SHAPED CHARGES, PLATTER CHARGES, EXPLOSIVE FORMED PROJECTILES (EFPs)
A shaped charge is based on an effect peculiar the physical form of an explosive and its effect against a hard target. It is called the Munroe Effect. An explosive that is set above a conical metal liner (linear copper or cylindrical copper liner, or steel or glass liner) will detonate and produce a focused blast wave ahead of the liner. The focal point is critical to good penetration of hard surfaces such as armor plate or concrete, and so a “stand-off” distance must be created between the open end of the cone and the target surface.
A platter charge is based on the fact that if a sheet of explosive (either rubberized sheet explosive or a thin sheet of plastic explosive) is backed by a plate of steel, when the explosive detonates, the blast wave will largely be projected away from the steel backing plate. If another lighter weight plate or disk is placed on the opposite face of the explosive charge, it will be projected like a missile in the opposite direction. Small projectiles such as ball bearings placed on the front ace of the sheet will also be projected at high speed away from the detonating explosive. This is called the Misznay-Schardin Effect.
The U.S. Claymore Mine and copies of it made by many countries, are based on this effect.
An Explosive Formed Projectile or Self-Forging Projectile is a device that takes advantage of the Misznay-Schardin effect. It is a steel cylinder with steel backing plate or disk. It is filled with a high explosive charge such as TNT or C4. At the opposite end is a concave copper disk about ¼ inch to 3/8 inch thick, dished inward about ¼ inch at the center. When the explosive detonates, the dish everts and elongates into a high velocity slug or projectile. It is capable of penetrating through armour plate at distances up to 100 meters. A disk that starts off as a concave copper plate 6 inches in diameter X 3/8 inch thick, will evert (the reverse of invert) and elongate, to become a rod about 1 inch in diameter by 8-10 inches long.
Securesearch manufactures inert training aids of these devices, which are essential for classroom demonstration of the various devices and their effects. We can produce them in several different forms and dimensions to suit your training requirements. We can also manufacture them in cut-away form.