# Metric Calculations — General

### General

The following metric formulas may be used for demolition projects when working with personnel familiar with the metric system. Use of metric formulas and construction and placement of charges are the same as for U.S. Corps of Engineer formulas and charges. Since the formula results give kilograms of TNT, the relative effectiveness of other explosives must be considered. For demolition formulas see FM 5—25, or Demolition Card (GTA 5—10—9).

Add 10 percent to a calculated charge of less than 22.5 kilograms.

 1 Breaching radius. The breaching radius (R) is the distance in meters which an explosive charge must penetrate and within which all material is displaced or destroyed. For example, if it is desired to break a 2-meter concrete wall by placing a charge on one side then the value of R, in the formula Kg = 16 R3KC is 2. 2 Material factor (table IV). The values of material (K) for various types of construction are given in the following tables. 3 Tamping factor. The value of the tamping factor depends on the location and the tamping of the charge. No charge is fully tamped unless it is covered to a depth equal to the breaching radius. 1 Number of charges. For calculations to determine the number of charges, see FM 5—25.