Technical Reports

Effects of Rail Profile Variation

  • 01
  • Mar
  • 1986
AUTHOR: G. W. Walker
SUBJECT: Rail and Infrastructure Integrity
KEYWORDS: Heumann Wheel Profile, Rail Corrugation, Rail Grinding, Rail Wear, Rail Wheel Radius
ABSTRACT: Railroads in various countries including the United States have found that benefits may be obtained by grinding rails to an 'asymmetric' profile rather than to the original 'new' rail profile. To investigate these findings further, the Federal Railroad Administration (FRA) and the Association of American Railroads (AAR) sponsored and conducted a Rail Profile Variation test at the Transportation Test Center (TTC) in Pueblo, Colorado. The first objective of the test was to select, from among four prospective designs, the one specific rail profile with the best computer-predicted performance after mating that profile with a modified Heumann wheel profile. The selected profile then served as the design base for tests of three specially ground rail profile designs and an unground control rail (standard 136-lb RE). The four profile designs were then tested, in track, by designating one zone for the unground control rail and grinding three other zones to the specifications of the profile designs. Five separate curves in the TTC track layout, of 1.5, 3.0, 4.0, 5.0 and 7.5-deg of curvature, were prepared with the four-zone test segments. In-track testing was conducted with a 'mini-consist' of locomotive, two buffer hopper cars, a loaded hopper car with instrumented wheelset, and an instrumentation car. Results showed that profile grinding can effectively reduce lateral and longitudinal forces and decrease the rate of rail wear on unlubricated track. Severe grinding proved more practical for curves of less than 4 deg, while moderate grinding proved effective for curves of more than 4 deg.