The International Union of Marine Insurance (IUMI) has conducted a research, after noticing rising concern on the matter, regarding the safe carriage of electric vehicles (EVs) and has subsequently released a set of recommendations.
Setting the numbers straight
ccording to IUMI, research 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 (approx. 80%) fuelled by the car body and interior parts rather than the propulsion system.
- 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 fire-fighting onboard roro and ropax 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 fire-fighting 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 ropax vessels should be permitted subject to relevant risk assessments and control measures. Safety mechanisms built into EVs are usually activated during charging.
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.
… said Lars Lange, IUMI Secretary General
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.
Roros and PCTCs
In the paper, IUMI makes important distinctions between roros and pure car and truck carriers (PCTCs) noting that many roros will stow cars on open decks where air flow makes fire-fighting more challenging.
Ropax 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.
Recommendations and best practises
#1: Loading process and loading condition of cars
In light of the safety systems incorporated into EVs, new cars present a lower risk as compared to used vehicles. There are currently no documented cases of factory-new electric vehicles causing a fire on board. In contrast, used cars may have had accidents causing mechanical damages, which may negatively impact the intactness of the battery pack.
Roros and PCTCs: A clear policy on the cargo that is accepted or rejected for roro spaces should be in place. Vehicles should be screened, and used or second-hand vehicles in particular should be carefully checked before being allowed on board. If there is suspicion that the battery of an EV is damaged or defective, they should only be allowed if their battery is removed and if they are free from leakages.
IMDG Special Provisions 961 and 962 address requirements for vehicles that are being carried on board a transport vessel.
#2: Charging on board
Roros: Charging on board Ro-Ro passenger ships can be permitted if the ship operator conducts a comprehensive risk assessment and approves and implements appropriate risk control measures. Research indicates that charging an EV on board is the safer option, as inbuilt safety mechanisms are activated during charging. As mentioned above, information regarding safe charging on board is available in the EMSA Guidance on the Carriage of AFVs in RO-RO spaces.
PCTCs: PCTCs are not equipped with charging stations.
#3: Detection and confirmation/verification
Roros and PCTCs: Detection and verification or confirmation of a fire are key to enabling successful firefighting operations. These two steps should not be considered separate but as one. The time between detection and confirmation or verification must be reduced to the shortest possible time. The installation of technologies that enhance early detection is therefore supported for these vessel types.
Options include gas detection systems, thermal imaging cameras, and AI-powered systems.
Roros: The EU’s LASHFIRE project has shown that drencher systems are effective to fight fires on board roro and ropax vessels. Full-scale tests show that a drencher system has the same impact on the fire regardless of whether the source of the fire is an ICEV or an EV. Drencher systems are thus effective in managing and controlling EV fires.
This is reflected in the revised requirements developed by the IMO’s Sub-Committee on Ship Systems and Equipment (SSE). The amendments to SOLAS and the Fire Safety Systems (FSS) Code will mainly apply to new passenger ships and include, inter alia, requirements for a fixed fire detection and fire alarm system to be provided for the area on the weather deck intended for the carriage of vehicles; an effective video monitoring system; and a fixed water-based fire extinguishing system based on monitor(s) to be installed in order to cover weather decks intended for the carriage of vehicles.
PCTCs: CO2 extinguishing systems, if applied quickly after the detection and verification or confirmation of a fire, have worked successfully to fight fires on board PCTCs. To further improve its usefulness, the CO2 capacity on board PCTCs should be doubled. Research projects are ongoing to methodically assess and evaluate the effectiveness of the CO2 extinguishing systems.
PCTCs: Research indicates that while high-expansion foam fire extinguishing systems were unable to stop thermal runaway (like any other fixed systems), they hindered the ignition of flammable gases, including gaseous electrolyte from the batteries. The system effectively prevented heat transmission from a vehicle on fire as long as it was submerged in the foam. This suggests the potential effectiveness of high-expansion foam fire extinguishing systems.
PCTCs: Early detection, confirmation or verification, and a short response time are crucial to fighting a fire successfully. The fixed firefighting systems should be applied first, rather than manual firefighting by the crew.
PCTCs and RoRos: Different design, resources, equipment, and circumstances have to be considered for each vessel. Individual risk assessments and tactics are essential to ensuring an effective response in the event of a fire on board.
The IMO’s Sub-Committee on Ship Systems and Equipment (SSE) will start work on the “Evaluation of the 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. 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.
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.
… Lars Lange, IUMI Secretary General said on the matter
To remind, new guidelines and measures were also introduced by ClassNK last week, to improve the security of electric vehicle transport via ship.