was no obvious damage to ships more than one-half mile from the 

 burst. 



SECTION III 



Observations and Conclusions, Both Tests 



The operations of Joint Task Force One in conducting the tests 

 have set a pattern for close, effective cooperation of the Armed 

 Services and civilian scientists in the planning and execution of 

 this highly technical operation. Moreover, the tests have provided 

 valuable training of personnel in joint operations requiring great 

 precision and coordination of effort. 



It is impossible to evaluate an atomic burst in terms of con- 

 ventional explosives. As to detonation and blast effects, where the 

 largest bomb of the past was effective within a radius of a few 

 hundred feet, the atomic bomb's effectiveness can be measured in 

 thousands of feet. However, the radiological effects have no parallel 

 in conventional weapons. It is necessary that a conventional bomb 

 score a direct hit or a near miss of not more than a few feet to cause 

 significant damage to a battleship. At Bikini the second bomb, 

 bursting under water, sank a battleship immediately at a dis- 

 tance of well over 500 feet. It damaged an aircraft carrier so that 

 it sank in a few hours, while another battleship sank after five days. 

 The first bomb, bursting in air, did great harm to the superstruc- 

 tures of major ships within a half-mile radius, but did only minor 

 damage to their hulls. No ship within a mile of either burst could 

 have escaped without some damage to itself and serious injury to 

 a large number of its crew. 



Although lethal results might have been more or less equivalent, 

 the radiological phenomena accompanying the two bursts were 

 markedly different. In the case of the air-burst bomb, it seems cer- 

 tain that unprotected personnel within one mile would have suf- 

 fered high casualties by intense neutron and gamma radiation as 

 well as by blast and heat. Those surviving immediate effects would 

 not have been menaced by radioactivity persisting after the burst. 



In the case of the underwater explosion, the air-burst wave 

 was far less intense and there was no heat wave of significance. 

 Moreover, because of the absorption of neutrons and gamma rays 

 by water, the lethal quality of the first flash of radiation was not 

 of high order. But the second bomb threw large masses of highly 

 radioactive water onto the decks and into the hulls of vessels. These 

 contaminated ships became radioactive stoves, and would have 



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