Strabag, together with its group company Züblin, has been awarded the structural construction contracts for the ABS Gäubahn Nord project, a major railway upgrade in southwestern Germany that includes the Pfaffensteig tunnel.
The tunnel is an important component of the current extension of the Gäubahn railway line. DB Projekt Stuttgart–Ulm supervises the project as client.
Although Strabag did not disclose the financial details of the contract, in February this year the federal government committed 1.7 billion euros to the construction of the Pfaffensteig tunnel.
The Pfaffensteig tunnel will feature a double bore design, measuring approximately 11km in length, with each borehole hosting a single railway track.
This new connection will directly link Stuttgart Airport’s long-distance train station with the existing Gäubahn line.
The route aims to reduce travel times between Stuttgart and the Swiss border and will facilitate better rail connections across Europe.
According to Strabag, the project is divided into two main sections. The first section involves the construction of the main tunnel, which covers about 11 km, of which 9.8 km will be excavated with tunnel boring machines.
Additional works will include the underpass of the A8 motorway and the integration with the Stuttgart Airport train station, both of which will be carried out using conventional construction techniques.
For the second section, the works will include a tunnel segment constructed by the cut-and-cover method that will extend around 240 m, followed by a trough structure and above-ground rail connections to the Sindelfingen-Goldberg S-Bahn station.
This section includes the construction of several support structures, railway underpasses and a level crossing. An approximately 3 km above-ground segment will be upgraded for travel speeds of 200 km/h and partially realigned.
Strabag and its partners will use an integrated project delivery (IPD) partnership model for all phases of the work. This method brings together all parties from the design stage and aims to improve efficiency, accelerate project timelines and reduce costs.
Several Strabag Group companies are carrying out work on three main procurement packages for the project.
Ed. Züblin carries out in collaboration with Wayss & Freytag Ingenieurbau the tunnel construction works of package 2, as well as the structural engineering works of package 4.
Strabag is responsible for Package 3, which covers the earthworks component of the project.
This collaboration allows Strabag and its partners to contribute significantly to the completion of the tunnel project.