DNV GL has published new guidelines for designing and operating of vessels carrying cargoes at risk of liquefaction and sloshing, “now the most significant factor in lives lost at sea for bulk carriers”.
Sloshing of cargoes such as iron ore fines, nickel ore and various mineral concentrates have likely caused the loss of six vessels of more than 40, 000dwt since 2009 with 111 seafarers losing their lives to incidents since 2010. “These incidents have shown that cargo liquefaction is an issue that has not been sufficiently dealt with,” said DNV GL Bulk Carriers business director Morten Løvstad. “While the general safety level of modern bulk carriers has been significantly improved over the last decades, recent incidents have shown that cargo liquefaction remains a major safety issue.”
The guidelines highlight a number of measures to reduce the risk of liquefaction, including raising the centre of gravity by ballasting the top wing tanks, adjusting trim, retesting moisture levels in the event of rain, and keeping a seven-day-or-less time interval between moisture testing and loading.
On the design side, the guidelines examine the potential for carrying cargoes with high moisture content onboard specially constructed vessels, in compliance with the IMSBC Code.
“Cargo liquefaction is probably now the most significant factor in lives lost at sea for bulk carriers,” said Løvstad. “With this guideline we wanted to help our customers by not only increasing awareness and building competence around the phenomenon, but also to offer some strategies, both in design and operation, to reduce these risks.”