To put in context, 50k gallons is about the size of the largest in-ground pool you might see in the back yard of an upscale suburban home. A normal tanker trailer you see on the highway carrying gasoline or whatever has a 7,500 gallon capacity, so over six of those. Quite a bit of water to dump on one car.
It's also worth keeping in mind that rural fire departments that all have tanker trucks typically carry only 1,500-3,000 gallons and need to continuously fill up from a pump site, drive to the scene, dump in a pond, and continue. Typical gasoline car fires will take less than 1,000 to extinguish. EVs are challenging from this perspective, and departments are just now starting to learn how to deal with them, it's a whole new ballgame.
The context is what was required to extinguish the vehicle, and the fire retardant was not specifically required otherwise they would not have called it precautionary after the fact.
Was it needed as part of the process in this instance? Yes. Was it needed to extinguish the vehicle in this instance? No.
To put in context, I'd need to know how many gallons it normally takes to extinguish similar fires. I do agree that's a large volume of water but unclear if it's comparatively a lot?
they were dumping it on a semi not a car, it seems like fire dept just needs to get more efficient, hopefully they are not trying to fight these fires in the same traditional way
As a firefighter/paramedic, pray tell, how would you suggest we "just get more efficient"? Part of the challenge is access, between heat and explosive risk.
It's not about being more efficient - it's about kicking out one or more legs of the fire triangle, with water, that being heat and oxygen. The problem is that physics dictates that overcoming the BTUs being put out by a battery fire requires rather a lot of water.
Use of other liquids to absorb this heat is ... problematic. One, you have to transport it to the fire, and two, runoff. It's bad enough having structure fire water runoff going to the ground and water supply, let alone another (most likely noxious) chemical.
I wonder if anyone bothered to test some of this water runoff for dangerous chemicals… I’m no scientist, but generally the liquids inside batteries should stay inside the batteries whenever possible.
Though I guess normal car fires would have gasoline-tainted runoff anyway!
Managing runoff is a factor in any vehicle fire, secondary to immediate protection of life, of course. Runoff is contained in binding, by digging ditches, etc. Contaminated runoff may then need to be removed by a specialised hazmat crew, depending on what’s in it and where is draining to.
Australian here, but I can’t imagine there’s much difference on this issue.
There was an article some time ago about how this is handled for a normal sized car like a model S. Basically they put out the flames with traditional foam spraying, then dump the whole car in a large container with water. Let it sit under water for a few days until the battery fire is done.
The battery fire is self sustaining, so only way to stop it is large amounts of continuous cooling for a long time. That's what the water container is for.
At least that's the method used in the Netherlands. Which obviously isn't practical for a semi truck sized fire.
Well if it is already on fire, what is the worst thing that can happen? Yes you get energetic reaction, but you were having one already and after wards, it is not that big of deal... Just thinking how long does piece of metallic lithium last in container.
A big battery "fire" is not really a fire, in the normal meaning of that word.
The job the FD faced might better be described as "supply continuous cooling, until the self-powered/no-oxygen-needed battery meltdown runs low on electrical energy". Though if the FD's training & equipment is for traditional fires - then they are stuck using a "pretend it's a fire, and call in 10 more tanker trucks" playbook.
How long will it take for that to happen in one of these semis? What if the fire needs to be extinguished before then because of risks it poses to surroundings?
You're pretty much SoL, because the "fire" is more like a pair of electrical cables that are shorting together.
With seriously specialized heavy equipment (and probably an expendable robot or few), you might tap into the semi's electrical system, to drain off some of the electrical energy to a giant resistor. Or chop the battery out of the possibly-mangled semi's structure, and haul it away in a "burning battery containment" truck.
Legislators really need to come up to speed on Tesla and crack down on this shit. There are going to be many collisions involving these trucks. Doesn't even have to be the fault of the driver or Tesla. That's simply life on the highways.
