BOMB TEST

Otago Daily Times, Issue 26199, 9 July 1946, Page 4

BOMB TEST

COMPLETE SUCCESS FIRST-HAND ACCOUNTS OBSERVERS IMPRESSED (P.A.) AUCKLAND, July 8. Every ship lying within about half a mile of the first atom bomb explosion was put out of action, said Dr Karl T. Comptno, an internationally famous physicist and a member of the American Joint Chiefs of Staff Evaluation Board, who was among the party of scientists which reached Auckland today from the atomic tests at Bikini atoll. He added that three ships were sunk immediately, two foundered on the following day, one was beached, and one was damaged so severely that it had to be towed away. Dr Compton is president of the Massachusetts Institute of Technology. During the war he was chairman and a member of many United States Government scientific boards. “As an experiment the first test was a complete success,” Dr Compton said. “The scientific data which we sought is coming along in. fine style. Watching the effects at a distance of 23 miles, some of the observers were disappointed, because the spectacular seemed to be lacking, but as we entered the lagoon and began a proper survey we became more and more impressed. Although all the ships within half a mile of the explosion were put out of action, vessels lying over a mile away suffered very little damage." Delayed Radio Activity The radio-active effects of the gamma rays had not yet been assessed, Dr Compton said, more particularly because they were often delayed in their appearance. He considered, however, that the slow effects of the gamma rays would be a good deal more significant than the effects of the blast. The opinion that the underwater detonation of the second experimental atomic bomb would create more impressive and spectacular effects • was expressed by Major-general Thomas F. Farrell, second member of the Evaluations Board. Major-general Farrell. who in peace-time is engineer-in-chief of the New York State, was deputy to General Groves in the Manhattan atomic bomb manufacturing project, and was in charge of the assembly of the bombs used in the devastation of Hiroshima and sakiThere were reasons for the assumption that the underwater explosion would present more striking features than the first experiment when the explosion occurred above the sea, he said. They were based on the fact that the energy liberated by the detonation would be confined long enough to produce such effects as a tall plume of water rising vertically from the sea. More ship damage could also be expected as the water was a better conductor of energy than air. and the ships’ bottoms were weaker than their topsides. Discussing the damage to Hiroshima and Nagasaki, which he had inspected as head of the investigation commission, Major-general Farrell said that the two cities had suffered a tremendous shattering. For the type of bomb now in use, cities were better targets than ships,, although it was difficult to speculate what the results would be when the bomb was brought down to the water Future Developments “The atom bomb is only at the beginning of its development,” he added. “ Only two models have been made, and only four bombs have been detonated. There is no question that they can be increased in number and improved in size, power, and area of destruction. They are already big enough for any ordinary city; and they can be made to go far beyond this.” “Just a big bomb—that is all,’’ was the laconic comments of Vice-admiral John Hoover, U.S.N., another member of the Evaluations Board, “ but it may have a lot more features than we yet know about. Thousands of instruments have yet to tell their tale.”

From the lessons learned from the first test, it was hoped to take up a much closer position for the second experiment, Vice-admiral Hoover said. In their positions over 20 miles away from the site of the explosion, they had seen a cloud of smoke rising from the lagoon, but the flash and the sound of the bomb could not be detected.