OF SECTION MODULI OF MIDSHIP
SECTION OF HULL GIRDER
1 When calculating the transverse section modulus of the ship's hull girder, the sectional area of all
continuous longitudinal strength members is to be taken into account.
2 Large openings, i.e. openings exceeding 2.5m in length or 1.2m in breadth and scallops, where
scallop welding is applied, are always to be deducted from the sectional areas used in the section
modulus calculation.
3 Smaller openings (manholes, lightening holes, single scallops in way of seams, etc.) need not be
deducted provided that the sum of their breadths or shadow area breadths in one transverse section does
not reduce the section modulus at deck or bottom by more than 3% and provided that the height of
lightening holes, draining holes and single scallops in longitudinals or longitudinal girders does not
exceed 25% of the web depth, for scallops maximum 75mm.
4 A deduction-free sum of smaller opening breadths in one transverse section in the bottom or deck
area of 0.06(∑B - b) (where B = breadth of ship, ∑b = total breadth of large openings) may be considered
equivalent to the above reduction in sectional modulus.
5 The shadow area will be obtained by drawing two tangent lines with an opening angle of 30˚.
8 Continuous trunks and longitudinal hatch coamings are to be included in the longitudinal sectional
area provided they are effectively supported by longitudinal bulkheads or deep girders. The deck
modulus is then to be calculated by dividing the moment of inertia by the following distance, provided
this is greater than the distance to the deck line at side:
yt = y 0.9 + 0.2
X
B
where:
Z10.4 III-3
Z10.4 APPENDIX 2
cont'd
DIMINUTION LIMIT OF MINIMUM LONGITUDINAL STRENGTH
OF SHIPS IN SERVICE
1 The diminution limit of the minimum section modulus ( Zmc) of oil tankers in service is given by
the following formula:
2 3
Zmc = cL B ( Cb + 0.7)k (cm )
where
L = Length of ships. L is the distance, in meters, on the summer load waterline from the
fore side of stem to the after side of the rudder post, or the centre of the rudder stock if
there is no rudder post. L is not to be less than 96%, and need not be greater than 97%,
of the extreme length on the summer load waterline. In ships with unusual stern and
bow arrangement the length L may be specially considered.
c = 0.9 cn
L - 300
1.5
L - 350
1.5
k = 1.0 for mild steel with yield stress of 235N/mm2 and over;
k = 0.78 for high tensile steel with yield stress of 315N/mm2 and over,
k = 0.72 for high tensile steel with yield stress of 355N/mm2 and over.
2 Scantlings of all continuous longitudinal members of the ship's hull girder based on the section
modulus requirement in 1 above are to be maintained within 0.4 L amidships. However, in special cases,
based on consideration of type of ship, hull form and loading conditions, the scantlings may be gradually
reduced towards the end of 0.4 L part, bearing in mind the desire not to inhibit the ship’s loading
flexibility.
3 However, the above standard may not be applicable to ships of unusual type or design, e.g. for
ships of unusual main proportions and/or weight distributions.
-----
▲
▲
Z10.4 III-4
IACS Req. 2001
Z10.6
1. General
1.1 Application
1.2 Definitions
1.3 Repairs
2. Special Survey
2.1 Schedule
2.2 Scope
2.2.1 General
2.2.2 Dry Dock Survey
2.2.3 Tank Protection
2.2.4 Hatch Covers and Coamings
2.3 Extent of Overall and Close-up Survey
2.4 Extent of Thickness Measurement
2.5 Extent of Tank Testing
3. Annual Survey
3.1 Schedule
3.2 Scope
3.2.1 General
3.2.2 Examination of the Hull
3.2.3 Examination of Hatch Covers and Coamings
3.2.4 Suspect Areas
3.2.5 Examination of Cargo Hold
3.2.6 Examination of Ballast Tanks
4. Intermediate Survey
4.1 Schedule
4.2 Scope
4.2.1 General
4.2.2 Dry Cargo Ships 5 - l0 years of Age
4.2.3 Dry Cargo Ships l0 - 15 years of Age
4.2.4 Dry Cargo Ships Exceeding 15 years of Age
5. Preparation for Survey
5.1 Conditions for Survey
5.2 Access to Structures
5.3 Equipment for Survey
5.4 Survey at Sea or at Anchorage
Z10.6 ENCLOSURES:
cont'd Table I: Minimum requirements for Close-up Surveys at Hull Special Surveys of General Dry
Cargo Ships.
Table II: Minimum requirements to Thickness Measurements at Hull Special Surveys of General
Dry Cargo Ships.
Table III: Guidance for Additional Thickness Measurements in Way of Substantial Corrosion.
Table IV: Procedures for Certification of Firms Engaged in Thickness Measurement of Hull
Structures.
1. GENERAL
Z10.6
cont'd 1.1 Application
1.1.1 The requirements apply after construction to all self-propelled General Dry Cargo Ships 500gt and
above carrying solid cargoes other than:
1.1.2 The requirements apply to surveys of hull structure and piping systems in way of cargo holds,
cofferdams, pipe tunnels and void spaces within the cargo area and all ballast tanks. The requirements are
additional to the classification requirements applicable to the remainder of the ship.
1.1.3 The requirements contain the minimum extent of examination, thickness measurements and tank
testing. The survey is to be extended when Substantial Corrosion and/or structural defects are found and
include additional Close-up Survey when necessary.
1.2 Definitions
1.2.1 A Ballast Tank is a tank that is being used primarily for salt water ballast..
1.2.2 Spaces are seperate compartments including holds and tanks.
1.2.3 An Overall Survey is a survey intended to report on the overall condition of the hull structure and
determine the extent of additional Close-up Surveys.
1.2.4 A Close-up Survey is a survey where the details of structural components are within the close
visual inspection range of the surveyor, i.e. normally within reach of hand.
1.2.5 A Transverse Section includes all longitudinal members such as plating, longitudinals and girders
at the deck, side, bottom, inner bottom and hopper side plating, longitudinal bulkheads and bottom
plating in top wing tanks. For transversely framed vessels, a transverse section includes adjacent frames
and their end connections in way of transverse sections.
1.2.6 Representative Spaces are those which are expected to reflect the condition of other Spaces of
similar type and service and with similar corrosion protection systems. When selecting Representative
Spaces account is to be taken of the service and repair history on board and identifiable Critical
Structural and/or Suspect Areas.
1.2.7 Critical Structural Areas are locations which have been identified from calculations to require
monitoring of from the service history of the subject ship or from similar ships to be sensitive to
cracking, buckling or corrosion which would impair the structural integrity of the ship.
1.2.8 Suspect Areas are locations showing Substantial Corrosion Substantial and/or are considered by
the surveyor to be prone to rapid wastage.
1.2.9 Substantial Corrosion is an extent of corrosion such that assessment of corrosion pattern indicates a
wastage in excess of 75% of allowable margins, but within acceptable limits.
Protective coating is usually to be epoxy coating or equivalent. Other coating systems may be considered
acceptable as alternatives provided that they are applied and maintained in compliance with the
manufacturer’s specifications.
Where soft coatings have been applied, safe access is to be provided for the surveyor to verify the
effectiveness of the coating and to carry out an assessment of the conditions of internal structures which
may include spot removal of the coating. When safe access cannot be provided, the soft coating is to be
removed.
▲
Z10.6-1
IACS Req. 2002
Z10.6
1.2.13 Special Consideration as used in this document is taken to mean as a minimum, that sufficient
close-up inspection and thickness measurments are taken to confirm the actual average condition of the
structure under the coating.
1.2.14 A Prompt and Through Repair is a permanent repair completed at the time of survey to the
satisfaction of the surveyor, therein removing the need for the imposition of any associated condition of
classification.
1.3 Repairs
1.3.1 Any damage in association with wastage over the allowable limits (including buckling, grooving,
detachment or fracture), or extensive areas of wastage over the allowable limits, which affects or, in the
opinion of the Surveyor, will affect the vessel’s structural, watertight or weathertight integrity, is to be
promptly and thoroughly (see 1.2.14) repaired. Areas to be considered include:
1.3.2 Additionally, when a survey results in the identification of significant corrosion or structural
defects, either of which, in the opinion of the surveyor, will impair the vessel’s fitness for continued
service, remedial measures are to be implemented before the ship continues in service.
2. SPECIAL SURVEY *
2.1 Schedule
2.1.1 Special Surveys are to be carried out at 5 years intervals to renew the class certificate.
2.1.2 The first Special Survey is to be completed within 5 years from the date of the initial classification
survey and thereafter within 5 years from the credited date of the previous Special Survey. However, an
extension of class of 3 months maximum beyond the 5th year can be granted in exceptional
circumstances. In this case, the next period of class will start from the expiry date of the Special Survey
before the extension was granted.
2.1.3 For surveys completed within 3 months before the expiry date of the Special Survey, the next
period of class will start from the expiry date of the Special Survey. For surveys completed more than 3
months before the expiry date of the Special Survey, the period of class will start from the survey
completion date.
2.1.4 The Special Survey may be commenced at the 4th Annual Survey and be progressed with a view to
completion by the 5th anniversary date.
* Some member Societies use the term “Special Periodical Survey” others use the term “Class
Renewal Survey” instead of the term “Special Survey”.
▲
Z10.6-2
IACS Req. 2002
Z10.6
2.1.5 A survey planning meeting is to be held prior to the commencement of the survey.
Z10.6
cont'd 2.1.6 As part of the preparation for the Special Survey, the thickness measurement is to be dealt with, in
advance of the Special Survey. The thickness measurement is not to be held before the 4th Annual
Survey.
2.2 Scope
2.2.1 General
2.2.1.1 The Special Survey is to include, in addition to the requirements of the Annual Surveys,
examination, tests and checks of sufficient extent to ensure that the hull and related piping are in a
satisfactory condition and that the ship is fit for its intended purpose for the new period of class of 5
years to be assigned, subject to proper maintenance and operation and to periodical surveys being carried
out at the due dates.
2.2.1.2 All cargo holds, salt water ballast tanks, including double bottom tanks, pipe tunnels,
cofferdams and void spaces bounding cargo holds, decks and outer hull are to be examined, and this
examination is to be supplemented by thickness measurement and testing as deemed necessary, to ensure
that the structural integrity remains effective.
The examination is to be sufficient to discover Substantial Corrosion, significant deformation, fractures,
damages or other structural deterioration.
2.2.1.3 All piping systems within the above spaces are to be examined and tested under working
conditions to ensure that the condition remains satisfactory.
2.2.1.4 The survey extent of ballast tanks converted to void spaces is to be specially considered in
relation to the requirements for ballast tanks.
2.2.3.1 Where provided, the condition of corrosion prevention system of ballast tanks is to be examined.
For tanks used for salt water ballast, excluding double bottom tanks, where a Protective Coating is found
in POOR condition as defined in 1.2.11 and it is not renewed, where soft coating has been applied, or
where a Protective Coating was not applied from time of construction, maintenance of class is to be made
subject to the tanks in question being examined at annual intervals.
When such breakdown of coating is found in salt water ballast double bottom tanks and it is not renewed,
where a soft coating has been applied, or where a protective coating was not applied from the time of
construction, maintenance of class may be subject to the tanks in question being examined at annual
intervals. When considered necessary by the surveyor, or where extensive corrosion exists, thickness
measurements are to be carried out..
2.2.3.2 Where the protective coating in spaces is found to be in a GOOD condition as defined in 1.2.11,
the extent of close-up surveys and thickness measurements may be specially considered by the
Classification Society.
2.2.4.2 Checking of the satisfactory operation of all mechanically operated hatch covers is to be made,
including:
- stowage and securing in open condition;
- proper fit and efficiency of sealing in closed conditions:
▲
- operational testing of hydraulic and power components, wires, chains and link drives.
Z10.6-3
2.2.4.3 Checking the effectiveness of sealing arrangements of all hatch covers by hose testing or
Z10.6 equivalent.
cont'd
2.2.4.4 Thickness measurement of the hatch cover and coaming plating and stiffeners is to carried out
as given in Table II.
2.3.2 Each Special Survey is to include a close-up examination of sufficient extent to establish the
condition of the shell frames and their end attachments in all cargo holds and salt water ballast tanks as
indicated in Table I.
2.4.2 Thickness measurement to determine both general and local levels of corrosion in the shell frames
and their end attachments in all cargo holds and salt water ballast tanks is to be carried out. Thickness
measurement is also to be carried out to determine the corrosion levels on the transverse bulkhead
plating. The thickness measurements may be dispensed with provided the surveryor is satisfied by the
close-up examination, that there is no structural diminution, and the Protective Coating where applied
remains efficient.
2.4.3 The Surveyor may extend the thickness measurements as deemed necessary. When thickness
measurements indicate substantial corrosion, the number of thickness measurements are to be increased
to determine the extent of substantial corrosion. Table III may be used as guidance for these additional
thickness measurements.
2.4.4 Transverse sections are to be chosen where the largest reductions are suspected to occur or are
revealed from deck plating measurements.
2.5.3 Tanks are to be tested with a head of liquid to the top of the air pipes for ballast tanks, deep tanks
or fuel tanks.
3. ANNUAL SURVEY
3.1 Schedule
3.1.1 Annual Surveys are to be held within 3 months before or after anniversary date from the date of the
initial classification survey or of the date credited for the last Special Survey.
3.2 Scope
3.2.1 General
3.2.1.1 The survey is to consist of an examination for the purpose of ensuring, as far as practicable, that
the hull, hatch covers, coamings and piping are maintained in a satisfactory condition.
▲
Z10.6-4
Z10.6
cont'd
3.2.2 Examination of the Hull
3.2.2.1 Examination of the hull plating and its closing appliances as far as can be seen.
3.2.2.2 Examination of watertight penetrations as far as practicable.
3.2.3.2 Where mechanically operated steel covers are fitted, checking the satisfactory condition of:-
- hatch covers; including close-up survey of hatch cover plating;
- tightness devices of longitudinal, transverse and intermediate cross junction ( gaskets, gasket
lips, compression bars, drainage channels);
- clamping devices, retaining bars, cleating;
- chain or rope pulleys;
- guides;
- guide rails and track wheels;
- stoppers, tec;
- wires, chains, gypsies, tensioning devices;
- hydraulic system essential to closing and securing;
- safety locks and retaining devices.
Where portable covers, wooden or steel pontoons are fitted, checking the satisfactory condition of:
- wooden covers and portable beams, carriers or sockets for the portable beam, and their securing
devices;
- steel pontoons, including close-up survey of hatch cover plating;
- tarpaulins;
- cleats, battens and wedges;
- hatch securing bars and their securing devices;
- loading pads/bars and the side plate edge;
- guide plates and chocks;
- compression bars, drainage channels and drain pipes (if any).
3.2.3.3 Checking the satisfactory condition of hatch coaming plating and their stiffeners including close-
up survey.
3.2.3.4 Random checking of the satisfactory operation of mechanically operated hatch covers is to be
made including:
- stowage and securing in open condition;
- proper fit and efficiency of sealing in closed condition;
- operational testing of hydraulic and power components, wires, chains, and link drives.
3.2.4 Suspect Areas identified at previous Special or Intermediate Surveys are to be overall and close-
up surveyed. Thickness measurements are to be taken of the area of substantial corrosion and the number
of thickness measurements are to be increased to determine the extent of substantial corrosion. Table III
may be used as guidance for these additional thickness measurements.
b) When considered necessary by the surveyor, or where extensive corrosion exists, thickness
measurement is to be carried out. If the results of these thicknesss measurements indicate that
Substantial Corrosion is found, then the number of thickness measurements are to be increased
to determine the extent of substantial corrosion. Table III may be used as guidance for these
additional measurements.
▲
Z10.6-5
IACS Req. 2002
Z10.6
c)When considered necessary by the surveyor, or where extensive corrosion exists, thickness
measurement is to be carried out. If the results of these thickness measurements indicate that
Substantial Corrosion is found, then the number of thickness measurements are to be increased
to determine the extent of substantial corrosion. Table III may be used as guidance for these
additional measurements.
d) All piping and penetrations in cargo holds, including overboard piping, are to be examined.
4. INTERMEDIATE SURVEY
4.1 Schedule
4.1.1 The Intermediate Survey is to be held at or between either the 2nd or 3rd Annual Survey.
4.1.2 Those items which are additional to the requirements of the Annual Surveys may be surveyed
either at or between the 2nd and 3rd Annual Survey.
4.2 Scope
4.2.1 General
4.2.1.1 The extent of survey is dependent on the age of the vessel as specified in 4.2.2 to 4.2.4
b) Where POOR Coating Condition, ( as defined in 1.2.11),corrosion or other defects are found in
salt water ballast spaces or where a Protective Coating was not applied from the time of
construction, the examination is to be extended to other ballast spaces of the same type.
c) In salt water ballast spaces other than double bottom tanks, where a Protective Coating is
found in POOR condition as defined in 1.2.10, and it is not renewed, where soft coating has
▲
Z10.6-6
been applied, or where a Protective Coating was not applied from time of construction,
Z10.6
cont'd
maintenance of class is to be subject to the tanks in question being examined and thickness
measurements carried out as considered necessary at annual intervals. When such breakdown
of coating is found in salt water ballast double bottom tanks, where a soft coating has been
applied, or where a coating has not been applied, maintenance of class may be subject to the
tanks in question being examined at annual intervals. When considered necessary by the
surveyor, or where extensive corrosion exists, thickness measurements should be carried out.
d) In addition to the requirements above, areas found suspect according to 1.2.8 at the previous
Special Survey are to be overall and close-up surveyed.
a) All salt water ballast tanks are to be examined. If such inspections reveal no visible structural
defects, the examination may be limited to a verification that the Protective Coating remains
efficient.
4.2.4.2In lieu of the requirements of 2.2.2, an under water survey may be considered as equivalent.
5.1.1 The owner is to provide the necessary facilities for a safe execution of the survey.
5.1.2 Tanks and Spaces are to be safe for access, i.e. gas freed, ventilated, illuminated, etc.
5.1.3 Tanks and Spaces are to be sufficiently clean and free from water, scale, dirt, oil residues, etc, to
reveal significant corrosion, deformation, fractures, damages or other structural deterioration. In
particular this applies to areas which are subject to thickness measurement.
5.1.4 Sufficient illumination is to be provided to reveal significant corrosion, deformation, fractures,
damages or other structural deterioration.
▲
Z10.6-7
5.2.2 For Close-up Surveys in any cargo hold and salt water ballast tanks, one or more of the following
means for access, acceptable to the Surveyor, is to be provided:
- permanent staging and passages through structures;
- temporary staging, e.g. ladders, and passages through structures;
- lifts and movable platforms
- other equivalent means
5.3 Equipment for Survey
5.3.1 Thickness measurement is normally to be carried out by means of ultrasonic test equipment. The
accuracy of the equipment is to be proven to the Surveyor as required.
5.3.2 One or more of the following fracture detection procedures may be required if deemed necessary
by the Surveyor:
- radiographic equipment
- ultrasonic equipment
- magnetic particle equipment
- dye penetrant
5.4.2 A communication system is to be arranged between the survey party in the spaces under
examination and the responsible officer on deck.
6.1 General
6.1.1 Thickness measurements required, if not carried out by the Society itself, are to be witnessed by a
surveyor on board to the extent necessary to control the process. The thickness measurement operator is
to be part of the survey planning meeting to be held prior to commencing the survey.
6.3 Reporting
6.3.1 A thickness measurement report is to be prepared. The report is to give the location of
measurements, the thickness measured as well as corresponding original thickness. Furthermore, the
report is to give the date when the measurements were carried out, type of measurement equipment,
names of personnel and their qualifications and has to be signed by the operator.
6.3.2 The Surveyor is to verify and countersign the thickness measurements report.
▲
Z10.6-8
7.2 Reporting
7.2.1 The survey and thickness measurement reports are to be issued to the Owner and placed on board
the vessel for reference at future surveys.
▲
▲
Z10.6-9
Z10.6 TABLE I
cont'd TABLE OF THE MINIMUM REQUIREMENTS FOR CLOSE-UP SURVEY AT HULL SPECIAL
SURVEYS OF GENERAL DRY CARGO SHIPS
Special Survey No.1 Special Survey No.2 Special Survey No. 3 Special Survey No. 4
and Subsequent
Age < 5 5 < Age < 10 10 < Age < 15 Age > 15
(A) Selected shell (A) Selected shell (A) All shell frames in (A) All shell frames in
frames in one frames in all cargo the forward lower all cargo holds and
forward and one aft holds and tween cargo hold and 25% tween deck spaces
cargo hold and deck spaces. frames in each of the including upper and
associated tween (B) One transverse remaining cargo lower end
deck spaces. bulkhead in each holds and tween attachments and
(B) One selected cargo cargo hold. deck spaces adjacent shell
hold transverse (B) Forward and aft including upper and plating.
bulkhead. transverse bulkhead lower end
(D) All cargo hold hatch in one side ballast attachments and Areas (B —F)as for
covers and coamings tank, including adjacent shell Special Survey No. 3.
(plating and stiffening system. plating.
stiffeners). (C) One transverse web (B) All cargo hold
with associated transverse
plating and framing bulkheads.
in two representative (B) All transverse
water ballast tanks bulkheads in ballast
of each type (i.e. tanks, including
topside, hopper side, stiffening system.
side tank or double (C) All transverse webs
bottom tank). with associated
(D) All cargo hold hatch plating and framing
covers and coamings in each water ballast
(plating and tank (i.e. topside,
stiffeners). hopper side, side
(E) Selected areas of all tank or double
deck plating inside bottom tank).
line of hatch (D) All cargo hold hatch
openings between covers and coamings
cargo hold hatches. (plating and
(F) Selected areas of stiffeners).
inner bottom plating. (E) All deck plating
inside line of hatch
openings between
cargo hold hatches.
(F) All areas of inner
bottom plating.
See Figs 1 and 2 for the areas corresponding to (A), (B), (C), (D), (E) and (F) .
Note: Close-up survey of cargo hold transverse bulkheads to carried out at the following levels:
• Immediately above the inner bottom and immediately above the tween decks, as applicable.
• Mid-height of the bulkheads for holds without tween decks.
• Immediately below the main deck plating and tween deck plating.
▲
Z10.6-10
IACS Req. 2002
Z10.6
Z10.6 TABLE II
cont'd
TABLE OF MINIMUM REQUIREMENTS FOR THE THICKNESS MEASUREMENT AT HULL
SPECIAL SURVEYS OF GENERAL DRY CARGO SHIPS
Special Survey No. 1 Special Survey No. 2 Special Survey No. 3 Special Survey No. 4
and Subsequent
Age < 5 5 < Age < 10 10 < Age < 15 Age > 15
1. Suspect areas. 1. Suspect areas. 1. Suspect areas. 1. Suspect areas.
2. One transverse 2. Two transverse 2. Within the cargo
section of deck sections within the length:
plating abreast a amidships 0.5L a) A minimum of
cargo space within the abreast of two three transverse
amidships 0.5L. different cargo sections within
3. Measurement for spaces. the amidships 0.5L.
general assessment 3. Measurement for b) each deck plate
and recording of general assessment outside line of cargo
corrosion pattern of and recording of hatch openings.
those structural corrosion pattern of
members subject to those structural c) Each bottom
close-up survey members subject to plate, including
according to Table I. close-up survey lower turn of bilge.
according to Table I. d) Duct keel or pipe
4. Within the cargo length, tunnel plating and
each deck plate outside internals.
line of cargo hatch 3. All wind and water
openings. strakes full length
5. All wind and water port and starboard
strakes within the 4. Measurement for
cargo length area. general assessment
and recording of
6. Selected wind and
corrosion pattern of
water strakes outside
those structural
the cargo length area.
members subject to
close-up survey
according to Table I.
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.
3 may be reduced to one and the number of transverse sections at Special Survey No. 4 and subsequent
surveys may be reduced to two.
▲
Z10.6-11
TABLE III
Z10.6
cont'd GUIDANCE FOR ADDITIONAL THICKNESS MEASUREMENTS IN WAY OF SUBSTANTIAL
CORROSION
Plating Suspect area and adjacent plates. 5 point pattern over 1 square
meter.
Stiffeners Suspect area. 3 measurements each in line
across web and flange.
Z10.6-12
TABLE IV
Z10.6
cont'd
PROCEDURES FOR CERTIFICATION OF FIRMS ENGAGED IN THICKNESS
MEASUREMENT OF HULL STRUCTURES
1. Application
This guidance applies for certification of the firms which intend to engage in the thickness
measurement of hull structures of the vessels.
5. Cancellation of Approval
Approval may be cancelled in the following cases:
(1) Where the measurements were improperly carried out or the results were improperly reported.
(2) Where the Society's surveyor found any deficiencies in the approved thickness measurement
operation systems of the firm.
(3) Where the firm failed to inform of any alteration in 4 above to the Society.
▲
Z10.6-13
Z10.6
cont'd
(E)
Transverse
Side shell frames bulkhead (B)
and end brackets
Double bottom
tank
(E)
Tween deck
Z10.6-14
L
C
Z10.6-15
Z11.1.2 To clearly indicate to shipowners and the users of Member Societies' register books
those ships which are subject to an enhanced survey programme, the following notations
shall be included within the class notation assigned to all such ships, built and/or
maintained in accordance with a Member Society's Rules and Regulations.
The ship type notation "OIL TANKER", or equivalent, and the notation "ESP" shall be
assigned to sea going self propelled ships having integral tanks and intended for the
carriage of oil in bulk. This type notation shall be assigned to tankers of both single and
double skin construction, as well as tankers with alternative structural arrangements, e.g.
mid-deck designs. Typical midship sections are given in Figure 1.
Fig. 1
Z11-1
IACS Req. 1993/Rev 2 2000
Z11.2.2-Z11.2.3
Bulk carrier of single side skin construction means a bulk carrier where one or more
cargo holds are bound by the side shell only or by two watertight boundaries, one of
which is the side shell, which are:
a) less than 760 mm apart in bulk carriers, the keels of which are laid or which are at
a similar stage of construction before 1 January 2000,
b) less than 1000 mm apart in bulk carriers, the keels of which are laid or which are
at a similar stage of construction on or after 1 January 2000.
Fig. 2
The ship type notation "ORE CARRIER", or equivalent, and the notation "ESP" shall be
assigned to sea going self-propelled single deck ships having two longitudinal bulkheads
and a double bottom throughout the cargo region and intended for the carriage of ore
cargoes in the centre holds only. A typical midship section is given in Figure 3.
Fig. 3
Z11-2
.2 The ship type notation 'ORE OR OIL CARRIER", or equivalent, and the notation
"ESP" shall be assigned to sea going self-propelled single deck ships having two
longitudinal bulkheads and a double bottom throughout the cargo region and
intended for the carriage of ore cargoes in the centre holds or of oil cargoes in centre
holds and wing tanks. Typical midship sections are given in Figure 4.
Fig. 4
.3 The ship type notation "OIL/BULK/ORE (OBO) CARRIER", or equivalent, and the
notation "ESP" shall be assigned to single deck ships of double skin construction,
with a double bottom, hopper side tanks and topside tanks fitted below the upper
deck, and intended for the carriage of oil or dry cargoes, including ore, in bulk. A
typical midship section is given in Figure 5.
Fig. 5
Z11-3
Fig. 6
Z11-4
The above is not intended to include maintenance and overhaul to hull, machinery and equipment in
accordance with manufacturer’s recommended procedures and established marine practice and which
does not require the Classification Society’s approval; however, any repair as a result of such
maintenance and overhauls which affects or may affect classification is to be noted in the ship’s log and
submitted to the attending Surveyor for use in determining further survey requirements.
Note: Annexed “Guidelines for the Survey of Voyage Repairs” is a recommendation and is not a
mandatory requirement under this UR Z13.
▲ ▲
Z13 ANNEX
cont'd GUIDELINES FOR THE SURVEY
OF VOYAGE REPAIRS
The purpose of these notes is to provide guidance to the field Surveyors in dealing with voyage hull
repairs and is to be considered in addition to the Rules of the Classification Society; no part of this guide
is intended to conflict with Rules of the Classification Society.
A. A meeting is to be held with the owners prior to commencement of hull repairs during a vessel’s
voyage to discuss and confirm the following :
4. Verification of new materials regarding certification, grade and scantlings. Verified mill
sheets to remain on board and to be provided to attending Surveyor examining completed
repairs.
8. Review of the intended provisions to facilitate sound weldments, i.e. cleaning, preheating
(if applicable) adherence to welding sequence principles.
Further, it might be necessary to restrict welding to certain positions and prohibit welding
in more difficult positions when the ship’s motions might influence the quality of the
welding.
11. Completed repairs are to be examined and tested as required to the satisfaction of the
attending Surveyor.
Note: All details and results of subject meeting to be covered by a memorandum. A copy of this
memorandum is to be placed on board and to be provided to the attending Surveyor
examining repairs. In addition, a copy is to be sent/faxed to the arrival port where
completed repairs will be examined.
▲
Z13 Annex - 1
Z13 B. Any contemplated repairs to primary hull structures, i.e. main longitudinal and transverse
members and their attachments, are to be submitted to the Classification Society for review prior
cont'd to commencing voyage repairs.
Any repairs to primary hull structures shall require attendance by a Surveyor riding-ship survey or
at regular intervals to confirm fit-up, alignment, general workmanship and compliance with
recommendations.
Repairs to other hull structural parts may be accepted based on examination upon completion of
repairs.
1. The initial meeting had been carried out and conditions found satisfactory.
1.1 Scope
The Surveys required herein are relevant to ships designed for the carriage of liquefied gases in
bulk. These requirements are related to cargo installations and are additional to those already specified
in Z1 and Z7.
1.2.1 The surveys are intended to include all installations and equipment related to the carriage and
handling of liquefied gases. These survey requirements do not cover fire protection, fire fighting
installation, portable equipment, and personnel protection equipment.
1.2.2 The annual survey is preferably to be carried out during a loading or discharging operation.
Access for cargo tanks or inerted hold spaces, necessitating gas-freeing/aerating will normally not be
necessary unless required by the Rules of the individual Society.
1.2.3 The intermediate survey required in Section Z 16.4, intends to supplement the annual survey by
testing cargo handling installations with related automatic control, alarm and safety systems for correct
functioning. The intermediate survey is preferably to be carried out with the ship in a gas-free condition.
The extent of the testing required for the intermediate survey will normally be such that the survey
cannot be carried out during a loading or discharging operation.
2 Special Survey
2.1 General
2.2.2 Special attention is to be given to the cargo tank and insulation in way of chocks, supports and
keys. Removal of insulation may be required in order to verify the condition of the tank or the insulation
itself if found necessary by the Surveyor.
Where the arrangement is such that the insulation cannot be examined, the surrounding structures of
wing tanks, double bottom tanks and cofferdams are to be examined for cold spots when the cargo tanks
are in the cold condition unless voyage records together with the instrumentation give sufficient evidence
of the integrity of the insulation system.
2.2.3.1 Non-destructive testing is to supplement cargo tank inspection with special attention to be given
to the integrity of the main structural members, tank shell and highly stressed parts, including welded
connections as deemed necessary by the surveyor. The following items are, inter alia, considered as
highly stressed parts:
2.2.3.2 For independent tanks type B, the extent of non-destructive testing shall be as given in a
programme specially prepared for the cargo tank design.
2.2.4 The tightness of all cargo tanks is to be verified by an appropriate procedure. Provided that the
effectiveness of the ship’s gas detection equipment has been confirmed, it will be acceptable to utilize
this equipment for the tightness test of independent tanks below deck.
2.2.5 Where findings of Z 16.2.2.1 to Z16.2.2.4 or an examination of the voyage records raises doubts
as to the structural integrity of a cargo tank, a hydraulic or hydro-pneumatic test is to be carried out. For
integral tanks and for independent tanks type A and B, the test pressure is to be in accordance with IACS
UR G 1.10.5 or G 1.10.7 as appropriate. For independent tanks type C, the test pressure is not to be less
than 1.25 times the MARVS.
2.2.6 At every other special survey (i.e., 2nd, 4th, 6th, etc.), all independent cargo tanks type C are to be
either:
2.2.6.2 Subjected to a thorough, planned non-destructive testing. This testing is to be carried out in
accordance with a programme specially prepared for the tank design. If a special programme does not
exist, the following applies:
At least 10% of the length of the welded connections in each of the above mentioned areas is to be tested.
This testing is to be carried out internally and externally as applicable.
2.2.7 As far as practicable all hold spaces and hull insulation (if provided), secondary barriers and tank
supporting structures are to be visually examined. The secondary barrier of all tanks is to be checked for
their effectiveness by means of a pressure/vacuum test, a visual examination or another acceptable
method.
2.2.8 For membrane and semi-membrane tanks systems, inspection and testing are to be carried out in
accordance with programmes specially prepared in accordance with an approved method for the actual
tank system.
2.2.9 The pressure/vacuum relief valves, rupture disc and other pressure relief devices for interbarrier
spaces and hold spaces are to be opened, examined, tested and readjusted as necessary, depending on
their design.
▲
Z16 2.2.10 The pressure relief valves for the cargo tanks are to be opened for examination, adjusted,
function tested, and sealed. If the cargo tanks are equipped with relief valves with non-metallic
cont'd membranes in the main or pilot valves, such non-metallic membranes are to be replaced. Where a proper
record of continuous overhaul and retesting of individually identifiable relief valves is maintained,
consideration will be given to acceptance on the basis of opening, internal examination, and testing of a
representative sampling of valves, including each size and type of liquefied gas or vapor relief valve in
use, provided there is logbook evidence that the remaining valves have been overhauled and tested since
crediting of the previous Special Survey.
2.3.1 The cargo, liquid nitrogen and process piping systems, including valves, actuators, compensators
etc. are to be opened for examination as deemed necessary. Insulation is to be removed as deemed
necessary to ascertain the condition of the pipes. If the visual examination raises doubt as to the integrity
of the pipelines, a pressure test at 1,25 times the MARVS for the pipeline is to be carried out. After re-
assembly the complete piping systems are to be tested for leaks.
2.3.2 The pressure relief valves are to be function-tested. A random selection of valves is to be opened
for examination and adjusted.
2.4 Components
Cargo pumps, compressors, process pressure vessels, liquid nitrogen tanks, heat exchangers and
other components, including prime movers, used in connection with cargo handling and methane boil-off
burning are to be examined as required in the Rules of each individual Society for periodical survey of
machinery.
2.5 Miscellaneous
2.5.1 Systems for removal of water or cargo from interbarrier spaces and holds are to be examined and
tested as deemed necessary.
2.5.2 All gas-tight bulkheads are to be inspected. The effectiveness of gas-tight shaft sealing is to be
verified.
2.5.4 It is to be verified that all cargo piping systems are electrically bonded to the hull.
3. Annual Survey
3.1 General
3.1.1 The log books are to be examined with regard to correct functioning of the cargo containment and
cargo handling systems. The hours per day of the reliquefaction plants or the boil-off rate is to be
considered.
3.1.2 All accessible gas-tight bulkhead penetrations including gas-tight shaft sealings are to be visually
examined.
3.1.3 The means for accomplishing gas tightness of the wheelhouse doors and windows is to be
examined. All windows and sidescuttles within the area required to be of the fixed type (non-opening)
are to be examined for gas tightness. The closing devices for all air intakes and openings into
accommodation spaces, service spaces, machinery spaces, control stations and approved openings in
superstructures and deckhouses facing the cargo area or bow and stern loading/unloading arrangements,
are to be examined.
▲
Venting systems, including protection screens if provided, for the cargo tanks, interbarrrier spaces
and hold spaces are to be visually examined externally. It is to be verified that the cargo tank relief valves
are sealed and that the certificate for the relief valves opening/closing pressures is onboard.
3.4.1 The instrumentation of the cargo installations with regard to pressure, temperature and liquid level
is to be verified in good working order by one or more of the following methods:
3.4.2 The logbooks are to be examined for confirmation that the emergency shutdown system has been
tested.
Inert gas/dry air installations including the means for prevention of backflow of cargo vapour to
gas-safe spaces are to be verified as being in satisfactory operating condition.
3.6 Miscellaneous
3.6.1 It is to be verified that all accessible cargo piping systems are electrically bonded to the hull.
3.6.2 Arrangements for burning methane boil-off are to be visually examined as far as practicable. The
instrumentation and safety systems are to be verified as being in good working order in accordance with
Z 16.3.4.1.
3.6.3 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.
3.6.4 Mechanical ventilation fans in gas dangerous spaces and zones are to be visually examined.
4. Intermediate survey
4.1 General
4.2.1 The instrumentation of the cargo installation with regard to pressure, temperature and liquid level
is to be visually examined and to be tested by changing the pressure, temperature and level as applicable
and comparing with test instruments. Simulated testing may be accepted for sensors which are not
accessible or for sensors located within cargo tanks or inerted hold spaces. The testing is to include
testing of alarm and safety functions.
▲
Z16 4.2.2 The piping of the gas detection system is to be visually inspected for corrosion and damage as far
as practicable. The integrity of the suction lines between suction points and analyzing units is to be
cont'd verified as far as possible. Gas Detectors are to be calibrated or verified with sample gases.
4.2.3 The emergency shutdown system is to be tested, without flow in the pipe lines, to verify that the
system will cause the cargo pumps and compressors to stop.
4.4 Miscellaneous
The instrumentation and safety systems for burning cargo as fuel are to be examined in
accordance with the requirements of Z 16.4.2.1.
▲
▲
Z17-1
Z17 1. General
cont’d 1.1 Firms providing services on behalf of the owner of a ship or a mobile offshore unit, such as
measurements, tests or maintenance of safety systems and equipment, the results of which are used by
Surveyors in making decisions affecting classification are subject to approval by the Society in
accordance with the mandatory procedures in this unified requirement and its Annex 1.
1.2 Where such services are used by Surveyors in making decisions affecting statutory certifications,
the firms are subject to approval by the Society where the Society is so authorised by the relevant flag
Administration. For such services the Society may accept approvals done by the flag Administration
itself or duly authorised organisations acting on behalf of the flag Administration.
2. Objective
2.1 The objective of this procedure is to set basic standards for qualifying service suppliers.
3. Application
3.1 This procedure applies to the approval of the following categories of service suppliers:
3.3 Detailed requirements specific to the various categories of suppliers are given in Annex I.
National and/or international requirements may give additional requirements. Reference to such national
and/or international requirements are given in Annex I.
4.1.1 The following documents are to be submitted to the Society for review. General requirements
concerning suppliers are given in 4.2, and specific requirements as relevant, in Annex I.
Z17-2
Z17 ·
·
A guide for operators of such equipment
Training programmes for operators/technicians/inspectors
cont’d · Check lists and record formats for recording results of the services referred to in section 1
· Quality Manual and/or documented procedures covering requirements in 4.5
· Evidence of approval/acceptance by other bodies, if any
· Information on the other activities which may present a conflict of interest
· Record of customer claims and of corrective actions requested by certification bodies
· Where relevant, list and documentation of licenses granted by equipment’s manufacturer
4.2.1 Extent of Approval: The supplier shall demonstrate, as required by 4.2.2 – 4.2.9, that it has the
competence and control needed to perform the services for which approval is sought.
4.2.2 Training of personnel – The supplier is responsible for the qualification and training of its
personnel to a recognised national, international or industry standard as applicable. Where such
standards do not exist, the supplier is to define standards for the training and qualification of its personnel
relevant to the functions each is authorised to perform. The personnel shall also have an adequate
experience and be familiar with the operation of any necessary equipment.
Operators/technicians/inspectors shall have had a minimum of one (1) year tutored on-the-job training.
Where it is not possible to perform internal training, a program of external training may be considered as
acceptable.
4.2.3 Supervision – The supplier shall provide supervision for all services provided. The responsible
supervisor shall have had minimum two (2) years experience as an operator/technician/inspector within
the activity for which the supplier is approved. For a supplier consisting of one person, that person shall
meet the requirements of a supervisor.
4.2.4 Personnel records – The supplier shall keep records of the approved
operators/technicians/inspectors. The record shall contain information on age, formal education, training
and experience for the services for which they are approved.
4.2.5 Equipment and facilities – The supplier shall have the necessary equipment and facilities for the
service to be supplied. A record of the equipment used shall be kept. The record shall contain
information on maintenance and calibration.
4.2.6 Procedures – The supplier shall have documented work procedures covering all services supplied.
4.2.7 Subcontractors – The supplier shall give information of agreements and arrangements if any parts
of the services provided are subcontracted. Particular emphasis shall be given to quality management by
the supplier in following-up of such subcontracts. Subcontractors providing anything other than
subcontracted personnel or equipment shall also meet the requirements of sections 4.2 and 4.5.
4.2.8 Verification – The supplier shall verify that the services provided are carried out in accordance
with approved procedures.
4.2.9 Reporting – The report shall be prepared in a form acceptable to the Society. Special guidelines
may be given in Annex I. The report shall include a copy of the Certificate of Approval.
4.3 Auditing of the Supplier – Upon reviewing the submitted documents with satisfactory result, the
supplier is audited in order to ascertain that the supplier is duly organised and managed in accordance
with the submitted documents, and that it is considered capable of conducting the services for which
approval/certification is sought.
Z17-3
4.5.2 A documented Quality Assurance system complying with the ISO 9000 standard or equivalent
and including the above items, would be considered acceptable.
4.6.1 A company which works as a service station for manufacturer(s) of equipment (and as a service
supplier in this field), shall be assessed by the manufacturer(s) and nominated as their agent. the
manufacturer shall ensure that appropriate instruction manuals, material etc. are available for the agent as
well as of proper training of the agent’s technicians. Such suppliers shall be approved either on a case
by case basis, or in accordance with 4.6.2.
4.6.2 If a manufacturer of equipment (and service supplier) applies to a Society for inclusion of his
nominated agents and/or subsidiaries in the approval, then he must have implemented a quality assurance
system certified in accordance with ISO 9000 series, with effective controls of his agents and/or
subsidiaries, and when these agents/subsidiaries have an equally effective quality control system
complying with ISO 9003. Such approvals shall be based upon an evaluation of the quality assurance
system implemented by the parent company against minimum ISO 9002. The Society will follow-up the
adherence to this quality assurance system by performing audits on such agents or subsidiaries against
ISO 9003.
5. Certification
5.1 Upon satisfactory completion of both the audit of the supplier and the demonstration test, if
required, the Society will issue a Certificate of Approval stating that the supplier’s service operation
system has been found to be satisfactory and that the results of services performed in accordance with
that system may be accepted and utilised by the Society’s Surveyors in making decisions affecting
classification or statutory certification, as relevant. The Certificate shall clearly state that the type and
scope of services and any limitations or restrictions imposed. The supplier will also be included in the
Society’s records of approved service suppliers.
5.2 Renewal or endorsement of the Certificate is to be made at intervals not exceeding five (5) years
by verification through audits that approved conditions are maintained. Individual Societies may require
renewal or endorsement of the Certificate at intervals shorter than five (5) years and may require
intermediate audits.
5.3 Where several servicing stations are owned by a given company, each station is to be assessed and
approved except as specified in 4.6.2.
6.1 In case where any alteration to the certified service operation system of the supplier is made, such
alteration is to be immediately informed to the Society. Re-audit may be required when deemed
necessary by the Society.
▲
Z17-4
7.1.1 Where the service was improperly carried out or the results were improperly reported.
7.1.2 Where a Surveyor finds deficiencies in the approval service operation system of the supplier and
appropriate corrective action is not taken
7.1.3 Where the supplier fails to inform of any alteration as in 6 above to the Society
7.1.4 Where intermediate audit, if requested as per 5.2, has not been carried out
7.2 The Society reserves the right to cancel the approval and to inform the IACS Members
accordingly.
7.3 A supplier whose approval was cancelled, may apply for re-approval provided he has corrected
the non-conformities which resulted in cancellation, and the Society is able to confirm he has effectively
implemented the corrective action.
8. Existing Approvals
Approvals granted before the date of implementation of UR Z17 may remain valid as stated in the
respective certificates for a period up to but not exceeding 3 years. Renewals of such certificates have to
be carried out in accordance with UR Z17.
Z17-5
Z17 ANNEX 1
cont'd Special Requirements for Various Categories of Service Suppliers
1.2 Supervisor – The responsible supervisor shall be qualified according to a recognised national or
international industrial NDT standard (e.g. EN 473 level II or ISO 9712 level II).
1.3 Operators – The operators carrying out the measurements shall be certified to a recognised
national or international industrial standard (e.g. EN 473 level I or ISO 9712 level I) and shall have
adequate knowledge of ship structures sufficient to elect a representative position for each measurements.
1.4 Equipment – On coated surfaces, instruments using pulsed echo technique (either with
oscilloscope or digital instruments using multiple echo, single crystal technique) are required. Single
echo instruments may be used on uncoated surfaces, which have been cleaned and grinded.
1.5 Procedures – Documented work procedures are at least to contain information on survey
preparation, selection and identification of test locations, surface preparation, protective coating
preservation, calibration checks, and report preparation and content.
1.6 Reporting – The report shall be based on the guidelines given in UR Z10.1, Z10.2 or Z10.3, as
relevant.
1.7 Verification – The supplier must have the Surveyor’s verification of each separate job,
documented in the report by his signature.
· Have knowledge of different hatch designs, their functioning and sealing features
· Be able to document a theoretical and practical training onboard in using ultrasonic equipment
specified
2.3 Equipment – The ultrasonic equipment to be used shall be type approved by the Society. It shall
be demonstrated for the Surveyor that the equipment is fit for the purpose of detecting leakages in hatch
covers.
2.4 Procedures – The supplier shall have documented work procedures which shall include the
manual for the ultrasonic equipment specified, its adjustment, its maintenance, its operation and approval
criteria.
3. Firms carrying out in-water survey of ships and mobile offshore units
3.1 Extent of engagement – In-water survey of ships and mobile offshore units.
▲
Z17-6
Z17 3.2 Training of personnel – The supplier is responsible for the qualification of its divers and the
diving equipment utilised when carrying out survey. Knowledge of the following shall be documented:
cont'd
· Ship’s underwater structure and appendages, tail shaft, propeller, rudder and its bearings, etc.
· (void)
· Under-water video monitoring with TV-monitors on deck, as well as still picture work
· Special equipment and tools like hull cleaners, grinders, cutters, etc.
3.3 A plan for training of personnel in the reporting system, minimum Rule requirements for relevant
ship types, ship’s underwater structure, measuring of bearing clearances, the recognition of corrosion
damage, buckling and deteriorated coatings, etc. shall be included.
3.4 Supervisor – The supervisor shall be qualified according to the supplier’s general requirements
and shall have minimum two (2) years’ experience as a diver carrying out survey.
3.5 Divers carrying out survey – The diver carrying out the survey shall have had at least one (1)
year’s experience as an assistant diver carrying out survey (minimum 10 different assignments).
· Equipment for carrying out thickness gauging, non-destructive testing and measurements, e.g.
clearances, indents, etc., as relevant to the work to be performed.
3.7 Procedures and guidelines – The supplier shall have documented operational procedures and
guidelines for how to carry out the survey and how to handle the equipment. These shall include:
· Guidance of the diver along the hull to ensure complete coverage of the parts to be surveyed
3.8 Verification – The supplier must have the Surveyor’s verification of each separate job,
documented in the report by his signature.
▲
Z17-7
Z17 4. Firms engaged in surveys and maintenance of fire extinguishing equipment and systems
cont'd Extent of engagement – The supplier shall have the professional knowledge of fire theory, fire
fighting and fire extinguishing appliances sufficient to carry out the surveys and to make the necessary
evaluations of the condition of the equipment.
5.1 Extent of engagement – Servicing of inflatable liferafts, inflatable lifejackets, hydrostatic release
units and/or inflatable rescue boats.
5.2 Equipment and premises – IMO Res. A.761(18) gives recommendations on conditions for the
approval of servicing stations for inflatable liferafts which shall be observed as relevant.
5.3 Procedures and instructions – The supplier shall have documented procedures and instructions for
how to carry out service of equipment. The procedures should include requirements to record the nature
and extent of damages to and defects found in equipment during servicing and repair work. This data
shall be made available to the Society upon request.
5.4 The supplier shall provide evidence that it has been authorised or licensed to service the particular
makes and models of equipment for which approval is sought by the equipment’s manufacturer.
6.1 Extent of engagement – Inspection, testing, and/or measurement of radio equipment aboard ships
or mobile offshore units for compliance with SOLAS regulations.
6.2 Reference documents – The supplier shall have access to SOLAS 1974 as amended, IMO Res.
A.789(19): Specification on the survey and certification functions of recognised organisations acting on
behalf of the administration, ITU Radio Regulations, and IMO Performance Standards as well as relevant
parts, if any, of the Society’s Rules and Guidelines.
6.3 Supervisor – The supervisor shall have minimum two (2) years education from a technical school
and experience as an inspector, and should preferable hold a General Operator’s Certificate (GOC).
6.4 Radio inspector – The inspector carrying out the inspection shall have passed the internal training
of the supplier in Radiotelephony, GMDSS, and initial and renewal surveys, as applicable. The inspector
shall also have at least one (1) year’s technical school and at least one (1) year experience as an assistant
radio inspector.
6.5 Equipment
6.5.1 The supplier shall have the major and auxiliary equipment required for correctly performing the
inspection. A record of the equipment used shall be kept. The record shall contain information on
manufacturer and type of equipment, and a log of maintenance and calibrations.
6.5.2 A standard which is relevant to the radio equipment to be tested shall be available for the
equipment and shall be cited in the inspection report.
6.5.3 For equipment employing software in the conjunction with testing/examination, this software
shall be fully described and verified.
▲
Z17-8
· Equipment for measuring output and reflect effect on VHF and MF/HF
· Equipment for measuring modulation on MF/HF and VHF (AM, FM, PM)
6.7 Procedures and instructions – The supplier shall have documented procedures and instructions for
how to carry out testing and examination of radio equipment. Procedures and instructions for operating
of each item of the testing/inspection equipment shall also be kept and be available at all times.
7. Firms engaged in inspection and testing of centralised gas welding and cutting equipment
The supplier shall document and demonstrate that it has knowledge of gas welding, of associated
central gas installation systems and of current safety requirements applicable to such equipment by
national administrations, sufficient to carry out the inspection and testing and to make the necessary
evaluations of the state of the equipment.
The supplier shall document and demonstrate that it has knowledge of the equipment and systems
sufficient to carry out the inspections and testing of self-contained breathing apparatus to identified
standards and to make the necessary evaluation of the condition of the equipment.
9. Firms engaged in the examination of Ro-Ro ships bow, stern, side and inner doors
9.1 Extent of engagement - inspection of securing and locking devices, hydraulic operating system,
electric control system for the hydraulics, electric indicator systems, and supporting, securing and
locking devices and tightness testing.
9.3 Reference documents - The supplier shall have access to SOLAS 1974 as amended and IACS
Guidelines No. 8 - Check-list for Surveyors of Ro-Ro Ships Shell and Inner Doors Guidelines for
Surveyors, or its equivalent, by the relevant class society.
9.4 In addition to 4.2.3 of Z17, the Senior Service Engineer (Supervisor) shall have a minimum two
(2) years education from a technical school.
9.5.1 For Inspection of Supporting Securing and Locking Devices, Hinges and Bearings.
· Equipment for measuring clearances (i.e. feeler gauges, vernier calipers, micrometers).
Z17-9
· Digital multi-meter
9.6.1 The supplier shall have access to drawings and documents, including the Operating and Inspection
Manual.
9.6.2 The supplier shall have access to the service history of the doors.
9.6.3 The supplier should use, complete and sign a checklist which has been found acceptable by the
classification society.
▲
▲
Z17-10
1. General Requirements
2. Survey of Boilers
Note: Ex-M20 was re-categorized as Z18 in November 2001, excluding section M20.2
“Surveys of Propeller Shafts and Tube Shafts” which was separately relocated to Z21.
▲
Z18-1
1.1.1 Special Surveys are to be carried out at 5 years intervals to renew the Class Certificate.
1.1.2 The first Special Survey is to be completed within 5 years from the date of the initial classification
survey and thereafter 5 years from the credited date of the pervious Special Survey. However, an
extension of class of 3 months maximum beyond the 5th year can be granted in exceptional
circumstances.
In this case, the next period of class will start from the expiry date of the Special Survey before the
extension was granted.
1.1.3 For surveys completed within 3 months before the expiry date of the Special Survey, the next
period of class will start from the expiry date of the Special Survey. For surveys completed more than 3
months before the expiry date of the Special Survey, the period of class will start from the survey
completion date.
1.1.4 The Special Survey may be commenced at the 4th Annual Survey and be progressed with a view
to completion by the 5th anniversary date. When the Special Survey is commenced prior to the 4th
Annual Survey, the entire survey is to be completed within 15 months if such work is to be credited to
the Special Survey.
2. Survey of Boilers
2.1 Water tube boilers used for main propulsion, including reheat boilers, all other boilers of essential
service, and boilers of non-essential service having working pressure exceeding 0.35 N/mm2 (3.5 bar)
and a heating surface exceeding 4.5 m2, are to be surveyed internally twice in every five year period. The
period between surveys will not exceed three (3) years.
2.2 External survey of boilers is to be carried out annually in the course of the Annual Survey of a ship.
1 Some Member Societies use the term “Special Periodical Survey”, others the term “Class
Renewal Survey” instead of the terms “Special Survey”.
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Z18-2
3.2 Turbine casings should be opened at the next Special Survey and subsequent Special Surveys.
4.2 This requirement applies to all member Societies and Associates from 1 January 2001.
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Z18-3
1. General
Inspection, measuring and test equipment, which Surveyors rely on to make decisions affecting
classification or statutory certification, are to be individually identified and calibrated to a recognized
national or international standard.
The Surveyor may accept simple measuring equipment (e.g. rulers, measuring tapes, weld gauges,
micrometers) without individual identification or confirmation of calibration, provided they are of
standard commercial design, properly maintained and periodically compared with other similar
equipment or test pieces.
3. Shipboard Equipment
The Surveyor may accept equipment fitted on board a ship and used in examination of shipboard
equipment (e.g. pressure, temperature or rpm gauges and meters) based either on calibration records or
comparision of readings with multiple instruments.
4. Other Equipment
The Surveyor shall satisfy himself that other equipment (e.g. tensile test machines, ultrasonic thickness
measurement equipment, etc) is calibrated to a recognized national or international standard.
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Z19-1
1.1 Application
1.1.1 These requirements apply to an approved Planned Maintenance Scheme for
Machinery (PMS) as an alternative to the Continuous Machinery Survey (CMS).
1.3.1 The chief engineer shall be the responsible person on board in charge of the
PMS.
1.3.2 Documentation on overhauls of items covered by the PMS shall be reported
and signed by the chief engineer.
Z20-1
(i) clauses iii, iv, v and vii as well as changes to other clauses in 2.2.1;
(ii) clause iii of 2.2.2,
(iii) full trend analysis (including spectrum analysis for vibrations) of
machinery displaying operating parameters exceeding acceptable
tolerances.
2.3.4 An Annual Audit shall be carried out to maintain the validity of the PMS (see
3.2).
2.3.5 The survey arrangement for machinery under PMS can be cancelled by the
Society if PMS is not being satisfactorily carried out either from the maintenance
records or the general condition of the machinery, or when the agreed intervals
between overhauls are exceeded.
2.3.6 The case of sale or change of management of the ship or transfer of class
shall cause the approval to be reconsidered.
2.3.7 The shipowner may, at any time, cancel the survey arrangement for machinery
under PMS by informing the Society in writing and for this case the items which have
been inspected under the PMS since the last annual survey can be credited for class
at the discretion of the attending surveyor.
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Z20-2
Z 20 3 Surveys
cont’d
3.1 Implementation Survey
3.1.1 The Implementation Survey shall be carried out by the Society’s surveyor
within one year from the date of approval.
3.1.2 During the implementation survey the following shall be verified by a surveyor
to ensure:
(i) the PMS is implemented according to the approval documentation and
is adapted to the type and complexity of the components/system on
board;
(ii) the PMS is producing the documentation required for the Annual Audit
and the requirements of surveys and testing for retention of class are
complied with;
(iii) the onboard personnel is familiar with the PMS.
3.1.3 When this survey is carried out and the implementation is found in order, a
report describing the system shall be submitted to the Society and the system may be
put into service.
3.2.4 The performance and maintenance records shall be examined to verify that the
machinery has functioned satisfactorily since the previous survey or action has been
taken in response to machinery operating parameters exceeding acceptable
tolerances and the overhaul intervals have been maintained.
3.2.7 At the discretion of the surveyor, function tests, confirmatory surveys and
random check readings, where condition monitoring equipment is in use, shall be
carried out as far as practicable and reasonable.
3.2.8 Upon satisfactory completion of the above requirements, the Society shall
retain the PMS.
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Note: * The term audit , in this context, is not related to ISM audit.
Z20-3
IACS Req. 2001
Z 20
3.3.2 Any repair and corrective action regarding machinery under PMS system shall
be recorded in the PMS logbook and repair verified by the Society s surveyor at the
Annual Audit.
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Z20-4
(a)(i) Where the propeller shafts and the tube shafts are fitted with continuous liners, or approved oil
sealing glands, or made of corrosion resistant material, the interval of survey is to be:
• from three (3) to a maximum of five (5) years for single shafting arrangements;
• from four (4) to a maximum of five (5) years for multi-shafting arrangements.
where
- the propeller is fitted to a keyed shaft taper the design details of which are approved,
and a non-destructive examination is made at each survey by an approved crack-
detection method of the after end of the cylindrical part of the shaft (from the after end
of the liner, if any), and of about one third of the length of the taper from the large end,
or
where
- the propeller is fitted to a solid flange coupling at the aft end of the shaft,
the shaft and its fittings are not exposed to corrosion,
the design details are approved, and
a non-destructive examination is made at each survey by an approved crack-
detection method of the after flange fillet area of the shaft,
or
where
- the propeller is fitted keyless to the shaft taper,
the shaft is protected from seawater,
the design details are approved, and
a non-destructive examination is made at each survey by approved crack-detection
method of the forward part of the aft shaft taper.
(ii) In all other cases, the interval of survey is to be 2 1/2 years (+/- 6 months).
However, for oil lubricated arrangement all exposed areas of the after shaft area as described in
1 (a) are to be examined by an approved crack-detection method without drawing of the shaft,
where
- clearances and weardown of the bearings,
- records of lubricating oil analysis, oil consumption and bearing temperature, and
- visible shaft areas
are found satisfactory.
Note: Ex-UR M20.2 “Surveys of propeller Shafts and Tube Shafts” was re-categorized as UR Z21 in
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November 2001.
Z21-1
IACS Req. 2001
Z 21
Z 21 Lubricating oil and bearing temperature controls are to be performed as specified in 2(d).
cont'd Where any doubt exists regarding the findings of the above, the shaft is to be sufficiently drawn to
permit an entire examination.
2. Modified Survey
(a) For single and multi-shafting arrangements the modified survey may be accepted in any of the
following three (3) cases subject to:
- the shaft is fitted with oil lubricated bearings and oil sealing glands, and
- the shaft and its fittings are not exposed to corrosion, and
- new oil seals may be fitted without removal of the propeller (except in the case of
keyed propeller), and design details are approved.
where - the propeller is keyed on the shaft taper and suitable crack-prevention measures are
taken, or
where - the propeller is fitted to a solid flange coupling at the end of the shaft, or
(b) The modified survey is accepted at alternate five (5) yearly (maximum) surveys instead of the
Normal Survey, provided that the clearances of the aft bearing are found in order and the oil and
the oil sealing arrangements have proved effective.
• drawing the shaft to expose the aft bearing contact area of the shaft,
• examining the forward bearing as far as possible and all accessible parts of the shaft including
the propeller connection to the shaft, and
• for keyed propellers, performing a non-destructive examination by an approved crack-detection
method of about one third of the length of the taper from the big end, for which dismantling of
the propeller will be required.
• for keyless propellers performing a visual examination to confirm the good condition of the
sealing arrangements.
(d) Where a lubricating oil analysis is carried out regularly at intervals not exceeding six (6) months,
and the oil consumption and bearing temperature are recorded and considered to be within
permissible limits, drawing of the shaft to expose the aft bearing contact area of the shaft may not
be required.
The documentation on lubricating oil analysis is to be available on board. Each analysis should
include the minimum parameters:
• water content,
• chlorides content,
• content of bearing metal particles, and
• oil aging (resistance to oxidation).
Z21-2
IACS Req. 2001
Z 21
Z 21 3. Partial Survey
cont'd (a) For shafts where the modified survey is applicable, consideration may be given, upon application
by the Owner, to a prolongation of the intervals between Normal Survey, provided a partial
survey is performed.
(b) The partial survey consists of checking the oil sealing glands and the clearance of the bearings.
For keyed propellers, the propeller is to be dismantled to expose the forward part of the taper and
a non-destructive examination by an approved crack-detection method is to be performed.
(c) In no case is the interval between Normal Survey exceed 1.5 times the due interval.
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Z21-3