THE German state of Baden-Württemberg has published the results of a review into the provision of station capacity in Stuttgart following the completion of the new underground Stuttgart main station being built as part of the Stuttgart 21 project.

The review was commissioned by the state government, a coalition of the conservative CDU party and the Green Party, under their official coalition agreement. The Green Party has long supported constructing an additional new terminus station using part of the existing station site, and crucially the approach tracks, which are scheduled for removal once the new main station opens.

The review has found that the additional terminus station is not required, but only in the context of several major, and in many cases unfunded and currently only conceptual new sections of railway being built before 2030-2040.

The proposed infrastructure interventions, which together add substantial new capacity to the rail network in the Stuttgart region, and which are considered necessary by 2030, are:

  • building the planned Wendlinger Curve as double rather than single track, allowing connections from towns such as Tübingen to the new Stuttgart Airport high-speed line and station to continue to the new Stuttgart main station. This curve is already partly complete as a single track connected to the eastbound track of the new high-speed line, and adding the extra track is considered relatively simple.
  • the 11km Pfaffensteig tunnel connecting the Singen - Horb - Stuttgart Gaubahn line to the new Stuttgart Airport mainline station, and via it to the Ulm - Stuttgart high-speed line, which is already being planned with possible construction from 2026 to allow completion and opening in 2032. The twin-bore tunnel would be used by long-distance Zürich - Stuttgart and regional trains.
  • retaining the existing Stuttgart - Singen line in the Stuttgart suburbs and introducing new local services. This line, known as the Panorama Bahn, is only used by non-stop services. A new transport interchange based around the existing Stuttgart North S-Bahn station, which will be served by the new Panorama Bahn services, is planned and will increase overall network resilience, and
  • the addition of two new high-speed approach tracks in the northern suburbs of Stuttgart linking the existing high-speed line to Mannheim and Karlsruhe via a rebuilt station at Feuerbach with the new underground network of lines serving the new Stuttgart main station.

This last project had been identified as necessary to deliver the full Deutschland Takt regular-interval timetable but is currently unfunded and not in the planning process, as are most of the other 115 more minor infrastructure enhancements identified by the report, which are costed at €3.9bn. Baden-Württemberg expects the federal government via DB Network to meet this funding requirement.

State minister of transport, Mr Winfried Hermann, who previously advocated building a new regional terminus station in addition to the planned through main station (IRJ March p16), appears to have changed his mind. He told media that the targeted doubling of demand in all public transport will lead to more than tripling the number of regional trains in the Stuttgart hub compared with 2010. He says that both new infrastructure, including the rollout of ETCS, and the new fleet of Coradia Stream trains ordered by the state from Alstom in May 2022 were key to meeting this demand.

“This will achieve the goal that the state was striving for with an underground supplementary station, reached in a different way,” he says. “I have been convinced that this is an exemplary case in which digitisation can replace infrastructure expansion.”

The Stuttgart Digital Nodes (DKS) project is underway to install ETCS across the 60km core of the city’s S-Bahn network as well as 65km of connecting lines under the first two phases of the project, which are on course for completion for the official opening of Stuttgart 21 in December 2025. The third phase of the project will extend the rollout of ETCS to 500km covering DB Network’s Stuttgart and Plochingen districts by 2030.

Crucially, the majority of the rollout is based on operating the network solely with ETCS rather than in conjunction with the Class B signalling system. DB teams working on the scheme told IRJ that simulations have shown that the network will have sufficient capacity to meet future demand at the new underground Stuttgart main station, which has eight platform tracks. Their objective is to operate trains every five minutes on average at peak times at each of the platform tracks.

They add that platforms can be operated with double occupancy, which is part of the planning process for the resignalling project. In addition, they reject suggestions that excessively steep gradients in the new station will cause operational issues.

The April 2023 edition of IRJ will include a detailed overview of the Stuttgart Digital Nodes project.