Batteries and Hydrogen - Page 4

 

snip: "Discusses the photos that
show vertical demarcations where the fire is on one side of a vertical
support member and not the other.  The theory is that *if* it were
spreading
by flame propagation along the skin material, there wouldn't be such a
'fire
barrier'."

OTOH, if it was the doped fabric burning, the places where it was
stretched taut over an aluminum structural member could become quench
zones, where the propagation of the flame front is stopped or delayed
because the cold (and thermally conductive) aluminum sucks away so
much heat that the fire is quenched.

I saw a television program regarding this theory on the Discovery
Channel a couple of years ago, and it seemed fairly convincing. They
placed a fragment of Hindenburg envelope fabric in a spark gap, and it
ignited almost instantly and burned with a brilliant white flame,
shedding a few sparks, as well.

It was the outer skin which was doped; not the gas bags. The dope was
made of nitrocellulose binder, which was common enough in those days,
but the pigment contained both powdered aluminum and iron oxide. Those
two mixed together form a product known as Thermite, which can be used
for welding iron or steel, and as a filler for incendiary bombs.

The thermite reaction is simply the reduction of iron oxide by
aluminum, with the evolution of enough heat that the reduced iron is
in the molten state. Burning skin fabric on the Hindenburg would shed
a great many sparks, composed of tiny droplets of white-hot molten
iron. Needless to say, once these sparks penetrate the gas bags, the
hydrogen burns as well.

It's still true we may never know whether the hydrogen ignited first,
and then the skin, or if the reverse was true. According to the TV
show mentioned above, the Graf Zeppelin, practically a sister ship to
the Hindenburg, used a different formulation for the dope on its skin,
and it, of course never burned.

Food for thought, anyway.

 

You are wrong about the Hindenburg: Hidrogen was not the guilty. The
Hindenburg was constructed with highly combustible materials; an electrical
spark made them to explode.

"Addison Bain collected actual samples from the Hindenburg--the cloth bags
that contained the hydrogen--which were saved as souvenirs by the crowd
awaiting the Hindenburg at Lakehurst, New Jersey on May 6, 1937. When these
samples were analyzed by modern techniques, Bain discovered that the bags
had been coated with cellulose nitrate or cellulose acetate--both flammable
materials. Furthermore, the cellulose material was impregnated with aluminum
flakes to reflect sunlight, and aluminum powder is used in rocket fuel.
Essentially the outside of the Hindenburg was coated with rocket fuel!
Addison now believes that the Hindenburg probably caught fire from an
electrical discharge igniting the cellulose-coated gas bags. Remember, the
ship docked at Lakehurst with electrical storms in the area, which was
against regulations. "

Go to the bellow link to read more:
http://www.ch2bc.org/hindenburg.htm