NSWC/WOL TR 7 6-15 5 



The number of fish of a given average size at each test specimen 

 location and summaries of the injuries evaluated upon post-shot 

 disection are listed in the last 5 columns of Tables 3.1.3 and 3.1.4. 



Thus, e.g., on Shot 531 (Table 3-1.3) at the 76.2 meter range 

 position there were 10 Spot, all 10 of which received injuries of 

 level 1 or greater, 7 of which received injuries of level 2 or greater, 

 5 of which received injuries of level 3, and none of which received 

 level 4 injuries. (There were no injuries of level 5 observed on 

 either the 1973 or 1975 tests.) 



Table 3.1.5 is a condensed version of the code used to evaluate 

 the explosion damage to the fish upon post-shot dissection. 3 

 Successive injury levels are of increasing severity and each fish is 

 classified to fall into one and only one level of injury. Figure 

 3.1.2 depicts this fundamental design of the injury code. Thus, the 

 fundamental physical problem of this report is to estimate test condi- 

 tions for the transitions from one injury level to the next. We will 

 do this by estimating the probability of events such as "occurrence of 

 injury level 3 or greater" as a function of the calculated damage 

 parameter Z (Equation 3.1.5). It is convenient — but not fundamental 

 to the analysis -- that such "cumulative" injuries are also what is 

 of practical interest in explosion testing. For example, the event 

 "injury of level 3 or greater" has been found to correlate with the 

 observed fish-kill* on underwater explosion tests. And, the event 

 "injury of level 2 or greater" has been considered to give the fish 

 "little chance to survive predation . " 



3. The injury evaluation code is due to: Hubbs , C. L. , Schultz, E. P., and 

 Wisner, R. , Unpublished preliminary report on "Investigation of Effects on Caged 

 Fishes from Underwater Nitro-Carbo-Nitrate Explosions," U. of California, Scripps 

 Institute of Oceanography, 1960. The complete code is also listed in reference 1. 



* The term "observed fish-kill" refers to the dead and dying fish found on the 

 surface and bottom following an underwater explosion. 



35 



