Home Rail News RSSB Sponsored Double and Variable Rate Sanders Trial: The Results

RSSB Sponsored Double and Variable Rate Sanders Trial: The Results

In November 2017, Rail Engineer reported on tests sponsored by RSSB being carried out at RIDC Melton to evaluate the use of both sanders on more than one wheelset on the train, and sanders that can deliver sand at a variable rate with the aim of providing more dependable braking in challenging adhesion conditions. Results were due in early 2018. On 6th and 7th February, the results were presented to the industry.

The Adhesion Research Group (ARG) had challenged developers to provide solutions that could achieve a braking rate of 6%g (0.6m/s2) in challenging adhesion conditions. If successful, the following benefits could be delivered:

  • No need to adjust schedules in the autumn
  • Virtual elimination of adhesion related SPAD incidents
  • Virtual elimination of adhesion related platform over runs.

It would also contribute to the Rail Technical Strategy objectives of running trains all year round “timed and delivered to the second” and “closer together”.

The results were transformational and offer the potential of a step change in performance; certainly the ARG’s challenge was delivered during the tests. A gross summary below of the very detailed and complex results highlights the benefit.

For braking in “step 3” (0.9m/s2) demand from 55mph on low adhesion rail with an untreated friction level of 0.02 (very challenging), the following stopping distances were recorded with sand applied continuously throughout the stop:

  • No sanders: >1200m,
  • Single, axle 3, fixed rate sander: 800m (the current good practice for most modern trains),
  • Two fixed rate sanders: approx. 650m,
  • Single variable rate sander: approx. 600m,
  • Two variable rate sanders: 400m.

Put simply, putting down more sand in the right places halves the stopping distance compared with today’s current good practice.

The challenge is now to encourage the industry to adopt the results and work rapidly to develop modifications to existing and new trains to implement the findings. There’s a lot of benefit, and the industry estimates that autumn adhesion problems cost the industry nearly £350m per annum.

Read more: On board ScotRail’s new Class 385



Please enter your comment!
Please enter your name here

This site uses Akismet to reduce spam. Learn how your comment data is processed.

Must Read


A future role for Bennerley Viaduct

A proposal to install a public access route across Bennerley Viaduct in the East Midlands is currently being considered by planning authorities.

“A little water never hurt anyone…”

Plantworx & Railworx a success despite the summer weather Every two years, the Construction Equipment Association organises a big...

Rail Electrification: Rebuilding Confidence

The Institution of Mechanical Engineers recently held the latest in a series of roughly biennial seminars highlighting railway electrification, with the emphasis being mainly...

Barnard’s Lock Underbridge

A Spongy and Successful Lift Barnard’s Lock is a rail underbridge structure spanning the river Kennet, located 3.7km west...

New main-line interlocking enters service

The Shepperton branch line in the south west of London and north Surrey, which is part of the Feltham signal box area, connects...