The first of the groups assembled to conduct nuclear weapons tests on Enivetok Atoll orcanizaticnally came into being on 18 October 1947. Called Joint Task Force Seven, the group was composed of personnel from many U.S. governmental Agencies.@ | Not having significant ground facilities on Eniwetok Atoll. the Task Force Seven operated from their many surface ships. Three nuclear detonations were made in this Operation Sandstone, which occurred during April and May in 1948.3 The detonations were on. 200. ft. towers in the lagoon; the first off Engebi, the second off Aemon, and the third off Runit. The largest yield was the second with a yield of 49 kilotons.4°9 This kiloton terminology means that the explosive energy of the nuclear detonation equals 49 thousand tons of high explosive. ' (For these and following tests, table at the end of this section gives the test name, date, time, location, height of burst, position (airdrop, barge, ground surface, or underwater) of nuclear explosive and yield). In preparation for the next series of nuclear tests, the Atomic Energy Commission in mid-1949 decided to facilitate further testing by improving ground-based structures and by providing more adequate technical facilities at Eniwetok Atol].° This work was based on a survey submitted by Holmes and Narver, Inc., on 7 January 1949. The Commission approved the recommendation for construction in April 1949, and the contract was signed in June.6 2. 3. 4, 5. 6. BEST AVAILABLE COPY Reference 1, p 85. Reference 1, p 86. -.~ Samuel Glasstone, The Effects of Nuclear Weacons, Department of the “Army Pamphlet No. 39-5 (February 1964), and Mary A. Edwards, “Tabulation of Data on Announced Nuclear Detonations by .All Nations through 1965," Report UCPL-14786, 17 March 1966 (Available from clearing house for Federal Scientific & Tech Info, Springfield, Va.) Reference 1, p 87. ‘ Reference 1, pp 113, 115 n (@)