of necessary materials to the jobsite. The final result of the delay in receipt of money, the late submission of criteria, and the late construction was that, again, experimenters were pressed for time to prepare their stations. The early shots, however, were delayed only briefly by the construc~ tion delays. The construction required by revisions to the firing schedule, starting with the Teak and Orange move and ending with the Quince move from Bikini to Eniwetok, was handled entirely in the field. Its accomplishment was made possible by the initial overstocking of equipment for shot barges and "T" boat hulls and by the great cooperation of the contractor's construction forces. On April 1 the contractor estimated that to move Teak and Orange and supporting experimentation to Johnston Island would require over 6 months. Three months later, on July 7, all Johnston Island construction had been completed. After the operation was well under way, construction for 13 new shot sites, including 5 BC type barges, 5 T boat hulle (one a Pinex type), Fig and Quince ground shots, and a new Teak/Orange site, was initiated. Construction on each of these was accomplished within the time set when it began. The work order system in effect during Hardtack makes it impossible to estimate the number of work orders and specific taska laid upon the contractors. The operation required the construction and support of a total of 1155 stations. Nearly 5500 man-hours of machinist time were expended in the J-6 shop in support of the TG mission. Intra-atoil Airlift. Intra-atoll airlift at Eniwetok was provided by CTG 7.4 using 9 H-21 and 6 H-19 helicopters augmented by 6 L-20 Liaison aircraft. At Bikini CTG 7.3 provided 15 USMC H-19 type helicopters augmented by 3 of CTG 7.4's liaison aircraft, At Eniwetok, the airlift requirement was at a sustained maximum from the beginning of the operational period in March through the month of June. Helicopters flew an average of 760 hr per month, carrying almost 6000 pas~ sengers and 70,000 lb of cargo each month. The L-20's averaged 350 flying hours, carrying 2200 passengers and 10,000 Ib of cargo each month. Shipments of small, urgently needed pieces of equipment on J-~4 manifest totaled 2106 lb for the operation. The basic 7.1 evacuation and recovery requirement involving intra-atoll flights at Eniwetok was to obtain immediate support of emergency scientific needs created during dry runs and postshot surveys. On the first -1 day, it became evident that the reaction time for laying on support missions was excessive when the aircraft and the Transport Control Agent were on Fred while the users were on Elmer. Thereafter, it became the practice that, at least on -1 aud De-days, the aircraft and a 7.4 Operations Officer were stationed gn Elmer. This, combined with maximum utilization of fixed schedule airlift, ultimately led to an optimized arrangement which culminated on the last D~day in 23 precisely timed takeoffs on very critical recovery missions, all of which were completed in less than the allotted time. Since there may be an extended interval before the next operation, it should be recorded that H-21 aircraft, because of their ability to carry greater loads, wer2 used to sustain the scheduled airlift, while the H-19's were used for photo missions because of their greater stability, and for radsafe and sample recovery missions because their engine position reduced the radiation hazard to the pilots. At Bikini, the total traffic was considerably less than at Eniwetok, 86