6.2 Rail planing issues
Rails are planed in order to remove a significant depth of damaged material (typically >1mm) or deliberately to change the rail’s transverse profile. Discontinuities in profile that give rise to high contact stresses can be created more easily than with grinding, because of the greater depth of metal removal. This is the case here, where a central plateau with abrupt edges has resulted from planing. The characteristic coils of swarf that result from this operation sometimes lie alongside the rail.