ALTMA NSNT m ||| a Fh hae bl ave 4 fs toe CHAPTER Il, SECTION 3 MY f ! ‘ Figure 2-27. Tower cabs were equipped with roll-up shutter doors on three sides, which permitted operation by remote control and closing by means of a timing signal. Siding was removable on the elevator side of the cab, and a personnel door led to the towers’ vertical ladders. The LASL stations had a hand-operated bridge crane with a 6-ton chain hoist; the UCRL stations were equipped with bridge cranes using electrically-driven hoists of two-ton capacity. Shielding for Stations 6 and 7 consisted of concrete and paraffin which was supported by structural steel members; lead was used for Station 3; none was required for Stations 1, 2 and 4. As designed and built, the strength of the towers was controlled by the capacity of the ‘web system. Further increases in strength could therefore be obtained by reinforcing the web system and enlarging guy footings to match the tower leg strength. It was assumed in the design that when the tower was subjected to blast overpressure, all cab doors would be rolled up and the removable siding taken off. In addition to having its doors and cab siding rolled up the Station 7 tower was reinforced for heavy Page 2-46 Base of Station 3 overpressure on one side by removing all elevator and ladder appendages and by leaving the erection guys at the 100-foot level in place. A pile foundation was mandatory for all anchor blocks located on ocean reefs. To ensure a stable footing, four 12-inch H-piles were driven to a depth of 25 feet into the reef or coral base locations. Forms were then built around the piling and concrete placed. During the process of tower erection, tem- porary guy lines were used at the 100 and 200foot elevations. In order to keep the tower plumb during erection of each 25-foot section, a tensioning devise was fabricated with which the tower guys were jacked to final position using hydraulic jacks. The pressure in the jacks was indicated by a calibrated pressure gage. Permanent guy lines were tensioned to 10.4 tons. Sites of tower erection varied from the usual coral base and ocean reef locations to a man-made island connected by a causeway for Station 1, Sally. To construct the man-made island, a total of 21,860 pounds of rail piles was driven into the reef to an average depth of 15 feet and a cutoff elevation of plus 10 feet.