The second Aker Wirth tunnel boring machine (TBM) is on the verge of being launched on the Koralm tunnel, which will link Graz and Klagenfurt in Austria with a new high speed rail link.
The telescopic shield machines, which have a diameter of 9.93m, will drive main 18km long sections of the twin bore 32.9km tunnels. The installation of the TBMs was a complex task with the main components lowered via a 60m deep shaft into an assembly cavern.
Main contracting joint venture Strabag and Jäger Bau launched the first TBM in December last year and the second TBM was due to be launched as GE went to press. Trains are expected to start running through the tunnel by 2022.