Photo: Klaus Holsting, Banedanmark

Improvement of railway switches

Transport and logistics Materials
A collaboration between Banedanmark and DTU has identified several new opportunities for smarter monitoring and maintenance of switches.

Switches are one of the more complex parts of railways. Switches consist of moving parts and are exposed to high impact. This makes them expensive to install and repair. There is therefore a strong interest in finding out how best to monitor switches in other to identify the right time for maintenance and ensure the greatest possible safety and least possible inconvenience to train services.

To investigate these issues, Banedanmark and DTU have carried out the Intelliswitch project, supported by Innovation Fund Denmark. The project has led to the development of new methods for assessing the condition of Banedanmark’s switches, as well as many scientific publications and materials which will later form the basis for a book that can serve as a university textbook on the subject.

“The project has involved many different competences from DTU. For instance, knowledge of typical fault mechanisms, optimum materials for use in switches, development of sensors to measure the condition of switches, use of big data, modelling, and much more,” says Professor Dorte Juul Jensen, DTU Mechanical Engineering, who has been the Intelliswitch project manager. 

“During the project, we set up 12 sensors on a switch in Tommerup, and collected data from the measurement trains that already operate on the railways, measuring tracks and switches. Based on a large amount of measurement data, we’ve prepared various models for how best to monitor switches and plan maintenance.”

Knowledge transfer
Banedanmark and DTU have worked closely together on the project in order to create the best opportunities for putting the researchers’ knowledge into practice. The researchers have not yet fully determined exactly how the knowledge should be implemented in Banedanmark’s workflows, but a lot of knowledge, experience and models have already been transferred.

"We’ve been very ambitious with the Intelliswitch project. Railway switches pose a complex challenge."
Professor Dorte Juul Jensen, DTU Mechanical Engineering

“We’ve been very ambitious with the Intelliswitch project. Railway switches pose a complex challenge, and even though we might have dreamed of one at the start of the project, there’s no easy solution or magic formula that can tell you when to start the maintenance work, for instance when the measurements or sensors read 12,” says Pernille M. Jøndrup, General Manager at Banedanmark.

“But the project has given us a wide range of input on how we can continue to work with sensors and modelling to improve the maintenance of the switches. And we’ll definitely keep working on it when we’ve identified which of the new opportunities will offer the greatest value when they are implemented.”

Contributions from European experts
One of Europe’s leading experts in switch components, Jan Swier from ProRail in the Netherlands, has followed the Intelliswitch project and its results closely.

“The work on using vibration sensors is extremely interesting and innovative,” he says. “Experienced railway mechanics use exactly this technology—they go down onto the tracks, listen to the switch and feel the vibrations in order to assess whether it’s time for maintenance. If we can automate this information, we’ll have made important progress,” says Jan Swier.

During the project, DTU involved four European universities—Chalmers University of Technology, NTNU Trondheim, University of Birmingham, and TU Graz—which together represent the most advanced knowledge in the field. This has helped give DTU itself extensive knowledge of wear and tear, breakdowns and maintenance of railway switches.