Free ride to the “Internet of the Railway”

The world’s first digital interlocking eliminates the need for thousands of tons of cable and enhances the efficiency of rail transportation.


by Katrin Nikolaus

Siemens is the world’s first company to put a digital interlocking into operation and received the official authorization from the German Railway Authority. The new technology called Trackguard Sinet separates the processes of information transmission and power supply. The interlocking system and the field devices at the train station Annaberg-Buchholz South in the Saxon Ore Mountains of Germany are now exchanging data via Ethernet. So it means free ride to the “Internet of the Railway”.


The major challenge was to ensure the high safety standard required by Germany’s largest railway operator, Deutsche Bahn, for infrastructure technology. The control devices are intrinsically safe and are continuously monitored by the interlocking system. The digital interlocking system has now been in successful operation for several months.

Savings of 25 percent to 30 percent

Virtually nobody remembers those days when switches were set by hand. Previous control units generally set the electric drive system for the mechanism in motion. They receive the command and the power via a thick bundle of cables from the nearest interlocking computer system, which is linked to a superior interlocking control center. Let’s say a point with a 380-volt three-phase drive has to be set. The laws of physics restrict the distance between an interlocking processor and a point machine or a signal. For this reason, an interlocking processor had to be located in the area of every train station until recently. The digital interlocking system Trackguard Sinet eliminates this need.

Norway wants to make its railway fit for the digital age: Siemens will equip the Norwegian railway network with Trackguard Sinet by 2034.

In the pilot project, the system comprises 12 combination signals, a shunt signal, three sets of points and 16 track vacancy detection sections. With conventional technology, these field instruments could only be controlled via cooper wire. The positioning instructions of the traffic controller are now transmitted digitally via network technology. According to estimates by Deutsche Bahn, savings of 25 percent to 30 percent can be realized compared with conventional technology. Every field instrument can be controlled via its own IP address. The kilometer-long cable bundles can now be reduced to optical fiber connections. With cost-effective industrial components, the digital interlocking is a decisive contribution to the economical operation of rail networks. Trackguard Sinet will open up many new applications in the future, such as predictive maintenance of previously unconnected field instruments.

Norwegian Railway Network to be completely Digitalized

These advantages have convinced the Norwegian State Railways: Siemens will equip the entire Norwegian railway network with Trackguard Sinet by 2034. Norway wants to make its railway fit for the digital age. With a fully digitalized, IP-based system, the Norwegians intend to do something more than save a whole lot of hardware, but also expand capacities in order to bring rail passengers to their destinations faster and without interferences – only one interlocking for an entire country.

Deutsche Bahn is also considering equipping its railway network with digital interlocking technology throughout the country in the foreseeable future. In ongoing pre-series projects, all component manufacturers will demonstrate interface compatibility. 


Katrin Nikolaus

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