Cable Crane

(cableway crane), a structure used to raise and lower loads and to transport loads horizontally over distances of 100-1, 500 m. Such cranes are used in open mine workings (strip pit rock, ore, block rubble, and so on) and at construction sites (earth or concrete).

A cable crane installation consists of two supports with a supporting cable stretched between them. A carriage equipped with a block-and-pulley hoist and a suspended scoop or car that can be raised or lowered moves along the cable on rollers. The carriage is driven by a traction cable, which passes through guide pulleys on the supports to the driving (traction) pulleys of a winch. The block hoist and the load are raised and lowered by the winch through a hoist cable. The supports are of the tower type. The tower containing the drive equipment and operating gear is the machine tower; the opposite tower is the support tower. The supports may be stationary or mobile. If stationary towers are used, additional transportation within the quarry (ditch) becomes necessary. Mobile towers usually move along rails, in parallel if both towers are mobile or radially if only one tower can move. The height of supports is up to 50 m. To increase the output of the installation, cable cranes may be equipped with two scoops, each of a capacity of up to 10 cu m.

Cable cranes have a load capacity of 5-50 tons, a span of 100-1, 500 m, and a hoisting height of 50 m or more. For large spans the speed of movement of the carriage on the supporting cable is up to 8-10 m/sec, the speed of lowering is 1.3-1.5 m/sec, the speed of movement of the supports is 1.3-1.5 m/sec, the number of cycles per hour is up to 25-30, and the power consumption is 7-9 kilowatt-hours per ton-km.