An analytical approach to study a special case of booted sleeper track rail corrugation

The present paper examines a specific kind of short pitch corrugation as observed on the low rail in some of the sharp bends that form part of a specific section of a railway line in the Bilbao area. The periodic irregularity appeared spontaneously when ballasted track was replaced by STEDEF slab track and separation between sleepers was changed from 600 to 1000 mm. This corrugation has an average wavelength of 66.6 mm and is particularly present at midspan, as described by Vadillo et al. [Effect of sleeper distance on rail corrugation Wear 217 (1998) 140]. This last characteristic differs from the majority of cases reported in the bibliography. To explain this rare behaviour, this study uses the simple linear model for corrugation developed by Frederick [A rail corrugation theory, in: Proceedings of the International Symposium on Contact Mechanics and Wear of Rail/Wheel Systems II, 1986, pp. 181–212]. Using experimental receptances and mobilities, and a model for computation of quasi-static wheel/rail forces and creep while negotiating the bend, the corrugation model obtains the expression that reveals the rate of wear at a specific point in the span, the function G(f). As a conclusion, it has been demonstrated that corrugation must initially be present at midspan. This result tallies with experimental observations and measurements undertaken, both in terms of location and frequency.