Under-the-car "cow catchers" would need forwards positioning to handle the problem of angular objects that rotate upward when first hit, producing a pole-vault effect that punctures the armor. That flat cover in front of the battery case needs a left-right ridge that goes as low as the rear of the battery at highway speeds. Puncturing the front cover would probably capture the object and prevent the same thing from happening to the battery armor. Of course, that might damage other parts instead. If nothing under the cover needs re-positioning for safety, it would be a cheap retrofit. The row of screws that connect the cover to the front bumper might be used to mount an L-shaped bar, one alternative to a replacement cover with a molded ridge.
Protecting the battery from road debris I started a new topic on protecting the battery from road debris. This photo shows the basic idea: View attachment 35097
Is the purpose of having a bar like that to try and obliterate the solid steel debris on the road, or to make the car airborn for a few milliseconds before it crashes down on the debris again further back in the car?
Come on man, it's brainstorming. Don't diss someone just because they're thinking outside the box. I agree with you, but would have put it a bit more nicely...
or they can put that air dam that is in under the front of the Chevy Volt. Its pretty low to the ground and is likely to push aside objects such as a tow hitch.
I still don't see how fire could get from the battery that start way behind the front wheels, into the front bumper. What "material" carries it infront of front wheels? Is it cooling hoses? Electric cables? What?
Objects the are about 1 foot in length in "L" or "T" shaped (in one or more planes) can, have, and will easily defeat this type of preventive measure. Three of the objects run over were of this description.
The problem of some of the deflection based ideas is that there's not many places for the item to go except to the two sides, which may damage the wheels/suspension and cause the car to become out of control. I would rather have the car burn down after coming to a safe stop than lose control and possibly crash.
I would at least angle it like a cowcatcher. Otherwise, you're just dragging the "sample object" along the ground with great spectacle.
I think they just need to prevent the car itself from catching fire, so maybe the battery just need an exhaust that will direct the flames away from the car itself. this way the only thing that would get damaged would be a few cell modules.
I meant no offense to wcalvin - this has been suggested many many times on this thread and others in one form or another. I just happened to have picked this one to respond to, but nothing personal :redface:.
I think the best way to avoid such issues is to pay attention to your driving and slowdown not have an object go under the car like that. My commute is 200miles a day and I have never seen a hitch or axle in the road that could damage my Tesla. I'm also concerned why someone would allow the fire to completely burn the entire front of the car. I carry a fire extinguisher in the trunk of my Tesla that could be used on mine or anyone who would be on fire. Something is fishy going on with these fires. Crazy that three fires cost Tesla 50B in value. People are just wacked in the head.
To reiterate, the problem is to minimize damage from an angular object that causes the pole-vault effect. If the debris is tall enough to hit the battery, better that a ridge beneath the front bumper hit it first, as it will then lever up into the panel behind the bumper rather than into the battery casing itself. One makes the ridge the same height as the battery at high speed.
Sometimes you just can't avoid it. Like when you are driving on a 3 lane freeway. You are in the center lane. There is a car to your left, there is a car to your right. Ever happen before? Of course. So, you can not see through the cars in front of you. Some piece of debris appears immediately in front of you because the car in front of you just passed over it. What can you do? You can't stop fast enough to not hit it (not to mention you become the hazard, not just the debris), and you can't drive through the car to your right or your left. So you only choice is to slow down as much as you can before you hit it. This certainly has happened to me. Usually it is semi truck tie parts from exploded re-caps or road kill. But it could be anything, it's the risk we take every time we get on the freeway. It would be nice if our car didn't start on fire from such an event, and I from what I see on this site it usually doesn't. But that battery is a big area under the car, so it is a large target. IMHO, the battery needs to be able to take abuse. One the flip side, I think the media and the market reaction to this event totally overblown.
Tesla has access to the Mercedes parts bin. A Houston Tesla owner suggested this to Tesla already, but perhaps they could use the 2014 Magic Body Control option to auto-raise the Model S (for cars with air suspension) and/or flash deploy a Kevlar cow catcher: NEW 2014 Mercedes S-Class MAGIC BODY CONTROL - YouTube