The influence of wheel profile on the safety index

Railways around the world are seen to use data from wayside detectors to drive vehicle maintenance strategies and to increase safety by finding and fixing the 'bad actors'. VALE, one of these railway companies, has installed a truck performance detector and one wheel profile detector on the Estrada de Ferro Vitoria Minas (EFVM). Although it is well known that the wheel profile has a strong influence on vehicle dynamics, especially on safety parameters such as lateral over vertical forces at the wheel rail contact (L/V), each railway has its own particular vehicle-track interaction. On EFVM, wheel re-profiling is typically done because of thin flanges. This article shows the correlation between wheel profiles and safety performance predicted by modelling to find out the wheel profile limits that should be applied from the safety point of view. Wheel-rail contact theory and vehicle dynamics have been studied. L/V values and hunting speeds have been calculated. Many wheel profiles have been analysed. The results show that it is possible to set the limits used by wayside detectors to identify 'bad actors' and to increase the overall safety.