WEAR IN SIMULATED RAILWAY OVERHEAD CURRENT COLLECTION SYSTEMS

The wear rates of the pantograph contact strips and the overhead contact copper wire are investigated using a wear machine simulating a railway current collection system. The contact strip material used for the tests is the actual copper and lead-impregnated carbon used by British Rail (MY7D Grade) on all pantographs. Wear rates of the contact strip and copper disk (simulating the overhead contact wire) are presented and discussed. The dependence of the wear rate on the current (0 - 300 A both a. c. and d. c. ), the static contact force (1. 0 - 250 N) and the dwell time for intermittent sliding has been determined. The dwell time, representing the time lapse between pantograph passes, is shown to have a crucial effect on the copper wear depth per passage, owing to the formation and subsequent removal of an oxide layer on the copper surface. 29 Refs.