Development of resin cappings for wire ropes in mines - part 2: service trials on friction-winder ropes

More than thirty years of development work, incorporating field trials and recent service experience, have culminated in the adoption of the Wirelock resin capping system for locked-coil mine hoisting ropes in the United King dom. A previous publication covered the history of the development of resin cappings in the United Kingdom; a summary is now presented of the findings from both the early trials and trials to study the effect of an extended s ervice life of up two years on the integrity of the cappings. The various f actors that influence the strength of a capping are discussed; the importan t features are illustrated; and the problems and defects encountered during the trials and in later service are analysed. Some changes to the brushing methods originally used with white metal were found to be necessary, especially where cappings were required to remain in service for extended periods. Among the important aspects discussed are th e manner in which the end of the locked-coil rope is opened out to form the brush so as to ensure that no sharp bends or twists are produced in the fu ll-lock outer-layer wires in the critical area at the root of the brush; th e shaping of the brush and its symmetry; adequate degreasing of the brushed wires; and, after curing, the vital few millimetres of bedding-in movement of the resin cone into the socket as soon as a load is applied to the rope .