Attack of Fortified Places. Including Siege-works, Mining, and Demolitions. / Prepared for the use of the Cadets of the United States Military Academy

by James Mercur

When l = r and l´ = r´, we have

C : C´ :: (11/6)l : (11/6)l´3,

and

C´ = C[(11/6)(l´3)/(11/6)(l3)] = C[(l´3)/(l3)] (2)

Equation (2) is applicable to common mines, and shows that in common mines the charge varies as the cube of the line of least resistance.

Assuming C_´ as the charge which will produce a crater with a volume of unity, equations (1) and (2) become, by omitting the primes from l and r,

C = C´(11/6)lr2, (3)

and

C = C´(11/6)l3 (4)

Equation (4) gives the rule for determining the charge for common mines whose L. L. R. is given, viz.: Multiply ¹¹/₆, the cube of the line of least resistance in yards, by the quantity of explosive required to throw out one cubic yard.