Date:         Sat, 11 Nov 2000 20:29:43 +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: Fire, and Halon extinguishers
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>In a matter of fact I think I will install a automatic Halon system in
>the back of my Van.

I was on a fire-safety course late last year, and I believe halon is now
unavailable in the Western world. What's wrong with carbon dioxide, other
than its being a bit heavy and sinking to the ground like halon? It doesn't
make a mess, as it's just a clean gas. We were told that the dry powder
extinguishers are best, but these really DO make a mess! All that "baking
soda" (sodium bicarbonate?) gets into everything. But hey, if it stops the
bus burning...The foam extinguishers were pretty good, but can't remember
what the foaming agent was.

And NO type of extinguisher will be effective in an engine fire where the
fuel is still being introduces to a hot spot or spark. As soon as the
extinguisher stops spraying the continued stream of fuel will reignite. You
have to stop the fuel flow first! Hoping your fuelpump wires haven't melted
and shorted, keeping the engine running or at least turning, and fuel
churning out!

Had a fire in my Fiat 850 Sport, and the starter cable and fuelline burned
through; the engine kept turning,
pouring more fuel on. I had to get into the trunk (front) and rip off the
battery cable to stop the fuel source...

Unless carrying explosives, a burning car CANNOT explode (I class a gas
cylinder such as LPG or CNG as an explosive, ans a car carrying such is
spectacular when it does go up...saw a video of a CNG-powered Holden
Commodore which caught fire, and I wouldn't have wanted to be within 30
meters of it). A gasoline tank is not sealed, and so cannot explode. Normal
cars just go "woof" and burn more rapidly. A gas cylinder is sealed and can
hold quite a lot of pressure; when it gets hot the pressure builds, and
when the pressure exceeds the cylinder's limits the walls fracture and the
tank bursts violently; the fuel vaporizes instantly and then ignites in a
fireball. Nasty stuff, which is why a CNG  tanker-truck catching fire can
wipe out a small town (happened in Spain or Portugal quite a few uears
back).

Andrew Grebneff
Dunedin, New Zealand
VW & mollusc nut
1984 Caravelle (currently SVX engine waiting for a trans)
1985 Mitsubishi Galant Sigma 2.0 (FWD)
1986 CE80 Toyota Corolla 1.8DX diesel
1989 CE96 Toyota Corolla 1.8DX diesel van/wagon
1989 CT170 Toyota Corona Select 2.0 diesel