Following the fire and subsequent explosion in the battery room of the Norled ferry Ytterøyningen in early October, the Norwegian Maritime Authority (NMA) has issued a warning highlighting the hazards associated with lithium-ion battery systems.
Although the initial fire that erupted on board the diesel-electric ferry was small and contained – with all ferry passengers disembarking safely when the vessel reached the harbour – a serious gas explosion took place the battery room overnight, causing significant damage. While no passengers or crew were injured as a result of the fire, 12 firefighters received medical treatment due to being exposed to hazardous gases associated with the batteries, as reported by Norwegian broadcasting company NRK.
The Norwegian Maritime Authority subsequently launched an investigation to determine the cause of the explosion; the findings of that investigation are yet to be published. However, the NMA has since recommended that all owners of battery-equipped vessels carry out a new risk assessment of the dangers connected to possible accumulations of explosive gases in the battery systems. The NMA circular SM3-2019 also recommends that shipowners review their emergency procedures. The circular also offers advice on what to do in case of a gas release that occurs when lithium-ion cell temperatures exceed the thermal runaway threshold resulting in the sudden release of flammable, toxic gases and excessive heat that could result in an explosion.
In response to the incident, the supplier of the 1989 kWh-capacity lithium-ion battery installed on Ytterøyningen, Corvus Energy, has stated that certain actions should be adhered to immediately to maximise safety. This includes the warning that operators should not sail without communication between the shipboard energy management system and the battery packs, and that battery packs must be kept powered up to maintain this communication link. A powered down battery pack will not communicate vital data to the bridge or energy management system, the supplier cautioned. Corvus Energy also stated that if gas release or a fire is suspected in the battery room, the crew should not power down the battery equipment. Instead, they should call the Corvus 24/7 technical support helpline and refer to the manufacturer guidance document on response after a thermal event.
Safety concerns surrounding battery use will come as bad news for Norwegian ferry operators who have invested heavily in the technology in the past decade to allow their vessels to sail under hybrid diesel-electric or fully electric mode when operating in environmentally sensitive areas, such as the Norwegian Fjords and along the country’s coastline.