Risk Analysis in Railways

Considering the railway investments in Turkey, it is expected that there will be a significant increase in railway transportation in the near future. Train speeds will increase in parallel with train traffic in railways and improvements in train technology. With increased traffic intensity and train speeds, the risks for the operation safety will also increase. Train traffic and high speeds will accelerate the deterioration of the railways, which in turn will increase the number of maintenance and renewal works. These activities will cause the operation to be interrupted even more shut down the line for operation. In order to increase the efficiency of railway operation and competitive capacity with other transportation systems, maintenance and renewal work during the operation will become inevitable. During maintenance and renewal work under the operation, it will become even more important to take the necessary precautions and to carry out risk analyzes in order to ensure the safety of the train operation and workers on the line. For this purpose, the European Union has developed and implemented the standards EN 50126 and EN 16704. EN 50126 provide guidance on RAMS (Reliability, Availability, Maintainability and Safety) for the rail industry. EN 16704 is about to define common approach to the safety of workers regarding the railway risks in relation to work on or in proximity of the truck. In this study, reliability and risk analyzes were carried out for Turkish Republic State Railways (TCDD) in accordance with EN 50126 and EN 16704 standards. Statistical distributions such as Exponential, Poisson and Weibull were used in reliability analysis. In the risk analysis, Fault Tree Analysis, Event Tree Analysis and Failure Mode and Effect Analysis were used. As a result of the analyzes made, the maintenance and renewal studies carried out in TCDD were evaluated and suggestions were presented.