11. As of September 2014, the motor drive is being serviced and the rope and sheave method is once again in use. 12. Sheave and rope wear may be significantly reduced by ensuring that all ropes have equal tension, thus sharing the load evenly.13. Where there is no space to rig a sheave the requisite distance from the drum, two additional spooling devices are available. 14. By decreasing the width of the sheave on the input shaft of the transmission, the belt would ride higher in the groove. 15. The diameter of a head block sheave used for galvanized aircraft cable is typically at least 48 times the diameter of the cable. 16. The main sheet block is a fiddle attached to the slide, and a dual sheave block on the boom with the upper. 17. The sheet comes off the upper large sheave to a block / camcleat mounted to the deck swivel for 6 : 1 purchase. 18. Sheave blocks, winches and snatch blocks were used to facilitate the lifting, and cables inside the pylons were stressed with jacks.19. The lifting device was a winch attached to a cable that fed over sheave ( pulley ) mounted on a mast behind the cab. 20. The dome tower and equatorial room are original save a motor drive which replaced the old rope and sheave method of rotating the dome.
