Roping in uncertainty – measuring the tensile strength of steel wire ropes

Abstract

The CSIR Rope Testing Laboratory is responsible for destructive tensile testing of samples from steel wire ropes used on mine winders throughout South Africa. The regular testing of winder ropes are not only a legal requirement, but also of critical importance to enable early detection of degradation of the condition of the rope so that it may be replaced before the safety of people and equipment is endangered. To this end it is important the result of the tensile strength test is reported with known uncertainty. The estimation of the uncertainty of the measured breaking strength poses some interesting challenges for which practical solutions had to be developed.