DCN October Edition 2019

MARITIME LAW
The facts of liquefaction
A recent tragedy in
Indonesia shows more
needs to be done to
prevent liquefactionrelated
shipping disasters,
writes Alexis Cahalan
THE SAFE CARRIAGE OF BULK
in water pressure leads to liquefaction. If
Cargoes Code (IMSBC Code) issued by the
cargoes liable to liquefaction is integral to
liquefaction occurs, the cargo, in behaving
IMO became mandatory on January 1, 2011
the safety of life at sea. The International
like a liquid, can shift causing a vessel to
under the provisions of the International
Association of Dry Cargo Shipowners
lose stability, tilt and potentially capsize.
Convention for the Safety of Life at Sea.
(Intercargo) has identified that between
The IMSBC Code replaced the previously
2009 and 2018, 101 lives and nine bulk
“LIKE MELTED ICE CREAM”
known Code of Safe Practice for Solid Bulk
carriers were tragically lost due to cargo
There are other extraneous factors that
Cargoes. It is an internationally recognised
failure caused by liquefaction. Of these
can contribute to liquefaction occurring
code of safe practice to be followed when
vessels, six had been loaded with nickel ore
as was the case with the Padang Hawk. The
transporting hazardous solid bulk cargoes
from Indonesia, two with iron ore from
vessel loaded a cargo of nickel ore in New
on board bulk carriers.
India and one with bauxite from Malaysia.
Caledonia on July 17, 1999 and during its
The primary aim of the code is to
More recently, on August 25, 2019, the
voyage to Australia, encountered rough seas
facilitate the safe stowage and shipment of
bulk carrier Nur Allya while carrying a
causing it to roll and pitch. Some days into
bulk cargoes, to give information about the
cargo of nickel ore to Sulawesi Province
the voyage the vessel developed a 15 degree
cargo to the vessel and to identify dangers
in Indonesia, made a distress call in the
list to port. The crew on checking the cargo
and risks particular to the cargo.
Banda Sea while underway. The vessel
in the hatches found that it had settled and
Appendix 2 of the IMSBC Code includes
was carrying 25 crew members and is
shifted to port and that the cargo looked
the testing and certification requirements
feared to have sunk with all hands due
“like melted ice cream”. The master was
to be followed to ensure that the moisture
to cargo liquefaction.
able to adjust the ballast on the shipowner’s
content of cargoes is sufficiently low. These
recommendations and pump the cargo
tests include the flow table, penetration
WHAT CAUSES LIQUEFACTION?
hold bilges at regular intervals to correct
tests and the “Can Test” which provide the
Cargo liquefaction is the conversion in
the vessel listing and ultimately proceed to
shipper with a “safe” moisture content.
behaviour of a substance from solid to
Townsville. At the time of this incident there
The Can Test is a simple on-site
liquid state. It occurs due to reduction of
was no known test for the TML. The nickel
procedure for providing an estimate of
pore space between fine particles in cargoes
ore prior to loading had been stockpiled in
moisture content and is as prescribed by
such as nickel ore and iron ore due to the
areas open to the weather, which increased
section 8.4 of the IMSBC carried out by half
motion of a ship. Cargo is prone to liquefy
the moisture content of the cargo.
filling a one-litre cylindrical container with
where there is a high proportion of fine
Catastrophic loss of vessels and
a cargo sample and taking the can “in one
particles and a moisture content in excess
crews due to liquefaction has led to the
hand and bring it down sharply to strike
of the transportable moisture limit. A
International Maritime Organization
a hard surface…repeat the procedure at
TML is the maximum moisture content
codifying safe practices in relation to
one-or two-second intervals”. The presence
for a given cargo which is considered safe
cargoes susceptible to liquefaction.
of moisture on the sample surface will
for carriage in ships. The combination
of the reduction of space between the
particles with the concomitant increase
CATEGORIES PRONE TO LIQUEFACTION
The International Maritime Solid Bulk
indicate excessive moisture content. This is
used to supplement but not substitute for
laboratory testing.
Id-Video
56 October 2019
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