JED - September 2011 - (Page 30)

By John Knowles When NATO began its 2009 surge in Afghanistan, the threat from improvised explosive devices (IEDs) was picking up. There were more Taliban IED attacks and more NATO casualties than the previous year. This was not unexpected by NATO forces, but it was not welcomed either. Just as they were in Iraq, IEDs have become the Taliban’s weapon of choice in Afghanistan. However, the IED threat in Afghanistan is far more diverse than it was in Iraq which makes finding them a much more difficult job. vated detonators can be fashioned from a variety of materials, such as wood or plastic, with metal restricted to the contacts needed to complete the electrical circuit. (Sometimes, the contacts are nothing more than wires wrapped around the carbon core from a battery or a simple dowel initiator. These are connected to the explosive by a pair of wires and a small battery. When the IED’s pressure detonator is activated, the electrical circuit is completed and the bomb detonates. The bomb may be located with the detonator or it may be located separately (several meters away) in order to cause damage to another vehicle. Sometimes the IEDs are daisy-chained to blow up several vehicles in a convoy. The idea in these cases is to plant the explosives ahead of the detonator so that the lead vehicle in a convoy drives past the explosives and then hits the detonator, blowing up the vehicles behind it. Typically however, the Taliban’s goal is to stop the convoy by blowing up the lead vehicle and then sometimes ambushing the remaining vehicles in the ensuing chaos. For the Taliban’s IED emplacement teams, there are several factors to consider. The bomb teams do not want to expose themselves to detection by airborne surveillance, so they are not likely to spend a lot of time burying their IEDs too deep in the road. Burying the IED near the surface also serves a second purpose of reducing the amount of explosive they need to use. (The deeper the IED is buried, the harder it can be to detect. But this also typically requires UNFRIENDLY ROADS NATO’s wide deployment of IED jammers has driven many Taliban bomb makers away from wireless remote controlled devices. Instead, they often build simpler IEDs that are triggered by the pressure of a vehicle’s weight. In this way, they can be tailored to work against certain targets (heavy military vehicles, for example) and avoid others (lighter civilian cars and pick-up trucks). Pressure activation is a fairly indiscriminate means of detonating the bomb, and many Afghan civilians are killed by them every month. Still this method gives the Taliban bombers more security, since they do not need to be present to detonate the device. For the IED makers, the goal is to build a device that avoids discovery by the metal detectors used to detect IEDs and landmines. Explosive materials often consist of locally available fertilizers and other chemicals encased in plastic fuel containers. Pressure-acti-

Table of Contents for the Digital Edition of JED - September 2011

The View From Here
Conferences Calendar
Courses Calendar
From the President
The Monitor
Washington Report
World Report
Detecting and Defeating IEDs
Developing Critical EW Technologies: Digital Devices Move Into the Analog Space
New Products
EW 101
AOC News
Index of Advertisers
JED Quick Look

JED - September 2011