Drums, wire-rope, design

When working near thie miriimUm design factor, consideration should b given to, the efficiencies of, wire rope bent around sheaves, fittings, or drums. Figure 4-70 shows how rppe, can bfe affected by beriding,... 

The proper design of sheaves, drums, and other equipment on which wire rope is used is very important to the service life of wire rope. It is strongly urged that the purchaser specify on his order that such material shall conform with recommendations set forth in this section. 

Application of synthetic rope technology to Iriction hoists in deep underground mines has the potential to allow for effective production from significantly greater depths than currently possible with steel wire ropes. The primary difference between the application of steel and synthetic ropes to friction hoists at today s and future depths is that steel rope is limited by the strength per mass properties of the rope while synthetic rope is limited by the friction over the drum generated by the coimterbalance mass and system design. 

Calculations and optimization for a friction hoist rely on the friction over the drum, the counterbalance mass, and the strength of the hoist motor. Replacement of steel wire with synthetic rope results in a dramatic reduction in hanging mass, which in turn affects each of these design parameters and their interactions. A system model was developed to determine the hmitations and adjustments to design factors for a range of hoist depths. 

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