Experience of premium grade rail steels to resist rolling contact fatigue (RCF) on GB network

Network Rail is involved in a number of initiatives to reduce rolling contact fatigue (RCF) crack initiation on wheels and rails on the GB network. One of these is the trial of premium grade rail materials to determine whether they provide enhanced resistance to RCF crack initiation. The sites where trials have been undertaken have been selected to comprise a range of track and traffic conditions, and were regularly monitored. This paper describes the results from one of these trial sites, on a tight radius curve, where it was found that the risk of RCF actually increased with the use of premium grade rail. It is shown that, although this was initially considered surprising, it is consistent with the current understanding of the mechanisms of RCF initiation. This demonstrates that premium grade rail steels may not always be the best solution to prevent track damage and that careful consideration of the track geometry, operating conditions and traffic should be taken when considering the most appropriate rail grade to select for use at a given location.