ABSTRACT
The shaped-charge or high-explosive anti-tank warhead has been around since before World War II. As seen in Chapter 3, the way it works is simple and elegant. High explosive, contained within a metal casing, is detonated resulting in a fast-moving shock front. This fast-moving front eventually encounters a copper liner that is essentially collapsed and turned inside out forming a stretching, fast-moving jet of material. Remarkably, contrary to popular myth, the material that forms the jet is not molten but rather a stretching plastically deforming rod. It is usually referred to as a ‘jet’ mainly because it is assumed that it behaves like a fluid in the models used to simulate its behaviour. However, due to the very high velocity of the tip (even velocities of over 12 km/s are possible), the jet possesses a very high energy concentrated over a very small area. This means that it is able to penetrate a large amount of steel armour such as rolled homogeneous armour (RHA). It is this fact that potentially makes armoured fighting vehicles (AFVs) vulnerable to attack from warheads such as the RPG 7* (see Figure 9.1), and consequently, it is a dangerous as well as a prolific threat. There are several approaches that are used to defeat these types of threats; these are reviewed in this chapter.
