STRABAG awarded major contract for construction of Pfaffensteig Tunnel in Germany

After two years of design-and-build preparation, STRABAG, in partnership with Group company ZÜBLIN, was awarded the contract for the structural implementation of several procurement packages for the project ABS Gäubahn Nord / Pfaffensteigtunnel. The scheme is regarded as one of the key infrastructure schemes in the expansion of the Gäubahn rail line in south-west Germany and plays a decisive role in strengthening climate-friendly, future-oriented mobility. The client is DB Projekt Stuttgart–Ulm GmbH.
 

New link for shorter journey times

The Pfaffensteig Tunnel, around 11 kilometres long, will be constructed as a twin-bore tunnel, with one track in each tube. The tunnel will establish a direct connection between the new long-distance railway station at Stuttgart Airport and the existing Gäubahn line. The new link will significantly reduce journey times between Stuttgart and the Swiss border, thereby strengthening trans-European connectivity – an important step in further advancing the mobility transition in the region. The project is divided into two project approval sections. The first section comprises the construction of the approximately 11 km long main tunnel, of which 9.8 km will be excavated using two tunnel boring machines. The undercrossing of the A8 motorway and of the new railway line, including the connection to the underground long-distance railway station at Stuttgart Airport, will be carried out using conventional techniques.

The second section includes, among other elements, a tunnel section of around 240 metres constructed using the cut-and-cover method, followed by a trough structure, as well as the above-ground connections to the Sindelfingen-Goldberg S-Bahn station, including several retaining structures, railway underpasses and a grade-separated crossing. In addition, the approximately 3 km long above-ground section will be upgraded for a design speed of 200 km/h, partially re-aligned and fully upgraded.

Rail partnership model for greater efficiency in infrastructure construction

The Pfaffensteig Tunnel will be delivered under a partnership model across all relevant project phases. Integrated project delivery (IPD) describes a multi-party contractual model for the design and construction of complex building projects. The aim of the partnership model is to deliver construction projects with particular efficiency. As all project partners contribute their expertise from the final design and building permission application stages onwards, processes can generally be accelerated significantly and costs reduced.

Several Group entities are involved across three procurement packages, enabling STRABAG to make a substantial contribution to the delivery of this key infrastructure project.

• Package 2 – Tunnelling: executed by Ed. Züblin AG in a joint venture with Wayss & Freytag Ingenieurbau AG
• Package 3 – Earthworks: executed by STRABAG AG
• Package 4 – Structural Engineering: executed by Ed. Züblin AG in a joint venture with Wayss & Freytag Ingenieurbau AG