a 3-8 weather problems during summer onths, this should include ten Be57B and four Be57D type aircraft. From this and other meetings of the Eniwetok Planning Board, from the device and experimental programs of the twoLaboratories, and from the exe perimental programs of the DCD and Sandia Corporation and the fEC/D0D support prozrams, Task Group 7.1 developed an Operation HARDTACK General Concept, given linsited distribution in draft form on April 12, 1957, June 1, 1957. It was issued or. The foreword stated, "+-as usual at this stage of an overseas operation, prior to receipt of JTF SEVEN plannin~ documents and without CUTF SEVEN approvel, in order to provide the early planning guidance needed by the personnel of Task Group 7.1 who will particinte in the operation," ‘The shot schedule given in the Concept included 27 shots, listed in Table 3.2. Planning assumptions and besic principles included the following: 1. Operation HARDPACK will be similar to Operation Redwinz. However, the number of devices and weapons to be tested will be greater, 2. Both Bikini and Eniwetok «tolls will be used as ahot sites, and shots covering a wide range in yield will be fired at each. 3. So far as possible, firing 2t either atoll will proceed independ-= ently of activities at the other. This concept includes the possibility of simultaneous firings at both atolls. 4. &# capability to conduct operations from afloat will be maintained at Bikini Atoll and an emergency evacuetion capability will be maintained at Eniwetok. 5« Consideration is being given,to the use of Taongi Atoll as a third area of operation. cept was issued.) 6. (This provision was elimin:ted a week after the Con- The detonztion time for each shot will be determined by pertinent operation:1 and experimental considerations. The probable detonation time for most shots will be between one hour and one-half hour before sunrise, There were three revisions of the General Concept before Task Group 7.1 Operation Plan No, 1-58 was issued on January 15, 1958. Changes in schedule resulted in a total of 26 shots, including two one=points, plus two conting . gencies,, There were also chances in planning assumptions and basic principles. * COPIED /p-- dane pee as pine p