Featured Tesla Semi crashed and caught fire. I-80 closed for a day

*sounds of insurers loading and cocking their actuaries*

 

I'm remembering some diesel trucks burning so completely that there was nothing much left to need much cooling down. Just drag away the axles, pry or peel up any rivulets of melted / re-solidified aluminum, sweep up some other debris, then quickly repave the damaged pavement before reopening the road.

In one case of a fuel tanker climbing I-82 towards Manastash Vista and rear-ending another fuel tanker parked disabled on the shoulder, while the front driver jumped to safety, there wasn't enough of the rear cab left to even locate a driver's body, it was fully cremated. Though that fact that both rigs were loaded fuel trucks did cause the wreckage to burn more completely than normal.

 

VWs using magnesium engine blocks required a back hoe to come in, dig a hole, and then bury the entire burning car.

A couple here burned under overpasses, requiring major repairs to those bridges.

Edit: There are car sized fire blankets available to contain the smoke, and help smother the fire. Plus, they are working on nozzles that go under the vehicle to spray the battery from underneath. Less effective on something this big, but the concerns of EV fires are being addressed.
Salesforce B2B Commerce

 

New technologies have both pros and cons.
Why are there no cars powered by nuclear reactors on the roads until now?
Apparently, if such a car catches fire, the highway will be closed for more than one year.

 

Didn't BMW start using magnesium engine blocks on at least some of their cars?

Perhaps the real reason the VW engines caught fire was from the grommet that protected the metal fuel line that came in through the firewall tin was right over the #3 cylinder's exhaust primary. That, and the fuel tank was higher than that point. So if the grommet failed the metal fuel line would start leaking right onto the hot exhaust primary, which once that caught fire would not stop from the ever flowing fuel, which then got things hot enough to get the magnesium to catch fire, which at that point was impossible to put out. Under normal circumstances it is very hard to ignite a magnesium crank case, but this design had a major flaw for those who didn't keep an eye on that grommet. Which is why I would not only make sure the grommet was in good condition, I'd also install a solenoid valve on the fuel line at the fuel tank on my air-cooled VW's.

 

Tesla is still running preproduction or early production semi trucks. I suspect this will accelerate getting AutoPilot/FSD on them ASAP. From CBS:

The National Transportation Safety Board says it opened a safety investigation in coordination with the California Highway Patrol into this week's Tesla semi-truck crash and fire in Placer County.

The electric-powered semi-truck went off the roadway along eastbound Interstate 80 near the Emigrant Gap area just after 3 a.m. Monday and crashed into trees.

The crash caused the vehicle's battery to catch fire, and it burned for several hours causing a full closure of the freeway through the evening. Though the semi-truck had veered off the road, the CHP said the crash had created a hazardous materials situation due to the toxic fumes released from the burning battery.

No one was injured in the crash or fire.

In a statement on Thursday, the NTSB noted they will be taking a hard look at the electric semi's batteries.
. . .​

Good! However, the semi trucks are using 2170 cells. Tesla recently had a breakthrough with 4680, dry-electrode, cells which I understand will soon be part of these early production semi trucks. There are a lot of 2170 cells on the road and the NTSB will be researching a soon to be past, not the future.

An early video:

Per the video, the firefighters have been there since 3 AM suggesting a crash after midnight. It begs the question of the driver falling asleep.

Bob Wilson

 

I think the problem is the size and chemical composition of the pack , not the form factor. Accidents will happen, but as opposed to a tesla vehicle with 60kwh-100kwh of battery, these require a lot of water (a model S required 7000 gallons to cool the battery pack to stop it from reignighting after the fire was out ) but this is available. Now a semi having a 900 kwh pack probably needs at least 40,000 gallons of water -that means instead of 3 water carriers you would need at least 14 or have to refill them with water. It calls for a more stable chemistry. Someone correct these figures if they are wrong.

Good news is there are safer battery technologies for these very large packs. This is why it is good to start with only a small number of these trucks to work out the dangers and benefits.

 

Found this interesting video about electric bus fires:

Bob Wilson

 

I don't think getting Autopilot/FSD onto other models fast is possible. Does the Cybertruk have either?

You can find magnesium parts on many cars these days; it's light weight. At least those that can get hot enough are an alloy that takes more to ignite, if not inflammable.

 

There is a recent video of a dog chewing a lithium ion battery (cell phone battery ?)and it catches fire. The two dogs made it out through a dog door they said. Interesting to watch the dogs as the fire gets going. I think they were barking to alert someone but no one was there. I don’t know how to post the link.

 

Speculation but "wet storage" worked in WW-2 to minimize ammunition 'cook off.' Perhaps having the parallel cells in a water bath might reduce battery fire in a crash.

The 4680 cells with dry.electrode coating should have a fairly low quantity of the flammable electrolyte compared to 2170.

Bob Wilson

 

I'm not sure what alloys they are using, but even the alloys used in the VW's were still pretty hard to catch on fire. Their ignition temperature is around 650 °C (1200 °F) and to reach that temperature you have to heat up a rather thick and bulky crank case, which takes a lot of heat energy. You're not going to get that kind of heat just from an electrical fire or oil grime on the engine catching on fire. As I said before, the reason they caught on fire was from a leaking gasoline line right onto the engine that couldn't be stopped. Continuously pour gasoline into a fire on the top of any magnesium part for a long enough period of time and I'm sure it will eventually catch on fire.

 

Wow! A car or truck catching on fire? Never heard of such a wacky thing! What with worldwide electric vehicle sales spiraling ever out of control upward .....
EVs, Hybrids Set to Exceed 50% of China Car Sales for First Time - Bloomberg
.... it's doubly hard to imagine! Didn't even know anything in any vehicle was combustible!
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Last month in NJ. Even set the sewers on fire from the fuel draining down.