Assessment of Turnout-Related Derailments by Various Causes

Train derailments can mainly result in not only financial losses in the form of damaged rolling stock and infrastructure, but also more importantly in causalities and operational shut-down. Therefore, it is crucial for the railway industry to sustain a reliable and efficient operation and eliminate safety concerns. Analysis of accidents caused by train derailment is highlighted as one of the most crucial steps in the risk management chain. Considering various operational environment, the analysis enables reduction in the occurrence of derailment and prevents derailments in the most cost-efficient manner, as a variety of different causes and their frequency and severity are determined. In this paper, the methodology includes gathering and analysis of information on major derailments occurring at the turnouts from the UK. The causes have been categorised and then prioritised in accordance with the proportion of train derailments occurring within each category. The research objective is to determine the proportion of train derailments at turnouts and provide a starting point for the detailed analysis. In short, the aim of the paper is firstly to understand which factors under which circumstances pose the greatest risk at turnouts, secondly to quantitatively evaluate the relationship between derailment severity and frequency and thirdly, to determine the characteristics that cause major derailment and compare results with the characteristics in mainlines. The review analyses train derailments in UK over the last 15 years and demonstrates that the overall number of derailments have declined gradually and most derailments have occurred in yards. The dominant causes are identified as operational failures and component faults during track-train interaction, and track geometry problems are also seen to have a significant impact on derailment at turnouts, particularly in shunting yards. Furthermore, literature-based recommendations are used to address the issues arising from risks. The research outcomes are expected to aid the rail industry in developing, evaluating, prioritizing and gaining different perspective of derailment at turnouts to efficiently improve transportation safety and also to open a new gate to better understand the existing risk on railway turnouts.