The design of an IED is more complex than you might guess. They can be command-operated by a remote "trigger puller" or victim-operated through use of a switch. The switches can be simple pressure switches attached to say, a garden hose, that activates when stepped on or rolled over or the switches can be sophisticated infrared sensors with heat-seeking capability. They can be connected to a cell phones internal circuitry such that when that cell phone number is dialed, the IED activates.
The "bait" for a victim-operated IED can be anything that will get someone's attention. Dead animals, traffic cones, trash piles, and abandoned vehicles have been used. Stuff animals have also been used which as you might surmise would get a child's attention. MRE pouches given away to locals have turned up wired to IEDs. Anything out-of-place or unusual has to be viewed with suspicion. One of our colleagues at Kandahar told me the story of insurgents wiring an IED to the dismembered leg of a US soldier that resulted in more casualties by members of that soldier's unit. He had treated them at Walter Reed.
The explosives are surprisingly simple made from easily obtained ingredients. ANFO is a combination of ammonium nitrate found in fertilizer and diesel fuel oil. A dense biomass booster agent such as flour or sugar or powdered drink mix can be added to increase the energy release and the destructive potential. The powdery result can then be combed into dirt to hide its content. This makes it hard to find. The homemade explosive (HME) labs are important insurgent resources and a critical target for coalition forces. They are usually chemistry lab-in-a-kitchen or -garage setups.
The penetrating power of the IED can be increased using a shaped charged known as an EFP, or energy formed projectile. These are curved copper plates with explosive behind it. The energy of the explosion bends the copper into a torpedo-shaped projectile that can penetrate armored vehicles. These types of devices are believed to be made in Iran and imported into the theater.
|EFP's in cement|
The US military has made a concerted effort to counter the IED threat by creating a whole new generation of armored vehicles. Known as MRAPs, mine-resistant, ambush protected, these have helped reduce the loss of life by US service members. Still the game of one-upmanship continues. Some of the IED explosives are in the 500-1000 lb range, capable of tossing these vehicles into the air.
Our brief at Dix consisted of six hours of Powerpoint which, as I mentioned was anything but "brief." However, there were some videos shown that kept your attention by the truly disturbing content. Insurgents, it seems, like to post video on the web of their handicraft in action. Jihadist soundtrack included. War-trophys for the internet age, I suppose.
One video showed an explosion that launched the Humvee gunner about 25 feet into the air and about 50 feet forward. Another video, made by a French film crew, showed the stages of construction of an IED. The construction site was a busy street corner in broad daylight where hundreds of cars and onlookers passed by. Guess nobody, including the film crew, was moved to report it because the video finished with footage of it hitting a convoy. (With friends like the French....) Finally, one showed an IED blast hitting a convoy followed by the rescue effort at the rear of the destroyed vehicle. About a dozen soldiers gather trying to pull the wounded from the wreck. This turns out to be a second "kill zone" and the insurgent/video taker detonates a second device that hits all of the dismounted troops including the wounded.
It makes you realize what we are up against.