Calculation of the dynamic loads acting upon a rope grip as it passes around the bull wheel on a fixed grip quad chair lift

Abstract

In the case of fixed grip chair lifts, the carriers pass around the bull wheels at full rope speed. The introduction of loading carpets made it possible to further increase rope speeds with a view to shortening trip times. When passengers attempt to leave the lift at bull wheel exits, the relatively high rope speed leads to a risk of the passenger failing to vacate the chair in time and thus travelling around the bull wheel. If this happens, the centripetal acceleration in particular causes excessive wear on the grip, hanger arm, and carrier. The aim of this paper was to develop a method, and subsequently a computer program, which would make it possible to calculate the dynamic loads on the rope grip and hanger arm when the carriers travel around the bull wheel. The simulation program developed was verified by recalculating an existing installation, the 4-CLF quad chair lift Saloberkopf/Schrocken/Vorarlberg supplied by the Austrian manufacturer Doppelmayr of Wolfurt.