Protection and indemnity clubs have issued warnings of the liquefaction risks of bauxite cargoes, following the sinking of Gearbulk's Supramax bulker Bulk Jupiter on New Year's Day.

The ship was carrying over 46,000 tonnes of bauxite from Kuantan, Malaysia, when it sank off Vung Tau, Vietnam, leaving all but one of its 19 crew members dead or missing.

Liquefaction results in cargo shifting and loss of ship stability, a major cause of marine casualties.

In a circular, Norwegian P&I Club Skuld said, "There has been some debate on this issue, not least because bauxite cargo may come with a particle constituency of varying sizes and dimensions which could see cargoes be a mixture of fine particles, smaller particles, as well as lumps and rocks."

Skuld urged members not to be blasé even if cargoes are described as Category C under the IMSBC Code. Category C cargoes are described as being neither prone to liquefaction nor being a chemical hazard.

Skuld said, "In practice, however, the Association has had experience of shipments of bauxite which appeared to show signs of liquefaction and indeed expert advice on the issue would suggest that depending on the composition of the cargo, it is possible for liquefaction to occur.

"Particularly, this may be the case where the cargo is pre-filtered to separate fine and large particles, water may be introduced in to the cargo in this process and/or the cargo has undergone some other form of partial processing/crushing. Depending on the particular circumstances of any given shipment, it would appear that bauxite may come with the risk of liquefaction."

The North of England P&I Club noted that the sinking of Bulk Jupiter is similar to other cases involving liquefied cargoes.

It emphasised that only cargoes that have moisture content between 0% and 10% and consist of 70-90% lumps with a size between 2.5mm and 500mm and 10-30% can be regarded as being completely free of liquefaction risks.

The London P&I Club recently cautioned of the potential risks arising from using water cannons to wash bauxite fines and lumps through sieves in mines in Indonesia. This process significantly increases the moisture content of the cargo, reportedly to approximately 15% by the time the bauxite is loaded onto the ships.

The London P&I Club said, "As we understand it, the process that takes place in Indonesia of sieving the cargo to reduce lumps to below 100mm not only reduces the particle size of the cargo (possibly to smaller than that specified in the IMSBC Code), but also increases the moisture content to that exceeding the levels specified in the IMSBC Code.