Shipping Regulations and Guidance
December 2012
Safe shipment
of coal
introduction
The shipment of coal, the industrial revolution and the start of a modern shipping era beyond the
sail, all go hand in hand together. While no longer used as a common ship fuel, coal remains a
major cargo with hundreds of millions of tons being shipped every year for power consumption
and industrial uses like steel production. The vast majority of coal traded is moved by sea.
Shipping this cargo safely is a key concern for the dry bulk industry. The cargo can self-heat,
it can give off explosive gasses, ooze corrosive chemicals, and it can liquefy. Done well, the
cargo is taken safely from load to discharge Port without incident, but if not done well, the
shipment can lead to loss of life and serious vessel damage.
Christian Ott
Vice President Claims/
Loss Prevention and
Recurring Claims
Assuranceforeningen
SKULD (Gjensidig)
Prepared with Technical
advice from Nico Zurcher
and Dr Thomas Hill of
Hannaford Forensic Services
www.skuld.com
Today coal production, use and shipment are greater than at any time in recorded world history.
the cargo and its nature
Coal was formed from dead vegetation, deposited around 300 million years ago, through a
combination of biochemical and geological processes. One of the difficulties with transporting
large quantities of coal in bulk is that it is a cargo capable of self-heating to the point of ignition,
which has often posed a serious challenge to those carrying it.
Self-heating is defined as the initiation of exothermic reactions leading to a rise in temperature
in the combustible material. This occurs when the rate of heat production exceeds that of heat
loss, leading to a rise in temperature which then accelerates the rate of oxidation, potentially
leading to ignition and a fire.
The conditions that are required for self-heating cargoes to progress to ignition include:
€€ A ready supply of oxygen from the air
€€ A large surface area over which the oxidation reaction can take place
€€ The presence of moisture
€€ Insulation against heat loss
As well as self-heating, coal emits methane, a flammable gas with a low explosive limit (LEL)
of 4.4% in air. Explosions resulting from the ignition of methane in cargo holds can result in
damage to vessels, personal injuries and loss of life. Bituminous Coal has a low methane
content, whereas Anthracite Coal can contain several orders of magnitude more. Whilst it
is acceptable to transport coal capable of emitting methane, the Shipper should provide the
vessel with details on its safe carriage. By ventilating the holds, the methane concentration can
be managed so that these are well below the LEL, although, unfortunately, whilst ventilating the
cargo removes methane, it also reintroduces oxygen into the hold, thereby creating a situation
conducive to self-heating. It is essential that gas readings for carbon monoxide and LEL are
accurate, so that informed decisions can be made about how much ventilation to allow.
As with all bulk cargoes, rules regarding their safe carriage are given by SOLAS and the IMSBC
Code, as briefly outlined for coal below.
solas and imsbc code requirements
Under SOLAS, coal is defined as dangerous goods in solid form in bulk.
Documents
In all documents relating to the carriage of dangerous goods in solid form in bulk by sea, the
bulk cargo shipping name of the goods shall be used.
Each ship carrying dangerous goods in solid form in bulk shall have a list/manifest setting forth
the dangerous goods on board and location. A copy of one of these documents shall be made
available before departure to the person or organisation designated by the Port State Authority.
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Shipping Regulations and Guidance
December 2012
Stowage and requirements
When the coal is loaded it must
accordance with the nature of the
to spontaneously heat or combust,
unless adequate precautions have
the likelihood of the outbreak of fire.
If there is a fire or self-heating has progressed to an advanced
state, the Vessel should:
be done safely and in
cargo. As coal is liable
it should not be carried
been taken to minimise
€€ Close all ventilation to the holds
€€ C
ommence boundary cooling of the affected holds and
consider heading towards the nearest port as a refuge
Coal is a cargo covered by the International Maritime Solid
Bulk Cargo (IMSBC) Code, which provides regulations for its
loading and carriage.
€€ T
he P&I Club should be notified without delay as an
emergency response may need to be triggered including
the attendance of an expert
The IMSBC Code requires Shippers to provide cargo details
including moisture content, sulphur content, particle size, and
information on whether the cargo is liable to emit methane,
self-heat, or both. The IMSBC Code requires that the Vessel
has the following:
€€ E
nsure all spaces adjacent to the holds are checked prior
to entry and that no-one enters confined spaces without
confirming that it is safe to do so
€€ P
rovide Owners and the P&I Club with all temperature and
gas monitoring records for the voyage
€€ A
n instrument capable of measuring oxygen, carbon
monoxide and methane
The best Loss Prevention: if the Master is in any way
concerned prior or during loading, or he is not provided
with proper cargo documentation: do not load the cargo.
€€ Gas sampling ports on all holds
€€ A
means of measuring the pH values of bilge water
samples
gas detectors and
thermal detectors
Further, the Code recommends that the vessel has a means
of measuring cargo temperature, both during loading and the
voyage, such as an infra-red heat detector.
The IMSBC Code requires vessels carrying coal to carry gas
detectors, and that their crew are trained in their use. The gas
detector should first be checked in a gas-free area, before
entering enclosed spaces or taking hold measurements.
Most gas detectors are fitted with electrocatalytic sensors
to detect flammable gases and are capable of operating
reliably in atmospheres with more than 15% oxygen. Below
10%, readings of flammable gas levels using electrocatalytic
sensors should be regarded as unreliable. Vessels carrying
coal should consider obtaining a gas detector with an infrared sensor which does not require oxygen to provide accurate
flammable gas readings.
The IMSBC code states that coal should not be loaded if its
temperature exceeds 55°C. After loading, and unless advised
otherwise, the holds should be ventilated for the first 24 hours
or until the methane concentration is acceptably low, i.e.
below 20% LEL.
Once the cargo has been loaded and hatch covers closed,
evidence of self-heating can easily be checked by monitoring
carbon monoxide levels. The atmosphere in each hold should
be monitored daily. If the cargo is being ventilated to remove
methane, then ventilation should be stopped at least four
hours prior to sampling. According to the IMSBC Code, carbon
monoxide levels above 50 ppm, or a steady rise of the cargo’s
temperature over three consecutive days, indicate that selfheating is taking place, and the Master should contact Owners
and the Shipper. As coal is a good insulator, hot spots within
the bulk of the cargo can still go undetected, even if the crew
take bilge well temperature readings or surface temperature
measurements.
Although not required by the IMSBC Code, having an infrared thermometer can greatly assist the crew in monitoring the
surface of the cargo prior to and during loading, to ensure that
it is not loaded above 55°C.
summary
When transported in bulk, coal is capable of self-heating
to the point of ignition. Nevertheless, the majority of
vessels carry coal cargoes without incident, and adhering
to the requirements and recommendations in the IMSBC
Code greatly reduces the risks. Using the correct gas and
temperature detecting equipment provides the necessary
information needed to manage the transportation of coal
cargoes safely. However, to be effective, detection equipment
must be used correctly, maintained in good working order and
any limitations understood in subsequent analysis.
Prior to departure, and during the voyage, the Master should
also ensure that:
€€ The cargo is trimmed flat to reduce its surface area
€€ G
as monitoring equipment on board is well maintained
and calibrated in accordance with the manufacturer’s
instructions
€€ A
ll enclosed spaces adjacent to the holds are regularly
monitored and adequately ventilated
€€ N
o one should enter confined spaces without first
confirming that it is safe to do so
€€ If the cargo behaves differently from that specified in the
cargo declaration, the Master should report this to the
Shipper, his Technical Managers and P&I
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