The first of the groups assembled to conduct nuclear weapons tests on Eniwetok Atoll organizationally came into being on 18 October 1947. Called Joint Task Force Seven, thé 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; the first on Engebi, the second on Biijiri, and the third on Runit. ‘The largest yield was the second with a yield of 49 kilotons.4°° This kiloton terminology means that the explosive energy of the nuclear detonation equals 49 thousand tons. , of high explosive. (A table at the end of this section gives for each of these and the following tests at Eniwetok the test name, date, time, location, height of burst, position (airdrop, barge, ground surface, or underwater) of nuclear explosive, cloud height, and yield.) In preparation for the next series of nuclear tests, the Atomic Energy Commission in mid-1949 decided to facilitate further testing by refurbishing Eniwetok with improving ground-based structures and by providing more adequate technical facilities? 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 .® 2. 3. 4. Reference |, p 85. Reference 1, p 86. BEST AVAILABLE COPY Samuel Glasstone, The Effects of Nuclear Weapons, Department of the Army Pamphlet No. 39-3 (February 1946), and Mary A. Edwards, "Tabulation of Data on Announced Nuclear Detonations by All 5. 6. Nations through 1965," Report UCRL-14786, 17 March 1966 (Available from clearir house for Federal Scientific & Tech Info, Springfield, Va.) Reference 1, p 87. Reference 1, pp 113, 115 2 (&)