Strabag, together with its group company Züblin, has been awarded the structural construction contracts for the ABS Gäubahn Nord project, a major rail upgrade in south-west Germany featuring the Pfaffensteig Tunnel.
The tunnel forms a significant component in the ongoing expansion of the Gäubahn railway line. DB Projekt Stuttgart–Ulm is overseeing the project as the client.
Although Strabag did not reveal the financial details of the contract, the federal government in February this year committed €1.7bn towards the construction of the Pfaffensteig Tunnel.
The Pfaffensteig Tunnel will feature a twin-bore design, measuring approximately 11km in length, with each bore accommodating a single rail track.
This new connection will link Stuttgart Airport’s long-distance railway station directly with the existing Gäubahn line.
The route aims to reduce travel times between Stuttgart and the Swiss border and will facilitate improved 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, spanning about 11km, with 9.8km to be excavated using tunnel boring machines.
Additional works will include the undercrossing of the A8 motorway and integration with the Stuttgart Airport railway station, both of which will be undertaken with conventional construction techniques.
For the second section, works will include a tunnel segment constructed using the cut-and-cover method extending around 240m, followed by a trough structure and above-ground railway connections towards the Sindelfingen-Goldberg S-Bahn station.
This section involves building several supporting structures, railway underpasses and a grade-separated crossing. An approximately 3km above-ground segment will be upgraded for 200km/h travel speeds 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 companies within the Strabag Group are delivering work across three main procurement packages for the project.
Ed. Züblin, in a joint venture with Wayss & Freytag Ingenieurbau, is carrying out the tunnelling works known as Package 2, as well as the structural engineering tasks under Package 4.
Strabag is responsible for Package 3, which covers the earthworks component of the project.
This collaboration enables Strabag and its partners to contribute significantly to the completion of the tunnel scheme.
Strabag Management Board member Jörg Rösler, who is responsible for the North + West segment, said: “The Pfaffensteig Tunnel is far more than an impressive infrastructure project – it is a key building block for sustainable, future-proof mobility.
“At the same time, the project underlines the importance of partnership-based contractual models as key to accelerating infrastructure projects when all parties involved work together from the design phase onwards. As such, it sends a strong signal in support of Germany’s modernisation drive.”
