Richard Garland talks about 'Explosive Ordnance Disposal' and 'Public Safety Bomb Disposal'

Bomb disposal is the term referring to the methods by which hazardous devices are rendered safe. Bomb disposal is the generic term used to describe the separate fields of military (Explosive Ordnance Disposal), public safety (Public Safety Bomb Disposal, PSBT) and civilian (Unexploded Ordnance, UXO) operations.

Since the tragic events of September 11th the world has become increasingly aware of the threat posed by terrorists to our various societies. In response to these ever present and increasing acts of terror various civil and military organizations have taken on a more public and active role in addressing this threat. The combination of cutting edge technology and advanced training techniques has led to an unprecedented advance in the protective equipment and disposal techniques that the bomb disposal technician now has available to complete the hazardous task of identification and destruction of a suspected explosive device.

New Developments

EOD technicians have had to adapt to rapidly changing methods of construction of an Improvised Explosive Device (IED) from the simple, yet deadly, shrapnel device in a tin can to the sophisticated remotely detonated military style devices that are becoming increasingly common in various conflict zones around the world. The function of the operator is primarily to identify the device as either a threat or not. In the event of the device being identified as a potential threat several factors must be taken into consideration before attempting to disarm it. Since IEDs are generally unstable devices and pose a great threat to both the safety of the operator and the public at large, a decision to remotely detonate the device is usually considered. In the event that this is not an option the operator has now to face the manual disarming of the device. It is at this point that the effectiveness of the Personnel Protective Equipment that operators have at their disposal becomes critical to their safety.

In response to the threat faced by the EOD technician, manufacturers of Personal Protective Equipment, such as Global Armour, have embarked upon a massive research and development programme to improve upon the equipment that is currently available. In the past such equipment was bulky, heavy and restricted the movement of the operator. With the advent of new and improved materials many of these restrictions have been reduced to an acceptable level. The necessity for accurate communication between the base station and field operative has led to a dramatic increase in the effectiveness of the available communications systems. Removal of the potentially hazardous necessity of having to rely solely on radio communication links has been achieved with a 100 metre, full duplex cable system that is fed directly into the operator's protective helmet. This system is constructed so that the primary power supply is supported from the base station. This in turn limits the necessity of carrying heavy and potentially explosive batteries in the suit. This "hands-free" method of communication negates the potential of an operator having to manipulate complex and unsighted controls during a hazardous disarming procedure. The development of a hands free or VOX operated radio system that is directly linked to the operator's helmet has dramatically reduced this concern but, in the event of facing a remotely detonated device the potential for accidental detonation by the radio frequency being used by the operator remains.

The primary defence mechanisms available to the operator are the full body suit and the completely enclosed helmet. The combination of both standard and new materials for the construction of these items has led to a marked improvement in the effective level of protection offered to the operator. Exotic materials such as the Global Armour's inherently flame retardant outer suit fabric with UV stabilization have advanced the durability and effectiveness of the equipment on offer. Combination with the tried and tested multi-layered hybrid armour system has increased the effective protection level of the garment. The addition of a hard armour blast plate system comprising a truly composite matrix has markedly increased the protection level of the suit. The ridged-sandwich-construction helmet with wrap-around visor has increased the overall field of view available to the operator. Inbuilt NBC (nuclear, biological and chemical), filter systems allow the operator to function in the most potentially dangerous of circumstances the dreaded terrorist "dirty bomb" scenario.

Sequences and Consequences

In a blast scenario the primary blast wave is the first to strike the suit and pushes around the body and helmet of the operator. This causes an overpressure wave that is the difference between the high pressure in the front of the suit and helmet and the low pressure area behind the suit and helmet. This causes the operator to be thrown backwards. Once this pressure wave passes the operator a vacuum is left in the front of the operator causing the operator to be rapidly drawn forwards, this causes a 'snap' to the head area and extremities.

This can lead to serious neck injuries and even death. The Global Armour EOD Suit is designed such that the head is held in intimate contact with the main body of the suit, causing the operator to be drawn forwards as a single entity and therefore lessening the potential for neck and spinal injury. The proprietary padding system inside the helmet is designed to lessen the 'rattle' space inside the helmet. During acceleration the helmet moves at the velocity of the blast wave and when coming into contact with an object, such as the ground, will come to an abrupt stop: the head will continue to move in the direction of the applied force and will, unless cushioned, come into contact with the side of the helmet, potentially causing severe injury or death. The unique system of padding uses varying densities of closed cell high, medium and low density foams to decelerate the head in a staged manner to lessen the potential for injury.

The second threat to the operator is the one posed by fragments of material, either intentionally set, such as nails or ball-bearings, or environmental objects such as glass fragments and stones. These fragments are accelerated at high velocity and come into direct contact with the external suit and helmet worn by the operator. Depending on the initial threat assessment most EOD Suits are designed to protect against these fragments at prescribed velocities. The higher the threat level the more advanced the armour system that is used to counter these fragments. A typical fragment velocity that can be countered is that of 1600 metres per second, and the suit is designed so that various areas of the body are protected at varying levels. The operator is usually in a kneeling position, so the upper torso and head receive the highest concentration of fragmentation and therefore require the highest level of protection. Global Armour has developed a system of lightweight blast plates and hybrid polyamide armour specifically designed to absorb a vast number of fragmentation particles without being compromised.

The third factor facing the operator is that of heat and flame. The blast generates a large amount of heat during detonation, and this heat wave passes over the operator and could seriously injure an unprotected or exposed area. The potential for this heat wave to be drawn into the lungs of the operator is countered in the Global Armour EOD suit by the inclusion of a forced-air filtration system. This system uses the latest in NBC technology to limit the operator's exposure to harmful elements. The position and placement of the system on the suit allows the operator to continue to be assured of clean air flow during the most hazardous of operations. Given that often the result of a blast is conflagration of the surrounding area, the EOD suit is designed to be inherently fire retardant, negating the potential danger of suit ignition. Coupled with the cooling suit worn under the outer garment, the operator is spared from the excess of heat and flame.

Saving Lives is the Goal

The ever-present and continually changing circumstances of a terrorist threat have led to the marked and determined involvement of specialized EOD Suit Manufacturers, such as Global Armour, who recognize that the threat posed is one that faces the entire world and must be dealt with in a determined manner. The primary goal of the development work is preservation of the operator's life. While every available technological advantage is considered for incorporation into a full EOD helmet and suit, and the highest levels of training are given to the individual operators, the potential for disaster is still present.