Date:         Tue, 9 Apr 2002 21:07:09 +1200
Reply-To:     Andrew Grebneff <andrew.grebneff@STONEBOW.OTAGO.AC.NZ>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Andrew Grebneff <andrew.grebneff@STONEBOW.OTAGO.AC.NZ>
Subject:      Re: Vanagon crash safety/Projectzwo bull bars
In-Reply-To:  <p04330102b8d75aa79cbb@[192.168.99.102]>
Content-Type: text/plain; charset="us-ascii" ; format="flowed"

It's not about MASS. It's about RIGIDITY vs controlled crumpling
rates. An iron anvil doesn't crumple easily, so gives ZERO protection
in a head-on.

The body of a car (passenger variety; of course vans, SUVs etc are
cars, car being a contraction of carriage) is designed to ABSORB
collision speed by progressively crumpling in a controlled way,
bringing the vehicle to a more "gentle" (relative term, that!) halt.
Of course head-on accidents usually occur at a higher combined speed
than the crush zones of any vehicle can hope to cope with, so if you
have a decent head-on you're almostr certainly dead, no matter what
you drive, including Incursions.

The VW T3 has no engine and only a short body length in front of the
driver, so it must trade crushability for rigidity. The chassis and
body metal is designed to maximize rigidity and bending resistance,
with a small crush built-in. These vehicles have proven themselves
well in frontal (and rear-end) accidents; they are extremely strong,
and use the other vehicle as a crush zone. However, as with a tank
like a LandCruiser, a vehicle lacking crushzones will transfer the
full brunt of impact to its occupants, hence the danger. The vehicle
itself may survive... but the passengers may be nowhere near as
well-off. Say, strained through their seatbelts while having their
skulls shattered against the dash (despite being belted in).

>*Any* front-engine vehicle has *much* more protection -- not
>necessarily intentionally engineered -- than a Vanagon does.
>
>Look at how much mass is between your knee caps and the other vehicle
>(bridge abutment, etc.). Any other vehicle has an entire engine and
>probably transmission, which is anchored to the chassis, and 4 feet
>of double-fender and hood mass, etc.
>
>It's all about mass. Yes, the Vanagon has huge mass, but most of it's
>behind you. I'm sure that in a head-on collision our Vanagons' rear
>bumper would come out better than any other vehicle's, but I'm not so