The Australian Road Research Board (ARRB) is conducting research into the safety risk of fires caused by electric vehicles versus non-electric vehicles in road tunnels.
A vehicle fire demonstration was recently conducted in the Sydney Harbour Tunnel, with a car used for the purpose of the investigation.
A non-electric car was set alight in the southbound tunnel, in a controlled environment about 800m from the northern entrance. After an initial explosion that caused some vehicle parts such a window glass to scatter around the vehicle, the car fire started and triggered the tunnel sprinkler system which kept the fire at bay. The tunnel exhaust system was also engaged to remove harmful smoke from the tunnel. Professional fire fighters then extinguished the fire.
ARRB says the big question is how EV fires need to be treated. Considering their large batteries and their high energy content, an EV fire can be harder to extinguish. Large volumes of water are required to suppress the battery fire. There is also a risk that the battery reignites after the fire has stopped.
Senior professional leader, Mobility Futures, Dr Robert Kochhan, believes Europe’s systems set a good example for other countries with their alpine tunnels.
“We should look at Europe where testing has already been undertaken and studies are available. The general consensus is that there are no significant concerns regarding EV fires there,” Kochhan said.
Though he added that more detailed research needs to be conducted to investigate the applicability of overseas findings in Australia, and additional studies and tests may need to be carried out to ensure that our tunnels are fit for the wave of EVs coming to Australia.
Bob Allen, general manager and current tunnel operator of the Sydney Harbour Tunnel says EV-precautions regarding high voltage need to be taken. If it is unknown whether the vehicle on fire is an EV or not, the EV’s high voltage systems are a safety risk. First responders need to be aware of the vehicle technology to manage the incident appropriately and not put anyone at risk, including themselves or vehicle occupants.