68 
For T.N.T. the ratio Sa) can be expressed as 
b 
Gla) . oor HEL)? sieevih cindy | 68S tame Met oad kiteioanean (510) 
Ts 
where L is in centimetres. 
B9. Equations B8, B9, and B10 are sufficient to determine a‘ and z' 
as functions of time subject to given initial values. For most purposes 
it is sufficient to take a’ = O when t =O and if the charge is exploded 
at a depth z, below the level 33 ft. above the sea surface, the initial 
conditions can be written 
when t = 0 ere eee eos eee eve (B11) 
Since equations B8 and B9 are non-linear, they can in general only be 
solved by a numerical step-by-step process. Moreover, equation B10 
involves L explicitly and since L varies with the size of charge, each 
calculation must be carried out separately for a particular size of 
charge and a given depth. 
