A case study of 54 mm ropes operating on a double drum rock winder

In mid November 2004, Lonmin Platinum at their Marikana Operations, northwest of Johannesburg, installed two 1100 m long 54 mm diameter CASAR Turboplast ropes on the Karee No. 3 Main Shaft double drum rock winder. This was the first time a rope with eight compacted outer strands and a plastic coated steel core was used by the mine for vertical shaft mine hoisting. At the time of completion of this paper (June 2007) the ropes had completed 220,000 cycles and hoisted a total of 440,000 skips or 7.0 million tonnes of rock. The most recent magnetic non-destructive test showed that the ropes do not have any broken wires. The current operating life is approximately double the standard triangular strand rope life achieved previously on the same winder. This paper describes the full operating history of the ropes, the lubrication system used and the general maintenance practices. Through collaboration between the mine and the rope manufacturer, it has been possible to safely increase the number of cycles between backends (drum crops) from the standard 10,000 cycles to 30,000 cycles. This change, combined with fewer rope changes, has significantly benefited production efficiency and shaft safety.

Author(s): J. Kleynhans, J. Kapp, G. Rebel and B. Schmitz