Re: Impact safety (was Re: Fuel cells)
Sun, 6 Jun 1999 13:31:28 EDT

In a message dated 99-06-06 01:27:18 EDT, (James Rogers) wrote:

> While safe in a structural sense, I am not so sure such a vehicle would be

> very safe for a human passenger. When two vehicles collide, the difference
> in relative momentum has an enormous impact on the injury suffered. While
> a lightweight vehicle may offer similar structural impact resistance to a
> steel framed vehicle, the protective value to a human is considerably
> different.
> As purely anecdotal evidence, I have been hit many times while in a variety
> of different vehicles. In one case I was hit by a Honda Accord while
> driving a '79 Toyota Corolla (a dinky tin death trap). Needless to say,
> the impact was quite bone-jarring and it shoved the car pretty hard, but I
> walked away the worse for wear. I have also been slammed by a similar
> Honda Accord while stationary in a Ford Bronco. It totalled the Honda and
> I was mildly annoyed when the Bronco shuddered under the impact, but
> otherwise barely noticed I'd been hit. I've been hit a number of times by
> a lot of other vehicles (and once or twice, I did the hitting), but I chose
> these two because the circumstances were very similar but in wildly
> different vehicles. I can say with great certainty that structural mass
> makes a big difference where vehicle-vehicle collisions are concerned. For
> this reason alone, I drive heavy, steel-framed vehicles. Considering the
> relatively high odds of dying due to traffic fatalities, I view big, heavy
> vehicles as an insurance policy. (On the other hand, I am increasing the
> odds that the other person involved in a collision with me will be mortally
> injured.)

As a notorious sports car fanatic, I had to grit my teeth at this. Of course the physics of your post is unassailable, but I find my little fiberglass hotrod increasingly threatened by massive steel SUV behemoths. I sense an arms race of mass going on around me on the freeway. Building light, high-performance (in many senses of the term) cars is more challenging than just welding on more steel, but there are certainly ways to make very light cars very safe: As just a couple of examples, crush zones and air bags are huge advances over the death traps of my youth. (I sat in a beautifully restored 1962 Thunderbird recently and felt threatened by the dashboard while the car was sitting still!)

Thinking up new, higher-tech auto safety systems is a drive-time hobby of mine. I've imagined compressed-gas (or even explosive) reactive crush zones, automatic fire-fighting systems and a whole panoply of intelligent driver-augmentation IT systems, from collision avoidance laser radar warning systems to intelligent emergency management "assistants" that take over more or less control of the car in fast-breaking situations. Of course, as fast as I think of these things, I read about them as just-over-the-horizon developments in actual automobile engineering practice. I'll certainly defend anyone's right to buy and drive an SUV, but they ARE the lowest tech vehicles on the road -- and at a time that can only be characterized as a golden age of automotive engineering and design . . .

     Greg Burch     <>----<>
     Attorney  :::  Vice President, Extropy Institute  :::  Wilderness Guide   -or-
                         "Civilization is protest against nature; 
                  progress requires us to take control of evolution."
                                      -- Thomas Huxley