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Isn't it pretty standard for a vehicle to catch on fire when significantly damaged? I've personally witnessed a few that were the result of wrecks, and just th

by Zikes 13y ago

Isn't it pretty standard for a vehicle to catch on fire when significantly damaged? I've personally witnessed a few that were the result of wrecks, and just the other weekend I drove by a couple guys trying to put out a flaming engine on a beat up old truck. How exactly do these compare to gasoline/diesel powered vehicles?

hemancuso 13y ago
Running over a tow hitch seems to be a pretty low standard for significantly damaged.
- Zikes 13y ago
  But is it completely improbable that a gasoline-powered car could suffer from the same result? It just feels like somebody's looking for an excuse to go after Tesla. I read these articles about people leaping over concrete barriers and wrapping their car around a tree and just wonder "what the hell did you expect would happen?"
  - ars 13y ago
    > But is it completely improbable that a gasoline-powered car could suffer from the same result? Yes, quite improbable. It might break the engine, but there is nothing in the front of a car that would catch fire from such an impact.
  - jusben1369 13y ago
    Good Lord no. This isn't about going after Tesla. Just think of it in terms of %. 3 fires in 5 weeks. If they Toyota Camry had the same ratio that might be something like 3000 fires in 5 weeks. I'm a big Tesla fan and hope they succeed but this is starting to look like a real issue.
    - astrodust 13y ago
      > According to the U.S. Fire Administration, there are around 194,000 vehicle fires on U.S. roads each year. So 194,000 vehicle fires per year, or 18,602 within any given five week period. Toyota's market share is 14.2%, so if the fires are evenly distributed, there would've been 2,641 vehicles of that brand catching fire. That's pretty close to 3,000.
      - tedunangst 13y ago
        2461 new toyotas catching fire?
        astrodust 13y ago
        I'm not sure the data on vehicle age is available like that.
      - jusben1369 13y ago
        "There are 300 million cars in the USA in 2012" so your 194,000 is a % of 300 million.
  - Kylekramer 13y ago
    Well, you are changing the subject of conversation. This is the second time that a fairly minor accident (nothing like the Mexican crash) resulted in a fire because of the placement of the battery. If the Tesla were gas powered, it is almost completely improbable that either of the two American fires would have happened as they don't have large amounts of flammable material under the front of the car where road debris can cause damage. Tesla isn't the victim of a smear campaign, this is fairly minor news that gets amplified in the HN/tech bubble.
    - Zikes 13y ago
      I wouldn't say it's a change of subject, but I can see your point.
- stcredzero 13y ago
  I had the entire oil pan emptied out in a Volvo 850 because of an unfortunate rendezvous with a piece of rebar -- at low speed in a parking garage. The oil pan on that particular Volvo 850 was also aluminum, and from what I remember around the same thickness. The key is that in both cases, the entire mass and momentum of the vehicle were contributing to the intrusion of a piece of steel into an aluminum vessel. No engineering in the world is going to stop that steel from penetrating in that case. A different material and/or different placement will be needed to improve the situation.
Shivetya 13y ago
* I posted this comment on the same story elsewhere. Face it, battery technology is not sufficiently advanced to deliver good range without some serious trade offs. The trade off of the Tesla may prove to be the wrong choice long term. No one would ever suggest lining the bottom of a car with a gasoline tank, fortunately we don't have too because the power density is so high. Hence they can put tanks where a collision or road debris damage are least likely to damage them. However Tesla needs a stupendous amount of battery to get its range. Hence we get large cars where they have chosen to isolate the entire pack at the floor of the car. They made the choice to dispense with a central tunnel which could hold more batteries, not use the front engine area or any trunk space. There were two or more reasons for their design choice, first because of the sheer amount of batteries needed and second because of pack swapping. I don't think the trade off is worth it. They can use some of the front "frunk" area to have a raised stack of batteries where the traditional firewall is and do similar in the rear. The could have a raised tunnel down the center line and reduce the need of having batteries so far forward. There were many choices available but they wanted swappable packs. What statistic I want to see is, how many penetration events have their been versus how many fires. How many cells have to be penetrated to create a fire? Is there some flaw that another component is failing during these minor accidents that is causing the fires?
- stcredzero 13y ago
  As a short term fix, raise the car 1/4", reinforce the front battery section with kevlar, and include a system that can flood at least one of the packs with some kind of fire retardant foam. As a longer term fix, move the battery pack rearward and design in a little more protection.
  - moocowduckquack 13y ago
    Just do the foam thing, but do lots of it all round the battery so in the event of a battery fire the battery pops out and is enclosed and the car ends up sitting on a couple of feet or so of foam.
- umsm 13y ago
  I don't think placement could solve the points you mention. Sure, debris can damage the underside and cause the car to catch fire, but putting the packs in the front or rear of the car can cause it to explode on impact as well. Having it on the underside will probably cause fewer fires than having it in the front for example. That said, consider gasoline cars: The fuel needs to travel from the tank to the engine. Effectively, an impact anywhere on the fuel line can cause a fire.
ars 13y ago
The main reason gasoline engines catch fire is they overheat - i.e. not due to an accident, but rather poor maintenance. So when you read statistics on car fires you should try to exclude those if you can. Fire from road debris would be very very unlikely. How would that even happen? I suppose it could cut a water pipe, and then cause overheating. Fires from a violent crash do happen of course, and no one would criticize Tesla for those types, but from road debris? That shouldn't happen.
- ceejayoz 13y ago
  > So when you read statistics on car fires you should try to exclude those if you can. How on earth would that make a better comparison?!
  - tedunangst 13y ago
    All of the Teslas sold so far are presumably well maintained, so doesn't it make sense to compare them to well maintained gas vehicles?
  - ars 13y ago
    Are we analyzing the owner of the car (maintenance) or the car (effects of minor road incidents)?
- stcredzero 13y ago
  The main reason gasoline engines catch fire is they overheat - i.e. not due to an accident, but rather poor maintenance. So when you read statistics on car fires you should try to exclude those if you can. Then to be fair, one should also take into account the increased reliability of the electric drivetrain.
stcredzero 13y ago
http://en.wikipedia.org/wiki/Fuel_tank#Placement_and_safety http://en.wikipedia.org/wiki/Fuel_tank#Placement_and_safety There have been a lot of problems with fuel tank placement, with some designs being responsible for spraying passengers with flammable fuel, which subsequently catches fire. The design criteria for internal combustion cars seems to be to place the energy storage such that it minimizes the chance of damage, and to take steps to ensure that the contents do not endanger the passengers. Gas tanks are not designed to withstand highway speed collisions with pointed steel objects and never burn. To apply such standards to electic cars is a double standard. By the general standards of passenger cars, I'd say that the Tesla model S is a bit fragile, but still quite safe.
- 001sky 13y ago
  I'd say that the Tesla model S is a bit fragile, but still quite safe What's fragile about 6mm armour plate? And what's safe about 100% of the fires having a single source? It sounds like TSLA needs to put the battery somewhere more protected. They have it exposed right now (presumably for lower CoG and better handling). That might just be a design flaw. I think we can still keep an open mind on LiIon untill the designs are iterated upon more.
  - stcredzero 13y ago
    What's fragile about 6mm armour plate? Urgh. Nice context switch. To be fair, the system as a whole seems to be a bit fragile, which is what I was actually saying. But in this specific strawman context: Lots of things are "fragile" when a piece of steel has a significant fraction of the momentum of a car behind it. To me, still very dependable and robust for something with sportscar performance.

by Zikes 13y ago

hemancuso 13y ago

Running over a tow hitch seems to be a pretty low standard for significantly damaged.

Zikes 13y ago
But is it completely improbable that a gasoline-powered car could suffer from the same result? It just feels like somebody's looking for an excuse to go after Tesla. I read these articles about people leaping over concrete barriers and wrapping their car around a tree and just wonder "what the hell did you expect would happen?"
- ars 13y ago
  > But is it completely improbable that a gasoline-powered car could suffer from the same result? Yes, quite improbable. It might break the engine, but there is nothing in the front of a car that would catch fire from such an impact.
- jusben1369 13y ago
  Good Lord no. This isn't about going after Tesla. Just think of it in terms of %. 3 fires in 5 weeks. If they Toyota Camry had the same ratio that might be something like 3000 fires in 5 weeks. I'm a big Tesla fan and hope they succeed but this is starting to look like a real issue.
  - astrodust 13y ago
    > According to the U.S. Fire Administration, there are around 194,000 vehicle fires on U.S. roads each year. So 194,000 vehicle fires per year, or 18,602 within any given five week period. Toyota's market share is 14.2%, so if the fires are evenly distributed, there would've been 2,641 vehicles of that brand catching fire. That's pretty close to 3,000.
    - tedunangst 13y ago
      2461 new toyotas catching fire?
      - astrodust 13y ago
        I'm not sure the data on vehicle age is available like that.
    - jusben1369 13y ago
      "There are 300 million cars in the USA in 2012" so your 194,000 is a % of 300 million.
- Kylekramer 13y ago
  Well, you are changing the subject of conversation. This is the second time that a fairly minor accident (nothing like the Mexican crash) resulted in a fire because of the placement of the battery. If the Tesla were gas powered, it is almost completely improbable that either of the two American fires would have happened as they don't have large amounts of flammable material under the front of the car where road debris can cause damage. Tesla isn't the victim of a smear campaign, this is fairly minor news that gets amplified in the HN/tech bubble.
  - Zikes 13y ago
    I wouldn't say it's a change of subject, but I can see your point.
stcredzero 13y ago
I had the entire oil pan emptied out in a Volvo 850 because of an unfortunate rendezvous with a piece of rebar -- at low speed in a parking garage. The oil pan on that particular Volvo 850 was also aluminum, and from what I remember around the same thickness. The key is that in both cases, the entire mass and momentum of the vehicle were contributing to the intrusion of a piece of steel into an aluminum vessel. No engineering in the world is going to stop that steel from penetrating in that case. A different material and/or different placement will be needed to improve the situation.

Shivetya 13y ago

* I posted this comment on the same story elsewhere. Face it, battery technology is not sufficiently advanced to deliver good range without some serious trade offs. The trade off of the Tesla may prove to be the wrong choice long term. No one would ever suggest lining the bottom of a car with a gasoline tank, fortunately we don't have too because the power density is so high. Hence they can put tanks where a collision or road debris damage are least likely to damage them. However Tesla needs a stupendous amount of battery to get its range. Hence we get large cars where they have chosen to isolate the entire pack at the floor of the car. They made the choice to dispense with a central tunnel which could hold more batteries, not use the front engine area or any trunk space. There were two or more reasons for their design choice, first because of the sheer amount of batteries needed and second because of pack swapping. I don't think the trade off is worth it. They can use some of the front "frunk" area to have a raised stack of batteries where the traditional firewall is and do similar in the rear. The could have a raised tunnel down the center line and reduce the need of having batteries so far forward. There were many choices available but they wanted swappable packs. What statistic I want to see is, how many penetration events have their been versus how many fires. How many cells have to be penetrated to create a fire? Is there some flaw that another component is failing during these minor accidents that is causing the fires?

stcredzero 13y ago
As a short term fix, raise the car 1/4", reinforce the front battery section with kevlar, and include a system that can flood at least one of the packs with some kind of fire retardant foam. As a longer term fix, move the battery pack rearward and design in a little more protection.
- moocowduckquack 13y ago
  Just do the foam thing, but do lots of it all round the battery so in the event of a battery fire the battery pops out and is enclosed and the car ends up sitting on a couple of feet or so of foam.
umsm 13y ago
I don't think placement could solve the points you mention. Sure, debris can damage the underside and cause the car to catch fire, but putting the packs in the front or rear of the car can cause it to explode on impact as well. Having it on the underside will probably cause fewer fires than having it in the front for example. That said, consider gasoline cars: The fuel needs to travel from the tank to the engine. Effectively, an impact anywhere on the fuel line can cause a fire.

ars 13y ago

The main reason gasoline engines catch fire is they overheat - i.e. not due to an accident, but rather poor maintenance. So when you read statistics on car fires you should try to exclude those if you can. Fire from road debris would be very very unlikely. How would that even happen? I suppose it could cut a water pipe, and then cause overheating. Fires from a violent crash do happen of course, and no one would criticize Tesla for those types, but from road debris? That shouldn't happen.

ceejayoz 13y ago
> So when you read statistics on car fires you should try to exclude those if you can. How on earth would that make a better comparison?!
- tedunangst 13y ago
  All of the Teslas sold so far are presumably well maintained, so doesn't it make sense to compare them to well maintained gas vehicles?
- ars 13y ago
  Are we analyzing the owner of the car (maintenance) or the car (effects of minor road incidents)?
stcredzero 13y ago
The main reason gasoline engines catch fire is they overheat - i.e. not due to an accident, but rather poor maintenance. So when you read statistics on car fires you should try to exclude those if you can. Then to be fair, one should also take into account the increased reliability of the electric drivetrain.

stcredzero 13y ago

http://en.wikipedia.org/wiki/Fuel_tank#Placement_and_safety http://en.wikipedia.org/wiki/Fuel_tank#Placement_and_safety There have been a lot of problems with fuel tank placement, with some designs being responsible for spraying passengers with flammable fuel, which subsequently catches fire. The design criteria for internal combustion cars seems to be to place the energy storage such that it minimizes the chance of damage, and to take steps to ensure that the contents do not endanger the passengers. Gas tanks are not designed to withstand highway speed collisions with pointed steel objects and never burn. To apply such standards to electic cars is a double standard. By the general standards of passenger cars, I'd say that the Tesla model S is a bit fragile, but still quite safe.

001sky 13y ago
I'd say that the Tesla model S is a bit fragile, but still quite safe What's fragile about 6mm armour plate? And what's safe about 100% of the fires having a single source? It sounds like TSLA needs to put the battery somewhere more protected. They have it exposed right now (presumably for lower CoG and better handling). That might just be a design flaw. I think we can still keep an open mind on LiIon untill the designs are iterated upon more.
- stcredzero 13y ago
  What's fragile about 6mm armour plate? Urgh. Nice context switch. To be fair, the system as a whole seems to be a bit fragile, which is what I was actually saying. But in this specific strawman context: Lots of things are "fragile" when a piece of steel has a significant fraction of the momentum of a car behind it. To me, still very dependable and robust for something with sportscar performance.