Field and laboratory investigation of the relationship between rail head check and wear in a heavy-haul railway

Head checks (HCs) are widespread in railway tracks. They can cause rail fracture. In theory, and under some laboratory conditions, a proper amount of natural wear exists which is just enough to suppress HC initiation and growth and is called magic wear rate. It will minimize the costs of rail maintenance. In practice, such magic wear rate still seems elusive. This paper is an attempt to investigate the feasibility of magic wear rate under operational conditions. To such an end, the growth of and competition between HCs and wear in the high rail of a curve of a heavy-haul railway is analyzed. The length and depth of the HCs were measured by laboratory examination and image recognition from rail specimens sampled at different traffic gross tonnages. Rail wear was calculated from the measured rail profile. Three phases of HCs and wear evolution and competition were identified. It was found that the wear rate was almost constant for a broad range of traffic tonnages, even though the rail hardness varied significantly. With such a wear rate the initially severe HCs were reduced in size, indicating the feasibility of engineering magic wear rate to avoid HCs by the proper design or selection of the materials and profiles of the rails. (C) 2014 Elsevier B.V. All rights reserved.