North CARGO User manual

CARGO
Carriage
of Coal

Carriage of Coal
CONTENTS
Introduction................................................................................................... 01
Exporters ........................................................................................................ 01
The Main Hazards....................................................................................... 01
Precautions Prior to Loading ............................................................... 04
Coal Cargo Bilge Water........................................................................... 04
Summary........................................................................................................ 04
Introduction
Over a billion tonnes of coal are traded internationally each
year, the vast majority of which is shipped by sea without
incident. The hazards associated with the carriage of coal are
well-known and it has a comprehensive entry in the IMSBC
Code. Coal should always be carried in strict accordance with
the requirements of the IMSBC Code.
Despite many carriers being experienced in the trade, and
comprehensive advice being available from numerous sources,
serious incidents involving coal cargoes still occur. Typically
these problems stem from sub-standard handling procedures
by shippers before loading. But all coals have a propensity to
self-heat or produce methane to some extent and caution
should always be exercised.
The purpose of this briefing is not to repeat the comprehensive
advice given in the IMSBC Code and elsewhere, but rather to
provide some general practical information for seafarers and
shipowners. This guidance focuses on the hazards associated
with coal and stresses the need for preparedness and vigilance
by vessel operators and crews.
Exporters
Quality shippers in well-established markets are likely to have
comprehensive and satisfactory handling procedures for coal
before it is shipped and as such, problems during the voyage
should be fewer. However, where the market has grown rapidly,
such as in Indonesia over the last decade, shippers with less
knowledge and experience of handling coal may enter the
market. This can lead to problems during the voyage due to
sub-standard handling of the coal before loading and there may
be a higher risk of coal cargo problems, which requires higher
levels of vigilance.
www.worldstopexports.com/coal-exports-country/3265
Six top coal exporters increased their international sales from
2013 to 2017: Mongolia (up 99.3%), Philippines (up 51.8%),
Russia (up 14.5%), Colombia (up 9%), Australia (up 6.1%) and
China (up 4.1%).
Decliners were led by North Korea (down 71.7%), Czech
Republic (down 43.8%) and Poland (down 34.1%).
The Main Hazards
There are five main hazards associated with coal:
Flammable atmospheres
Liquefaction
Asphyxiation
Self Heating
Corrosion
Of these hazards, self-heating and the creation of a flammable
atmosphere create the most problems during the voyage.
The coal schedule in the IMSBC code states that coal is a Group
A and B cargo - unless classified as Group B only upon the
successful outcome from a modified Proctor/Fagerberg test
procedure specifically for coal or if its particle size distribution
meets the following:
1. not more than 10% by weight of particles less than 1 mm
(D10 > 1mm); and
2. not more than 50% by weight of particles less than 10 mm
(D50 > 10 mm)
A blend of two or more coals shall be classified as Group A and
B unless all original coals in the blend are Group B only.
The IMSBC Code contains advice that deals with each of these
hazards in turn and coal should always be carried in strict
accordance with the IMSBC Code.
Tip: use the mnemonic FLASC to help you recall the hazards
associated with coal.
Flammable Atmospheres
Coal can emit methane gas which in mixture with air can lead
to fire/explosion where a source of ignition is present. Shippers
01 Cargo / Carriage of Coal
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Copyright © 2019 The North of England P&I Association Limited
Figure 1: World’s Top Exports November 2017

are required to declare whether or not the coal they are
exporting is liable to emit methane. However, owners and
masters should be aware that some shippers do not declare
their cargoes as liable to emit methane even where there have
been previous incidents involving the emission of methane.
The Code requires monitoring for methane in all circumstances
and anticipates a situation where methane concentrations
remain high. Guidance is provided in the IMSBC Code in relation
to the monitoring and ventilation procedures to be followed
and on the avoidance of creating sparks where methane is
being produced.
It is vitally important that vessels have on board gas detectors
suitable for use in oxygen-depleted atmospheres.
There have has been cases where catalytic-type gas detectors
have been used to test the atmosphere in an oxygen-depleted
hold. This type of instrument relies on the presence of oxygen
to test for methane and if used in an oxygen-depleted
atmosphere it will not give accurate readings.
The gas detector should be maintained and operated in
accordance with the manufacturer’s instructions which will
include regular calibration.
Liquefaction
A cargo which contains a certain proportion of small particles
(particles less than 7mm) and a certain amount of moisture
may liquefy, that is, reach a flow state under the influence of
external forces such as vibration, impaction or ship’s motions.
Prior to loading, the master should sight the cargo and ensure
that the cargo presented matches the description on the
shipper’s declaration. There have been occasions when coal
cargoes have been incorrectly declared as Group B when in fact
the cargo is Group A and B.
A simple method of testing the cargo for the presence of fine
particles is to use a sieve constructed of 7mm x 7mm wire
mesh to separate a sample of the cargo.
Once the sample has been separated the approximate
proportion of fine particles and lumps can be estimated as
shown in Figure 4.
The master can then perform a ‘can test’ of the fine particles to
check for the possibility of liquefaction.
The Can Test
Section 8 of the IMSBC code gives details of the can test
procedure which should be carried out by the crew. Can tests
should be performed with samples from different areas of the
cargo stockpile, particularly any groups of fine particles and
during the loading sequence. This is critical as even a layer of
cargo containing a high proportion of fine particles has the
ability to partially liquefy and de-stabilise the entire cargo in
that hold.
The results of can tests should be supported with photographic
evidence showing the outcome of the test. If the can test
results raise concerns, the master should request the
attendance of a cargo surveyor.
The master should not delegate testing for liquefaction to any
attending surveyor. They should perform the test themselves
with the assistance of a surveyor if necessary. There have been
cases where all the tests were performed solely by the
surveyor.
North’s can test training package can be downloaded here.
Visual Inspection
The master must be satisfied that the cargo is safe to load and
this can only be done by physically inspecting the cargo.
Carriage of Coal (cont.)
02 Cargo / Carriage of Coal
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Copyright © 2019 The North of England P&I Association Limited
Figure 2: Sampling point in hatch coaming
Figure 3: Separating fine particles and lumps of coal
Figure 4: Coal sample after separation approximately 60% fine particles and 40% lumps.

Inspection is important as a coal cargo may appear to be dry as
seen in Figures 5 and 6.
An initial inspection might suggest this cargo is dry. But a closer
inspection could prove that only the surface of the coal is dry.
There are clear signs of moisture underneath this crust. It is
very possible that the moisture content of is this cargo is above
its TML.
The crew must continue to monitor the cargo during loading
operations. Watch out for muddy splattering in the cargo holds
as this could be another indication that the cargo has a
combination of fine particles and high moisture content.
Asphyxiation
It is extremely dangerous to enter cargo holds or adjacent
spaces when carrying coal. The atmosphere may be
dangerous. Coal can produce methane, carbon dioxide and
carbon monoxide; all of which may lead to a depletion of
oxygen in the hold and result in asphyxiation.
Persons should not enter holds or adjacent spaces unless
absolutely necessary and not until they have been properly
ventilated and the atmosphere tested.
The IMSBC Code contains details on hold entry precautions to
be followed. North’s guidance on safe enclosed space entry
can be read here:
www.nepia.com/media/868999/Enclosed-Spaces-April-2016-
LP-Briefing.PDF
Self-heating
There may be many different types and grades of coal cargo,
some of which may be more liable to self-heating than others.
Shippers must declare whether or not the coal they are
exporting is liable to self-heat. Ship owners and masters should
be aware that some shippers do not declare their cargoes as
liable to self-heating or to produce methane even where there
have been previous incidents involving these problems from
the same source.
An indicator of self-heating is the level of carbon monoxide
produced in the hold. The IMSBC Code contains advice on the
monitoring of the carbon monoxide levels and the action to be
taken by the master is self-heating is suspected.
Another consideration is that coal emits methane, an
odourless, flammable gas, presenting a fire and explosion risk.
Monitoring coal cargoes for self-heating and emissions of
methane is vital. Careful monitoring allows for early action by
the vessel and can avoid serious problems.
The IMSBC Code contains advice on the monitoring that should
be done and the necessary equipment.
Firefighting, life-saving and smoke detection equipment must
be well maintained and tested at all times.
Carriage of Coal (cont.)
03 Cargo / Carriage of Coal
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Copyright © 2019 The North of England P&I Association Limited
Figure 5: Dry crust of coal cargo
Figure 6: Damp coal underneath a dry crust
Figure 7: Steam rising from heating coal
Figure 8: Coal on fire in a ship’s hold

Corrosion
Coal can react with water to produce corrosive acids. As well as
the risk of corroding the vessel’s steelwork, this process has the
potential to produce hydrogen gas. Any accumulation of water
in the holds needs to be monitored and any build up pumped
away using the bilge system.
The IMSBC Code contains advice on bilge water testing for
corrosion.
Precautions Prior to Loading
Ensure that the vessel receives the shipper’s declaration with
the information described in the IMSBC Code coal schedule.
The declaration must include a section on whether or not a
cargo is liable to emit methane or self-heat. Unless the coal
cargo has been classed as Group B only, it must be
accompanied by certificates showing:
Transportable Moisture Limit (TML); and
Moisture Content (MC).
The interval between sampling/testing for moisture content
and the commencement of loading should never be more than
seven days. If the cargo has been exposed to significant
precipitation between the time of testing and the
commencement of loading the shipper must retest the cargo.
The coal schedule in the IMSBC Code contains specific advice
on weather precautions when loading Group A coal.
The schedule also contains details of the monitoring
equipment that must be on-board and it is important that this
equipment is fully operational and fitted in line with the
requirements of the code.
Cargoes with a temperature above 55oC should never be
accepted for loading. This is a key safety precaution. The
Master can easily check the surface temperature of the cargo
using an infrared thermometer as see in Figure 9.
Masters should exercise extreme caution when presented with
hot cargo even where the cargo has not been declared as liable
to self-heating. This can be the case with Indonesian coal
cargoes which, in general, are liable to self-heat but which are
regularly declared as not liable to self-heating.
Burgoyne’s, a firm of cargo experts with many years of
experience dealing with problematic coal cargoes, have
produced a useful briefing note on Indonesian coal cargoes
which may be read here.
Coal Cargo Bilge Water
Accurate bilge pumping records should be maintained to avoid
shortage claims at the discharge port.
This is because when moisture from coal collects in the bilges
and is pumped overboard, the weight of the coal will effectively
be reduced even though the actual quantity remains the same.
The bilges can only be pumped overboard if the cargo is not
classed as Hazardous to the Marine Environment (HME) and in
accordance with MARPOL Annex V.
The shipper’s declaration should state whether or not the cargo
is HME.
Summary
Coal has well-known hazards and the conditions for safe
carriage are described at length in the IMSBC Code. As long as
the provisions of the IMSBC Code are followed and the cargo is
monitored closely throughout the voyage there is no reason
why, even where problems start to develop, the vast majority
of situations cannot be managed onboard.
Three Key Points – Think SMS!
Stop unsuitable cargo coming aboard. Cargo above 55oC
should not be shipped.
Monitor the cargo loaded for signs of self-heating or methane
production throughout the voyage.
Seek expert advice if carbon monoxide or methane levels are
giving cause for concern.
Early intervention can prevent potentially dangerous situations
from developing into serious incidents.
We are grateful for the assistance of Peter Cook of Burgoynes
in preparing this briefing.
For more information contact the loss prevention department
at [e-mail]
Disclaimer
The purpose of this publication is to provide a source of information which is
additional to that available to the maritime industry from regulatory, advisory,
and consultative organisations. Whilst care is taken to ensure the accuracy
of any information made available no warranty of accuracy is given and users
of that information are to be responsible for satisfying themselves that the
information is relevant and suitable for the purposes to which it is applied.
In no circumstances whatsoever shall North be liable to any person whatsoever
for any loss or damage whensoever or howsoever arising out of or in
connection with the supply (including negligent supply) or use of information.
Unless the contrary is indicated, all articles are written with reference to
English Law. However it should be noted that the content of this publication
does not constitute legal advice and should not be construed as such.
Members should contact North for specific advice on particular matters.
Published February 2019.
Carriage of Coal (cont.)
04 Cargo / Carriage of Coal
For more information, please visit www.nepia.com
Copyright © 2019 The North of England P&I Association Limited
Figure 9: Smart AR882A IR Device for measuring temperature of the coal surface before loading
or in the hold