Re: Armour Piercing 201 (Advanced Ceramics)

From: "Katie Lauren Lucas" <katie@fysh.org>

> Quoting Alan and Carmel Brain <aebrain@webone.com.au>:
> > but that's another matter. Your "ceramic fragments and steel
absorbs"
> > bit
> > might well
> > be important, I dunno, I didn't study those domains, just the worst
> > cases.
>
> It's more for the pure penetrator cases - as soon as you start playing
with any
> of the more advanced rounds, things do get complicated...
>
> {In the realm we were looking at armour types for, we're looking to
defend
> against sharp, high-impact objects - axes, notably. Splash isn't so
much
of a
> problem as complete penetration. The other advantage to ceramics is
that
the
> surfaces are easier to curve in multiple directions to help deflect
cutting
> tools and pincers. Which don't tend to be an issue with proper
armoured
> vehicles... oh, and ceramics don't melt. But then neither do many
metals
at the
> temperatures the flame-throwers are limited to...}

Your "cermaic fragments and steel absorbs" reminds me of the "Plastic
Armour"
of the dark days in 1940.

From: http://www.angelfire.com/art/enchanter/concrete.html

Ed Sackett writes:-
An interesting type of armor was developed to replace concrete. It was
code-named Plastic Armour (see? I'm not afraid to use a British
spelling)
and consisted of several inches of asphalt poured hot into forms built
around the vulnerable deck structures. It was backed with 3/16" mild
steel -
hardly what you'd call armor plate. The ingenuity lay in what was mixed
into
the asphalt: clean, sharp, ¾" granite gravel, about 1 part to 2 parts
of
asphalt. Once the mixture had set the forms were taken away, and this
very
unlikely stuff proved quite effective at stopping machine gun bullets
and
even 20 mm shells.

It worked because the gravel tilted on impact, pivoting inside the
asphalt
matrix and inducing keyholing by the bullet, which spent its kinetic
energy
going sideways instead of straight in. The mild steel backing flexed
inward,
spreading the shock over a wide area and thus preventing penetration.
When
we recall that some German aircraft MGs fired ammo the equivalent of
proof
loads, that's an impressive level of protection. 20 mm shells were
similarly
defeated. Strafing attacks suddenly became less lethal, and Plastic
Armour
was in great demand by bridge and deck crews.

http://webhome.idirect.com/~jproc/radiostor/000818b.jpg shows plastic
armour
around the gun positions of the Liberty Ship SS John Brown.

Funnily enough, although it would stop high velocity rounds, you could
put a
nail through it.
"Shute passed through this world deflating egos and mocking the high
seriousness of men at war, but he all the while smiled benignly and
played
small practical jokes such as tacking a card to a colleague's new
plastic
armor, proclaiming it "THE ONLY ARMOUR PLATE WHICH WILL TAKE A THUMB
TACK."!
from http://www.nevilshute.org/SmithBio/chap5.html