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Tesla's Inherent Safety Saves Five Joyriding Teenagers In Germany (arstechnica.com)
According to German newspaper Merkur, one 18-year old and four of her friends lost control of her father's Model S electric vehicle. The car reportedly flew more than 80 feet into a field before it came to a stop. Even though the driver and two of the passengers were airlifted to hospitals, none of their injuries were life-threatening, thanks largely in part to Tesla's skateboard chassis. Ars Technica writes, "The skateboard chassis used by the Model S and Model X is extremely safe, with crumple zones that are unconcerned with engines that can transfer kinetic energy into the passengers during a frontal collision." The images of the crash are not pretty, but one could imagine how much worse they would be if a front-engined internal combustion vehicle were involved instead of the Tesla Model S.
I recall an anecdote from a few years ago. Apparently, the Model S uses a variety of weld for its frame/roll cage that was previously only used in spacecraft. When the NHTSA went to do its rollover safety tests by crushing in the roof of the Model S to simulate how it would hold up in a roll, their crushing machine broke before the Tesla did. The NHTSA had to get a more powerful machine before they could successfully measure how much the Model S could take. Results like those were why the Model S got the highest safety scores of all time (a perfect score across the board).
The German news site has a slideshow showing the car from a variety of angles. We've likely all seen the woeful pictures of luxury cars after rolls. Quite often the roofs are buckled, the passenger compartment is barely visible, and while you can see how someone's body might contort in the space so they could survive, it looks like it would still have to be a miracle. In contrast, this car was so intact that they were able to just open the door. The roof looks like it only has a few scratches. Meanwhile, the entire front is just gone, and the back is smashed to bits.
Say what you will, but I have NEVER seen pictures after a rollover crash like this with the passenger compartment so remarkably intact.
Never in a month of sundays did that car roll.
It rolled, but never touched the ground. It looks like it went off the road, dug in, and flipped endo (end over end), and bounced off the trunk, and landed on the bottom (or landed on the tail or nose and settled upright). It never touched ground on the sides or top, but did "roll". You are thinking the wrong axis.
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It is news for nerd, at least me as a nerd, interested into security things like crumple zone , doing finite element analyzis etc... And if Tesla is using a different method with better effect then yeah that's highly interesting.
I think the problem is the way the information is delivered. TFA sounds more like a marketing guff than an informed analysis.
This being a news for nerds site, should have it's summaries tailored to this audience, not junk click bait from TMZ.
Given that most of the glass is still intact, I'm leaning towards this being either a low velocity impact, or a med/high velocity crash spread over a long distance and time (which also means low impact forces). Which means the fact that the front end shattered like that is really troubling. Perhaps the additional mass of the battery pack (the Tesla weighs as much as an SUV because of the battery pack) contributed to demolishing the front end despite the low impact forces? In an ICE vehicle, the bulk of the mass (engine) is in the front and it absorbs impact forces directly instead of through the structural beams. In a Tesla, the bulk of the mass is in the battery pack underneath the passenger compartment. Since the passenger compartment is designed to remain intact, the kinetic energy of the battery pack has to be fully absorbed by the structural beans in the front or rear.
I would assume Tesla strengthened the beams by a corresponding amount to pass the crash safety tests. But those tests only cover direct front impacts, not a car leaving the ground and impacting the ground at (say) a slight nose-down pitch. The cantilever forces in such an impact due to the additional torque caused by the heavy battery pack behind it could account for the front shattering and shearing off like that.
The Tesla has a much better crumple zone in front because it doesn't have a huge heavy engine block in there. Just look at the pictures, the front end is essentially gone yet the passenger compartment is intact. I would say that's a pretty important advantage, and it may have been just the difference required to save their lives. If it had been a Mercedes, where would the engine have gone? Even if it didn't go into the cabin, it sure would have left much less room for crumpling to absorb the impact.
The passenger compartment is also extremely strong, they actually broke the testing equipment when they tried to crush the roof, for example. They overengineered the hell out of that car. Tesla is pretty new in the car business: when they designed the Model S they hadn't figured out yet that you have to compromise on safety if you want to compete in the market. They just made it as strong as they could. Fortunately the car is compelling enough that rich people don't mind spending the extra money. The Model 3 will probably be pretty safe, but I doubt it's going to break any testing equipment. For $35000 something will have to give.
Also, the car didn't catch fire. I know real cars don't automatically burst into flames while airborne like they do in the movies, but in this kind of crash some kind of fire would have been pretty likely. Here's one from not long ago, a crash between a Tesla and an ICE vehicle, the ICE caught fire while the Tesla didn't. Yes, I know, some Teslas have caught fire as well in other accidents but it was always after at least 10 minutes or so, giving people plenty of time to get out first. With an ICE, as soon as a fuel like breaks, you have to run away fast.
Being that there are so few Tesla cars out there, and they are really expensive, I doubt you will see too many real world car wrecks of Teslas. People were always a bit curious about the safety of electric cars, electrical fires, getting electrocuted... Now granted many of these concerns are less of an issue compared to riding a car powered by explosions. However because it is new, people worry about the safeguards in place. And how would such a car fare in real world accidents. Especially lately companies have been cheating the system to change their results from the test to real world.
The point of the story actually was the tesla design allowed for much more crumple zone than standard cars to improve passenger safety.
If something is so important that you feel the need to post it on the internet... It probably isn't that important.
Would a concrete wall (at around 100mph) followed by a tree count? With the fronts wheels completely sheared off? Driver walked away. There was a fire (after the driver exited), but the body blocked it from the passenger compartment.
Quote below from the link (photos at link):
http://insideevs.com/tesla-rev...
We believe these changes will also help prevent a fire resulting from an extremely high speed impact that tears the wheels off the car, like the other Model S impact fire, which occurred last year in Mexico. This happened after the vehicle impacted a roundabout at 110 mph, shearing off 15 feet of concrete curbwall and tearing off the left front wheel, then smashing through an eight foot tall buttressed concrete wall on the other side of the road and tearing off the right front wheel, before crashing into a tree. The driver stepped out and walked away with no permanent injuries and a fire, again limited to the front section of the vehicle, started several minutes later. The underbody shields will help prevent a fire even in such a scenario.
I realize it's a fan site link for EVs, but it has the coverage as I remember it.
And I'm not a fan boy, I respect Elon Musk and his RESULTS. He's pretty good in the results category, and in the dream categories.
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That's not the impression I get after googling something like "Mercedes crash images" (just to pick a random luxury car brand). In head on collisions the mangled engine always seems to remain in front of the cabin. I can't find a single picture with an engine underneath the cabin.
I do remember Mercedes being very proud of that feature in their old A-class models. Those were indeed engineered that way. But for most other cars, the engine just stays in front.
The actual article is behind a pay wall, but the Daily Mail summary unambiguously says:
- That was finding of a study looking at particles from tyre and brake wear
- Made heavier by batteries and parts meaning tyres and brakes wear faster
The Daily Mail article itself continues with multiple references to brake wear. Not once does it mention regenerative braking.
Now I do admit that I should know better than to assume that a Daily Mail article about a paper would be in any way related to the actual contents of the paper, and it's entirely possible that the actual paper, behind the paywall, says exactly the opposite. Maybe it will even say that EVs are cleaner after all.
You can quite clearly see what happened by looking at the pictures presented by the Bavarian newspaper.
http://www.merkur.de/bilder/2016/05/04/6373067/1613361945-unfall-icking-sportwagen-gaulke-PXHG.jpg - You see the curve there in the background? The one behind the black and the white BMWs?
The driver went around that corner in her father's car, lost control and slid off the road into the grass. Probably either distracted, bad driver or just too faster for physics...
Normally not a problem, you probably fucked up the under-carriage a bit and the front bumpers, but nothing a few days in the shop couldn't fix. But the girl got unlucky. Right after the corner is a small stub road leading into the field for the farm equipment. The black and white BMWs will help with lining up the viewing angles of the pictures.
The car hit the stub road and the effect must have been similar to driving up a ramp for an Evel Knievel styled jump: http://www.merkur.de/bilder/20...
The car rolled length-wise and must have hit the ground twice before coming to rest on the trashed wheels again. You can see the impact points in the field nicely on http://www.merkur.de/bilder/20... and http://www.merkur.de/bilder/20....
That allows you to reconstruct the flight path: Lift-off at the stub road, front hits the ground first, momentum carries the car forward and leads to the first roll as the front is still embedded in the field. Car is hitting with the trunk next, still rolling with ample forward momentum which means the car will not be burried in the field but land on the wheels next. And that's where the car came to rest.
You can look at the bumper and other plastic parts strewn all over the place, they match up nicely with that order.
If you now look at the car at rest http://www.merkur.de/bilder/20... and http://www.merkur.de/bilder/20... you'll see how the glass is not completely shattered? This means little impact force onto the passenger cell and most of the impact just hit the front. Not even a direct frontal impact but mostly torsion forces hitting the bottom of the car front from the impact into the field.
Based on all that evidence I'd say the 5 kids in the car were supremely lucky that they hit an empty field in a decent car. The airbags came in very handy, no doubt.
But I think it is a bit premature to claim this shows anything like inherent safety of Tesla or even just that electric cars are safer than over conventional vehicles... That's purely the marketing department talking...