Work starts on Vienna metro expansion

21 December 2020

A 50/50 consortium of Austria’s two largest construction companies, Strabag and Porr, has won the tender for the first phase of the expansion of the Vienna metro.

Awarded by Vienna public transport provider Wiener Linien, the €500m (US$602m) Lot A contract involves a total of 7km of tunnels and four new stations built as part of the redirection of the U2 line. The works will form part of the first construction phase of the U2/U5 line expansion in the Austrian capital.

Construction work in the inner city is expected to be challenging given the high density of development. Tunnelling in close proximity to buildings and conveying material to and from the site through narrow alleyways around Neubaugasse are just some of the anticipated difficulties.

Mining the tunnels below the inner city will require the tunnelling team to work in round-the-clock shifts. Around 4km will be driven by tunnel boring machine (TBM), while another 3km will be bored using the New Austrian Tunnelling Method (NATM). Construction of the 40m wide and 50m-long station boxes will first require bored piles follow by the top-down method of construction for the stations. All work, including tunnelling, structural engineering, ground engineering and railway construction, will be provided in-house by the consortium.

As part of the metro expansion, the U2 line between Karlsplatz and Rathaus will become part of the U5 line, while the U2 will branch down towards the south of the city. This includes phases U2/17-21 (U2/17 driven by TBM, U2/18 Matzleinsdorferplatz station, U2/19 Reinprechtsdorfer Straße station, U2/20 Pilgramgasse station and U2/21 Neubaugasse station).

The expansion of Vienna’s inner-city metro network is seen as a huge milestone in the capital’s urban development and is hoped to result in enhanced performance, direct links for passengers and significant environmental benefits. Construction is set to begin in February 2021 and continue until mid-2028.