Appendix 14 



Test C (Cancelled) 



Prior to its cancellation by the President, the proposed "Test 

 C" was the center of much discussion. In this test an atomic bomb 

 was to be exploded at great depth beneath the surface of the 

 water. 



Persons favoring holding such a test believed that it would 

 produce an underwater shockwave of almost incredible violence. 

 Ships might be crushed at ranges not equaled by explosions in air 

 or by shallow-underwater explosions. Involving an entirely new 

 kind of explosion, the test might till a large gap in physicists' under- 

 standing of explosion phenomena. Would a great "gas bubble," 

 hundreds of yards in diameter, break through the surface? Or 

 would the surface remain unbroken? Would great waves be pro- 

 duced? Some cynics, believing that this type of test would pro- 

 duce the most damage, thought the Navy would try to avoid it. 



To many persons it was clear that this test would be less im- 

 portant than the other two. On the technical side it was obvious 

 that little or no thermal radiation would reach the surface. Neutron 

 and gamma radiations also would be almost completely muffled by 

 the intervening layer of water. The tactical considerations were 

 even more pertinent. Nearly all harbors are shallow ; most coastal 

 waters are shallow. Thus a deep underwater explosion could never 

 be used in these important regions. It would be applicable only 

 in the open ocean, and here, of course, a fleet could be dispersed as 

 widely as necessary so that only one or two ships could be sunk 

 by one atomic bomb. 



Nevertheless, plans were made to hold Test C, and a considerable 

 amount of preparatory work was done. Studies were made as to 

 how to position the target ships accurately. Anchoring being im- 

 practical in very deep water, thought was given to "streaming" 

 the ships. They could be fastened to a small island by means of 

 long cables, and then allowed to take up more or less fixed positions 

 determined by the direction of the ocean currents and by the 

 lengths of the cables. Or perhaps the ships could be powered and 

 underway, steered by radio. Work was started also on methods of 

 lowering the bomb to the desired depth, holding it in the desired 

 position despite the ocean currents, and firing it. It was expected 

 that the test would be held near Bikini Atoll, and construction 

 crews went to work preparing necessary installations there. 



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