Research methodology for evaluation of top-of-rail friction management in Australian heavy haul networks

Abstract

Managing the coefficient of friction at the wheel/rail interface through wheel flange/gauge face lubrication is an accepted practice in railway systems. However, the coefficient of friction between the top of rail and wheel tread is not well addressed using this method, with traction, braking and some steering forces causing significant rail and wheel damage. Top-of- rail friction management uses friction modifiers to control the coefficient of friction within a defined range, and is being used in some North American rail networks with beneficial results. In Australia, there has been limited use of top-of-rail lubrication and where it is applied, it is mainly utilised to improve steering forces and mitigate wheel squeal. This research project sought a holistic understanding of top-of-rail lubrication and management of wheel/rail friction in the Australian context. A systematic approach for experimentation and analysis of the application of a friction modifier was developed in this study. The approach utilised an engineering analysis based on experimental results and publications and a numerical study for three-dimensional analysis. Vehicle system dynamics and wheel/rail operating conditions were then modelled through GENSYS simulation to understand variations in wear index with respect to friction conditions at the wheel/rail interface.