Familisrization with equipment used on Tumbler-Snapper and detection of methods of improvement were a valuable part of the training program for Operation Ivy. Some of the equipment operated satisfactorily and will be used on Ivy without change. Other equip~ ~ ment will require further laboratory testing and radical modification prior to its use in Ivy. B. Transport Dewar and Cryogenic Operational Tyass Cambridge Corporation has participated in several filling and test convoy runs with the transport dewars. Tests have been \ conducted both at Boulder and at Los Alamos on six of the dewars to be used in Operation Ivy. | Careful studies of boil-off rates, hazards of operation, techniques for convoying, and operating characteristics Several minor problems Cambridge Corporation took part in the cryogenics tests at Los Alamos and the dewar's capability to transport liquid hydrogen over long distances te were discovered and minor modifications accomplished. x fo of the refrigeration system have been made. was demonstrated. system were conducted in June. These tests included trial hydrogen fillings of the reflux system. The piping system is being revised as a result of the experience gained in the filling operations. Another hydrogen filling is scheduled for July. At this time the piping layout will duplicate the proposed Eniwetok layout as closely as possible. ~ 19 « wh