Milestone on the U2: Tunnelling on track 2 completed
11 July 2025
- Half-time reached: Tunnel breakthrough at Augustinplatz
- First tunnel constructed: TBM has advanced the route by around 2 kilometres
- Consortium of STRABAG and PORR
The U2xU5 public transport extension, with the construction of the U5 line and the extension of the U2 line to the south, is Vienna's largest climate protection project and a construction project of superlatives. A consortium consisting of STRABAG and PORR was awarded the contract for the first construction phase of Wiener Linien's megaproject at the end of 2020. The contract: construction of the line tubes and new construction of four stations including emergency exits, for the U2 line. After construction began in 2021, the tunnel boring machine (TBM) ‘Debohra’ started driving on track 2, the first of the two new line tunnels for the U2 line, in autumn 2024.
The tunnel breakthrough at the Augustinplatz emergency exit was recently completed, marking the halfway point of the project and a significant milestone for the ARGE U2/17-21 consortium.
TBM digs its way through Vienna Tegel
Debora's birth began in Schwanau, at the German site of the Herrenknecht company. Employees of the consortium worked together with colleagues from the manufacturer to assemble the TBM from 27,000 individual parts, test its function and technically approve it in January 2024. The TBM, which was specially designed for Vienna, has a total length of 127 metres and weighs an impressive 1,300 tonnes.
Dismantled into individual parts, it was transported to Vienna in early 2024 and reassembled at Matzleinsdorfer Platz. In autumn 2024, the TBM started full operation through Vienna Tegel: similar to an operational "buttonhole method", the work with the TBM took place underground. All of the earth excavated by the tunnelling machine was removed via the central shaft at Matzleinsdorfer Platz. This saves 20,000 lorry journeys through the the city; as a result, 75 tonnes of CO2.
This marks the halfway point for Debohra: one of two new U2 tunnel tubes between Matzleinsdorfer Platz and Augustinplatz has been completed, and work on the second tunnel tube will continue in autumn. The two tunnels will connect the four new U2 stations Matzleinsdorfer Platz, Reinprechtsdorfer Straße, Pilgramgasse and Neubaugasse.
For the work on the second tunnel, parts of the TBM will be lifted out of the ground and returned to Matzleinsdorfer Platz, while the trailing gear of the TBM is pulled back through the tunnel to the starting point.