Planning Rail Grinding Using Crack Growth Predictions

Abstract

Rail grinding is a widely used rail industry technique for maintaining the quality and safety of railway track. Rail grinding can be used to restore the profile of the rails, remove surface plastic damage and remove or reduce in size very early stage surface breaking rolling contact fatigue cracks. This paper focuses on the use of rail grinding to extend the safe life of a rail that would otherwise be limited by rolling contact fatigue (RCF) defects. The optimum grinding strategy for a variety of conditions has been investigated using a model that predicts the growth of surface breaking cracks in rails loaded by rail vehicle wheel contacts, taking into account natural wear of the rail and rail grinding. It was found that a grinding strategy which removes incipient cracks in a specific period of time without being over-conservative and producing excessive material loss must take into account all traffic using the line, not just the traffic perceived to be most damaging. A mixed traffic case is modelled, revealing the potential for interaction between different vehicle types in determining maintenance requirements.