Deutsche Bahn has successfully driven all tunnels of the Stuttgart 21 project. In total, the tunnellers have dug around 56 kilometres of tunnel. With the last tunnel breakthrough on 14 September 2023 in the new airport tunnel, a milestone of the Stuttgart 21 project was reached.

In October 2021, construction work began on the new mine water drainage tunnel (MWDT) in the area of Germany’s northernmost coal mine in Ibbenbüren, which was closed in 2018. The costly pumps of the mine water drainage system have now been switched off and the mine water is to rise to a height of +63 m NHN (= meters above standard zero) and then be discharged via the new drainage tunnel to the mine water treatment plant at the Gravenhorst site, which is also to be newly constructed. This article presents the project task and reports on the status of the planning and construction work after a construction period of 24 months.

The work of the joint venture ARGE Tunnel Hauptbahn­hof (ATH) for the west tunnel construction and at Munich Central Station is making progress. The launch shaft in front of the Donnersberger Bridge will be ready for the TBM launch by around early summer 2024, work on the RS 3 rescue shaft has begun, and at the central station level E-2 is being excavated since September 2023. The work of ARGE Marienhof was already presented in detail in tunnel 4/2022 and the overall project in tunnel 2/2023. The article in tunnel 5/2023 gives an overview of the work of ARGE Tunnel Hauptbahnhof.

Work on the Marienhof station in the heart of Munich is going according to plan. The special civil engineering with the construction of the diaphragm walls and primary supports as well as the construction of the cover had already been completed by the time of the presentation of ARGE Marienhof in tunnel 4/2022. The article in tunnel 5/2023 provides an overview of the status of work in late summer 2023 at Germany’s deepest S-Bahn station at Marienhof.

In September 2023, the SBB started the fundamental overhaul of the Hauenstein Base Tunnel. The tunnel vault and technical installations of the railway tunnel will be renovated. This work will last until autumn 2026, with interruptions in the summer and at the end of the year.

Modern sprayed concrete technology and the use of steel fibers have made permanent, single-shell linings for tunnel construction possible. Until now, mainly temporary layers of sprayed concrete were used for stability, followed by a permanent concrete lining. But now such an inner lining can also be produced with high-quality, steel fiber-reinforced sprayed concrete.