KC Maritime Consultancy Ltd.

According to the INTERCARGO Bulk Carrier Casualty Report for the period from 2010 to 2019, 106 seafarers lost their lives due to solid bulk cargo liquefaction.

Actually, the total number of lives lost is 141, if the two bulk carriers for which the reported cause of the sinking is still classified as ‘unknown’ are included. Since both vessels were loaded with nickel ore, the likely cause was cargo liquefaction.

Out of 141 lives lost, six lives were lost due to iron ore liquefaction, 117 due to nickel ore liquefaction, and 18 lives were lost due to bauxite dynamic separation; a different phenomenon, albeit with the same end result.

Put simply, bulk cargo liquefaction occurs when a solid bulk cargo contains a certain proportion of fine particles and a certain amount of moisture and transforms from a solid state to a liquid state if shipped with moisture content in excess of its transportable moisture limit.

In the resulting viscous fluid state cargo may flow to one side of the ship with a roll but not completely return with a roll the other way. Consequently, the ship may progressively reach a dangerous heel and capsize quite suddenly, as described in the International Maritime Solid Bulk Cargo (IMSBC) Code.

The IMSBC Code contains information on individual cargo properties including hazards, precautions, and procedures to be followed when loading, transporting, and discharging solid bulk cargoes.

The Code had been adopted in 2008 and entered into force on 1 January 2011, from which date it was made mandatory under the provisions of the Safety of Life at Sea (SOLAS) Convention.

Bulk cargoes listed in the Code are divided into groups A, B, and C; cargoes which may liquefy, cargoes which possess chemical hazards, and cargoes neither liable to liquefy nor to possess chemical hazards or non-hazardous cargoes, respectively.

Since there are 183 types of cargoes listed in the IMSBC Code individual schedules, and many more in Appendix 4 of the Code, it is not likely at all that any Master in the world has the knowledge and experience of all the cargoes that he may have to carry.

Therefore, the IMSBC Code is the key reference to Masters regarding cargo properties apart from that obtained from shippers who unfortunately have been known for misdeclaring cargoes, and therefore, shippers’ declarations cannot be taken for granted.

 In addition to the overwhelming number of bulk cargoes, there are also:

– new cargoes not listed anywhere in the Code

– cargoes given different names to disguise their real nature, and

– known cargoes exhibiting brand new (harmful and/or deadly) properties.

One such known cargo exhibiting new property is bauxite; classified in the IMSBC Code as a Group C (non-hazardous).

The Bulk Jupiter, a Bahamas flagged bulk carrier, sank on 2nd January 2015 off the coast of Vietnam, carrying a cargo of bauxite on the voyage from Kuantan, Malaysia to Qingdao, China. Of the 19 crew, only one was rescued.

Unlike other Flag State authorities that take years to carry out and publish incident investigation reports (if ever), the Bahamas Maritime Authority commendably issued their report seven months after the incident.

The report indicated that the most probable cause of the tragedy was cargo liquefaction.

Before the loss of the Bulk Jupiter, the only known issue with bauxite was that if loaded wet or even very wet, water from the cargo would be draining during the voyage into the cargo hold bilges, and the quantities of water pumped out had to be recorded to avoid cargo shortage claims upon discharging.

Typically, Charterers’ voyage instructions would contain a remark on the need to record the quantity of bilge water pumped out during the voyage.

Therefore, since bauxite was Group C cargo, had been carried for decades without issues, and certainly had never been considered prone to liquefaction, the Global Bauxite Working Group was formed to investigate the behaviour of bauxite during ocean transportation.

Their report (issued in 2017) showed that bauxite cargoes containing a considerable amount of fine particles and moisture undergo ‘dynamic separation’. This is where the cargo separates during the voyage to form a free slurry surface on top of the solid cargo leading to a free surface effect which significantly affects the ship’s stability and has the end result the same as that of liquefaction; capsizing and sinking.

The investigation led to the introduction of an additional individual schedule in the IMSBC Code for bauxite: bauxite fines, Group A (may liquefy). The amendment came into force in January 2021 (six years after the incident).

However, the new schedule for bauxite fines is not helpful at all; it is stated that bauxite fines “may be carried as a group C cargo in accordance with the provisions of the individual schedule for BAUXITE where the shipper provides the master with a certificate… stating that the moisture of the cargo freely drains from the cargo so that the degree of saturation is not liable to reach 70%”.

This description, as well as the particle size description, leaves Masters with an impossible task of determining whether the cargo will suffer instability resulting in dynamic separation or not.

Another cargo that had also been listed in the IMSBC Code as a Group C cargo before two vessels were lost due to liquefaction in 2009, with one loss of life, was iron ore. The IMSBC Code was amended in 2017 (six years after the two casualties) to contain an individual schedule for iron ore fines, Group A.

Similarly to bauxite, the new individual schedule for iron ore fines allows the cargo to be carried in accordance with the individual schedule for iron ore “provided the master receives from the shipper a declaration of the goethite content of the cargo which has been determined according to internationally or nationally accepted standard procedures”.

The onus to provide accurate information is again on the shipper and it is on the Master to trust it. Or not.

Clay is one more cargo deemed not to liquefy, and yet it apparently did, only this time not on board a bulk carrier, but the general cargo vessel Xin Hong. According to the available information, whilst on passage from Malaysia to Hong Kong in December 2020, the vessel suffered a shift in stow and was lost.

Naturally, the question that pops in mind is: which non-hazardous cargo will prove deadly next?

As per both the IMSBC Code and the SOLAS, the onus is on the shipper to provide the Master with appropriate information on the cargo. The only other source of information on cargo properties to the Master is the IMSBC Code.

Apparently, sometimes both sources are unreliable, and with respect to cargoes which are now both Group A and Group C, it is all down to cargo particle size and moisture content for which no Master is an expert.

It is simply impossible to determine the cargo particle size during loading with any certainty. And the only available tool for Masters in determining transportable moisture limit is the so-called ‘can test’ which is also unreliable. Even the IMSBC Code states that even “if samples remain dry following a can test, the moisture content of the material may still exceed the transportable moisture limit”.

The IMSBC Code ambiguities and shippers’ failure to properly declare cargoes, place enormous responsibility on Masters’ shoulders and require special, even scientific knowledge that they do not have, nor are they expected to have.

While bulk cargo liquefaction and the resultant loss of life prove extremely difficult to control due to various reasons including wrongly declared cargo moisture content, cargoes considered and classified as Group C cargoes, present possibly even greater risk because there are no special hazards anticipated.

Therefore, instead of advising them to be cautious, vigilant, and savvy, Masters should be provided with all the assistance they can possibly get when the next bulk cargo is contemplated, even if classified in the IMSBC Code as non-hazardous.

INTERCARGO: Bulk Carrier Casualty Report (Years 2010 to 2019 and trends)

Global Bauxite Working Group: Report on Research into the Behaviour of Bauxite during Shipping

The Bahamas Maritime Authority: M.V. Bulk Jupiter – Marine Safety Investigation Report