On the news they were talking about Tesla battery fires being really hard to put out. I thought, why couldn’t you just slide a fireproof fabric of some kind under the burning Tesla. Pull that sucker up, and vacuum seal it.
Basically, why aren’t fires put out more often by cutting off oxygen? It seems like the most effective way as opposed to dousing it with water or sand.
In: Physics
The problem is getting anything under the fire is extremely dangerous. But a variant of this is very much the approach that Fire Departments are now training and equipping for – get a specialized blanket over the fire, smoother it, and secure the vehicle until it fully self-extinguishes.
The above is video from a Denver, CO area Fire Department, and shows how they handled an Electric Vehicle Fire.
Not all fires burn the same way. In your example, those batteries can generate their own oxidizer, so just covering them up and “cutting off the oxygen” may not put out the fire.
A fire tarp is actually the recommended way to put out an EV fire. It would work on any fire if you had a big enough blanket.
How are you going to get something **Under** a vehicle, especially if it’s burning? You’d have to either go in with heavy equipment and somehow lift it up, or somehow physically move a burning vehicle. None of which would be safe for the people doing it.
That’s called a fire blanket and they work really well. On fires that need external oxygen to keep burning. doesn’t even have to be high tech, a wet bath towel works on small fires.
Depending on WHAT is burning that may or may not be the case. Gasoline, sure it would work as long as you could seal it. The fire would consume the available oxygen inside the seal and then die.
Battery fires? Nope, they can keep going.
They can be. You don’t even have to wrap it. There are fire blankets designed specifically for fighting EV fires but they aren’t cheap to make and not everyone has them. If you do, it’s actually one of the more effective ways to deal with an EV fire.
It doesn’t actually stop the fire but it contains it. EV fires are hard to put out because the base of them isn’t actually fire, it’s thermal runaway. Batteries short, releasing the stored energy as heat and this causes fires. If you can prevent most stuff from burning when hot with the blanket it keeps it relatively controlled but you still have to dissipate the stored energy and the blanket has to survive that heat.
Sand and water tend to attack multiple sides of the fire triangle as they absorb heat, disrupt or dilute fuel presence, and can make it difficult for fuel and oxidizer/oxygen to mix.
Fire blanket just hinders outside oxygen getting in but because it doesn’t cool the system or dilute the fuel you can be left with an environment under the blanket that is full of very hot partially combusted fuel material which will violently react if oxygen/oxidizer is re-added to the system. Also if there is an oxidizer present the fire can continue to burn under the blanket which is not what the blankets are meant to be used on.
Similarly you would not want to seal the fire in in most cases as if the seal fails you can get violent reemergence of the fire resulting in explosion or jetting of flaming material compared to just letting it burn uncovered and unsealed. Fuel and oxidizer in a sealed space is liable to act like a bomb or rocket engine depending on how sealed the space is.
A blanket could surely help to localise a battery fire and stop it from spreading. Maybe not to vehicles next to the fire but allow other vehicles to be rescued.
Luton airport lost an entire carpark because of one suspected battery fire.
Reading through the answers here, nobody even touches my biggest question. How are you going to lift the burning Tesla to get the fireproof fabric underneath it?
In addition to the fire blankets that many commentors have mentioned, some fire services also use piercing tools that slide under an EV so they can pierce the battery pack and flood the compartment with water.
Cover the whole vehicle with a fire blanket and voila, fire is out.
Latest Answers