<VV> Seats (now safety)

airvair airvair@richnet.net
Tue, 24 Aug 2004 15:55:56 -0400

My, what a firestorm I created.....

And all I wanted to do is to caution him (and anyone else) that the
floor needs to be properly reinforced in order to keep the seat from
coming lose in an accident. A crash puts an incredible pull on the seat
belts, many times your body weight. Should it not be well-braced and you
hit something headon, the weight of your upper body, pulling on the top
of the seatback in a lever fashion, may just pull the mounts lose. This
will result in not only your upper body weight slamming into the
steering wheel (and maybe windshield) but you will be closely followed
by the weight of the seat as well. This is simple physics (force = mass
x acceleration). The result of this "Oreo cookie effect" would be a
compounding of injuries, and an even greater chance of a fatality.

True, one can engineeer a proper bracing, but even the best of
engineering is often tested just to make sure it performs as expected.
That is what my job was, to prove (or sometimes disprove) the worth of
the engineers' calculations. Without valid proof, engineering is an
educated guess. It's why auto companies still perform crash tests, just
to be sure.


RoboMan91324@aol.com wrote:
> Bill,
> With some modifications, I agree with you.  The seats with the integral
> shoulder straps are a good example.  The tested method of securing the seat belts
> is with the lap belts anchored in the floor and the shoulder belts anchored in
> the top for those cars equipped that way.  The seats with the shoulder straps
> in them transfer the forces created during a crash through the seat to the
> seat's bolts in the floor.  It is a large lever arm.  Is it safer?  Who knows?
> However, certain modifications do not need to be tested to be fairly certain
> that they are safety improvements.  Replacing a single master cylinder with a
> dual cylinder is a good example.  JMHO
> Doc
> ~~~~~~~~~~~~~~~~
> >
> > Oh, I am not offended by people making changes to their Corvairs, but I do
> > get bothered when people try to claim modern day safety standards and
> > practices to the changes.  Today's cars go through rigorous design and testing phases
> > to arrive at their ability to offer protection.  Adding components of modern
> > safety equipment to old cars does not have the same methodology, and the
> > results cannot be assumed to be the same. Remember, once you start modifying a
> > car you are moving away from the researched and tested design, and the end
> > product may or may not be safer than the original.  Unless you are able to put
> > your car through the same testing procedures (doubtful), at best you can only
> > guess as to the safety "benefit" of the changes.
> >
> > That is all I was trying to say.
> >
> > Bill Hubbell