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Elon Musk reportedly pushed for the investigation

The National Highway Traffic Safety Administration (NHTSA) announced that it will open a formal investigation into the recent fires associated with Tesla Motors' electric Model S. 

According to a new report from The Detroit News, NHTSA will officially investigate the Model S after three fires occurred -- two in the U.S., and one in Mexico -- in under a two-month time period. 

“The National Highway Traffic Safety Administration is deeply committed to safeguarding the driving public. The agency has opened a formal investigation to determine if a safety defect exists in certain Tesla Model S vehicles. The agency’s investigation was prompted by recent incidents in Washington State and Tennessee that resulted in battery fires due to undercarriage strikes with roadway debris,” said NHTSA.

NHTSA originally said it wouldn't open a formal investigation after the first fire occurred in Washington in early October. The second fire incident, which happened in Mexico, was out of NHTSA's jurisdiction. But after the third fire in Tennessee just a little over a week ago, NHTSA reviewed the situation and has decided to open a formal investigation. 

In fact, Tesla CEO Elon Musk pushed for the NHTSA investigation. 

"We have requested that the National Highway Traffic Safety Administration conduct a full investigation as soon as possible into the fire incidents," said Musk. "While we think it is highly unlikely, if something is discovered that would result in a material improvement in occupant fire safety, we will immediately apply that change to new cars and offer it as a free retrofit to all existing cars. Given that the incidence of fires in the Model S is far lower than combustion cars and that there have been no resulting injuries, this did not at first seem like a good use of NHTSA’s time compared to the hundreds of gasoline fire deaths per year that warrant their attention."

"However, there is a larger issue at stake: if a false perception about the safety of electric cars is allowed to linger, it will delay the advent of sustainable transport and increase the risk of global climate change, with potentially disastrous consequences worldwide. That cannot be allowed to happen."


NHTSA usually requires up to six months before deciding whether to upgrade a preliminary evaluation to an engineering analysis. If that occurs, it can formally ask an automaker to repair the vehicles.
 
Special focus is being placed on the fact that the Model S' battery is located close to the ground beneath the passenger cabin, making the battery an easy target when striking debris or hitting pavement. 
 
Tesla said all three fires were caused by crashes, not spontaneous events.

Source: The Detroit News



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Crashes?
By exeedorbit on 11/19/2013 11:50:50 AM , Rating: 2
I think their definition of the word "crash" differs slightly from mine. Striking debris on the road is not a crash.




RE: Crashes?
By grooves21 on 11/19/2013 12:06:00 PM , Rating: 2
How does "Striking _____" not meet the definition of crash?

The Mexico incident was a serious crash... the other two "road debris" incidents were both large metal objects that flung up and pierced a 1/4" metal plate. That is a pretty serious impact.


RE: Crashes?
By mm2587 on 11/19/2013 12:11:28 PM , Rating: 4
Which lets point out is far thicker then the floor boards on most vehicles meaning said "debris" would have ended up inside the passenger compartment of most vehicles. That's a serious incident.


RE: Crashes?
By Reclaimer77 on 11/19/2013 3:55:15 PM , Rating: 3
quote:
Which lets point out is far thicker then the floor boards on most vehicles meaning said "debris" would have ended up inside the passenger compartment of most vehicles. That's a serious incident.


That's ridiculous. When have you EVER heard of someone running over something and having it end up in the passenger compartment? It simply does not happen.

You act like nothing is between our feet and the road but a thin floorboard. Hello? Have you ever looked under your vehicle?

http://www.miata.net/garage/6mt_fluid/UnderCarBW.j...

Oh yeah, I can totally see something you run over piercing through all of this sh*t and ending up IN your car. Wtf, are you serious?


RE: Crashes?
By half_duplex on 11/19/2013 4:14:23 PM , Rating: 4
LOL

And 1/4" steel pierced? Did they run over an IED?


RE: Crashes?
By Reclaimer77 on 11/19/2013 4:18:08 PM , Rating: 2
They are proceeding from a false premise that 1/4 steel was pierced. Which yeah, maybe an IED or something would get through it lol.

But I've just discovered Tesla actually used aluminum! I don't know why they're all saying "steel plate" as if it's a fact.

I know I'll get down-rated and called a "hater". But I think this is a VERY important distinction they need to be corrected on. Aluminum doesn't even come close to offering the protection steel would.


RE: Crashes?
By JasonMick (blog) on 11/20/2013 1:36:01 PM , Rating: 2
This is just bizarre... I read this whole thread yesterday and wait till you hear what happened.

Today I was driving to my daytime office location and someone was coming up in the lane next to me, probably doing like a good 20 or so over, and the blow past me in the left lane (I was in the middle lane). Well anyhow, they hit a piece of road trash right as they pass.... a metal pipe or something similar (you could hardly see it)... it flies AT ME and hits my driver's side window and the mirror.

The mirror was the really lucky part as the plastic absorbed most of the blow and after both the mirror and window exploded it bounces off, leaving me relatively unharmed and doing no damage to the door panel. The impact was enough to pop the overlay off the mirror... scary stuff.

I'm really lucky that I survived without a scratch, and that it only damaged the mirror and window glass as the door would have been crazy expensive to replace. As is about a $500 repair and I'm still breathing. Poor '06 Accord!

http://imgur.com/puC7twO

And at least my car didn't catch fire! ;)


RE: Crashes?
By harshbarj on 11/19/2013 4:23:05 PM , Rating: 5
It happens all the time. About once a month a story like this is covered in my city.

here is an example out of Canada.
http://www.thestar.com/news/gta/2012/09/14/unknown...

And a photo from I don't know where...
http://i.imgur.com/GGMVyAj.jpg


RE: Crashes?
By Reclaimer77 on 11/19/13, Rating: 0
RE: Crashes?
By harshbarj on 11/19/2013 4:29:50 PM , Rating: 5
"When have you EVER heard of someone running over something and having it end up in the passenger compartment? It simply does not happen."

Case closed. You don't know what you are talking about. You said something, which means anything. Can't change your story now. That's called moving the goalposts.


RE: Crashes?
By Reclaimer77 on 11/19/13, Rating: 0
RE: Crashes?
By harshbarj on 11/19/2013 4:52:58 PM , Rating: 5
Just pointing out that you are wrong, and you don't like that. Next time do a bit more research before posting.

As for your claim " A steel plate would most likely not been punctured by a trailer hitch", Prove it.


RE: Crashes?
By Reclaimer77 on 11/19/13, Rating: 0
RE: Crashes?
By harshbarj on 11/19/2013 5:22:04 PM , Rating: 5
It's not my job to falsify your claims but yours to back them up.

You are also cherry picking things as only one of the three fires was caused by a trailer hitch. Your average road debris is not going to be a trailer hitch, but stuff like rods and posts. Stuff that has been demonstrated to puncture your average automobile.


RE: Crashes?
By Reclaimer77 on 11/19/13, Rating: 0
RE: Crashes?
By ritualm on 11/19/2013 5:46:25 PM , Rating: 3
quote:
I have better things to do.

Says the guy who keeps making inane replies just because he thinks someone is wrong on the internet .


RE: Crashes?
By Reclaimer77 on 11/19/13, Rating: -1
RE: Crashes?
By maugrimtr on 11/22/2013 5:55:03 AM , Rating: 2
quote:
Well actually no, you've been the dissenter here. It's on you, I have better things to do.


The sky is purple with pink polka dots and yellow stripes. It's true because I said so and no dissenters have offered evidence against my claim. So there! I have better things to do then look out a window and educate myself.


RE: Crashes?
By CU on 11/20/2013 8:54:22 AM , Rating: 2
While not a trailer hitch how about a piece of a drive shaft. That is not exactly rebar, AKA an arrow.

http://articles.sun-sentinel.com/1994-06-11/news/9...


RE: Crashes?
By Cheesew1z69 on 11/19/2013 7:31:48 PM , Rating: 2
quote:
You don't know what you are talking about.
Neither do you...


RE: Crashes?
By Roffles on 11/19/2013 10:09:25 PM , Rating: 2
All that aside, I live in the silicon valley and see many Model S' running around. I've seen it on three separate occasions... there is something wrong with the adjustable air suspensions. One day, on the freeway, I saw a Model S cruising with a family in it (looked like a family of 4). The car was so close to touching the ground that it appeared as if any harsh dip or speed bump would have bottomed out the car AT SPEED. I'm talking less than a few inches of ground clearance. According to the Tesla documentation, the ground clearance should never be less than ~5.25". The adjustable air suspension had obviously failed. This could be related to the issue of the car catching road debris.

As an automotive enthusiast, I find it somewhat embittering that people take a defensive stance with this generation 1 beta car like it can't have have any problems. It is absolutely common for first generation cars in general, regardless of manufacturer, to have problems. Doing a little research, I see this car has all sorts of reliability issues; more than any other modern car I've ever researched.

The honeymoon will be over when the warranty expires.


RE: Crashes?
By Roffles on 11/19/2013 10:11:23 PM , Rating: 2
oh, so I found this link... apparently I know what i'm talking about:

http://gigaom.com/2013/11/19/in-the-wake-of-fires-...


RE: Crashes?
By callmesissi on 11/19/2013 5:44:11 PM , Rating: 3
Yes it is true, it happened to me many years ago, i was driving my 95 dodge neon and suddenly i hear a terrible noise of something under the car and ! the steel 1/4" got inside the car and ALMOST pierced my daughter's head. just a couple inches away from her.

it's scary and almost unbelivable but IT DOES happen, and you just cant see those steel objects while driving at highway speed.


RE: Crashes?
By Just Tom on 11/19/2013 7:15:37 PM , Rating: 2
Do you own a Miata?


RE: Crashes?
By Close04 on 11/20/2013 3:56:54 AM , Rating: 2
A Tesla will have something extra there. A huge battery pack. That would count as quite a difference from a normal (petrol) car.


RE: Crashes?
By CU on 11/20/2013 8:40:53 AM , Rating: 2
Things can cause damage and puncture the floorboard of gasoline cars also. So yes he is serious.

Two cases mentioned in this article. In the first case road debris punctured the transmission pan causing them to wait for AAA. In the second case metal punctured the floorboard and wounded a person in the car.
http://articles.sun-sentinel.com/1994-06-11/news/9...

Fire that may have been caused by road debris, or at least something ruptured the fuel line. This also resulted in a death and injuries.
http://hamptonroads.com/2011/07/fuel-line-caused-n...


RE: Crashes?
By Reclaimer77 on 11/19/2013 4:14:46 PM , Rating: 2
Depends on what the metal in question is. In this case Tesla opted for aluminum.

http://blog.caranddriver.com/tesla-model-s-fires-m...

So when the ~5,000 pound Model S runs over something, and a thin soft piece of aluminum is all that stands between all that force and the batteries - it's no wonder.

Aluminum is just a very poor choice for such an application. I understand the need to save weight, but come on, the car is already a pig.

Musk needs to do a recall and replace every aluminum plate with a steel one. Problem solved.


RE: Crashes?
By nafhan on 11/19/2013 5:14:23 PM , Rating: 2
quote:
Musk needs to do a recall and replace every aluminum plate with a steel one. Problem solved.
It's unlikey that Ford, BMW, Toyota, etc. would do that in this situation without seeing a conclusive outcome from the NHTSA investigation.

You seem to both hate Tesla and feel like they should be held to a higher standard. Why?


RE: Crashes?
By Reclaimer77 on 11/19/2013 5:20:07 PM , Rating: 2
I'm "hating" Tesla because I pointed out that everyone saying the plate is "steel" is wrong?

Do you have a problem because it's ME saying it, or do you actually think a thin piece of aluminum is adequate here?


RE: Crashes?
By nafhan on 11/19/2013 5:49:07 PM , Rating: 2
quote:
I'm "hating" Tesla because I pointed out that everyone saying the plate is "steel" is wrong?
No. Look at the comment history. You were ranting about how Tesla better do a recall (among many other things, only some of which were about the material choices).

Anyway, since it sounds like you've very knowledgeable in the fields of metallurgy and mechanical engineering, what thickness of aluminum is thick enough? What thickness of steel is thick enough? I'd like to know. Thanks.


RE: Crashes?
By Reclaimer77 on 11/19/2013 6:33:37 PM , Rating: 2
Well in general terms without going nuts with the math (ductility, fracture strengths, contact area vs force), a 1/4 steel plate would provide three to four times more impact protection than the aluminum plate they went with. However I cannot find any details on what specific alloy they used. For cost reasons though I can't imagine it being all that exotic.

But basically a 3/4 inch aluminum plate would equal around the same protection as that 1/4 steel piece. But it would weight the same anyway as well as being thicker.

Given the gigantic area they have to cover, it's more cost effective imo to just have gone with a steel plate. But at a hefty weight penalty. Don't get me wrong, I don't envy their engineers having to decide this stuff.

I knew when I started posting here I would be accused of being "anti Tesla". But I really don't feel that is my motivation at all. And yes, given the utter POUNDING Toyota took for far less of an issue (people too stupid to keep floormats from pedal) I believe Musk should be more proactive on this issue.


RE: Crashes?
By Manch on 11/20/2013 1:48:43 AM , Rating: 2
Check out SFI 6.1, 6.2 specs for bell-housing aka scatter shield, and blocking plate applications. These are designed to contain the clutch/flywheel in case of catastrophic failure to protect your legs and your engine. Speeds that far exceed what road debris can do. Check out the thickness between aluminum vs steel. Big diff!


RE: Crashes?
By nafhan on 11/20/2013 12:59:10 PM , Rating: 2
Ah... real info - not just something regurgitated from a poorly written opinion piece. That's exactly the kind of thing I was looking for, and I'm going to check it out. Thanks!


RE: Crashes?
By Manch on 11/20/2013 5:39:18 PM , Rating: 2
The main part to look for in this is. Either steel or titanium(expensive!) is used for the bell housing/scatter shield. Aluminum can only be used in conjunction with steel because it will also shatter. Here's a link to a video called death of a trans am

http://www.youtube.com/watch?v=hJtJUVyEyYY

This is what happens when you don't replace your aluminum bell housing with a steel or titanium one and your clutch/flywheel catastrophically disintegrates!

I agree that a steel plate or deflector should be on the bottom of that car. Unlike an ice vehicle which has a lot of different parts underneath that will deflect road debris, that bottom of that car is flat and solid. Even the steel floor pan is typically double walled and will give a lot more before rupturing.

Also I wonder about the ground clearance. Unlike an ice vehicle this car doesn't have any cavities underneath. So when you hit something that exceeds your ground clearance your riding all the way over it. see pic. https://www.google.com/search?q=underneath+a+tesla...
Theres no place for it to go! so it's either going into that battery pack or slicing it open.


RE: Crashes?
By Solandri on 11/20/2013 5:05:05 AM , Rating: 2
See post below. Aluminum is stronger than steel on a per-weight basis. It is pretty much the best material for transportation applications (why the important parts in a car like the engine block are made of aluminum). The only reason steel is used is because it's substantially cheaper than aluminum.

Steel is stronger than aluminum on a per-volume basis, but you don't particular care about the volume of the materials when designing a car. You do care about the weight and the cost. So if you want to go cheap, you use steel. If price is no object, you use aluminum.

Other exotic materials like titanium or magnesium alloys are stronger than aluminum on a per-weight basis. But they're prohibitively expensive, while aluminum is only moderately more expensive than steel.


RE: Crashes?
By Mint on 11/19/2013 12:16:15 PM , Rating: 2
The initial damage from hitting debris in all these incidents would send every normal car to the repair shop, and possible result in cabin intrusion.

I call that a crash, especially the incident of a drunk driver jumping a curb and having the underside smash into a concrete fence:
http://insideevs.com/wp-content/uploads/2013/10/3_...
We're not talking about any debris. We're talking about the worst case scenarios.

Nonetheless, it's pretty clear that Tesla isn't as fireproof as the Leaf and Volt, which have yet to report any fires in the real world.


RE: Crashes?
By nafhan on 11/19/2013 12:41:37 PM , Rating: 3
quote:
it's pretty clear that Tesla isn't as fireproof as the Leaf and Volt, which have yet to report any fires in the real world.
The only thing that's clear is that the Model S has had more fires. I don't think three incidents is enough to be statistically significant, but I don't have stats on how many Leafs or Volts are on the road compared to the Model S. On top of that, I'd imagine people might drive the Model S a little more aggressively than the Leaf.

It might turn out that it's more fireproof, and it might not. You and I don't have enough info to say either way. I think Musk is doing the right thing by pushing for an investigation - something I don't think he'd do if he believed the Tesla to be inherently dangerous.


RE: Crashes?
By Solandri on 11/19/2013 1:57:47 PM , Rating: 4
quote:
The only thing that's clear is that the Model S has had more fires. I don't think three incidents is enough to be statistically significant

I already did the math on this:
http://www.dailytech.com/Article.aspx?newsid=33720...

tl;dr version:
For 3 fires in 20,000 vehicles, statistically, the margin of error is bigger than the incident rate. In other words, there isn't enough data to say with confidence if Teslas are more fire-prone than Volts or Leafs, or if they were just unlucky.


RE: Crashes?
By nafhan on 11/19/2013 4:48:13 PM , Rating: 2
Very nice.

We need to roll out the jump to conclusions mat for some of the other people on here.


RE: Crashes?
By NellyFromMA on 11/19/2013 1:10:07 PM , Rating: 2
I mean, before you can make an assessment like the Volt and Leaf are superior to the Tesla models in terms of fire prevention, wouldn't you also need to take into account volume of overall fleet for the given models? I don't think the Leaf and Volt combined have as much market share as Tesla. I could be wrong about that, but Tesla has been producing EV's longer than either Nissan or Chevy IIRC, although I think the Nissan and Chevy models are cheaper upfront so anything is possible.


RE: Crashes?
By Qapa on 11/19/2013 2:20:29 PM , Rating: 2
2 points where you're wrong:
- Leaf reached market in 2010, while Tesla S in 2012
- Leaf has a lot more sales (worldwide (WW) and US)

Leaf: 83k (WW), 35k US
Tesla S: 18,2k (WW)

These values are from September 2013 (seen in Wikipedia).

That though, doesn't mean you're not right in the fire prevention part... no conclusion can be made by the numbers alone.

There are more Leafs, but 3 Tesla S fires doesn't seem to be a statistically significant value.

Also possibly Tesla S are making more KMs (catching up to Leafs KMs which started earlier and has a wider base) as they have a higher range, and what must be compared is fires per driven KMs.


RE: Crashes?
By Souka on 11/19/2013 5:33:01 PM , Rating: 2
or maybe the leaf fires aren't making the news?


RE: Crashes?
By Reclaimer77 on 11/19/13, Rating: 0
RE: Crashes?
By grooves21 on 11/19/2013 12:18:18 PM , Rating: 2
How does "Striking _____" not meet the definition of crash?

The Mexico incident was a serious crash... the other two "road debris" incidents were both large metal objects that flung up and pierced a 1/4" metal plate. That is a pretty serious impact.


RE: Crashes?
By nafhan on 11/19/2013 12:25:58 PM , Rating: 2
The "piece of debris" was a solid steel trailer hitch capable of slicing through a quarter inch of steel. Whether or not you feel that this qualifies as a crash, that would do serious damage to just about any vehicle on the road.


RE: Crashes?
By tdktank59 on 11/19/2013 12:45:25 PM , Rating: 2
The fact that it went through a 1/4 in on those battery packs thats a pretty good impact.

Think of the floor in the car figuring the thickness of most cars floor boards these days is ~20 gauge (searched google for a bit, the older the car is the more likely it has thicker metal) thats 0.0359 in vrs the 0.25" for the battery on the tesla.

Pretty sure there is not much more you can do besides build a force field around it so that nothing can enter into its "personal space" bubble.


RE: Crashes?
By Reclaimer77 on 11/19/2013 4:10:19 PM , Rating: 2
Something smelled funny about that, so I looked it up myself.

I don't know who started this, or why you guys are parroting it, but the Model S does not use a "steel" plate. It uses aluminum! A soft and wimpy material to choose for any kind of impact protector.

If steel was used, the fires probably wouldn't have happened in the first place.

http://blog.caranddriver.com/tesla-model-s-fires-m...


RE: Crashes?
By nafhan on 11/19/2013 4:45:22 PM , Rating: 2
Thanks for the correction, I had read previously that it was a steel plate.

Still:
--1/4 inch of aluminum is nothing to sneeze at.
--3 fires (that did not injure anyone) warrant investigation, but that's it. Statistically, this doesn't mean much of anything.


RE: Crashes?
By Reclaimer77 on 11/19/2013 5:00:53 PM , Rating: 2
quote:
--1/4 inch of aluminum is nothing to sneeze at.


For this application it is. Aluminum has roughly a third the stiffness, or modulus, of steel.

quote:
--3 fires (that did not injure anyone) warrant investigation, but that's it.


It's not that there were fires. It's that the fires were all caused by the same circumstances that is raising eyebrows.

It's clear a recall is in order. A metal plate designed to protect the battery is being consistently pierced in the same manner, and leading to battery fires. Aluminum simply does not provide significant protection for this application.

It seems really obvious to me.


RE: Crashes?
By harshbarj on 11/19/2013 5:14:27 PM , Rating: 2
"It's clear a recall is in order. A metal plate designed to protect the battery is being consistently pierced in the same manner"
And yet floorboards are punctured nearly daily on standard cars and we don't see a recall. Also consistently? Really? we are talking about 3 fires over what, a year and a half? You really want to make something out of a none event. Thus far no one has been hurt.

How about a recall on this vehicle as someone was actually hurt.
http://www.theage.com.au/victoria/driver-impaled-a...

Seems you have an axe to grind against Tesla.


RE: Crashes?
By Reclaimer77 on 11/19/2013 5:25:36 PM , Rating: 2
Well offhand, the article doesn't say which vehicle she was driving. It could have been 10 years old or something, we don't know.

quote:
You really want to make something out of a none event.


The NHTSA is investigating "non events". Brilliant logic....

And who the hell are you anyway? You come in here with 14 posts, you're too stupid to even quote posts right, and you think you can walk up to ME, Reclaimer , and talk!? Sit your ass down!! When I care what you think I'll ask you to talk.


RE: Crashes?
By ritualm on 11/19/2013 5:37:45 PM , Rating: 2
Arguing on the internet is like competing in the special Olympics.

Even if you win, you are still retarded.

If I hadn't posted, I'd be amongst the users actively downranking your posts on this article. You are about as intelligent as Pirks, and that's pretty bad.


RE: Crashes?
By Spuke on 11/19/2013 6:40:06 PM , Rating: 2
quote:
You are about as intelligent as Pirks, and that's pretty bad.
Pirks is an idiot, albeit a really funny one. Rec at least backs up what he says with facts it's just that a LOT of you don't like to hear it because it doesn't coincide with your political/ideological leanings. I have my own favorite ideologies/philosophies but none trump facts. A lot of you act like you can't be wrong regardless of facts and will support BS simply because it matches your belief system. Beliefs don't always coincide with reality.


RE: Crashes?
By Cheesew1z69 on 11/19/2013 7:38:18 PM , Rating: 2
quote:
albeit a really funny one
No, he's not, he is a childish, foul mouth, down right rude and ignorant human being. Hardly funny.


RE: Crashes?
By nafhan on 11/19/2013 6:04:37 PM , Rating: 2
I like you follow the sarcastic statement "brilliant logic" by claiming that quantity of posts is what's important.


RE: Crashes?
By Cheesew1z69 on 11/19/2013 5:27:04 PM , Rating: 2
quote:
And yet floorboards are punctured nearly daily on standard cars and we don't see a recall.
What? LOL


RE: Crashes?
By Reclaimer77 on 11/19/2013 5:32:12 PM , Rating: 2
lol yeah. He's found like three incidents out of like a billion cars on the road, and it's an everyday thing....

But three out of a few thousand Tesla's burn up, in the same EXACT manner, and there's nothing to see here move along.


RE: Crashes?
By nafhan on 11/19/2013 5:54:54 PM , Rating: 3
quote:
It seems really obvious to me.
I hope you don't find this surprising, but that's not enough for me.


RE: Crashes?
By Solandri on 11/20/2013 4:57:08 AM , Rating: 2
Some serious misconceptions here.

quote:
For this application it is. Aluminum has roughly a third the stiffness, or modulus, of steel.

Modulus is just a measure of how much a given volume of material deflects under load. It doesn't tell you anything about the material's strength, just its flexibility.

For a more classical definition of strength, you should be looking at a material's yield strength or ultimate strength. For strength against penetration, you're more interested in the toughness.

The other important factor is that these material properties are measured on a volume or cross-sectional area basis. It's a handy baseline reference, but it isn't the only reference basis out there (and frequently isn't the one that's most important). Two other common references are on the basis of weight, and on the basis of cost cost. Steel is a popular building material because it's very strong on a per-volume and per-dollar basis.

Aluminum is stronger than steel on a per-weight basis. That's why we use it in airplanes. A 1/4 inch aluminum plate will resist puncture better than a steel plate of equal weight. Yes a 1/4 inch steel plate would've been stronger. It also would've weighed almost 3x as more. So the correct comparison is a 1/4 inch aluminum plate to a 1/12 inch steel plate. Or a 1/4 inch steel plate to a 3/4 inch aluminum plate.

In this case, aluminum was the correct material choice. You don't particularly care how thick the plate is (as long as it doesn't get ridiculous like several inches thick). But you do care how much it weighs. Tesla wanted the strongest plate they could put on the car for a given amount of weight. And for the same weight of material, aluminum is about twice as strong as steel.


RE: Crashes?
By Reclaimer77 on 11/20/2013 12:18:25 PM , Rating: 2
There are no misconceptions. Others claimed 1/4" steel, thereby I've constrained myself to that thickness.

I already stated that 3/4 inch aluminum eqivelency in my last post.

Weight savings are important, but not at the sacrifice of battery protection.

I think we're arguing two sides of the same coin. I'm just prioritising impact resist over weight savings.

Typed from phone, forgive any shorthand.


RE: Crashes?
By Reclaimer77 on 11/20/2013 12:18:26 PM , Rating: 2
There are no misconceptions. Others claimed 1/4" steel, thereby I've constrained myself to that thickness.

I already stated that 3/4 inch aluminum eqivelency in my last post.

Weight savings are important, but not at the sacrifice of battery protection.

I think we're arguing two sides of the same coin. I'm just prioritising impact resist over weight savings.

Typed from phone, forgive any shorthand.


RE: Crashes?
By Reclaimer77 on 11/20/2013 12:18:34 PM , Rating: 2
There are no misconceptions. Others claimed 1/4" steel, thereby I've constrained myself to that thickness.

I already stated that 3/4 inch aluminum eqivelency in my last post.

Weight savings are important, but not at the sacrifice of battery protection.

I think we're arguing two sides of the same coin. I'm just prioritising impact resist over weight savings.

Typed from phone, forgive any shorthand.


RE: Crashes?
By Keeir on 11/20/2013 8:10:34 PM , Rating: 2
No...

Many types of steel (more expensive than your standard construction steel true) have tensile strengths that are equal to or better than Aircraft grade aluminums on a per wieght basis.

However, when loaded to the type of tensile loads required to maintain a wieght advantage are significantly more prone to rapid fracture failure. On top of that many types of structure is made to resist non-tensile loading where geometry concerns lesson a materials nominal advantage in strength

The "real" issue here appears to be two fold.

#1. Most aluminum alloys are not "hard" in comparison to steel. Puncture/cut/abrasion resistance is low in comparison to steels.

#2. Out of plane stiffeness issues. I will assume this plate is fairly unsupport by the frame/etc over long lengths. Therefore deflection of the plate is also a concern.

To replace a (.25") thick peice of say 6-series aluminum with a stainless steel peice, would require ~.17" thick plate. This would result in nearly doubling the wieght, and if it was just the peice likely in question would be a wieght penalty of between 100-300 lbs when all said and done. And if the fires were deflection based, rather than puncture based, then it would not even solve the issue. Now, the news media has reported "puncture", so I will assume puncture.

A simple solution would be a titanium bolt-on panel. (I wouldn't be recommending stainless/steel due to issues with aluminum corrosion and the wet/chemical enviroment expected, but there has been success with certain type of passivated and coated steels) The panel could be as thin as .050" and provide the initial hardness that would significantly reduce puncture damage. Probably wieght around 30 lbs with attachment and could be "easily" retrofitted.


RE: Crashes?
By Keeir on 11/20/2013 8:17:15 PM , Rating: 2
In fact, if you examine aircraft, most aircraft have a similiar concept near the door entries. A thin peice of steel/titanium is bent around aluminum. The aluminum carriess the structural loading while the titanium/steel provides impact protection.

http://www.exoticmetals.com/products/aircraftstruc...


RE: Crashes?
By Monkey's Uncle on 11/19/2013 3:11:08 PM , Rating: 2
If you wanna be a grammar nazi about it and pick nits, another car on the road can be considered 'debris'. I would consider colliding with anything large enough to damage my car "crashing" into it.


Battery type
By coburn_c on 11/19/2013 5:13:27 PM , Rating: 2
The real issue is the Lithium batteries.

Nickel batteries, such as are used in most EVs, don't generally burn when shorted. Lithium ion batteries do. There are various formulations that are less likely to combust, but they aren't produced cheaply and in quantity.




RE: Battery type
By ritualm on 11/19/2013 5:34:22 PM , Rating: 2
The bigger issue is we don't have anything better than Li-ion to run cars with right now. Until someone can commercialize a cheaper option with higher energy density and other performance metrics than that, we'll keep hearing about these fires.


RE: Battery type
By Reclaimer77 on 11/19/2013 5:37:40 PM , Rating: 2
I don't agree with the OP. The batteries are fine. Tesla engineers simply didn't provide adequate impact protection for them. Which is kind of disappointing in itself, given the low ride height and clearance of the vehicle. Did they not think this would happen?

If a steel plate were used, as apposed to aluminum, we wouldn't be talking about this today.


RE: Battery type
By ritualm on 11/19/2013 5:44:36 PM , Rating: 2
What makes you think a 1/4"-thick steel plate will protect against a broken tow hitch flying into it at high speeds?


RE: Battery type
By Reclaimer77 on 11/19/2013 5:47:25 PM , Rating: 1
I know it protects better than aluminum. Why don't you?


RE: Battery type
By Solandri on 11/20/2013 5:15:17 AM , Rating: 2
A steel plate would've offered less protection, because the constraining property here is weight, not thickness. You don't really care how thick the plate is. You do care how much it weighs.

For the same weight of material, aluminum is about twice as strong as steel.


RE: Battery type
By Keeir on 11/20/2013 8:48:05 PM , Rating: 2
Better is not the same thing as sufficient.

Without a full evaluation of the damage, it is difficult to determine if 1/4" of steel would have prevented shorting/fire in any of the noted issues.


Underarmor?
By bildan on 11/19/2013 12:42:59 PM , Rating: 1
While the model S is a very nice car and I'd love to own one, the fires may have uncovered an issue that could be addressed. Even if it's not dangerous to drivers, having your car burn up after hitting road junk up is damned inconvenient.

Fortunately, it may not be that difficult to add a thin layer of lightweight armor to the underside of the car. It wouldn't completely protect the car, (armor is never perfect) but it might reduce the number of incidents. It could even be an aftermarket item for those who drive on dangerous roads.

On a different track, there are laws about dropping junk on highways. The fines and enforcement needs to be stepped up. We've all seen trucks with stuff falling off of them driving on freeways.




RE: Underarmor?
By daboom06 on 11/19/2013 1:01:46 PM , Rating: 1
thin layer of armor you say? how about a quarter inch of steel?

the retrofitting musk tesla will implement will be a (generalized) kill switch in the battery housing to prevent overheating due to a short caused by battery damage.

i had always assumed that in designing things that idiots are allowed to operate, every part of those things should be able to be specifically targeted by idiocy... such as direct impacts with a trailer hitch going 80 mph... without self-destructing.

cant blame the engineers. they started this project from the ground. there're not 100 years of testing for all the major components of the car. there's no way to know all the different ways stupidity will manifest itself.


RE: Underarmor?
By Rukkian on 11/19/2013 1:10:26 PM , Rating: 2
On top of that, it is approximately 8 times thicker than your standard floorboard. Since nobody actually got hurt in these issues, I think it would make you want one even more. If that same trailer hitch had hit a standard sports car, it would have gone right through the floor board (and possibly the driver).

While it is inconvenient to have the car catch fire, if you think of the alternative, it is a pretty good outcome imo. The insurance rate for the car may go up, but at this point, I see no reason this would stop somebody from buying it.

I would love one if I could afford it, but it is just not for people in my tax bracket.


RE: Underarmor?
By Reclaimer77 on 11/19/2013 4:22:28 PM , Rating: 2
quote:
how about a quarter inch of steel?


How about wrong? It's ALUMINUM!

http://blog.caranddriver.com/tesla-model-s-fires-m...

quote:
cant blame the engineers.


Well yes we can. They had to choose between weight savings and battery protection, so they made an ill-advised compromise. If a steel plate was used, we wouldn't be having this conversation.


RE: Underarmor?
By bildan on 11/19/2013 6:40:58 PM , Rating: 2
Well, there may be better options than heavy steel armor. Aluminum isn't all that great as armor either.

I was thinking of some of the super-polymers used by the military for body armor such as UHMWPE or Kevlar.


NHSTA should investigate.
By jmarchel on 11/19/2013 1:14:10 PM , Rating: 2
Weather it was serious crash or not is up to experts to investigate. Not every crash should cause fire in the vehicle. Clearly very few new gasoline vehicles burn in encounters with road trash. Gasoline vehicles typically burn in crashes where large part of the vehicle structure is severely deformed or when they are old clunkers poorly maintained. I wonder how many Volts for example had the same problem. I haven't heard a single Volt catching fire because of hitting road junk.




RE: NHSTA should investigate.
By docinct on 11/19/2013 2:05:02 PM , Rating: 2
Fires in Chevy Volt cars go back to early 2011; those were from crashes (caused by other cars or test gear) however.
In January 2012 , the NHTSA stated “NHTSA does not believe that Chevy Volts or other electric vehicles pose a greater risk of fire than gasoline-powered vehicles.”
I'm not sure how much more shielding Tesla can provide above and beyond the 1/4in steel. Since the fires seem to be front end, maybe relocating the batteries??


RE: NHSTA should investigate.
By tdktank59 on 11/19/2013 2:21:02 PM , Rating: 4
Well gasoline vehicles don't have a battery pack the size of the chassis. Rather it has a fuel tank typically near the rear of the car.

There are a few tubes that hold the gasoline that travel along the under carriage of the car and go to the engine.

Plus most times the fuel tank is not the bottom of the chassis, instead it is tucked up under the rear seats and not as exposed as a full under carriage of battery.


By danjw1 on 11/19/2013 3:53:32 PM , Rating: 2
I haven't seen anyone mention that the owner of the third car drove it after the car told informed him he shouldn't and that is when the fire started. Maybe it shouldn't have left the option up to him. Maybe the software should have disabled the car once it determined it wasn't safe to drive. But, the driver is at least somewhat at fault here.




High trees catch all the wind
By G-H PrB on 11/19/2013 6:06:41 PM , Rating: 1
Musk is always quick to reply and defends himself feverishly. His bold claims are seen as arrogance by some, who would take every chance to hit back at him.
So he should be careful about bending the truth about who initiated the NHTSA investigation and he should be careful about using skewed statistics. It might bite back at him.

http://left-lane.com/tesla-fires-numbers-dont-lie/




tesla fires
By tfg on 11/20/13, Rating: 0
FIND NEW JOBS.....
By emilinedbp157 on 11/20/13, Rating: 0
"A lot of people pay zero for the cellphone ... That's what it's worth." -- Apple Chief Operating Officer Timothy Cook

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