A design methodology for wheel and rail profiles for use on steered railway vehicles

Abstract

The geometry of the interface between steel wheels and steel rails can create conditions which affect the dynamics of a vehicle, the development of rail and wheel corrugation and noise. It has come to be expected that the worn profile of the wheel is uncontrollable and must be regularly corrected. This reflects the normal experience with non-steered trucks. Dynamicists have usually chosen a range of conicities to bound the performance of a vehicle design. Maintenance techniques have then been used to control the conditions occurring in service to be within these bounds. Hunting (instability generated by the self-centring action of the coned wheelset) is thereby controlled. Increasing demand for higher performance reduces the range of conicity allowable (using conventional truck technology). The cost of maintaining that conicity increases. The design technique described here enables wheel and rail profiles to be developed which have a limited range of conicity throughout their life, generate little noise, greatly reduce corrugation and, when used on steered axle vehicles, together with the described techniques of trade geometry control, can be virtually self-perpetuating. These are important benefits for the system operator.