Tesla Semi fire in California took 50k gallons of water to extinguish | Hacker News Reader

Tesla Semi fire in California took 50k gallons of water to extinguish

cnbc.com

40 pointsmfiguiere66 comments

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.

Plus it needed an airplane to dump fire retardant.

Cal Fire probably got involved because the cost of battling a wildfire in that area would be astronomically higher than 50k gallons of water.

This is true in _a lot_ of the areas where these trucks will be driving.

> Additionally, CAL FIRE used an aircraft to apply fire retardant to the immediate area as a precautionary measure

Seems like it was a precaution, rather than needed.

If it's part of some protocol then it's definitely needed.

Safety measures are put in place for a reason.

Precautions can be needed, like input validation on a web form.

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.

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

THIS.

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.

> until [..] runs low on electrical energy

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?

> What if...

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.

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.

Edit: Here is a picture from a news article: https://i.regiogroei.cloud/4561b78f-d49a-3ecc-adb4-6f535f896...

I realize the chemistry is different, but in my head the idea of submerging Lithium in _water_ to _extinguish_ a fire is pretty funny.

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.

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.

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.

Source: Firefighter in a rural dept

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?

Is that unusual? Nothing in the article compares it to other fires. Honestly curious.

Also, this was a little ironic…

> The Tesla truck, driven by an employee, was headed to the company’s battery factory in Sparks, Nevada

Well, I guess for gas-powered car 500 gallons would be sufficient, so 2 orders of magnitude less water.

EDIT: 500 gallons was originally just a wild guess, but here's an article where some firefighter gives 500-1000 gallons range: https://www.independent.co.uk/climate-change/tesla-crash-dri...

I had the same thought, how many gallons is a diesel semi truck fire?

The part that concerns me is once electric cars are more ubiquitous, say 50% of cars on the road. How will we handle a pileup, where there could be five cars that all need the same level of fire department effort? Could there be some domino effect?

> and required aircraft to dump fire retardant overhead

I don’t think that’s standard vehicle fire practice.

ICE vehicle fires take about 1000 gallons, and the average fire hydrant puts out about 500-1000 gallons per minute. Structural fire engines carry about 1000 gallons and the heavy duty nozzles and ground monitors/deck guns put out 500-1000gpm. This is a LOT of water for a vehicle.

More like 300-400 gallons for your average urban engine. That's enough (with not much to spare) to knock down your average ICE car fire, but it's really there to allow the crew to get to work while they ship a hydrant.

That's low for an electric vehicle fire. An average car takes 500-1000 gallons. Teslas can take up to 30000-40000 gallons. Fwiw, most fire trucks only carry up to like 3000 gallons.

Most "Fire trucks" - I'm assuming you mean Engines - carry 500-1000 gallons, usually more on the 500 size. A "Water Tender" generally around 2000 gallons.

Engineer here.

> Fire trucks" - I'm assuming you mean Engines

No-no-no, an engine is a part that makes a fire truck move. Fire trucks usually have a diesel engine.

tips fedora

Software engineer, or IFSAC Apparatus Operator engineer? On the west coast we absolutely refer to our pumping apparatuses as fire engines; when Engine 813 is dispatched from our station to a call we bring the whole vehicle and not just the engine block!

> Software engineer, or IFSAC Apparatus Operator engineer?

Yes, correct, engineer.

Same in my department.

(The generic term for some type of fire-fighting vehicle is Apparatus.)

Sparks

I read the fire sheets for other tesla cars and they say 8k gallons to suppress a battery fire. However, the Semi's sheet does not give a qty estimate.

https://www.tesla.com/firstresponders

Maybe semi-truck sized electric vehicles should not be allowed to use a battery technology subject to thermal runaway. Either lithium-iron phosphate, or, once it works, solid state battery technology.

They definitely need to be prohibited from using tunnels that don't allow flammable cargo. There are many tunnels that don't allow gasoline tankers.

Sodium-ion sounds pretty nice also. You don't have the restrictions of a standard passenger vehicle (you have more space).

I imagine in the future they'll look back on when we drove cars that were so combustible (ICE or lithium-ion) like how we look back at when everyone had lead-based house paint or asbestos ceilings.

A few weeks ago I randomly thought, "is there a market for a startup that creates EV fire extinguisher technology?" It seems even Tesla's recommendation right now is to just dump a ton of water on it.

I'm not sure the volume is there right now to justify a new company, but maybe 10 years from now? Just thinking out loud.

There has to be a better solution than letting them cook

There is no great solution because these fires are self-oxidizing and produce a hell of a lot of heat. If you could blow it apart with a bomb then that might spread the stuff out enough for it to quickly burn out. But other than that all they can do is wait for it to burn out and maybe cover it. Metal fires such as those in these batteries are uncommon but far from new, yet nobody has found a solution in decades.

I imagine if one of these goes up on (or under) a bridge, it'll compromise the bridge if it can't be extinguished. This happened some years ago with a (diesel) semi in Oakland, I recall, and it sounds like these burn much hotter.

That is a really good point, just a matter of time until a EV Semi catches fire under a bridge or overpass and causes massive structural damage.

Or a parking lot full of unextinguishable EVs under a high rise... The potential fallout from arson is astronomical due to how bad these fires are.

The solution will be to move to a safer energy storage system.

Solid state batteries as supposedly safer.

Better is a relative term when it comes to this issue. Batteries must be chemically unstable in order to be recharged (as I understand it) so practically any battery with high enough energy density is subject to that kind of event.

Search google for "EV fire blanket". They don't extinguish the fire so much as contain it.

Seems like something you'd, ideally, want to develop and license to an existing fire suppression tech company. One that already has all the municipal sales figured out.

If you really did go it alone, I think you could target the FDs in metros with outsized EV populations. I believe San Diego is among the top of the list.

> a ton of water

a rare case when "ton" is an understatement. 50,000 gallons is almost 200 tons.

EV fires seem to be less discussed when talking about going fully electric. They create their own fuel and as far as I know, there isn't a better option than taking it somewhere and letting it burn itself out or using crazy amounts of water for a long time (relatively)

They get talked about a lot from my POV.

This is about ~ 190 cubic meters of water! This is close to the average water usge of a european household of 4 people [1].

[1]

    household use, which accounts for around 12 %. On average, 144 litres of water per person per day is supplied to households in Europe.

https://www.eea.europa.eu/signals-archived/signals-2018-cont...

I think you mean close to the average water usage of ~1300 European households, as 1 cubic meter of water = 1000L.

144L * 4 people * 365 days = 210240 L per house per year

which is around 210 cubic meters. Is my math off?

What’s the environmental damage, as in fumes or air pollution and/or this water seeping into ground, from an EV battery fire?

Has it been studied or researched?

This study looked at water contamination:

https://www.ri.se/sites/default/files/2020-12/FRIC%20D1.2-20...

> Environmental impacts - electrical vehicles

> • Water analyses of selected metals relevant for batteries in electric vehicles did not show any lithium, and only low concentrations of cobalt.

> • This indicates that batteries in electric vehicles did not contribute to pollution of nearby water resources.

If someone was able to hack and root the computer(s) system(s) on the Tesla, but having no physical access car, could they strain/force/heat the battery to the point it will catch fire or something else that may be dangerous?

If that is possible, can it be done while the car is parked as well?

I’m curious. Can anyone tell me what would have happened if they had dumped a bunch of sand on it instead?

Not my area of expertise, but I remember in chemistry class we had a literal bucket of sand for certain types of chemical situations.

I was looking this up as well. When these batteries enter thermal runaway, the chemistry of the battery is basically self propagating heat which allows it to continue to heat up and ignite. It doesn't need oxygen to continue this process.

Burying it insulates it, which will increase the runaway, but isolate the issue. It's good for small batteries like cellphones and laptops because it allows you to move the battery somewhere else and contain the fire, but doesn't do anything to retard the runaway.

Water can cool it off and slow down/potentially halt the runaway. Someone smarter than me would need to comment on what to do after it's halted, because I assume it's still a problem waiting to reignite at that point.

https://en.wikipedia.org/wiki/Thermal_runaway#Batteries

Edit: This actually is a potentially interesting idea, a tomb vehicle that basically encases the burning vehicle in a heavily insulated trailer for relocation.

Can you pour liquid nitrogen on it?

Doesn't fires involve lot more than just batteries and fuel? At least with many of trucks, there is the cargo and the cargo compartment. Not a big deal with something like gravel or sand... But parcels, food, so on? Traditionally you deal with fuel and that cargo at same time and it is usually done when done, but what are probabilities with battery fires that you reignite whatever is left?

Lithium fires obviously need some form of chemical dousing.

Pouring tons of water is just not a good way to put out the fire.

There very well may be something more effective than water but the economics are probably a barrier here. Water has some pretty amazing at absorbing heat considering how abundant it is. Moving to anything else becomes pricey quickly in a serious quanitiy. Heck, even the foam used is quite expensive in much smaller quantities.

If you haven't seen a Tesla burn uncontrollably, emitting clouds of very poisonous smoke, search for video and watch it.

Same thing happens to e-bike batteries; you can find video of a man being spontaneously incinerated after carrying his e-bike battery into an elevator.

And of course the same thing happens to battery storage for the grid. Battery farms spontaneously start burning and it just spreads and spreads.

I think of this every time somebody argues that nuclear fission can be replaced by solar/wind + huge battery farms. For example, see the recent discussion here:

https://news.ycombinator.com/item?id=41526789

Imagine the battery fire.

I cringed when Musk embraced lithium-ion batteries for grid storage, there were better chemistries out there that got ignored. Guessing it set us back 20 years for that application.

I guess with grid batteries you can space them out to avoid that.

Since the objective is to slow down/halt the thermal runaway, would a cryogenic fluid be useful/more effective as a future solution?

Reply on news.ycombinator.com