center point to receive the snatch block hook from the ship's boom. Four ropes were tied to the corners and used to steady the cage during lifting and lowering operations. On the whole, the technique worked quite satisfactorily. : The primary evacuation and re-entry vehicles were LCU's, which were scheduled at various times. Helicopters (H-19's) were used to load priority personnel, late evacuees, and early re~entry personnel. Joint Task Force Seven appointed an Evacuation Officer for this opera- tion, through whonr*the task groups coordinated their requirements. Muster, manned stations, boat loading, helicopter, and priority re-entry personnel lists were published as a basis for Task Group transportation requirements and forwarded to JTF 7 for coordination and necessary action. The inflexibility of the personnel movement schedule made changes for technical reasons very difficult to accomplish. During the re-entry phase, the lack of command control and coordination of movement of priority personnel, helicopters, and ships caused abnormal delays and loss of some data. The loss of neutron data from a rocket nose cone was the direct result of VIP's receiving helicopter priority over the objects to be recovered. This underlines the importance of recovery operations to the complete success of a nuclear experiment, which is such that all actions and move- ments not directly connected with data recovery must receive low priority. The need for one person with command authority to move ships, aircraft, and people in the recovery operations again became apparent during the Orange event. This indiviaual must have complete appreciation of the type of data to be recovered andIts importance relative to other, similar, data. 3.8 PERSONNEL MUSTER AND EVACUATION Musters. On April 8, 1958, the TG 7.1 plan for the conduct of sightmusters in the EPG was published. This plan established a Task Group Muster Officer, and two Atoll Muster Officers, for Eniwetok and Bikini Atolls, respectively. The plan also provided Muster Officers to represent Headquarters and each of the various Task Units. Muster rosters were prepared by J-1, TG 7.1, at varying times, de- pending upon the number of changes occasioned by arrivals and departures from the EPG., During Hardtack a new system was initiated for compiling these muster rosters. An IBM card was punched for each individual in TG 7.1 participating in the operation. When an individual arrived at the EPG, his card was placed in the active file; cards of departed personnel were held in an inactive file. The active file, which included anticipated arrivals, was used by the IBM 704 Computing Section to prepare the rosters on IBM equipment. This new method of preparing rosters saved many man-hours of work previously required to type dittos and assembly rosters. The first muster was conducted on April 11 and 12, 1958, as a 1eak rehearsal, and the last one on August 18, 1958, for Fig. Musters were normally conducted on D—1 or D-day in order to minimize false starts. The shot site and the time of H-hour determined the commencement time of the muster and the details of operation. Therefore, the following is a discussion of only the most commonly used procedures. a. Shots at Eniwetok and/or Bikini Atoll 1. Muster of personnel at both Eniwetok and Bikini commenced at 1800 on D-l. 94