Dutch research results on wheel/rail interface management: 2001-2013 and beyond

This paper discusses the state-of-the-art procedures obtained in the research projects performed by Delft University of Technology and ProRail, together with other partners and experts, such as Netherlands Railways, to optimize the wheel/rail interface on the Dutch rail system. The wheel/rail interface has been the focus of a significant number of research projects and improvement measures in the Netherlands over the last 10 years. ProRail's rails are subjected today to a 'stress regime', with high friction and loads from their operation, certainly since the introduction of new rolling stock and new rail types. This has resulted in cracks and premature loss of rail life due to rolling contact fatigue (RCF), particularly in curves and turnouts. Once damage occurs, it accelerates the degradation of track. This can be avoided by grinding that introduces artificial wear and moving more towards a 'wear regime', where initial cracks do not 'survive' and do not have the possibility to initiate and grow to form deep defects. Following this philosophy, a preventive gradual grinding strategy has been implemented to remove developing fatigue damage. Also, resistance to stress and avoidance of stress on the rails have been identified as possible strategies. This has led to various developments. A new 'anti-head check' rail profile (54E5) and use of new rail steels have led to reduced contact stresses and RCF initiation. Wheel/rail interface conditioning is being introduced to reduce noise and contact stress using on-train applicators. Wheel profiles have been optimized based on the new 54E5 profile and ongoing research focuses more and more on a holistic approach to wheel, rail and bogie design. This paper presents key projects and outcomes of the RCF research programme.