A mine hoist uses a 2-in 6 x 19 monitor-steel wire rope. The rope is used to haul loads of 4 tons from the shaft 480 ft deep. The drum has a diameter of 6 ft, the sheaves are of good-quality cast steel, and the smallest is 3 ft in diameter.
(a) Using a maximum hoisting speed of 1200 ft/min and a maximum acceleration of 2 ft/s2, estimate the stresses in the rope.
(b) Estimate the various factors of safety