Adhesion in wheel/rail contact influences performance and safety of railway traffic. Low adhesion brings problems during braking and traction. Sanding is the most common way how to increase adhesion when the poor contact conditions due to a contamination occur. On the other hand, excessive sanding leads to higher wear of wheel and rail. To optimize the sanding process, description of the influence of sanding parameters on the adhesion in the contaminated contact is highly required.
In this work a new twin-disc machine in scale 1:3 was developed and addressed to the study of wheel/rail adhesion under different contact conditions. An influence of sanding parameters such as sand quantity, wheel slip and rolling speed was investigated using a real sanding system in the contact contaminated with water, leaves and wheel flange grease.
It has been shown that under wet, leaf or grease contamination, quantity of the sand applied during fixed time period has significant effect on adhesion recovery only for low wheel slip and low rolling speed. In the contaminated contact the effect of sanding on adhesion recovery increases with wheel slip and rolling speed.