The impact of summer heatwaves on railway track geometry maintenance

Abstract

Elevated summer temperatures are a disrupting factor on the rail network. Due to the risk of a track buckling under thermal expansion forces, geometry maintenance must be delayed during heatwaves, leading to an overall decreased network availability and reliability. Track asset management support tools are used to plan and schedule a variety of maintenance activities, with tamping and stoneblowing being the primary activities for geometry maintenance. No management tools seen in the literature consider the influences of weather on the scheduling and delivery of maintenance. This paper describes a Petri net modelling approach to railway track asset management. This is demonstrated to be a highly flexible method able to capture the complexities of degradation, inspection, and maintenance, and predict the evolution of track geometry quality over time. Different maintenance strategies are tested, varying the degradation thresholds, inspection intervals, policy decisions, and maintenance response times. Excessively hot weather is introduced as an inhibiting factor for all maintenance activities, resulting in extended periods where interventions are delayed. Simulation results show that frequent inspection and timely maintenance scheduling strategies could be followed to attain a highly performing and resilient track system. This asset management support tool could be added to the suite used by the rail industry, providing guidance on maintenance policy through a summer season where heatwave disruptions are expected.