Abrasive wear of railway track by solid contaminants

The operation of railway track is likely to involve the presence of solid contaminants on the line at some stage. This may be from the dispersion of freight goods such as coal or minerals, or the presence of ballast stone thrown on to the track either by the passage of the train or during ballast cleaning operations. In addition, where a driver experiences low traction (particularly on steep or liquid-contaminated track), sand may be deliberately placed on the track surface to improve traction. Railway track in dessert areas is also known to suffer from severe wear induced by wind-borne sand particles. The effect of these contaminants is of concern since they may cause damage and accelerated wear of both track and wheel. This paper attempts to examine the effect of brittle contaminant materials on the wear of railway track. A series of small-scale laboratory experiments has been carried out in which crushed granite ballast is fed into a rolling-sliding contact. The level of surface damage is shown to be slight and generally insignificant when compared to normal rail roughness. However, the repeated entrainment of solid particles can lead to excessive wear. An attempt has been made to quantify this wear process and to develop a simple empirical model.