Novel alternative particle systems for managing friction in the wheel/rail interface

At present, silica sand particles are used on GB railways for traction enhancement. In this study, novel particle systems with a range of properties were assessed to see if there was potential for particles to be more widely used in friction management. The tests were carried out at representative contact pressures, using the High Pressure Torsion (HPT) approach. Particles were applied to dry, wet and leaf-contaminated interfaces. A strong relationship was found between particle hardness and traction. Particle systems were identified that could be used to lubricate the interface (friction < 0.1) or provide intermediate levels of friction (0.2–0.3), and one that could be used for traction enhancement as an alternative to silica sand (increasing friction to above 0.1 with a leaf layer present).