California firefighters had to douse a flaming battery in a Tesla Semi with about 50,000 gallons (190,000 liters) of water to extinguish flames after a crash, the National Transportation Safety Board said Thursday.
In addition to the huge amount of water, firefighters used an aircraft to drop fire retardant on the “immediate area” of the electric truck as a precautionary measure, the agency said in a preliminary report.
Firefighters said previously that the battery reached temperatures of 1,000 degrees Fahrenheit (540 Celsius) while it was in flames.
The NTSB sent investigators to the Aug. 19 crash along Interstate 80 near Emigrant Gap, about 70 miles (113 kilometers) northeast of Sacramento. The agency said it would look into fire risks posed by the truck’s large lithium-ion battery.
How much water does it normally take to put out a semi fire? Say a tire fire, engine fire, or the entire contents of a semi in flames? I couldn’t find the answer googling, but I did find that combustion engine semis burn at the rate of 7000 per year.
https://plattner-verderame.com/blog/the-dangers-of-truck-fires/
I don’t even think this is the right metric to use.
You aren’t putting a lithium battery fire out with water. You’re just keeping it at bay until the energy is all used up. The more energy, the longer it’ll take.
We might need new ways to deal with these fires, but it’s not like we can completely submerge a semi in water.
I wonder how encasing the object in a fire retardant foam would behave, although we gotta think about the toxicity of that too.
Edit: I wonder if you could even calculate the amount of water you’d need to hold it off upfront based off the battery size and current charge.
There’s already tools to deal with lithium fires, class D fire extinguishers, sand and vermiculite. When I worked heavily with lithium non-rechargables we had lithium disaster plans for fires, explicitly in that was alerting fire fighters that it’s a combustible metal fire so they can react accordingly, those fires need to be smothered afaik, water was a big no no.
Generally though, the plan was, escape and enforce a quarantine zone because primary cells give off nasty stuff, if you can drop it in a bucket of vermiculite if it’s out of the containment vessels and pretty much let them do their thing. Then once it seems like it’s done, wait more time to make sure it’s actually safe with 30 minute gas tests, then package them for safe transport.
The problem though is how do you do that in the middle of nowhere on the highway like in this case? We need something big enough and portable enough. They clearly didn’t have that for this fire.
Totally fair, awareness is a big thing too, fire crews are professionals so I do think they made the best choice with what they were given, every firefighter I’ve met will absolutely do an assessment before doing anything.
Don’t know their situation, were they just told vehicle fire not lithium fire? Maybe more lithium specific crews/equipment in the future, maybe battery compartments that can help contain? (As I said, with lithium batteries I’ve worked with in the past, pressure vessels, if they went off it was at least contained to inside that, they’d vent gasses still but at least the threat of fire was minimised)
My bet is they were just told it was a fire, i doubt the person to drive by and report it would have known it was an electric truck.
The batteries definitely do have fire protections, to help delay the spread. Dousing it with 50k gals of water may have prevented the spread to another compartment for all we know. For something as big and higher risk like a semi though maybe there’s a way to eject compartments. Like if a fire starts in Module 1 of 4, modules 2 to 4 can eject themselves further away. Then were only dealing with a 250kwh fire instead of a 1mwh fire. It would add weight though.
Edit: And then while the firefighters keep the flames at bay, something could get attached to the other compartments and be dragged further away.