Tesla Goes Titanium To Keep Fires Away

Tesla's new unberbody shield pulverizing a concrete block.

After a series of fires last fall put Tesla in the news, CEO Elon Musk went on the defensive, pointing out that his company's cars - which scored high in crash testing and still haven't been involved in a single fatality - were getting called out for the wrong reasons. Still, understanding that perception can often turn into reality, Musk and the engineers at Tesla quietly went about seeing if they could improve the safety of the Model S even further, to cut the fire risk down. The result, which Musk announced today in a blog post on Medium consists of a new titanium shield and multiple aluminum deflectors. According to Musk, '[T]here is no safer car on the road than a Tesla. The addition of the underbody shields simply takes it a step further.'

At the time the incidents were gaining attention, I wrote:

But without attempting to re-engineer a vehicle in this space, it does seem apparent that some changes could be made beneath the vehicle. The battery shield could possibly be redesigned with multiple layers to better absorb impacts, for example... In addition, some sort of 'deflector' might be possible to shunt debris away from the undercarriage of the vehicle at freeway speeds.

Critically, I'm no structural engineer and the suggestions came from a combination of common sense and an examination of the two accidents where it appeared road debris penetrated the battery in some fashion. Apparently, Tesla's sophisticated examination came up with a more comprehensive version of the same idea. The solution is what Musk calls three 'shields' consisting first of a hollow aluminum bar designed to deflect road debris when possible. In the case of a tow hitch, which caused one of the accidents, or other 'self-stabilizing, ultra high strength object' the bar would cause the item to kick up ahead of the battery, damaging less sensitive components of the vehicle.

The second line of defense is a titanium plate designed to guard against intrusion into anything important while also protecting against road debris. And, if all that fails, Tesla has added, 'a shallow angle, solid aluminum extrusion that further absorbs impact energy, provides another layer of deflection and finally causes the Model S to ramp up and over the object if it is essentially incompressible and immovable.' It's worth mentioning that the original battery shield remains in place, which consists of 1/4 inch of ballistic aluminum plate. All these add-ons go on top of the original protective plate. Tesla says they will cut 0.1% off the range of the car and 'won't affect ride or handling,' according to Musk.

Modifications are on all Teslas built after March 6 and are free of charge for all existing owners with a normal service or anytime if an owner isn't due for one. He points out the odds of a fire in a Tesla are five times lower than in a gas-powered vehicle. It's worth noting that since the trio of fires ended in November - one of which involved a spectacular high-speed collision and should really not be considered an equivalent event - no reports of any Tesla fires have been received anywhere. These changes should reduce those odds even further.

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