An applicable topology-independent model for railway interlocking systems Original Research Article

In this article, two decision models for railway interlocking systems are presented. The first – for the case that the turnouts have spring switches- and the second – for the case that the turnouts should not be trailed through a switch set against-. In both cases, the algorithm is independent of the topology of the station and is based on the calculation of accessibility in an oriented graph. Both models are surprisingly brief and easy to implement in Maple V.4. The package analyzes any change in the position of the switches and the clearances given by the semaphores, and supervises if it is safe to authorize the change. Any turnout, that could be trailed through a switch set against, is also studied in the second model. In both cases, the fact that trains could occupy more than one section is considered. Some examples are included.