A : device to be tested, detection equipment, and other aces= sories are contained in a room at the top of the tower, called the "tower cab," There is usually an elevator, which is removed ‘prior to the stonetome a Ste ee * ‘There’ ape towers “for other purposes, |“guch as collinators, photography, and television. Cte . ! Balloon ‘winches and winch shelters are installed generally in areas that have bunkers and other installations used also in tower shots, Each balloon station has three winches installed in shelters to shield machinery from the nuclear detonation. Cables from the winches are used to raise and lower the balloons as necessary. A fourth holding cableis under the balloon, leading straight to the ground surface, Instrumentation and Structures. Through the years improve-= ments in the methods of testing nuclear devices have been as marked as the improvements in weapons themselves, This is particularly true of instrumentation ahd electronics engineering. In developing faster, more precise instruments the test organization has turned to trained manpower throughout industry, government, and the universities, Developments originating in this program have, as a by-product, contributed to the general development of instrumentation applicable to many other fields. The experiments require instrumentation ranging from very costly and complex electronics systems housed in monolithic, heavily-shielded underground recording shelters, to inexpensive and simple film badges and indenter gauges. There are cameras with framing rates in ranges from a few frames a minute up to 8,000,000 a second. There are neutron detectors, thermal instruments, and blast gauges. Each firing area is equipped with several permanent instrument stations, in addition to a wide variety of temporary stations and test structures used for one shot only, or at most for a Single series, Most stations, either permanent or temporary, receive power, telephone communications and timing signals from permanent local distribution points within various firing areas. A few outlying stations rely on portacle generators and radio for these services. Undefground Instrumentation Bunkers. Coaxial cables extend from the cab to an underground instrumentation bunker. They run direct from cab to bunker by the shortest practical line, rather than down the tower and across the surface of the ground, so signals will reach the bunker before radiation can shortcut the cables and before the cables are themselves disintegrated. In the ground, cables are laid in transite conduit, so that individual cables which may become defective with use can easily be pulled out of the conduits and be replaced. oi ~ iL, . ptt: re - 33 -_ Qe