Germany Group visit Stuttgart 21

Insight into the largest rail construction project in Germany

ICE and IMechE Germany Group in front of the Finance Building at Herrenknecht AG.
ICE and IMechE Germany Group in front of the Finance Building at Herrenknecht AG.

The Germany Group, comprising ICE and IMechE members, met on Friday 18 November 2016 to visit the Stuttgart 21 rail project in the morning, and the tunnel boring machine manufacturer, Herrenknecht, in Schwanau in the afternoon. The visit was organised by Hamish Douglas and the German Group Chair, Andy Storer.

Stuttgart 21 consists of two projects: S21 – reconstructing the Stuttgart rail node and NBL – new-build of the Wendlingen to Ulm line. The aim of the first is to transform the existing terminus station into a through station 12m underground, thereby connecting Stuttgart to the European high-speed rail network from Paris to Budapest and freeing up valuable real estate.

The second project will cut travelling time from Stuttgart to Ulm in half, to just 28 minutes. Instead of the current track next to the river through built-up areas in the Filstal, with speed restrictions of 70 kmh, the new route, passing through 20 tunnels, is designed for maximum speeds of 250 kmh.

The one-and-a-half-hour journey from Stuttgart to Herrenknecht AG in Schwanau passed quickly with lunch and much discussion. Herrenknecht, with some 5,000 employees, is one of the typical owner-run engineering businesses which are the backbone of the German economy.

However, its achievements in just 35 years are outstanding in that it has become the worldwide market leader in tunnelling technology. The scale of its operation was brought home by a state-of-the-art animated display wall. By touching any one of the hundreds of different pictures, details of that project, including the key facts, photos and type of boring equipment, were brought up on the wall. For example, no less than eight Herrenknecht tunnel machines (six Earth Pressure Balance Shields and two Mixshields) are being used by three consortia for the high-speed Crossrail project in London.

For the 10km long Filder Tunnel near Stuttgart, a 10.82m diameter Multi-mode TBM is being used. It is followed by a TBM for the Bosslertunnel and two for the so-called Albvorlandtunnel (all EPB-Shields), both part of the section towards Ulm. The largest boring machines made to date are up to 19m in diameter, an arch of this size has been placed in front of the Finance Building to help visitors visualise the scale of such equipment.