Quantifying the Effects of Railhead Treatments on Adhesion

Each year, the GB rail industry invests around £64.5M to mitigate and manage low adhesion problems. Measures include Rail Head Treatment Trains (RHTTs) and Traction Gel Applications (TGAs). While these treatments are widely used, there isn’t yet comprehensive in-service data to quantify their effects on braking.  

As well as these regular annual measures, industry also invests in new initiatives such as Double Variable Rate Sanders (DVRS) and the Adhesion Treatment Using Service Train (ATUST) system, a train-borne solution that deposits friction modifier to the wheel-rail interface at specific locations. 

An RSSB research project will evaluate the effects of different railhead treatment over the Birmingham Cross-City line. The leafy nature of this line means it has a number of low-adhesion risk sites.  

Building on RSSB research undertaken on the Cross-City line in 2018, this project will look at how low adhesion affects the ability to keep to timetable, and what level of braking improvement is generated by different railhead treatments. It will also consider the effect of other factors, such as driving style. 

Data on braking distances and adhesion levels will be collected from six class 323 units, and analysed alongside additional operational data supplied by West Midlands Trains and Network Rail. 

We expect to publish the results in time to inform seasonal preparedness strategies for autumn 2020.