UK accident investigators have warned of the dangers of hydrogen gas being released from ash cargoes after a double explosion injured an engineer on a German general cargoship.
The 2,600-dwt Nortrader (built 2012) was rocked by two blasts off Plymouth on 13 January this year, putting it out of action with extensive damage for more than three months.
The chief engineer was out of work for four months after suffering second-degree burns.
The ship, since renamed Fehn Calypso but owned at the time by NTO Shipping of Germany, was loaded with unprocessed incinerator bottom ash.
The first explosion was in the forecastle store, where the engineer was, and the second in the cargo hold.
The initial blast threw the seafarer on to the emergency fire pump starter panel. The second pushed him violently backwards and he fell on the deck under the starter panel.
The Maritime Accident Investigation Board (MAIB) established that the explosions were caused by the ignition of hydrogen gas released from the cargo.
No steps had been taken to seek approval from the competent authorities for its carriage, the report said.
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.
MAIB has made safety recommendations to the Maritime and Coastguard Agency (MCA) and the Environment Agency to work collaboratively to identify reliable methods and protocols for testing non-homogenous solid bulk cargoes for evolving flammable gases when wet.
