Slipping resistance of monocable aerial ropeway carrier grips

Abstract

In France, and in particular since a fatal accident with a chairlift in 1980, no relative displacement of the fastening versus the cable is considered acceptable. The French Ministry of Transport has been conducting a research program since 1987 to contribute to improving knowledge of the phenomena involved, fastening design criteria and conditions for qualification tests. A large-scale test apparatus has been set up and was presented at the OITAF congress in 1987 in Grenoble. At the last OITAF Congress in Barcelona, in 1993, we presented the results of tests that revealed a significant loss of the fastening's resistance to sliding when the cable was subjected to torsional movement. The present paper gives: -an analysis of the results of measurements on the torsional movement of fastenings on detachable chairlift and cable car systems; - a presentation of the state of our knowledge of the conditions under which the jaws of the fastening contact the cable and consequences on design of fastenings; - an analysis of conditions for qualification testing of fastenings at the industrial scale. The results of a stability study on a fastening, bearing the load of a car, on a cable sloped to 40 degrees and subjected to a twisting movement, are presented.