SPS Feasability Study SD76SA0239-2

Figure 3.4-1. Rotary Joint, Slip-Ring Structure, and Electrical Track supports from one to two meters apart. The insulator structure is mass- produced on the ground and installed and shimmed by long bolts that permit a 16-sided polygon of 50-meter tribeam trusses, each element side being approximately four bays long. The SPS structure facility is used to fabricate the truss elements as identified in Figure 3.4-2. The construction and maintenance cable crane-way devices transport the tribeam segments to the slip-ring. A completed slip ring and a partially-completed slip ring are shown. The rings have interconnecting trusses and wire-bracing that causes the two rings to rotate as a rigid-body single unit. 3.5 MICROWAVE ANTENNA TRUNNION STRUCTURE BUILDUP Completion of the slip-ring assembly permits the installation of the trunnion structure identified in Figures 3.5-1 and 3.5-2. The trunnion structure utilizes the 50-meter tribeam with special joint requirements due to angular relations of the structural elements. Fortunately, variations of the fittings illustrated in Figure 3.5-3 serve to connect most of the joints. 3.6 MICROWAVE ANTENNA ASSEMBLY The microwave antenna structure consists of an outer compression frame and three catenary tension-wire arrays that support the microwave antenna elements and maintain the flatness of the slotted array transmitting surface.