must be met for major scientific construction requirements and that a deadline of 1 June 1952 must be met for less complex structures. Approximately 800 sheets of drawings were prepared for this operation, and by 1 September 1952 all home-office designs had been completed. The first portion of construction for Operation Ivy was the cryogenics-area facility which was started in late 1951. By 20 October 1952 all construction had been completed in time for the previously established firing date. Because of the large amountof instruments and equipment to be installed in major scientific stations, it was necessary to work considerable overtime in order to complete construction by deadline dates. More than ten million dollars was required for construction on this operation. Of this amount, approximately seven million dollars was for scientific-test or test-supporting con- struction, and the remainder was for Parry Island base facilities. Scientific-test construction consisted of scientific stations to house instruments, recorders, cameras, etc. Test-supporting construction consisted of a causeway, marine pier and ramp, an airstrip, and two tent camps. Base facilities on Parry Island consisted of a 3000-kw power plant, machine shop, and various buildings for a cryogenics plant and appurtenances. Over 500 scientific stations were constructed on 30 separate islands in addition to reef locations on Eniwetok Atoll. These stations ranged from the simple, such as those on small rafts, to the complex, such as Station 1, which was the zero structure. Approximately 8600 cu yd of concrete had been poured in construction of all facilities as of 30 September 1952. Two temporary tent camps of 250- and 500man capacity, with roads and utilities, were constructed for housing scientific and construction personnel. Somedifficulties were experienced in construction because of slow delivery of critical materials and because adverse field conditions were encountered during the construction périod. Critical materials which required special action were submarine cable and aluminum, sheeting. Late in the construction period an existing submarine signal and communications cable failed, and it was necessary to obtain a replacement before the test date. By full ccoperation of all parties concerned, the cable was manufactured, transported by ship to the jobsite in September, and put in operation by the required date. Aluminum sheets necessary for the protection of a scientific station were transported by air and placed during October 1952. The large weight over a comparatively small area caused a scientific station to sink 3 in. a few days before the test date. Since there was not time to replace this facility and because the line of sight was an important factor in experimentation, there was considerable alarm. However, after a few days the structure reached a point of stability, and the experiment was successful. The steel strike during the summer caused some trouble, but most orders were delivered on time. High tides washed out a portion of the causeway, but, by fast work during low tide, the gap was filled. The contractor furnished support services to the scientific groups for the installation of their instruments and equipment. Major items of support services were the installation of cryogenics equipment and the transportation, loading, etc., of deep-well drilling equipment. Other instrumentation and labor support was furnished to the scientific groups as required. Housing, messing, laundry, and other ordinary municipal facilities were furnished to a peak population of approximately 900 personnel of the Task Force, exclusive of 1300 contractor personnel, on islands other than Eniwetok. The military garrison on Eniwetok reached a peak total of approximately 1600. The military garrison is self-sustaining except for maintenance of structures, which is furnished by the contractor. Marine transportation for intra-atoll travel is a contractor responsibility, but assistance is provided by the Navy during operational periods. 3.7.3 Intra-atoll Airlift Service The J-3 Section, Operations Section of TG 132.1, was assigned the responsibility for con- trolling the scheduling of all aircraft used in the intra-atoll air transportation service ina —~ ? 27