A new crash recently in Alabama, but a reminder to something that we all know. Burning Teslas are far more difficult to extinguish than any other car.
A new crash recently in Alabama, but a reminder to something that we all know. Burning Teslas are far more difficult to extinguish than any other car.
If the car is on fire already how does this work?
It looks like you would need to drag the burning vehicle into the dumpster and than fill it with water? That doesn’t seem to be a very viable option safety wise.
Different propositions. I think this particular design you hook up a metal cable + winch the car into the container, which has the risks like you point out.
In this design, a truck slams the container from the top down, and then I think like rubber-feet on the bottom try to prevent the water from leaking out. Of course there’s more leakage here, but less so than no container at all. So pros/cons for different methodologies.
The important thing is that these designs are being tested in Europe. USA seemingly has no response yet.
If you’re putting people at risk to sling it up you’re better off just letting it burn. It’s gonna be write off no matter what.
Not gonna be a thing in the USA since it’s dangerous to the people who would be using it. Instead of standing at a distance and using water/foam/sand or just letting it burn.
So there’s basically two phases of an EV Fire.
The initial fire, a blazing hot heat that’s dangerous – You just hit it with water from a distance. You’re correct on the analysis here.
The “reignitions”. Li-ion batteries, once damaged, will reignite spontaneously for hours after the initial fire. So the fire “has been put out”, but we all know that its only for a few minutes. There’s enough time to winch the car into these containers and fill it up with water in practice.
Its #2 that you’re probably missing. Water / Foam / etc. etc. is only good at stopping phase 1 of the fire. But the next 8+ hours, you need someone to babysit the fire with a hose and keep dribbling water on it before the fire is permanently put out. Or… you know… do like a European and use a container and fill it with water, so it can babysit itself.
Sand and some types of foam prevent #2.
The person would be at risk while rigging it up, you would have to stop spraying while getting it into the box, giving it time to reignite while the person is right beside it.
This is like those fire suppression grenades, great concept, but fails in theory since they are massive safety concerns to go with them.
And it can’t babysit itself, the FD would still be onsite while the vehicle sits in the tub, just let it burn off at that point and than it’s dealt with in a couple hours.
I don’t see Europe actively using these from any research I’ve done, just a few concepts and nothing more. Since it’s a safety concern to be able to use these.
Do you have a demo of this working? A .pdf report on the amount of sand and/or foam needed to achieve this?
European fire-departments are moving towards this full-submerge tactic because it works. Its one of the big developments in firefighting technique over the last 5ish years.
When we’re dealing with 1000lbs / half-ton battery packs, the sizes needed to actually effect these fires grows dramatically. I don’t think that fire-departments will be in the business of carrying dumpsters full of sand to try to extinguish these fires… but I dunno, if you got some numbers on the quantity of sand needed to achieve the suppression of the fire we can compare notes.
Yes plenty of places in the states have sand as their official policy. No real difference than your water container than for the sand container, but you can also just cover it without the container as well, this is the preferred method for personal safety, just would need more.
Same is also easier to remediate than the water as well, some places use wet sand. Best of both worlds, but still need to remediate the water.
How does sand stop the internal exothermic reaction, though? I could see wet sand maybe, but just straight sand? It’s not a normal fire and is self-sustaining.
Wouldn’t the transport and storage of the sand be prohibitive?
Why would it?
Weighs less and is easier to store and transport than water. Also what about places that freeze? Gonna have an ice cube with a car in it after.
Not every place is with it easy access of fire hydrants, what about the middle of a highway? Both water and sand would essentially be equally cumbersome to get there.
Every fire puts a firefighter at risk. That’s not a valid argument. This system does not require a person to stand right next to the fire. That’s why the box is deployed by a mechanical arm.
My guess is an electromagnetic crane. This isn’t a good option either. Just use halon fire extinguishers.
That’s not helpful.
A Li-ion fire is a runaway exothermic reaction. You need to cool the battery pack below the runaway thermal temperature. Using water to cool the battery-pack and keeping it cool for hours is the best known solution, for now.
If you “only” use a fire extinguisher, you choke out the fire’s reaction, and then 5 minutes later the exothermic reaction just continues (the battery is still hot and self-reacting at this point). The reason why water works is that it finally and sustainably cools the battery below the runaway temperature, and keeps the damaged battery pack below that critical temperature.
You can’t choke the reaction since it’s self oxidizing. Cooling down the reaction is the only way to stop it.
I appreciate the note about the reaction here. Chemistry was my weakest subject back in school. So I’m sure I’m getting lots of details wrong, lol.
But I’ve also watched what fire-departments are doing and read up on whitepapers / discussions on fire-department tactics. So while my chemical knowledge is probably terrible, I at least know what the fire-departments know and discuss.
Yeah, I’ve been vaping for like 12 years now (including building my own devices) and have done a ton of research into battery safety and such, so I always try to correct misinformation on posts about battery fires.
I’m sorry you keep getting downvoted because people don’t know what they’re talking about.
Halon extinguishers won’t work. Lithium battery fires are self oxidizing.
Oh, I didn’t know that. Thanks for the information.