Hacker News

points by orwin 1 day ago | 0 comments

I think you misread. The article state tesla Semi has had 2 fire in 2 years. The first one because the truck hist stuff and left the road in Nevada, the second (this one, the subject of the article) in California for unknown reasons. This is relevant because the Tesla semi fleet is small (86 vehicles 2 years ago, probably below 500 atm) and because battery fire are hard to stop, so we want to know what caused it. If EV fire last 10 time longer than diesel fire, but happen 10 time less often (we need more studies but it seems this is the initial consensus), this is not really an issue, but if they happen more often, we _need_ to know why and fix it.

Also i don't want trucks to catch fire everytime they hit a cow or a boar, the roads around where i used to live would be consistently closed :/

[–] cucumber3732842 1 day ago

Approx one (with a big error bar) fire per 100 vehicles per year sounds about right based on my unscientific dealings with auction oil field trucks.

My gut feel is that vehicles of all types seem way more disposed to fire than stuff from the 90s through 2010s.

[–] AlotOfReading 1 day ago

This vehicle was part of a manufacturer-owned highway fleet. That means it received proactive maintenance by trained personnel on a regular schedule, with full access to engineers for diagnosis and OEM replacement parts, and ran on good roads in the mild California climate. It's practically pampered compared to oilfield haulers, especially the ones that live long enough to be auctioned off. They're not comparable.

As an aside, some of the vehicles I've worked on serve in oilfields and I'd be horrified to discover 1% of them were catching fire annually.

[–] hansvm 1 day ago

For some other unscientific findings, that'd suggest 5 vehicle fires per year just from residents of my apartment complex. I've seen 1 in 8 years, and that was arson.

[–] bryanlarsen 1 day ago

Those trucks are probably doing over 200,000 miles per year and your apartment's cars under 20, so the fires/mile ratio seems comparable.

[–] hansvm 1 day ago

The fires/mile ratio seems like a good idea (skewed a bit by relative driving habits of professional vs typical drivers). It turns out those numbers are all pretty readily available. All miles from all sources (including semis) tally to 3.3T/yr. All car fires from all sources (including crashes, so in the context of semis spontaneously combusting these numbers will make the 1/100 rate look even better than it should be, though separate sources indicate that most car fires aren't from collisions, so that's perhaps a small effect) total to 210k/yr. You then find that, smoothing out all underlying subgroups and data, there's a fire every 15.5M miles.

Applied to residential apartments, there's an average miles per year of 14k or so (should be less here than average based on anecdata, high fuel prices discouraging driving, and everything being close even if you do drive and usually close enough to be walkable, but let's assume 14k/yr is a reasonable baseline), giving us a fire every 1100 vehicles, not every 100.

1/1k is more plausible to me (still "feels" high, but it doesn't trigger the baseline absurdity checks I have in the back of my mind). 1/100 suggests that every year in uni one of my classmates should've had their car burn down. 1/100 suggests that every year my hometown newspaper should report 30 cars burning down -- one every week or two (and given that the newspaper covers the entire county it should actually be 3/week). It's a pretty high rate. The typical person knows hundreds of people well enough that a car fire would often crop up in conversation eventually, and I don't think the typical person knows anyone whose car caught fire. Elaborating on that, I don't think the typical person doesn't know somebody whose car caught fire _ever_, much less in the last year.

[–] bryanlarsen 1 day ago

In my personal experience pretty much every old farmer has had multiple vehicle fires. It's quite likely location dependent -- if you're in an area which clogs up air filters quickly, and or where dry straw getting in where it shouldn't is a likely experience, vehicle fires are very common.

[–] hansvm 1 day ago

Maybe. That hometown I referenced has 3k people in the city (not farmers) and 12k people in the county outside the city (mostly farmers in varying capacities). It's the only place I've lived where it's common for people to cut, mill, and dry their own lumber for economic reasons, or (ignoring parts of Alaska I've lived in) for hunting to be an economically rational thing to do. There are literally zero vehicle fires. A home or business per year or two burns down, but at the 1/100 vehicle fire rate we expect 3 fires per week, and there are zero in the last decade. It's a hot, dry climate made up of mostly farmers with extremely shoddy equipment.

Anecdotes aren't everything. If there are 1/1k fires annually then those have to come from somewhere, so your "location dependent" idea makes a lot of sense. I'm passionately curious now as to where those fires actually happen though. It's not just farmers with bad equipment in bad scenarios.