Technical Reports

Influence of Contact Patch Resistance on Loss of Shunt at Highway-Railroad Grade Crossing

  • 01
  • Feb
  • 1997
AUTHOR: Federal Railroad Administration
KEYWORDS: Loss of Shunt; Island Relay; Whetting current; Contaminants; Films; Highway-Railroad Grade Crossings
ABSTRACT: Results of testing completed to date have revealed no promising mitigation techniques to reduce or eliminate loss of shunt on highway/rail grade crossing island circuits. During the course of this test program, results have shown that resistive films that develop on the running surfaces of wheels and rails are a major contributor to loss of shunt. Some untested mitigation techniques, however, have been developed recently and may offer an effective long-term solution for removing these resistive films. This phase of testing was based on results of the field monitoring effort performed at eight field locations throughout North America by the Association of American Railroads, Transportation Technology Center, Pueblo, Colorado, to document statistical occurrences of loss of shunt (interim report titled "Influence of Contact Patch Resistance on Loss of Shunt," August, 1993).