RSSB are to fund a two-and-a-half-year project to develop and install a full-sized prototype of the Repoint track switch, which completely re-engineers the conventional track switch that has been used thoughout the world since 1843.
It is a concept that Loughborough University patented after its validation through simulations and laboratory demonstrations of an actuator bearer and its control system.
The concept originated in 2010 with a call for research to reduce capacity constraints at junctions. This resulted in a design that reduced switch movement time to under a second from the four seconds required by a conventional switch.
Repoint also significantly reduces maintenance, failures, energy usage and cost. This has been made possible by the development of a fail-safe mechanism that could be operated by multiple actuators, providing a degree of redundancy which enables the switch to operate in the event of an actuator failure.
Repoint is essentially a stub switch in which rail are moved by a cam to align with the selected diverging rails. However, early railways abandoned the use of stub switches as they were prone to impact loading and thermal expansion. Repoint avoids this problem by the use of interlocking rail ends similar to a CWR breather.
Loughborough University’s new switch design offers significant potential benefits and has attracted significant interest in the UK and throughout the world. Discussions have been held with companies in South Africa, Australia and China.
More information about Repoint is available here.
Report by David Shirres
Image credit: Loughborough University
Has Repoint been tested for snow, ice, freezing rain, hail and leaves? These in my mind are the biggest risk, in that upon lifting the rails, such material can fall under it, preventing the rails’ full seating in the new position and becoming a derailment hazard.
Isn’t such real-world testing the point (sorry!) of installing a prototype?
If the objective is getting a faster switch throw time, London Transport were achieving this many years ago with high pressure pneumatic point machines operating conventional, albeit bullhead, switches. The engineering involved in their switch operation is transatable to flatbottom designs with little or no change, and avoids the potential problems of debris getting under the stub switch rails. Tramways have also been using solenoid operated point machines with similar operating times for many decades.