Tesla plunges 250 feet off a California cliff, all 4 occupants survive | Hacker News Reader

Tesla plunges 250 feet off a California cliff, all 4 occupants survive

cnn.com

84 pointspseudolus76 comments

Update: "Father Deliberately Drove Car Off Cliff, Authorities Say After Dramatic Rescue" https://www.nytimes.com/2023/01/03/business/devils-slide-cli...

https://archive.is/Xle53

Those poor kids, glad they all survived.

"the two adults suffered 'non-life threatening injuries' and the two children were 'unharmed.'"

Remarkable.

Is there something about a Tesla that could account for this or is it just modern best practices for safety along with a non-trivial amount of good luck?

A mix of modern safety, and also a major advantage of EVs in general (not just Tesla) - since there is no engine, the front of the car is basically just an empty crumble zone. That greatly increases survivability compare to traditional ICE cars in the same weight class.

What you say makes sense, but if it is true, why aren't all cars built with the engine in the rear, then?

Fwd is cheaper and easier to provide interior and storage space.

> Automakers began to abandon the rear-engined layout in the 1970s, with only a handful of cars still available in the 1980s. This was due to the fact that rear-engined, rear-wheel-drive cars were prone to oversteer, which caused vehicle instability.

https://www.topspeed.com/cars/car-news/10-rear-engined-cars-...

not to mention how awful they are in slippery (ice/snow) conditions, which is related to exactly what you mentioned with oversteer

Engines are only ~100kg usually. And a full fuel tank is also about 100kg.

So the fuel tank and engine could be swapped without affecting weight distribution.

What about everything else around the engine? You wouldn’t just move the engine to the rear but keep the transmission and the alternator and etc in the front.

Engines are only ~100kg usually

220lbs? Only the lightest ones. Let's also not forget the transmission/transaxle too.

https://www.gomog.com/allmorgan/engineweights.html

Sorry, you're way off there. My ancient car has a gigantic 90 litre fuel tank. At 720g / litre, that's 64.8kg. And that really is a huge tank - most cars are more like 40-60 litres.

The engine, meanwhile, well it depends what you count as "the engine". If we take it to mean "everything in the engine bay" - radiators, filters, pumps, etc. - you're going to be looking at several times that. Hell, even a battery is like 20kg.

The fuel tank is partially empty most of the time when we drive, and many drivers never refill to the top of the tank, or don't put more fuel until the tank is almost empty. Those 100Kg could be on average 30 or 40Kg.

Does it make sense? I thought there was a survival advantage to having a giant chunk of metal absorbing the impact of a head-on collision. Assuming that it is routed under you instead of into you - which it is.

Depending on the crash, the engine being pushed under can launch the car into the air, where it is more likely to roll over. Contrast this with EVs where the battery is basically a giant puck that the occupants are sitting on top of; the deformation of the crumple zone and the low center of gravity cause the vehicle to rotate away instead of being launched.

The comparison is between identical cars except that one has an engine between you and what you're hitting and one with empty space there and the engine behind you.

Also, I'm more than a little skeptical about the frequency of accidents in which a vehicle is launched into the air and rolls over due to the engine being pushed under the passengers.

And even if that scenario is common, I'm skeptical that the risk of that happening offsets the benefit of having an engine between you and a colliding object.

All sorts of reasons, but it's got a lot to do with packaging and handling. Generally you want the weight distribution of the car to be 50:50 front:rear for optimal handling.

A car will handle great if you can put the engine and transmission somewhere towards the middle, but obviously that isn't great news for passengers. Mid-engined cars exist, of course, but they're usually two-seater sports cars where space and comfort are lower down the list of priorities.

So you're left with putting the engine somewhere towards the front, or somewhere towards the back. Some manufacturers, like BMW, achieve ideal weight distribution by mounting the engine relatively far back in the front of the car, and putting the transmission and some other heavy bits at the back. This is elegant, but too complex and expensive for your average runabout.

With a front-engined car, you can safely put some of the engine forward of the front axle. Doing so means more space in the passenger cabin, but hanging the weight out front makes the car nose-heavy. In an average front-wheel-drive family car, this isn't necessarily a bad thing, and might even be desirable, as it means good traction and a tendency towards boring, predictable understeer.

Sling the weight out back, like a Porsche 911, and you get the opposite problem: the car naturally tends to want to swap ends in corners. Some drivers find this fun, right up until it kills them. If a 911 is a safe car today, it's because Porsche has spent decades pigheadedly perfecting a layout everybody else abandoned long ago for its tendency to send you backwards through hedges.

I like this reply very much except that I wonder why people say that sports cars are uncomfortable. I find all the ones I've driven, including two mid-engined ones, super comfortable. Maybe it's just me. (In any case, your point that they're not space-efficient stands.)

Super comfortable mid engine ... Cayman? If you give up the rear seats it does help quite a bit, but does limit your market.

In my case, an MG and a Toyota, both from around 2000.

BMW does not use Front Mid mounting on anything current that I’m aware of, and I don’t think they’ve ever used a rear mounted transaxle (except the M1).

Alfa 75’s are along the lines of what you said, but not any of the Germans.

It's more than just that. The skateboard design for dedicated EV platforms makes for a better-protected passenger cell. Whereas before you had to dedicate all this steel into keeping the car rigid while mounting this heavy 250kg engine all the way up front, usually in front of the wheels (and plus all the attendant powertrain stuff), now instead a lot of that steel is dedicated to maintaining the integrity of the passenger cell, concomitant to maintaining integrity of the battery skateboard.

As for why few companies put the ICE engine in the back, whereas front-engine layouts tend towards understeer, rear-engine layouts tend toward oversteer, which is a safety and usability issue for the 99th percentile of drivers (and that's after you put in the engineering to make it work). Porsche spent a lot of effort making rear-engine safe. The design also results in less room for storage.

Expense. Much of engine design is getting rid of heat, which is much harder in the wind shadow of the car. It also makes it harder to have a good weight balance, and you end up adding significant engineering to keep the rear heavy car from having undesirable handling characteristics ... which is something the Porsche 911 has been battling for decades.

I did some crash testing in a previous life and it's absolutely crazy to see this play out in high speed (slow-mo) videography. The camera angle from directly below a vehicle pointed upwards in a frontal collision is biblical--RWD driveshafts turn into giant spears! Engine blocks into kinetic missiles, blazing a trail of mechanical destruction after they shear the mounts. Suspension parts zooming across the screen as springs unload their tension. Steel acting like wet cardboard. Nuts and bolts and other flotsam levitating chaotically like flocks of birds. Surreal stuff.

This sounds both terrifying and remarkable. Are there any videos you can share?

Unfortunately not, it was long ago and the footage would not be my intellectual property anyway. I had a search on YouTube for equivalent footage and didn't see that angle represented.

I’d just like to say that “I did some crash testing in a previous life” makes it sound like maybe you were on the receiving end of it. :D

And I wondered whether he had a brain dump on an external hard disk before he died.

Sadly I have no access to such future technology. Like other posters on this board I believe I am trapped on this linear timeline.

Both kids were in car seats which held in place.

Teslas generally score among the safest vehicles. Lack of internal combustion engine in the front obviously helps a lot. Other than that I don't think they are doing anything completely differently than other cars. It's the small things that add up: fatter pillars, and small design choices like that overall seem to help.

In the near future when they begin to use gigacastings that could theoretically further increase their safety.

Maybe this will help the plummeting stock to skyrocket tomorrow.

The stock is still worth nearly 10x what it was in mid 2019.

Then it has a ways further still to plunge.

I wouldn't get your hopes up.

I don't have skin in the game one way or the other. Elon Musk's nature has been sufficiently exposed and reputation is already ruined.

I wanted to be a fan but I can't get excited for unharnessed narcissism and power seeking.

This one's crispy, Jim.

This is important context that needs to be provided more often. Lots of people talking about the “crash” when so many of the examples still are just in the range of the pre-COVID levels, which I don’t recall many people thinking was a bargain time to be buying the market!

They do seem impressively built. One broke the car crushing machine used for safety tests. Seems to be a combination of roller skate design (batteries in the floor) that helps prevent roll overs (one of the leading causes of serious injuries), being overbuilt, being a from scratch design (not a retrofit like some EVs), and generally designed well. In particular the A pillars are pretty massive.

One fairly unique feature I'm aware of is the glass roof. Apparently under load the glass absorbs substantial energy before shattering, and after shattering is pretty strong and will absorb additional energy as it's deformed. This (when combined with the skateboard design) keeps cabin intrusion from side impacts exceptionally low.

Another is progress for stamping 1/3rd of the car allowing a single piece of steel to replace what would normally be a dozen or more welded pieces of steel. The new model Y has a front piece, a rear piece, and the battery for the entire chassis. Seats are bolted onto the battery module and it's greatly reduced the part count, manufacturing time, alignment issues, and increased the strength/weight ratio.

Check out "Munro Live" on youtube for more info.

It appears to have happened at this fork in the road [1], just past the traffic light. The left fork continues down the highway, and the other (straight) fork basically goes off a cliff. Technically it's a bus stop, but it seems like it could be hard to tell as you're approaching.

[1] https://www.google.com/maps/@37.5707862,-122.5159555,3a,74.4...

Looks like a fairly steep slope down to a beach there.

I mean, it's called Devil's Slide for a reason. I can't tell if it's exactly the same canyon in Portrait In Black, http://reelsf.com/reelsf/portrait-in-black-drama-on-the-paci... although in that case, the car is pushed, not driven over the edge.

Video from fire/rescue on scene: https://twitter.com/CALFIRECZU/status/1610075687981023233

Local news: https://www.cbsnews.com/news/tesla-california-cliff-2-kids-2...

Reports suggest that the vehicle tumbled down the steep cliff rather than free-falling. Occupants are very lucky that the incident was witnessed, reported, and responded to quickly, and that rescuers used binoculars to observe movement in the wrecked vehicle and quickly shift from recovery mode to rescue mode.

For whatever reason the driver believed the trail to the bunker was a road and were going too fast.

> “As I’m driving by, I’m like, ‘Wow, he's driving extremely fast to take that exit. You're not even supposed to be going up that way,” she said. "And I can see in my rear-view mirror this car that just go over the edge and straight down."

https://www.nbcbayarea.com/news/local/peninsula/tesla-plunge...

They’re incredibly lucky.

The question is if it a) was an honest mistake (maybe in combination with reckless driving) or b) purposeful self-harm.

Sounds like it was deliberate: https://www.nytimes.com/2023/01/03/business/devils-slide-cli...

You can absolutely drive up there when no one is there to stop you, though I think park rangers will stop you otherwise. You'll get some nice photographs of your car if you do.

Last time I was there, though, the road had eroded quite a bit and had crevasses big enough to get a wheel stuck in there.

Several articles are calling this location "Devil's Slide"

This is incorrect, it is more accurately called "Devil's Bunker"

The car landed in this pile of stones here: https://goo.gl/maps/Y3w6KFeFDQaixs6c6

Devils slide is the historical spot for bad things happening, both cars going over the side and washouts. The old Devils slide is no more. A tunnel was built.

I love to roll my windows down and from a standing start run through the gears in my old little car with the big motor roaring.

Continue the drive from Frisco and stop Duarte’s in Pescadero for some grub. Or just pull off and walk on the beach. Ain’t noth’n better then a drive down 1.

Remember that the original roll-over crush test the Tesla broke the machine intended to crush the car. These things are like tanks.

It would be interesting to learn whether Autopilot was engaged. Looking at pictures of the scene, there is a short utility road that begins further back but which ends about 100 feet from where it splits from the main road.

Relatively straightforward for most human drivers to figure out it's not a through road (there are two sets of gates, though the first one might have been open), but very difficult for software to figure that out....especially one that has so many problems detecting stationary objects in front of the car, due to the lack of range-detecting sensors. However, it's also possible that the car (or human driver) noticed the dividing wall too late and made the wrong decision about how to avoid a collision.

ABC7 reported that CHP don't think AP / FSD was on.

Yeah, that report came after my comment and the edit deadline.

Sounds like it was deliberate: https://www.nytimes.com/2023/01/03/business/devils-slide-cli...

Based on the video footage, I think the car landed here: https://goo.gl/maps/UWGTDgMuytiS37Zr8

Teslas have shit quality assurance but the Department of Transporation consistently scores Teslas as some of the safest cars on the road. Glad they are earning that score.

Teslas has very high, better than almost all other cars, crash test scores for three main reasons:

1. They have a very low centre of gravity, due to the battery, less likely to roll.

2. They are heavy (again due to battery), the heavier car in a two car collision always comes off better.

3. There is no engine in the front, so larger crumple zones and no risk of finding an engine rammed into your legs.

All these properties are the same for all BEVs, Tesla "moat" of higher than standard crash scores is shrinking as other manufacturers launch BEVs.

The first two are the same for all BEVs the third not really look at how much crap EV manufacturers put under the bonnet. Heck the EQS SUV doesn’t only not come with a frunk but the bonnet can’t be opened by the end user they even had to make a special port to fill the wind washer fluid.

That said Tesla has remarkable scores for frontal collision, side collision not so much and they don’t do that great with pedestrian safety scores either.

Glad they survived, wow. Seems like some safety benefit from Tesla engineering perhaps? But also

> It veered off the roadway

So...?

Those cliffs are no joke, I drive on them at least 3-4 times a year and the vibe, especially in some spots in particular, is never not a dicey one.

And some of the beaches are just as bad...

(Nothing like watching your own family members run toward the water & past the signs on Portuguese Beach while you pause to give all the warnings a cursory read)

Hoping for a speedy recovery for the family in the article.

It's surprising the batteries didn't catch fire, this seems very lucky indeed.

I recall back when they added titanium shielding in front of the Model S battery in response to multiple fires caused by hitting road debris. The hazards in dropping off a tall, craggy cliff at speed seems pretty out of scope for those defenses.

Ironically a slight bump in the aluminum body causes immediate massively expensive damage. I guess the body has some magic protection in it if it can handle being thrown off a cliff.

I was most worried about damage to the battery injuring the passengers. It seems they aren't as fragile as I expected.

For a minute my Reddit persona/brain read this as Tesla Stock plummeted off a cliff, as if it were facetious. Not as if it was a real event.

Tesla stock plunges 250 dollars, all four shareholders survive.

This is exactly how I read it at first, I figured maybe a 3% drop to use a word such as "plummet" or "plunge." Or, a 25% drop. Either of those, or any drop in value whatsoever, is fair game for any suitably catastrophic falling word.

Told someone today to put their backseat belt on while I was driving

Seems weird authorities were like oh that cliff yeah we get those all the time

Huh?

my grandmother tells a story that my late grandfather rolled his car down devil's slide in the 60s. He landed up right on the beach. She's known to extend the truth, so who's to say if it actually happened.

Incredible that anyone, let alone all the occupants, survived that. Wow.

I think the big news here is that the batteries didn't catch fire.

Wow. Using a free fall calculator to put it into perspective.

Height: 250ft (76metres)

Speed at impact: 87mph (140kmph)

Time of fall: 4 seconds

I can't imagine the dread during those 4 seconds of free fall.

They wouldn't be in free-fall though.

They rolled down a steep slope to the beach.

Looking at the state of the car, I don't think it was freefall but more like a tumbling, which is definitely going to be more survivable than a head-on at 87mph.

When I read "Tesla plunges" I thought this was about the stock.

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