CHAPTER 5.16 ELECTRICAL POWER DISTRIBUTION The decision was made by J-Division to provide power plants for each of the headquarters islands and each of the main experiment is- lands, based on recommendations made by H& N. Consequently, the length of primary electrical power distribution lines was limited to not over two miles in any case. This led to the selection of 2400 volts as the generation and distribution voltage. Overhead, underground and submarine distribution were all used either individually or in combination as conditions dictated. Overhead distribution, being cheapest, was used for Eniwetok, Parry and Japtan Islands and for the camp areas on Engebi, the Aomon Group, and Runit. Underground direct burial cables were used for primary distribution and secondary feeders serving instrumentation and utility loads c. the experiment islands outside the camp areas and in the vicinity of airstrips, radio transmitter and receiver antenna farms and the Loran facilities provided for the Coast Guard. Submarine power cables were used for two water crossings. The experimental structures on Muzin were supplied from the power plant on Engebi and the photo tower on the reef south of Runit was supplied with power from the power plant on Runit. DESIGN The distribution systems were based on the criteria of locations, load, and other information known in the early part of 1949. As requirements increased changes were made, especially in the systems servicing experimental facilities, These changes sometimes resulted in less efficient power distribution system, but the flexibility of the overall system was maintained; and during the experiments, systems functioned well. Overhead lines were designed and installed for "medium-loading" in accordance with the requirements of the "Rules for Overhead Line Construction - General Order No. 95" of the State of California. The California rules were followed because they are nationally considered to be one of the best. This was fortunate in that it permitted a 50 per cent increase in the original system load with not more than a 5 per cent primary voltage drop and made the system flexible enough to permit many changes and additions to meet new requirements made by the more than twenty Users served. The overhead distribution system was designed to overcame many anticipated problems, It was sectionalized so that it would be possible to de-energize sections for the extraordinary maintenance that weather and salt spray would make necessary. Deterioration of transformer oil was foreseen, and oil testing and cleaning equipment was specified for this installation so remote from mainland electrical 5-231