Reliability analysis of track circuit of Indian railway signalling system

This paper deals with the reliability modelling of one of the vital subsystems of railway signalling, called track circuit. The track circuit, a complex repairable system, is used to identify the occupancy of a portion of railway track by a train. It is observed that operations of track circuit are affected by a number of problems in relation to its intensity of use, repair and maintenance and environmental stress. Keeping in view its operating efficiency to the effect of these problems, the recommended parametric model based on repairable system technique is applied to estimate the failure rate probability of the system. Two graphical methods, viz., Nelson−Aalen and Total Time on Test (TTT) plots, are used to analyse the trend of the failure time data for a set of representative track circuits in Kharagpur Division of Indian Railways. Finally, the intensity function of the track circuit is assessed and investigated.