Field studies of the effect of friction modifiers on short pitch corrugation generation in curves

This paper describes field evaluation on the effect of top of rail friction control on short pitch corrugation growth on different mass transit railways in Europe and Japan. Measurements were made during baseline conditions to evaluate the rate of growth of corrugations. Friction modifier (FM) was then applied using wayside application equipment, in some cases after grinding to re-establish an uncorrugated state. It was observed that FM application reduced the rate of corrugation growth by a factor of 6–11 times. In most cases there were little or no new corrugations when FM was applied on sites that formed corrugations rapidly under baseline conditions. Modelling showed that the test sites had a range of contact conditions, indicating that the effect of FM on corrugations is insensitive to changes in profile.