Influence of leaf, humidity and applied lubrication on friction in the wheel-rail contact: Pin-on-disc experiments

Abstract

A novel test method has been used to study how applied and natural lubrication (leaf and humidity) influences the coefficient of friction in the wheel-rail contact. A pin-on-disc tribometer placed in a climate chamber was used as the test equipment. The pin-on-disc contact simulates the wheel-rail contact caused by commuter train traffic on straight track. The results show that the coefficient of friction decreases when the relative humidity increases and decreases even more when a leaf is used as a lubricant. By using an elm leaf as the lubricant, the coefficient of friction is reduced by a factor of four compared with the unlubricated case. However, the coefficient of friction decreases even more when a rail lubricant is used.