Shaped Charge - Defense Against Shaped Charges

Defense Against Shaped Charges

During World War II, the precision of the charge's construction and its detonation mode were both inferior to modern warheads. This lower precision caused the jet to curve and to break up at an earlier time and hence at a shorter distance. The resulting dispersion decreased the penetration depth for a given cone diameter and also shortened the optimum standoff distance. Since the charges were less effective at larger standoffs, side and turret skirts (known as Schürzen) fitted to some German tanks to protect against ordinary anti-tank rifles were fortuitously found to give the jet room to disperse and hence reduce also HEAT penetration.

The use of add-on spaced armor skirts on armoured vehicles may have the opposite effect and actually increase the penetration of some shaped charge warheads. Due to constraints in the length of the projectile/missile, the built-in stand-off on many warheads is not the optimum distance. The skirting effectively increases the distance between the armor and the target, providing the warhead with a more optimum standoff and greater penetration if the optimum stand-off is not drastically exceeded. Skirting should not be confused with cage armor which is used to damage the fusing system of RPG-7 projectiles. The armour works by deforming the inner and outer ogives and shorting the firing circuit between the rocket's piezoelectric nose probe and rear fuse assembly. Cage armour can also cause the projectile to pitch up or down on impact, lengthening the penetration path for the shaped charge's penetration stream. If the nose probe strikes between one of the cage armour slats, the warhead will function as normal.