STEADY STATE CURVING AND WHEEL/RAIL WEAR PROPERTIES OF A TRANSIT VEHICLE ON THE TIGHT TURN LOOP

This report describes the results of a test series carried out on the Tight Turn Loop at the Transportation Test Center (TTC) at Pueblo, Colorado, in order to assess the curving and wheel/rail wear performance of a transit vehicle when negotiating a very tight turn. Tests were performed with and without a restraining rail, and were limited to dry rail to ensure constant coefficient of friction. Wheel/rail forces and wheelset angles-of-attack were measured using both onboard and wayside instrumentation. In addition, rates of wheel and rail wear were measured using special profilometers available at the TTC. This report details the test setup and results and stresses the comparisons between experimental data and computer model predictions, which in this situation showed exceptionally good correlation. A relationship between theoretical wear index and wheel wear is shown, but the corresponding relationship for rail wear was undetermined because of the lack of adequate rail wear. The report concludes with recommendations for improved experimental techniques, suggested developments to the computer model, and a proposal for further testing on the Tight Turn Loop.