Piloting Double Variable Rate Sanders on the GB Mainline

Demonstrating in service a new approach to sanding to drastically improve braking in low adhesion.

Previous research by RSSB has shown that using multiple and variable rate sanders provide a step change in braking predictability compared with the current fixed rate sander configuration. Tests using a 4-car class 387 multiple unit on Network Rail’s RIDC Melton test track showed stopping distances in low adhesion halved when using two sets of sanders, known as double variable rate sanders (DVRS), and delivered assured 6% g braking.

adhesion infographic

RSSB is now working with West Midlands Trains to pilot enhanced sanders to:

  • Accelerate the roll out of double variable rate sanders by supporting early adopters
  • Demonstrate in-service benefits to the wider industry
  • Capture in-service data to unlock potential benefits achievable via improved and reliable braking performance such as the removal of autumn timetable and longer-term capacity gains

West Midlands Trains has fitted two class 323 trains with double variable rate sanders. These trains were chosen as they work an intensive stopper, metro-style service over the Cross-City line (Birmingham). The leafy nature of this line means services suffer from a performance dip during the autumn period due to low adhesion, making it a perfect candidate to pilot and demonstrate the benefits of this innovative technology.

These retro-fitted enhanced sander trains were introduced to service in late 2019 with the braking performance monitored and compared against unmodified units. If you would like further information on this pilot, please get in touch.

Find out more about results from our double variable rate sanders trials in the video below.

 Find out what the testing programme entailed and how we went about simulating low adhesion conditions on Network Rail’s RIDC Melton test track.   


Trials of sanders and sand laying rates (T1107) - report
Trials of sanders and sand laying rates (T1107) - research brief
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