The REPOINT project has delivered a next generation railway track switch technology, which uses redundant, fault-tolerant operation to dramatically improve reliability. This improvement offers: reduced delays (and delay costs), improved capacity (faster switching), reduced maintenance and inspection costs.
Railway switches have worked the same way for over 200 years – switch blades are driven from one position to another to set the route the train will follow. If this movement is not fully completed, locked-in place and detected as such, then trains passing over the switch risk derailment. Each of these elements (move, lock, detect) are single elements which when they malfunction will cause switches to “fail” and potentially derail a train. To ensure safety, signalling and operational procedures have been developed to prevent a train approaching an unsafe switch; and maintenance and inspection routines have been developed in an attempt to improve operational reliability.
REPOINT combines passive failsafe locking, with redundant actuation and sensing, and a reimagined switch layout to remove the above constraints.
Our team, based at BCRRE, has worked with key stakeholders and partners to develop, and patent the new concepts.
The specific savings and benefits depend on the installation location as the challenges differ from:
- a station throat or goods siding
- high speed main-line
- a mining railway is not the same as a passenger railway.
However, we believe in each case this technology is game changing.
We are aiming to:
- Improved operational reliability.
- Reduced delay (and associated cost)
- Reduced maintenance cost
- Reduce the need for inspection.
- Make use of condition-based maintenance.
- Have a modular ‘Lego-block’ build (rather than bespoke layouts for every location).
- Offer a more compact solution for multiple (>2) routes.
- Enable (moving block signalling) capacity improvements around switches.
Repoint is a highly reliable, fault-tolerant switch:
Other switching solutions use a single motor to move the switch rails. If it fails, there is no back-up. For passengers, this means delays and cancellations whilst a maintenance team rushes to undertake an emergency repair. Our system has duplex or triplex redundancy – it will not fail.
Repoint is built with the same principles as an aircraft
Our architecture is similar to aircraft flight control systems with multiple channels for actuation, locking and detection. If a fault occurs in a single channel, the switch continues to operate – without the need for immediate repair – and services can continue to run as timetabled.
Research highlights
Stub-switch Concept
Bemment SD, Ebinger E, Goodall RM, Ward CP, Dixon R. Rethinking rail track switches for fault tolerance and enhanced performance. Proceedings of the Institution of Mechanical Engineers, Part F: Journal of Rail and Rapid Transit. 2017;231(9):1048-1065. Read about the Stub-switch concept.
Making the case for redundancy in track switching
Bemment SD, Goodall RM, Dixon R, Ward CP. Improving the reliability and availability of railway track switching by analysing historical failure data and introducing functionally redundant subsystems. Proceedings of the Institution of Mechanical Engineers, Part F: Journal of Rail and Rapid Transit. 2018;232(5):1407-1424. Read about making the case for redundancy in track switching.
Demonstration of actuation on classical switch
Olaby, O, Dutta, S, Harrison, T, P. Ward, C & Dixon, R, 'Realisation of a novel functionally redundant actuation system for a railway track-switch', Applied Sciences (Switzerland), 2021,vol. 11, no. 2, 702, pp. 1-20. Read about the demonstration of actuation on classical switch.