OIPEEC – International Organization for the Study of Ropes

Winder rope bottom layer (back end) maintenance

Mostert, S. and Musgrove, P. Winder rope bottom layer (back end) maintenance, Proceedings of the OIPEEC Conference ‘How to get the most out of your ropes’, September 2007, Johannesburg, paper no. ODN 0805 , 27-33, ISBN: 978-0-9552500-1-9.

The purpose of the paper is to describe appropriate maintenance practices for the entire bottom layer on drum winders and in particular the back ends (dead turns). To obtain good rope life it is very important to conduct regular assessments and maintenance. Visual assessments on a regular basis are important as these can identify the first signs of plastic deformation on the crown wires (tram lines). Magnetic rope condition assessments on the day of the back end cut can assist with the decision on the length of rope that needs to be pulled in. Experience over many years has shown that defects develop in this section of the rope and such defects can only be identified and properly assessed when the entire rope is reeled off the drum. The advantage of the back end cut is that it moves the crossover points which have a direct influence on the rope life. (2 refs.)

 

Grimestad, S. and Johansson, B. A method to increase the head rope life of single conveyance friction hoists at hoisting distances up to 2,000 m by reducing the static load range, Proceedings of the OIPEEC Conference ‘How to get the most out of your ropes’, September 2007, Johannesburg, paper no. ODN 0806 , 35-56, ISBN: 978-0-9552500-1-9.

The authors discuss the advantages of reducing the static load range of a single conveyance friction hoist for depths up to 2,000 m. These include: The rope service life for single conveyance friction hoists for deep shafts can be increased, or alternatively the hoisting distance for friction hoists can be increased, by reducing the static load range; the static load range can be reduced by reducing the tail rope mass compared with the head rope mass. This solution can be used for friction hoists with a hoisting distance from about 1,400 m to at least 2,000 m; and, for a single conveyance friction hoist the static load range can be reduced below 11.5 % without exceeding the acceptable margin against rope slip, even if the rope safety factor is as low as 6.0 at hoisting distance S < 1,850 m. (2 refs.)

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