Correlations among railway turnout geometry, safety and speeds

Railway turnouts are important parts of a railway track system which substantially influence train average speed and running safety. Although several investigations have been conducted on improving the geometry of turnout components from the perspective of turnout geometry deterioration, less attention has been paid to the effects of turnout geometry parameters on the safety of train running and permissible speeds. In this paper, the effects of turnout geometry parameters on railway running safety were investigated. The aim was to establish a relationship between turnout geometry parameters and permissible running speeds. For this purpose, a mathematical model of a railway vehicle and a turnout track was developed. The model accuracy was verified through field tests. Conducting sensitivity analyses of the model, the effects of turnout geometry parameters such as curve radius, switch initial angle and track gauge on running safety for various train speeds were investigated. The investigations were performed on turnouts with small and large curves. Mathematical relationships between the turnout geometry parameters and the permissible running speed were developed using the results obtained in this investigation.