Advanced maintenance strategies for improved squat mitigation

Squats/Studs are rail surface damage patterns which cause high maintenance costs and can lead to safety issues when not treaded appropriately. The mechanisms behind their formation are manifold, complex and still not fully understood. It is agreed that Squats/Studs represents a system level problem, where the chosen maintenance technology contributes to parts of this complex system. Based on a simulation tool chain and experiments it is shown that rail milling can produce high quality rail surfaces ensuring that existing Squats/Studs are removed and that the risk of generating additional potential initiation points by the milling process itself is very low. •Overview of Squat/Stud theories to date.•Explanation of white etching layer formation (WEL) on rail surface.•Simulation of milling process with respect to temperature development of rail surface.•Milling track tests at different rail loading levels before/after milling.•Rail milling as a gentle rail maintenance technology to mitigate Squats.