December 19, 2007:Â
An Israeli firm has devised a bolt-on reactive (exploding) armor panels
for trucks, that will provide protection from EFP (Explosively Formed
Projectiles). These are the precision weapons that have been coming from Iran.
An EFP is a precision weapon, not an ad-hoc assemblage of explosives (like most
roadside bombs). Your typical EFP is a cylindrical device, the optimal one
often described as similar to a coffee can. But the cylinder metal must be
thicker. You fill about 60 percent of the "coffee can" with explosives (C4,
also known as plastique, will do). Then you insert a detonator on the closed
end of the "coffee can" and a concave copper plug that is pushed into the
plastic explosive. The tricky part here is that the depth of the concave copper
part, and the thickness of the copper, have to be just right. It requires
someone expert at math and the chemistry of explosives to make those
calculations. You can make a mould for casting the copper plug, but you must
make sure you get the thickness just so, or the weapon won't work.Â
You set the device off with the detonator, either
via wire, or wireless, connection. When the C4 explodes, it forms the copper
cap into a blob of molten metal, moving faster than a speeding bullet (about
1,500 meters a second). The blob stays intact, and lethal, for a few hundred
meters, traveling pretty much in a straight line. But not straight enough to
hit something more than fifty or soÂ
dozen meters away. The Israeli protection system uses the explosion of
the reactive armor to break up the blob, making it largely ineffective against
armor.
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EFPs are difficult to aim. The user has to place it
so that, when it goes off, it will hit a vehicle sitting in a position the user
has already figured out. For this reason, EFPs are usually set up at places
where vehicles have to stop. When the EFP hits an armored vehicle, it burns and
punches its way through the armor. Once inside the vehicle, it injures or kills
whoever it hits, as well igniting combustible material and generally scaring
the hell out of everyone.
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EFPs weigh under ten pounds, are small and easily
carried and concealed. They are quick to set up. With all that, only about 600
have been used. Some appear to have been made in Iraqi workshops, in Shia parts
of the country. But most others appear to come from Iran. Naturally, these
"Iranian EFPs" don't have any distinguishing marks on them (indicating a state
arms factory, or a "Made in Iran" label). The Iranians are not stupid, they
don't want to admit supplying these weapons. But all indications are that, most
EFPs are made in Iran. And their main purpose is to kill American and British
troops, and cause more chaos in Iraq.
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