Technology Digests / Study of RCF Progression as Affected by a Rail Grinding Facet

TD26-019

Date Posted: August 21, 2026
Authors
  • Ulrich Spangenberg
  • Ananyo Banerjee
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Key Findings

  • Intersecting facets from rail grinding create a sharp ridge that affects wheel-rail contact but wears off quickly and does not cause RCF initiation but rather causes conformal wear of the wheel and rail, which ultimately reduces RCF cracking.
  • Testing on the RCFS showed RCF initiation occurring on the deep grooves created by the grinding stones and RCF growth happening at pre-existing RCF cracks.
  • Observations made using an optical microscope regarding the crack depth on samples showed the greatest number of surface cracks along the perpendicular direction. This observation highlights the importance of using non-destructive techniques to measure crack lengths and depths at different angles before and after grinding.

Study of RCF Progression as Affected by a Rail Grinding Facet

As part of the Association of American Railroads’ (AAR) Strategic Research Initiative (SRI) program, MxV Rail engineers investigated how a sharp intersection of two facets produced by rail grinding may influence the initiation and growth of rolling contact fatigue (RCF) cracks. MxV Rail’s Rolling Contact Fatigue Simulator (RCFS) was used to test a rail obtained from service. The current investigation builds upon the knowledge gained from testing and modeling that was reported in a previous Technology Digest.1 INTRODUCTION AND BACKGROUND Rail maintenance grinding is a well-known and well-established technology used to restore the rail profile to a template profile and reduce the severity of surface initiated RCF, among other things. The rail grinder uses multiple grinding stones, set to predetermined angles and pressures and driven by motors, to grind and shape the rail profile to comply with a desired, ideally smooth, template profile. A grinding facet is produced where each…