Special Report - C-IED
An anatomy of the Improvised Explosive Device (IED)
An Improvised Explosive Device (IED) is a crude but nonetheless highly effective ‘homemade’ bomb that is typically utilised by guerrilla, militant and other insurgent forces who lack the resources to field a conventional military capability. Designed to destroy or incapacitate personnel or vehicles or in certain instances be utilised as a distraction measure to entice opposition forces into ambushes or another form of attack, IEDs, also referred to as roadside bombs, are the current weapon of choice for Afghan and Iraqi insurgents.
IEDs are generally designed to attack a specific type of target and as their design sophistication increases, so they become more difficult to detect and protect against. Key determinants of device sophistication are the ingenuity and experience of the designer and the availability of materials and tools.
It has been said that IEDs represent psychological warfare at its most vicious.
Key IED components
Although IED design can be extremely diverse, there are three main components that are common to all IEDs namely the main charge, the initiating system and the casing.
- The main charge whose effect is often enhanced by a booster charge can be made of military munitions, which provide ready-made fragmentation, or military and/or commercial explosives such as TNT, ammonium nitrate (agricultural fertiliser) and PE4. Additionally, homemade explosives (HMEs) such as, reactive/energetic chemicals, flammables and industrial gases can also be used as the main charge in an IED. In Afghanistan 80% of the IEDs encountered by troops contain fertiliser based home-made explosives (HMEs).
- The initiation system is the mechanism that initiates the electrical charge to set off the device and includes a switch, initiator (usually consisting of a blasting cap) and power source.
- Casings can consist of almost any type of container from an animal carcass to a cigarette packet or soft drink can. Specific identification features are constantly changing based on the imagination of the bomb maker and available resources.
In addition to the above, IEDs often also contain armour penetration and/or anti-personnel components such as copper rods and shrapnel generating objects such as nails, nuts and bolts to achieve maximum levels of fragmentation. However, in order to reduce the possibility of device detection, Taliban fighters are now thought to be developing IEDs that contain no metal or electronic parts and rely primarily on blast effect to cause damage.
Main initiation methods
IEDs can be initiated by wide variety of methods. These methods include but are not limited to initiation based on command, time and victim activation.
Command based initiation, either via hard wire or wireless means, enables the insurgent to determine the exact moment of detonation and is an extremely common form of attack in Iraq and Afghanistan. Command initiation is often used against in transit targets that have established some form of routine movement pattern.
Time based detonation enables the bomber to set off the device at a particular time. This allows the bomber to make good their escape and avoid detection and/or target coalition forces that have created an identifiable pattern of activity.
Victim activated devices, as the name implies, are triggered by the intended victim. These IEDs include a wide variety of initiation devices including pressure and pressure release switches, trip or pull wire, and movement detection technology.
The victim activated pressure plate IED is the most common device in operation in Afghanistan today, followed by command wire and remote controlled activation.
As with all aspects of IED design, initiation methods are constantly evolving and are limited only by the bomb maker’s ingenuity. While current IEDs have fairly rudimentary detonation capability, in future wars the detonation technologies, together with the other technologies used on these devices will become increasingly sophisticated and therefore more difficult to counter.
IED delivery mechanisms
There are a multitude of IED delivery mechanisms available to insurgents.
Passive or disguised static devices are the most common type of type of IED delivery method utilised by insurgents in Afghanistan. Although primarily victim activated via pressure plate or trip wire or detonated by command wire or remote control, detonation can also be timer based.
Vehicle Borne IEDs (VBIEDS), which are able to carry large explosive payloads, can be detonated by remote control, insurgent suicide bombers or even drivers acting under duress (Proxy bombing) and are designed to target both infrastructure and personnel.
As well as having much higher blast potential than other types of IED due to payload size, (VBIEDS) have two additional features that add to their destructive capability. Vehicle destruction arising from the blast can cause additional shrapnel and fuel causes the vehicle to turn into an incendiary device.
ANA on route clearance patrol training exercise
Person-borne IEDs (PBIEDs) are primarily designed to attack personnel, both military and civilian.
The IED delivery mechanisms detailed above are by no means exhaustive but represent the most common methods being utilised in Afghanistan today.
Device sophistication in Afghanistan
The IEDs that troops in Afghanistan are encountering are fairly basic. They are constructed from everyday materials such as wood and saw blades and use fertiliser based explosives and simple detonation devices. However, it is anticipated that in future wars, IEDs will become increasingly sophisticated and therefore more difficult to defeat.