IEEE Spectrum September, 2008 - 25

BoMB-MaKInG MaterIaLS: A tip in March 2007 led Iraqi police to a cache of IED-making parts in Anbar province. U.S. soldiers inspected
the haul [far left], which included bags of blasting caps. An Iraqi Army raid turned up other IED items [center], including wires for triggering bombs
at a distance. In February 2007 [right], U.S. soldiers found copper liners and enough other components to make 150 explosively formed penetrators,
a particularly deadly form of IED. The materials were found in a Shia village north of Baghdad.
Photos, From LeFt: eros hoagLaNd/redux; Zoriah; roBert NickeLsBerg/gettY images

there were a few shrapnel pieces that were
inside the compartment. But, for the most
part, it missed us." Even so, he was bleeding
internally so badly that he had to be flown
to Germany, where his life was saved by an
8-hour operation that put in 600 internal
stitches. It was the fifth IED attack he'd
survived, and by far the worst.
It was a classic explosively formed
penetrator attack: the target was an
armored vehicle, and the projectiles
were fired at close range, in this case
from below the vehicle.
EFPs are associated particularly with
Shia militia groups. The U.S. military has
long contended that Iran is a supplier of
the EFP's key component-a concave copper disk, called a liner, that must be properly machined to work well. This disk is
fitted to one end of a metal tube that's
slightly longer than the diameter of the
disk. The tube is packed with a plasticized
military explosive, typically one containing cyclotrimethylenetrinitramine, also
known as RDX. Its detonation releases
an extremely fast-moving shock wave,
which turns the liner into hot, explosively
formed fragments moving at one to two
kilometers per second-faster than a highvelocity rifle round. The kinetic energy of
the fragments is so high that it penetrates
most kinds of armor.
EFPs are usually triggered by a
passive infrared sensor. The triggering
system also often has a radio-control
override that lets the triggerman enable
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the system when he sees a vehicle coming
that he wants to attack. The infrared sensor then detects the heat of the passing
vehicle and detonates the device. The U.S.
military has contended that the radiocontrol systems also come from Iran.
The EFP is a textbook case of measurecountermeasure-counter-countermeasure. For a time, coalition vehicles sought
to throw off the EFP's infrared trigger
with a simple countermeasure called a
rhino, basically a hot glow plug in a metal
can affixed to the front of the vehicle by
a rod of variable length. It reduced the
effectiveness of EFPs but not decisively
so, because the attackers varied the timing of the detonation to try to counteract
the rhino.
The triggering system, generally the
only complicated part of an IED, remains
the focus of strenuous countermeasures
because it is pretty much the only component you can attack with technology.
Early on, in 2003 and 2004, most IEDs
in Iraq and Afghanistan were triggered
wirelessly, often with cellphones, longrange cordless phones, key fobs, walkietalkies, and wireless doorbells.
Relying on modified existing hardware and Navy expertise, JIEDDO's predecessor quickly fielded jamming systems.
Installed in vehicles, the jammers provide a bubble of safety around the vehicle, within which radio-frequency power
overwhelms any signal being transmitted
to an IED's wireless trigger.

The jammer program became known as
CREW, for "counter radio-controlled IED
electronic warfare." The latest jammers
designed for U.S. vehicles are code-named
Jukebox and CVRJ and are manufactured
by EDO Corp. and other companies. They
cost upwards of $80 000 apiece. All told,
the U.S. military spent about $2 billion on
jammers in 2007.
The insurgents' response to the first
jammers, in late 2003, was swift. It established a Spy vs. Spy-like competition
between counter-IED specialists and
the bomb makers, in which sometimes
a measure was followed by a countermeasure within days.
As jammers proliferated, insurgent
groups quickly went back to using command wires-buried pairs of long enameled copper wires attached to a simple
switch-and also to "victim-operated"
triggers. These triggers, also usually
buried for concealment, include pressure plates and crush wire-flexible tubing with two conductors inside that touch
and make an electrical connection when
the tubing is squashed by a tire or a foot.

efeating the device" is
how JIEDDO refers to the
many things it does to deal
with an IED already in place:
searching for it, disposing of
it, and if all else fails, surviving its blast.
These tasks get a lot of attention because
the score is easily tallied. Column A: lives

SEptEmbEr 2008 * iEEE SpEctrum * NA

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Table of Contents for the Digital Edition of IEEE Spectrum September, 2008