As a result of inappropriate test protocols, the ignition of hydrogen gas released from the cargo caused two explosions on board the dry cargo vessel Nortrader in January this year, UK’s Marine Accident Investigation Branch (MAIB) said.
On January 13, the Antigua & Barbuda-flagged ship, which was anchored off Plymouth with a cargo of unprocessed incinerator bottom ash (U-IBA), suffered the explosions in quick succession. The first explosion was in the forecastle store and the second in the cargo hold.
The chief engineer, in the forecastle store at the time, suffered second degree burns requiring four months to recover. The vessel suffered extensive damage and was out of service until late April.
The MAIB investigation revealed that prior to this accident, there had been 34 similar shipments of incinerator bottom ash from Plymouth to the Netherlands and, despite it not being listed in the International Maritime Solid Bulk Cargoes (IMSBC) Code, no steps had been taken to seek approval from the competent authorities for its carriage.
The investigation also found that the testing protocols in place for assessing if the waste was capable of producing flammable gases were inappropriate and inadequate.
Following the accident, the MAIB has published a safety flyer to disseminate the lessons from this accident and improve awareness of the IMSBC Code. The Maritime and Coastguard Agency has set up tripartite agreements between the UK, the Netherlands and several other administrations for the safe carriage of incinerator bottom ash and proposed its inclusion in the code.
The agency has been recommended to update the Merchant Shipping (Carriage of Cargoes) Regulations to refer to the IMSBC Code and to work with the Environment Agency to ensure that test protocols for the classification of cargoes are fit for purpose.
Nortrader’s owner, NTO Shipping, has been recommended to review its safety management system to reflect the requirements of the code.