7.4.6 Power Operated Winches

A wide variation of power operated winches is available, which allow for higher capacities and longer rope movements than hand winches. They are used for applications where manual operation is impracticable or undesirable. The motive force may be electric, hydraulic, pneumatic or by petrol/diesel engine, the latter allowing for greater portability. In the case of hydraulic winches, the hydraulic pressure is developed by an integral compressor power pack which itself is driven by electric motor or petrol/diesel engine. Capacity varies with design. Electric winches are generally available with capacities up to 15 tonnes, pneumatic winches up to 25 tonnes and hydraulic winches up to 30 tonnes. However specially manufactured power operated winches may be available to far higher capacities and it is necessary to consult the manufacturer to establish the range of capacities they are able to offer, which may be in excess of 100 tonnes. Figure 7.4.6-1 , Figure 7.4.6-2  and Figure 7.4.6-3  illustrate some typical power operated winches.

Power operated winches are usually foot mounted for permanent or long term installation, either to a suitable foundation or for building into other structures. Design variations permit the wire rope to be taken off the drum either vertically or horizontally. It is necessary to consult the manufacturer to establish the rope drum storage capacity as these vary greatly and can be several hundred metres and drum sizes can often be varied to suit particular applications.

Operating speeds also vary with design. Power operated winches may be single speed or dual speed and a no load fast rope pay out facility is usually available. Again, it is necessary to consult individual manufacturers to establish the availability due to the wide range of variations possible.