USE OF AUTOMATIC SIGNALLING SYSTEM FOR REDUCTION OF THE RISK OF TRANSPORTATION INCIDENTS IN RAILWAY STATIONS

Abstract

Aim. Evaluating the risk of collision between trains during shunting operations in railway stations. Risk is the combination of the probability and consequences of an event. The most complicated task related to risk assessment is the choice of the evaluation model for the probability of an undesired event. The model must ensure practical applicability of the results. In the context of railway facilities the construction of analytical models of probability evaluation is of principal interest due to the possibility to demonstrate the factors that are taken into consideration by the model. The main purpose of this paper is to examine the extent to which the Shunting Automatic Cab Signalling System (MALS) contributes to the probability of side collision of trains involving shunting engines in railway stations. The main function of the Shunting Automatic Cab Signalling System is to ensure that shunting engines do not pass signals at danger in stations. Methods. Methods of the probability theory and theory of random processes, addition, multiplication formulas, composite probability, properties of Poisson flows. In [2] a method is suggested for calculating the probability of collision as the result of shunting or train locomotive passing a signal at danger. The development of the method was based on the main assumption that the flow of shunting consists for each switch is a Poisson flow. This paper suggests a modification of this method that takes into consideration the possible use of the MALS system with shunting engines. The input data for the algorithm of calculation of the collision probability are the station topology, passenger train schedule and their possible routes through the station, average train lengths and speeds, as well as the frequency of shunting consists passing over switches. Results. An algorithm has been developed for calculation of the probability of train-to-train collision involving shunting engines within a random time period. For different operating modes, e.g. pulling up, coupling, formulas are shown for calculation of the probability of collision with a passenger or freight train on a random switch. The algorithms consists in the following: 1) a time period is specified for which it is required to calculate the probability of collision; 2) passenger train timetable is designed using data from ASU “Express”; 3) overall number of passenger trains passing through the station within the specified time period is calculated; 4) passenger trains are renumbered according to the order of their arrival to the station; 5) probability of signal violation by shunting engine driver is calculated; 6) probability of violation of traffic safety by shunting engine driver in the “pull up” mode is calculated; 7) probability of violation of traffic safety by the shunting engine driver after coupling with the “coupling” mode off is calculated; 8) overall number of possible routes for each train is calculated; 9) for each train the frequency of one or another route is identified; 10) for each switch of each route a number is specified in the order of appearance; 11) probability that each passenger train on each route has at least one collision is calculated; 12) probability of at least one collision of each passenger train moving through the station is calculated; 13) probability of at least one collision in the station within the specified period of time is calculated. The paper considers the example of calculation of collision probability for an individual train route and the station as a whole within a month and a year. It shows that the use of MALS helps significantly reduce the probability of side collisions in railway stations.