Learning Objectives 5A

Solid Bulk Cargo

 Define solid bulk cargo
 Describe the hazards associated with the carriage of
solid bulk cargo
 Define : Angle of Repose, Moisture Content, Flow
Moisture Point, Transportable Moisture Limit,
Moisture Migration
 Describe the preparations of holds prior to the carriage
of solid bulk cargoes
 State the precautions prior to the carriage of solid bulk
cargoes
 Describe the methods used for loading and discharging
solid bulk cargoes

KNR/05-2006 SP-SMA Slide 1

 Solid Bulk Cargo

KNR/05-2006 SP-SMA Slide 2

 Introduction

 Carriage of solid bulk cargoes is

governed by Code of Safe Practice for
Solid Bulk Cargo
 Code published by International
Maritime Organisation (IMO).
 Apply to carriage of “dry” and “wet”
bulk cargo and do not apply to carriage
of Grain in Bulk, which have separate
regulations.

KNR/05-2006 SP-SMA Slide 3

 Code of Safe Practice for Sold Bulk Cargo
Consists of 12 sections and 9 Appendices.
Introduction – The aim of the code
Section 1 - Definitions
Section 2 - General Precautions
Section 3 - Safety of Personnel & ship
Section 4 - Assessment of acceptability of consignment for safe shipment
Section 5 - Trimming procedures
Section 6 - Method of determining the Angle of Repose
Section 7 - Cargoes which may liquefy
Section 8 - Cargoes which may liquefy -Test Procedures
Section 9 - Materials possessing chemical hazards
Section 10 – Transport of solid wastes in bulk
Section 11 - Stowage factor conversion tables
Section 12 – References to related information and recommendations
Appendix 1 – Individual schedules of solid bulk cargoes
Appendix 2 – Laboratory test procedures, associated apparatus and standards
Appendix 3 – Properties of solid bulk cargoes
Appendix 4 – Performance specification for the measurement of the density of solid
bulk cargo
Appendix 5 – MSC/Circ. 1146 – BC exempted from fire-extinguishing system
Appendix 6 – Procedures for gas monitoring of coal cargoes
Appendix 7 – Recommendations for entering enclosed spaces aboard ships
Appendix 8 – Recommendations on the safe useof pesticides in ships
Appendix
KNR/05-20069 – Index of solid bulk cargoesSP-SMA Slide 4
 Definitions

 Angle of Repose is the angle between the horizontal

and the slope of the cargo obtained when that cargo is
poured onto the horizontal. The greater the angle-it is
less likely to shift.

Angle of Repose

KNR/05-2006 SP-SMA Slide 5

 Definitions-Continue..
 Flow Moisture Point is the percentage moisture content (on a
wet basis) at which a flow state develops.
Vessels built specially for the carriage of bulk cargoes and
sufficiently sub-divided are not so highly restricted in their loading
procedures with concentrates as cargo vessels would be.

 Flow State is the state that occurs when a mass of granular

material is saturated with liquid to an extent that under the
influence of prevailing external forces such as vibration, impaction,
or the ship’s motion, it loses its internal shear strength and behaves
like a liquid.

 Moisture Content is the portion of a representative sample of a

material which consists of water, ice, or other liquid expressed as a
percentage of the total wet weight of that sample.
KNR/05-2006 SP-SMA Slide 6
 Definitions-Continue..
 Moisture Migration is the movement of moisture contained in a
bulk cargo by settling and consolidation of the cargo due to
vibration and ship’s motion. Water is progressively displaced which
may result in some portions or all of the bulk cargo developing a
flow state.

 Transportable Moisture Limit (TML) is the transportable

moisture limit of a cargo which may liquefy represents the
maximum moisture content of that cargo which is considered safe
for carriage in ships which are not specifically fitted or constructed
for cargoes for excessive moisture content. It is expressed as a
percentage of the flow moisture point. The TML is 90% of the
Flow Moisture Point.

KNR/05-2006 SP-SMA Slide 7

 General precautions with
bulk cargoes
Bulk cargo must be properly distributed throughout the ship in
order that the structure will never be over stressed.
1. A stability booklet provided giving relevant information pertaining
to loading, precautions and any necessary data should be provided
to the Master. Prior to sailing, the Master should calculate the
stability for the anticipated worst conditions during the voyage as
well as that on departure and ensure they are satisfactory.

2. An excessively stiff ship may roll very violently, resulting in

damage to the ship. However, a vessel with a relatively large GM is
better able to resist the tendency to list, if a shift of cargo should
occur.

3. When loading a high density bulk cargo with a S.F. of about

20ft3/ton (0.56m3/tonne) or lower, the loaded condition are different
from normal and particular attention should be paid to the
distribution of weights to avoid excessive stresses.
KNR/05-2006 SP-SMA Slide 8
 General precautions with
bulk cargoes
 A general cargo vessel is normally constructed to carry cargoes of
about 50 - 60ft3/ton (1.39 to 1.67m3/tonne) when loaded to full bale
and deadweight capacity. In such cases, the ship master should be
provided with comprehensive loading information so that the ship
may not be over stressed.
 Where above information is not available, the following
precautions should be observed :
a) The general fore and aft distribution of weight should not differ
appreciably from that found satisfactory for general cargo.
b) The maximum number of tonnes of cargo loaded in any space should
not exceed : 0.9 x L x B x D (tonnes)
c) If cargo is untrimmed, the height of the cargo pile above the floor (in
Metres) should not exceed :
1.1 x D x Stowage Factor (m)
where L=L of hold(m), B=Av breadth of hold(m), D=Summer Load
Draft(m), stowage factor in m3/tonne.

KNR/05-2006 SP-SMA Slide 9

 General precautions with
bulk cargoes (continue..)

d) If the cargo is trimmed, entire level, the maximum load in the lower
hold may be increased by 20% subject in compliance with (a) in the
preceding page.
e) In holds with a shaft tunnel, lower holds may be loaded to 10% in
excess of the trimmed or untrimmed values subject to compliance with
(a). A shaft tunnel has an extra stiffening effect.

KNR/05-2006 SP-SMA Slide 10

 Hazards associated with the
carriage of Solid Bulk Cargoes
1 Improper weight distribution resulting in structural damage
a) Excessive concentration on deck or inner bottom
b) Improper distribution of weights between holds
2. Improper stability or reduction in stability
a) Excessive stability (stiff ship) resulting in violent rolling and
possible cargo shift and structural damage.
b) Reduction of stability as a result of :
i) A transverse shift of the cargo surface as in the case of
“DRY” cargoes and cargoes which do not become fluid when wet.
ii) A transverse shift of “WET” cargoes which become fluid and
give rise to free surface effect.
3. Spontaneous heating may occur in some cargoes eg. Fine copper
ore, metal turnings and borings are subject to spontaneous heating.
4. Chemical reaction. Some categories of bulk cargo may be liable
to chemical reaction, eg coal cargo emits toxic or explosive gas and
have the effect of causing corrosion to steel structure.
KNR/05-2006 SP-SMA Slide 11
 Assessing the acceptability of
consignment
Before loading commences, the Master should be provided with
appropriate information concerning the characteristics and
properties of the cargo. Such information should contain as a
minimum :
 Chemical Hazards
 Flow Moisture Point
 Stowage Factor
 Moisture Content
 Angle of Repose

The Master should be given certificates which include :

 A certificate which states the Transportable Moisture Limit
 A certificate of moisture content
 A statement to indicate the actual moisture content of cargo at the
time the certificate is given to the Master
 Certificate listing the material with chemical hazards if carried.
KNR/05-2006 SP-SMA Slide 12
 Trimming Procedures

Preferably bulk cargoes should be trimmed to entire level. Where a

peak arises, following two categories should be considered:

 Cargoes with angle of repose LESS THAN OR EQUAL

TO 35 DEGRESS (non-cohesive).

 Cargoes with angle or repose GREATER THAN 35

DEGRESS (non -cohesive).

KNR/05-2006 SP-SMA Slide 13

 Non-cohesive bulk cargoes having an
angle of repose LESS THAN OR
EQUAL TO 35 DEGREES

 More dangerous category, subject to liquefaction process

 Usually small granules – shift easily when ship moves
 Granules liable to absorb moisture, may form sludge
affecting ship’s stability
 Code recommends:
1. Cargo be trimmed reasonable level, filing up all spaces-
no excessive cargo weight in one location
2. If cargo flow like grain, stowage procedures for grain to
be considered

KNR/05-2006 SP-SMA Slide 14

 Non-cohesive Bulk Cargoes with angle
of repose GREATER THAN 35
DEGREES

 Consists of lumps – interlocking – quite stable

 Can become heaped up to produce excessive pile
peak
 Major hazard if cargo shift, unable to return to
original position – may cause a permanent list
 Not usually subjected to liquefaction
 Code recommends:
1. If loading in Lower Holds only, trim to cover all
tanktop to shipside, reduce pile peak
2. Equalise distribution of weight

KNR/05-2006 SP-SMA Slide 15

 Methods of Determining Angle of
Repose

 Laboratory (standard test method -most

accurate)

 Shipboard method

 On-site method

KNR/05-2006 SP-SMA Slide 16

 CARGOES WHICH MAY
LIQUEFY
 Important section- all officers on board bulk cargo vessel must
familiarise
 Cargoes includes : Concentrates, certain coals & other
materials having similar properties as listed in Appendix “A” of
code
 Concentrates :
 heavy, dense cargo with very low SF
 absorb moisture until all the concentrate is wet- Moisture
Migration
 flow state develops if liquid permeates sufficient amount of
cargo
 Liquefaction produce dense sludge cause free surface effect-
affecting stability, structural damage
 If list develops can cause negative GM & ship may be lost

KNR/05-2006 SP-SMA Slide 17

 PRECAUTIONS -CARGOES
WHICH MAY LIQUEFY

 Trim cargo level- irrespective of Angle of Repose

 Moisture Content not exceed the TML
 Do not stow cargoes which contains liquid in space
above or adjacent to it
 Do not permit entry of liquid into cargo spaces
 If necessary to cool cargo –use water spray

 Specially constructed bulk carriers not so restricted

by virtue of their structural arrangements – but must
have evidence that it is suitable for the type of cargo
carried.

KNR/05-2006 SP-SMA Slide 18

 GENERAL PRECAUTIONS –PRIOR
TO LOADING BULK CARGO
 Safety precautions for crew and others working onboard must
be taken and to ensure minimum contact with moving
machinery used in loading.
 Holds inspected –in proper state for reception of cargo, paying
particular attention to ;
 Bilge wells and lines, Sounding pipes & other service units with
Protective coverings- checked & strengthened
 Bilge wells & strainers plates- facilitates drainage
 Prevent dust coming into contact with moving parts of deck
machinery
 Accommodation vents- screened or shut down
 Cargo hold lighting, fire detection & flooding system piping
covered
 Sound bilges at completion of loading
 Establish communication with terminal

KNR/05-2006 SP-SMA Slide 19

 METHOD OF LOADING /
DISCHARGING BULK CARGO

 Heavy duty conveyor belt systems used in most form of solid

bulk cargo loading
 Some forms of ore transported in “slurry” for – piping used for
handling
 Conveyor belt system led to ship loader equipped with vertical
telescopic chutes
 Control of dust is essential for loading fine powder bulk cargo-
complying to local reg’n and avoid loss of cargo
 Dust extraction equipment is fitted to ship’s loader conveyor
transfer point
 Loading controlled by one operator from elevated visibility
clear cabin- speed and rate adjusted to meet loading pattern
required by ship
 Ship loader is mobile – travel on tracks along wharf
 Automatic arrangement provided for measuring & recording of
quantity of cargo loaded
KNR/05-2006 SP-SMA Slide 20
 METHOD OF LOADING /
DISCHARGING BULK CARGO

 Discharging of bulk cargo is mainly done using

“Grabs” with ship’s/shore gears
 Conveyor equipment may be installed directly from
berth to stockpile/terminal
 Conveyor equipment connects “bucket” unloader
which by reason of arm extension “digs” into the ship
bulk in the hold.
 Elevator transports the bulk to stockpiles, terminal
or shore transportation
 This system is applicable to ore & coal commodities

KNR/05-2006 SP-SMA Slide 21

 Solid Bulk Cargo

KNR/05-2006 SP-SMA Slide 22