Does Rail Grinding Reduce Rail Defects

A primary benefit associated with rail profile grinding is the control of rail defects, particularly rail fatigue related defects. While numerous studies have looked at this effect, most studies to date have been on limited test zones or for limited time periods. However, one recent study, the subject of this article, took a long-term global view, examining the benefits of rail grinding on more than 20,000 miles on a major U.S. Class 1 railroad over a 5-year period. More than 30,000 rail fatigue defects were included. The main focus was an assessment of the effectiveness of rail grinding in reducing the occurrence of rail defects and the associated need for rail replacement. Thus, the detailed analyses focused on those rail defects affected by rail grinding, and specifically on fatigue related defects. The aim was to evaluate effectiveness of the railroad's grinding program from a perspective of effectiveness in maintaining rail track, reducing the rate of development of rail fatigue defects, and thus extending rail fatigue service life based on actual railroad experience with rail grinding. This effectiveness study used data from a major U.S. Class 1 railroad for the 5-year period from 2003-2007. Using railroad data showing territory (track) ground by the contractor's grinding equipment, the effect of rail grinding was examined by separating the railroad main line tracks into 2 broad categories: ground vs. not ground territories. These territories were then compared based on tonnage and traffic characteristics. Because of the scope of the study in terms of both time and territory, the data was of sufficient validity as to allow for a statistically significant analysis of the rail defect behavior. This included sufficient data in both the no-grind and the grind data groups to allow for a valid comparative analysis.