First digital signal box on ICE line in operation

Deutsche Bahn (DB) has officially commissioned the first digital interlocking (DSTW) on a high-speed line in Bavaria. The interlocking in Donauwörth replaces the two previous relay interlockings from 1958 and 1960 in Meitingen and Mertingen. Trains on the Munich-Augsburg-Nuremberg ICE line, which is part of the Scandinavia-Mediterranean trans-European rail corridor, will be able to travel at speeds of up to 200 kilometers per hour. DB, the federal and state governments are investing a total of 127 million euros in the DSTW, with the technology coming from Hitachi Rail.

In the pre-series project in Donauwörth, construction of which began in 2019, Deutsche Bahn intends to test components and prepare for the technology's later widespread use. The rail infrastructure's control and safety technology will then be modernized and digitalized by 2035. According to the company, "digital rail" will enable trains to run fully automatically and at shorter intervals. Another building block for this is the Europe-wide standardized train control system ETCS.

"Online for the first time"

"In the digital interlocking in Donauwörth, we are controlling signals online for the first time, making us a leader in Europe," said DB Board Member for Infrastructure Berthold Huber. The technology not only brings more capacity to the network, it is also easier to maintain and therefore more reliable. In passenger and freight transport, there will be additional and more punctual trains in future.

DB's network subsidiary operates a total of around 2,600 signal boxes, 67,000 points and 160,000 signals with a wide variety of technology, some of which is more than 100 years old. Since 2018, points and signals on a regional line in Annaberg-Buchholz, Saxony, have been controlled digitally. The railroad is also running other model projects for digital interlockings on the Koblenz-Trier line, the first digital interlocking for long-distance traffic has been in operation in Warnemünde on the Baltic Sea since 2019, and the Harz-Weser network between Braunschweig and Göttingen is also being digitally controlled. DB is building another interlocking in Plauen in the Vogtland region, which is due to be completed by 2025. In future, it will replace the twelve old interlockings in Wünschendorf, Berga, Greiz, Greiz-Dölau, Elsterberg, Barthmühle and Plauen.

In addition to relay interlockings, electronic interlockings (ESTW) and, more recently, their technological successor, DSTW, are also in operation on German railways. In both types of interlocking, redundant computer systems check and process the dispatcher's commands. However, the commands from the computers in an ESTW are transmitted to points, signals and level crossings using conventional electrical switching technology via copper cable bundles, and points and signals also report back, explains DB. Each element of the infrastructure has its own cable harness to the interlocking. A DSTW, on the other hand, transmits the setting commands digitally to points and signals and also receives the information from there digitally. The encrypted setting commands are transmitted via fiber optic cable loops.

(anw)