Genoa-based classification society RINA has established rigorous design standards for the modification or newbuilding of dry bulk cargo carriers to enable them to carry fine ores safely at any moisture content. A number of recent bulker losses have been attributed to the liquefaction of wet nickel ore cargoes. Using RINA’s standards, ships should be safe even if the cargo liquefied and the vessels would no longer have to conduct unreliable moisture tests at the load port.
Paolo Salza, Head of Technical Department, RINA, says, “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. But they don’t set out details of how to carry nickel ore and other unprocessed ores, which may liquefy during transportation, safely. Essentially, the rules say vessels may load these ores if the Transportable Moisture Limit is not exceeded. That is fine, but establishing that is difficult and the TML is easily affected by recent rain or other factors. It is much safer to design or convert the ship to withstand liquefaction of the cargo. That is what our new notation permits.”
According to the IMSBC Code, Group A cargoes are those cargoes which may liquefy if shipped at moisture content in excess of their Transportable Moisture Limit (TML). RINA’s new 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 TML. RINA’s new notation applies to a number of cargoes which may liquefy and a full list is available.
Says Salza, “Fine ores cargoes such as nickel ore at any moisture content can be safely carried on ships specifically designed or modified to the RINA criteria. Cargo sampling and testing for the purpose of verifying moisture content is not necessary when cargo is loaded on ships complying with RINA criteria. To meet RINA’s new standards vessels may have to install additional longitudinal bulkheads in some holds. The estimated investment for converting a supramax bulk carrier is around $3 million, but the vessel retains full deadweight capability and flexibility for other trades.”
RINA is also developing a service for certifying the actual moisture content of cargoes prior to loading for those ships which are not able to meet the standards set out in the RINA notation.