USING A MULTI THREAT OR SINGLE THREAT PROTECTION

Each threat requires different defensive solutions to defeat a particular threat. Leading body protection scientist and developer Digby Dyke says "Stabbing is of course not a lesser threat but a different one. 'Bullet-resistant' materials such as Kevlar® can be stabbed through by knives, 'stab-resistant' vests can be perforated by bullets, 'stab-resistant' vests made with wire mesh or chain mail can be perforated by spikes and needles, and 'bullet-resistant' and 'stab-resistant' vests can be perforated by fragments commonly referred to as 'shrapnel' - from exploding devices; It's as simple as that. Various single solution protective vests may not offer sufficient protection from blunt trauma attacks, such as metal pipes, kicking etc."

Dyke continues; "One case I recall from a few years ago was of a police officer in the US asking a colleague to stab him while he was wearing his new 'bullet-proof' vest. The officer subsequently died as a result of the wound received after the knife perforated the vest into his abdomen. He had believed stabbing to be a lesser threat than shooting."

"When I first got involved with body armour 17 years ago, the question I asked was, why should body armour have to be either bullet-resistant or stab-resistant; why not both? Why not just simply, 'body armour'?" asks Digby Dyke. "The reason, I discovered, was substantially because there were then no materials that were truly dual-purpose. There were bullet-resistant fabrics - Du Pont's Kevlar® being the best known and widest used, as it still is today - and there were various stab-resistant materials such as aluminium platelets, steel chain mail and wire meshes. When both bullet and knife protection were wanted, dual-purpose body armour vests were manufactured by combining the two material types together. This process is still used to some extent today; quite satisfactorily in many instances, but usually with limitations."

If vests are of wire mesh or chain mail they are not resistant to perforation by fine spikes and needles without the addition of other materials. Limitations on bullet and stab-resistant body armour vests include being not necessarily resistant to perforation by fragments from exploding devices. Fragments are substantially different from bullets. They may travel at similar velocities but their geometries and trajectories are very different. They tend to be irregular in shape and sharp and tumble in flight. Accordingly, military fragment-resistant vests ('fragmentation vests' as they are called) are tested differently from bullet-resistant vests. Projectiles are fired at them in a laboratory, but the projectiles are Fragment Simulating Projectiles ('FSPs'). These are differently shaped from bullets but are fired at test samples in exactly the same way that bullets are.

It cannot be taken for granted that a bullet-resistant vest will defend against fragments from exploding devices. Stopping bullets, knives, spikes and needles from perforating the vest is all very well, but it is only part of the need. Kinetic energy of the arrested bullet passing into the body of the wearer through the vest has the potential to cause very painful blunt injury to both superficial tissue and internal organs; and possibly even death.

'Blunt trauma' and 'behind armour blunt injury', as it is called, has also to be considered a threat. Good body armour should attenuate residual kinetic energy from the attack. A bullet weighing a typical 8.5 grams and travelling at 1000 miles per hour can do significant damage to the body behind the vest.

"Imagine you are shot and your vest stops the bullet but you suffer broken ribs and fall to the ground in agony! Consider for a moment how vulnerable you would then be to your oncoming attacker!" asks Dyke. "I remember interviewing a former British Army officer shot in the abdomen at close range with a revolver. His vest successfully stopped the bullet and immediately behind the point of impact there was bruising, as would be expected; but his injuries some distance away far from the point of bullet impact were much worse. His testes and scrotum and blood vessels in his left leg were severely bruised and swollen and he suffered a great deal of pain.'My b---s were like footballs", he said to me.

All this had been caused by energy from the stopped bullet transferring into his body and travelling down veins and arteries to regions remote from the point of bullet impact. It is worth noting that there have been more cases of police officers saved by their body armour from blunt injury in motor accidents than from violent attack." concludes Dyke.

As highlighted earlier in this document we believe that modern body armour should provide defence to the attack threats of  knife, needle & spike, ballistic, shrapnel (including flying glass) and blunt trauma (including being hit with pipes and other hard objects and being kicked). 

Digby Dyke says: "If you are responsible for equipping colleagues with body armour you must determine the true threat to which they are exposed. Is it bullet, knife, spike, needle, blast fragments, blunt injury, or what? And, frankly, for the majority of workers in the private security industry, thanks to terrorism, it is all of these."

Fortunately, it is now possible to have protection from all of these threats in a single body armour vest. Materials without metallic constituents providing protection from all these threats do now exist - from bullets, knives, spikes, needles, blast fragments and blunt injury.