The International Union of Marine Insurance (IUMI) has published recommendations on the safe carriage of electric vehicles (EVs). Notably, its research suggests that fires in battery EVs are not more dangerous than fires in conventional vehicles. 

IUMI outlines recommendations for the safe carriage of EVs

The recommendations have followed growing concerns within the shipping community, including marine underwriters, about fires breaking out on car carriers and ro-ro vessels, with the assertion that many of these fires are attributable to EVs. Lars Lange, IUMI secretary general, explained: “Our paper draws on a body of scientific research, which demonstrates that fires in battery EVs are not more dangerous than fires in conventional vehicles, nor are they more frequent. Although statistics continue to be gathered, they currently estimate that, in general, there are fewer fires from EVs compared with fires from conventional vehicles when driven over the same distance.”  

Research, IUMI continued, also proves that there is only a minor difference between total energy released during an EV fire and one that is related to an internal combustion engine vehicle (ICEV). Once established, vehicle fires are largely (approximately 80 percent) fuelled by the car body and interior parts rather than the propulsion system. However, the potential for thermal runaway ­– when the battery suffers an unstable chemical reaction – exists for EVs whereas it is not a consideration for ICEVs.  

Thermal runaway makes fires hard to extinguish, hence mitigation measures such as boundary cooling must be employed rapidly. Moreover, the risk of re-ignition is higher for an extended period of time.  

In the paper, IUMI makes important distinctions between ro-ros and pure car and truck carriers (PCTCs), noting that many ro-ros will stow cars on open decks where air flow makes firefighting more challenging. Ro-pax vessels (where passengers are also carried) present additional issues such as passengers wanting to charge onboard and the possibility of cars being loaded that are older and potentially less safe. Conversely, PCTCs tend to carry vehicles tightly packed leaving little room for emergency access and facilitating the rapid spread of a fire.  

In light of this, IUMI concluded: 

  • Early fire detection and verification/confirmation is critically important to reduce the time between detection and firefighting response to a minimum. Options, in addition to the conventional systems, could include thermal imaging cameras and AI powered systems. 
  • Drencher systems are effective for firefighting onboard ro-ro and ro-pax vessels both for EV and ICEV fires and should be installed alongside video monitoring systems. 
  • CO2 extinguishing systems, if applied quickly, are successful in fighting PCTC fires and their capacity should be doubled. High-expansion foam fire extinguishing systems have also proved to be effective to prevent heat transfer from one vehicle to another.  
  • Early detection, confirmation and a short response time are crucial to fight a fire successfully. On board PCTCs, fixed systems should always be applied before manual firefighting is employed. 
  • A clear policy is required on which cargo is accepted or rejected. Vehicles should be screened with used vehicles being checked carefully for hidden damage. 
  • Charging onboard ro-pax vessels should be permitted subject to relevant risk assessments and control measures. Safety mechanisms built into EVs are usually activated during charging. 

The IMO’s sub-committee on ship systems and equipment (SSE) will start work on the “evaluation of adequacy of fire protection, detection and extinction arrangements in vehicle, special category and ro-ro spaces in order to reduce the fire risk of ships carrying new energy vehicles”, beginning in March 2024. Lange said: “The regulatory process will be an opportunity to improve safety requirements making them fit for the new reality of large numbers of alternative fuel vehicles being carried on board vessels. IUMI will continue to contribute to this debate.” 

The full IUMI paper is available here