Ignition!
=========

An informal history of Liquid Rocket Propellants

by John D. Clark, Rutgers University Press Classics, 1972


Book is very heavy on the chemistry and science, but Clark does a good job of
painting a picture and injecting humor.


Card Gap Test p69, p156
-----------------------

p69:

> The card-gap test is used to determine the shock sensitivity of a
> potentially explosiv liquid. A 50-gram block of tetryl (high explosive) is
> detonated benath a 40 CC sample of the liquid in question, contained in a 3"
> length of 1" iron pipe sealed at the bottom with a thin sheet of Teflon. If
> the liquid detonates, it punches a hole in the target plate, of 3/8" boiler
> plate, sitting on top of it. The sensitivity of the liquid is measured by
> the number of "cards," discs of 0.01" thick dellulose acetate, which must be
> stacked between the tetryl and the sample to keep the latter from going off.
> Zero cards means relatively insensitive, a hundred cards means that you'd
> better forget the whole business. As may be imagined, the test is somewhat
> noisy, and best done some distance from human habitation, or, at least, from
> humans who can make their complaints stick.

p156:

> Two people can operate the card-gap apparatus, and three operators is
> optimum. But when LRPL did this particular job (the feather bedding at
> Picatinny was outrageous) there were about seven people on the site -- two
> or three engineers, and any number of rocket mechanics dressed (for no
> particular reason) in acid-proof safety garments. So there was a large
> audience for the subsequent events. The old destroyer gun turret which
> housed our card-gap setup had become a bit frayed and tattered from the
> shrapnel it had contained. (The plating on a destroyer is usually thick
> enough to keep out the water and the smaller fish.) So we had installed an
> inner layer of armor plate, standing off about an inchan and a half from the
> original plating. And, as the setup hadn't been used for several months, a
> large colony of bats -- yes, bats, little Dracula types -- had moved into
> the gap to spend the winter. And when the first shot went off, they all came
> boiling out with their sonar gear fouled up, shaking their heads and
> pounding their ears. They chose one rocket mechanic -- as it happens, a
> remarkably goosy character anyway -- and decided that it was his fault. And
> if you, gentle reader, have never seen a nervous rocket mechanic, complete
> with monkey suit, being buzzed by nine thousand demented bats and trying to
> beat them off with a shovel, there is something missing from your
> experience.

LRPL is the Liquid Rocket Propulsion Laboratory if Picatinny Arsenal. Formerly
NARTS, Naval Air Rocket Test Station, Dover New Jersey.


"Catastrophic self-disassembly" p113
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A phrase Clark attributes to "the British" to describe a damaging explosion
inside of a rocket engine.


Rocket on Rotor p120
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Research was done on performance improvements for helicopters through the
application of small jet engines on the tip of each rotor blade. The ROR or
Rocket-on-Rotor used peroxide monopropellant motors with about 50 pounds of
thrust to jump start the blades.

> The idea was to improve the performance of the chopper, particularly when it
> had to lift off in a hurry. (The means when somebody is shooting at you.)
> The work on this went on from 1952 to 1957, and was a spectacular success.
> I've seen and ROR helicopter operating, and when the pilot cut in his
> rockets the beast shot up into the air like a goosed archangel. The project
> was dropped, for some reason, which seems a shame. An ROR chopper would have
> been awfully helpful in Vietnam, where somebody usually _ is _ shooting at
> you.


Liquid Bullet Propellants p124
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Liquid propellants, even low-energy monopropellant, have far more energy per
gram than gun powder. Liquids are far more closely packed than grains of
solids. It has been experimented with several times but never commercialized.
"The main problems are more in the engineering than in the chemistry."


Spark Sensitivity p154
----------------------

Discussing NF compounds:

> Thermodynamically, it tends to react. And given the slightest provocation it
> will do just that. And the formation of four molecules of HF produces enough
> energy to make the resulting explosion really interesting. The things were
> shock sensitive. Many were heat sensitive. And some were so spark sensitive
> that they couldn't be poured. When you tried it, the tiny static charge
> formed was frequently enough to trigger detonation.