Fish Killing Potential of a Cylindrical Charge Exploded Above the Water Surface

Two special air-burst test geometries are compared with two typical underwater explosion test geometries in order to determine the relative hazard to swimbladder fish. The method consists of approximate calculations for extreme values of compression and extension of the fishes' gas-filled swimbladder in response to the explosion pressure waves. The kill probability is then calculated from the ratio of maximum to minimum radius during the oscillatory response using an experimentally determined function. Calculations are made for 1000-lb and 64,000-lb cylinders of H-6 explosive (L/D = 3.65) fired end-on, 1.3 diameters from the water surface. By assuming a uniform fish-density distribution throughout the water it is estimated that on the basis of fish-killed/kg explosive a typical underwater explosion is some 1000 times more hazardous for killing fish than these air-burst tests. (Author)