Investigating Friction Modification and Potential Wear Reduction in the Railroad Wheel to Rail Contact

Reduced friction with top of the rail friction modifiers continues to be investigated for improved energy efficiency and reduction in lateral forces between railroad car wheels and the rail. Another benefit often not considered is the potential reduction in wear of both the wheel and the rail surfaces. This paper details the results of fundamental laboratory test work to compare dry contact condition with one where a “friction modifier” has been applied, to define the difference in the surface deterioration and wear. The basics of this wear testing are described, along with information on the materials used for the testing. The results show a very significant difference in friction coefficients and the wear characteristics, suggesting substantial benefit potential in both reduced rail wear and wheel tread wear. Selected wheel wear tests are discussed and historical wheel wear information is provided. Wheel life data for two North American coal freight car fleets are reviewed to point out the average mileage of wheels in service. The potential for increasing wheel wear life, and therefore potential cost savings, is highlighted. Finally, recommendations for future work are offered.