A number of recent bulk carrier losses have been attributed to the liquefaction of different ore cargoes, especially nickel ore.
The mandatory application of the International Maritime Solid Bulk Cargoes (IMSBC) Code enhances the safety of bulk carriers through the setting of constructional and operative requirements.
RINA’s notation IMSBC-A may be assigned to ships specially constructed or specially fitted for the carriage of Group A cargoes having actual moisture content in excess of their Transportable Moisture Limit (TML).
The RINA criteria are applicable to a variety of ship types, e.g. bulk carriers with holds extending over the whole ship breadth, as well as to large ore carriers with two longitudinal bulkheads.
According to the IMSBC Code, Group A cargoes are those which may liquefy if shipped at moisture content in excess of their TML. It means that vessels, unless specifically designed or modified, may load these ores if the TML is not exceeded.
Establishing this parameter is difficult and the moisture content is easily affected by recent rain and other factors. It is much safer to design or convert the ship to withstand liquefaction of the cargo.
Fine ore cargoes, such as nickel ore, can safely be carried, at any moisture content, on ships specifically designed or modified to the RINA criteria.
Cargo sampling and testing for verifying moisture content is not necessary when cargo is loaded on ships complying with the RINA criteria.
Our notations on this field are:
IMSBC-A: Stability and strength requirements to verify the adequacy of the ships to support cargo liquefaction of IMSBC Group A cargoes, when transported at a moisture content exceeding the cargo TML
IMSBC-nitrate: Fire protection and stability requirements for the carriage of nitrate cargoes
IMSBC-non cohesive: Stability requirements for the carriage of bulk cargoes with angle of repose not greater than 30° (non-cohesive materials).
