Repoint is an electromechanical device designed to improve the reliability of the points in the railway network where trains transfer from one line to another. Based on fault tolerant engineering principles, it is an alternative to conventional track switches. It has the potential to reduce track maintenance costs and increase capacity on rail networks in the UK and around the world by reducing disruption to train traffic at signals and points. Ramboll supported the development with all aspects of signalling design, from lab-tests to full scale demonstration.
- Video summary
- Industry calls for a fresh approach
- The trouble with conventional railway switch actuation mechanisms
- How does Repoint track switching technology work?
- What are the benefits?
- How is Ramboll involved?
- Awards and media attention
- What next?
View this 2.5 minute video to find out why this deceptively simple rail track switch, developed at Loughborough University, is considered to be a breakthrough in capacity-enhancing technology ripe for exploitation by the rail industry.
Industry calls for a fresh approach
Repoint is a success story fostered through collective industry and academic initiatives. It originates from a call to action from the rail industry’s independent body Rail Safety and Standards Board (RSSB) to explore ways to increase network capacity and reliability.
The UK alone has over 20,000 switch and crossing units and they account for over 15% of Network Rail's track maintenance budget. Following discussions with industry stakeholders about the limitations of switch machines, and the extent of disruption caused by a single point of failure (SPOF), Loughborough University’s Control Systems Group took up the challenge as an area that could benefit from a fresh approach.
The patented Repoint technology was originally conceived in fundamental research funded by Engineering and Physical Sciences Research Council (EPSRC)/RSSB and progressed through key commercial milestones with further financial support from the university’s EPSRC IAA, the Higher Education Innovation Fund and RSSB.
Loughborough University is a member of the UKRRIN (UK Rail Research and Innovation Network - Centre of Excellence in Infrastructure), a £92 million partnership launched in 2019 between the rail industry and academia to spur innovation in the sector.
The trouble with conventional railway switch actuation mechanisms
The design concept of conventional track switching technology has not changed significantly for over 200 years. Point machines are complex mechanisms. They contribute to the unprecedented safety levels the modern railway enjoys yet cause delays bringing about network capacity and reliability constraints.
The rail network is designed so that if any part of the mechanism fails, the system goes into 'fail safe' mode to prioritise safety. This is achieved by building many single point failure modes (SPOF) into and around switches, which consist of control actuation (signalling), detection and locking systems.
Any one of the SPOFs will always halt a train before it passes over a faulty track switch, causing immediate disruption to services and delays until the fault can be fixed. For example:
- Signal failure caused by power cut or blown fuse in the circuit
- Locking system failure caused by blockages of debris or ice, or failure of the drive mechanism, or the points expanding too much in hot weather
The bottom line is that SPOFs are undesirable in any system where high availability or reliability is required – especially where it is not possible to stop for a fix when something critical fails, such as on modern aircraft.
How does Repoint track switching technology work?
Repoint is a deceptively simple switching mechanism for moving tracks at a set of points. Several actuators built into the switching mechanism provide additional redundancy thereby eliminating the conventional SPOF.
This means that in the event of a single point failure the remaining actuators in the switching mechanism continue to function. This additional redundancy allows rail traffic to pass safely and remedial maintenance can be scheduled without causing immediate disruption to services.
As proof of concept, a full scale trial of the technology was organised in January 2019. Fifty guests including rail operators, suppliers and potential investors gathered at the Great Central Railway’s Quorn and Woodhouse station for a demonstration of the results of the original research. The trial installation of the patent protected technology was completed to TRL 7 level (a technology demonstrator in a realistic environment). This equates to UK Network Rail, Rail Industry Readiness Level 5 (RIRL 5).
What are the benefits?
The main benefits of Repoint track switches compared to conventional rail track switches are:
- Greater reliability with multi-channel redundancy of actuation, locking and detection. Repoint allows for several points machines/actuators to act on the same points, so, in the event of one of the points machines/actuators failing, the remaining points machines/actuators continue to operate safely. For example, Repoint would continue to work normally in a three bearer assembly even if two out of its three points machines/actuators failed.
- Reduced risk of points failing in an indeterminate position. A unique ‘lift, hop and drop’ mechanism locks the switch into position when dropped, which prevents conflicting sideways movements of the switch blades. This means that trains can pass safely, even in the event of a power supply failure.
- Faster operation - ‘lift, hop and drop’ mechanism eliminates the friction experienced by the slide chairs used in traditional point machines, moving a switch in under two seconds compared to four seconds for conventional designs.
- A lower carbon footprint, with less energy consumption.
- Time and cost saving maintenance. Not only can maintenance be scheduled without affecting train services, Repoint has single line-replaceable unit construction, which means a modular component can be replaced in minutes.
- Remote condition monitoring exploits the built-in redundancy by identifying and correcting partial failures or wear-outs prior to any service impact.
How is Ramboll involved?
The Repoint fully-engineered product moved from lab tests to a full-scale demonstration as proof of concept under the leadership of Loughborough University with support from contractors RC Designs, Baker Engineering, Progress Rail and DEG Signal (now Ramboll).
Ramboll was appointed to the Repoint project because of our reputation working with different types of interlocking (mechanical, relay-based and solid-state) in countries around the world including Australia, Portugal, Poland and South Africa. This international experience will be of particular value when the production-ready Repoint is implemented.
For the trial installation at Quorn and Woodhouse station, Ramboll produced the Signalling Design Specification (SDS) and the design of a stand-alone Location case, which is a track side control box/interface capable of calling the points Normal/Reverse and can also isolate each of the three actuators separately. This involved supporting all signalling design activities for the installation, testing and commissioning.
Vitor Soares, Principal Engineer for Rail Systems at Ramboll said: “I believe Repoint is the future of point machines. This is because it provides huge advantages in availability due to fault tolerant engineering principles by using three bearers, which only one can perform the movement of the switch rails, and operational flexibility in a short space.”
Awards and media attention
In 2016, Repoint, won the prestigious Institution of Engineering and Technology (IET) Innovation Award in the Transport Category. The ultra-high availability/maintainability track switch technology triumphed over a quality field of nominations including Cambridge University and Heathrow Airport.
Repoint featured in the 2017 report 'Increasing Capacity: Putting Britain's railways back on track' by the Institute of Mechanical Engineers (IMechE).
In April 2019, the Rail Industry Association's Fellowship Programme organised a visit by Nicky Morgan MP to the University of Loughborough to meet the Repoint delivery team and showcase the technology. The programme seeks to showcase the best of the UK rail supply chain. The initiative pairs Parliamentarians and influencers with RIA members to promote the work of the organisations that build, maintain and enhance the UK’s railways.
The Loughborough University Control Systems Group’s long-term aim is to work with partners around the world to develop and manufacture Repoint systems appropriate to local needs and regulation.
Progress through further rail industry readiness levels is required to develop Repoint's capability and identify where further research work needs to take place before the technology is ready to be deployed.
More information at www.lboro.ac.uk/enterprise/repoint