Synthetic fibre ropes for mine winding
Mine hoisting is carried out from depths of up to 4 km. At these extreme depths, the steel wire ropes used are so heavy that a large part of their capacity is employed in lifting themselves. Consequently, deep mines have a costly intermediate winding station, and even at lesser depths the self-weight of the rope reduces the payload. Of course, steel wire ropes have, over the years, demonstrated exceptional reliability and acceptable lifetimes. Their use is supported by well established operating rules and sound NDT methods. However, lightweight ropes made from synthetic fibres could be of great benefit to the industry, with the prospect of eliminating two-stage winding and substantially increasing payloads. Initial tests have demonstrated that an aramid co-polymer fibre, Technora®, is a candidate for this application. This paper summarises the results of testing carried out on aramid co-polymer and other synthetic fibre ropes, results that hold out the prospect of exceptionally long service lives. Possible NDT methods are also reviewed. It is recognised that the introduction of aramid co-polymer ropes will require further extensive testing, and some suggestions for the scope of such testing are presented.