to consolidate with appropriate J Sections under the supervision of the J Section head. program. A somewhat similar arrangement was planned for the DOD TU~13 During the pre~operetional phase representatives of Armed Forces Special Weapons Project (AFSWP) were placed on duty for 2=3 days per week with fA J sections and would work full time during the operational phase. (12) Be. 1. The decision to use Bikini made possible the realization of CASTLE as originally contemplated, but certain problems inherent in a seven shot CJ thermonuclear program still remain, Factors such as the degree of instrumentation to be given each experiment, the estimated shock strengths, and possible radiation contamination, had to be weighed against the need to minimize the ‘ ' duration of the operation, the desire to avoid shipboard housing except for short periods of unavoidable evacuation, and to avoid damageto instrumentation being installed for subsequent experiments. 2. The new 7.1 organization got under way with intensified planning in an effort to bring the basic concept into operational focus. Prior to 1 Feb 53, it was acknowledged that the originally planned test dates of Fall 1953 were not realistic, and a period in Spring 1954 was accepted. From approximately February thru May of 1953 a planning phase prevailed, during~ which the scope of experimentation was continuously reviewed for the purpose of determining support requirements, This phase changed, during June thru September, into a requirements phases during which the findings of the previous ‘ phase were made known, projects became identified and definitive relations with participating agencies became a major subject. The activities of these two periods follow in greater detail. . (11) Ltr DWET to CTG 7.1, 20 Aug 53, File 21050 in 600 CASTLE - Re relationships between JIF, TG & AFSWP a