The two construction sections Göstritz and Fröschnitzgraben of the Semmering Base Tunnel are finally connected after seven years. Only ten percent are missing for the entire completion – but this turns out to be particularly challenging.
One exciting moment remains: the breakthrough in a tunnel when the two tubes meet. Numerous companies and workers worked towards this for seven years. So there was great joy that the masterpiece was achieved on Friday. The two construction sections between Göstritz (Lower Austria) and Fröschnitzgraben (Styria) are now connected. In Göstritz, the miners encountered the “Carl” tunnel boring machine still in the mountain in the Fröschnitzgraben section. This is currently being dismantled piece by piece, the front part – the drill head – is dismantled last. A narrow “passage” in the cutting wheel nevertheless made it possible for miners from the two construction sections to meet in the tunnel for the first time Project manager Gerhard Gobiet. Only a few meters are still missing in the second tube. But the part that is still missing is tough and poses major geological challenges, in particular a fault zone in the Grassberg during tunneling in the direction of Gloggnitz (Lower Austria). The Semmering Base Tunnel on the southern route connects Lower Austria with Styria. It has two tubes and is 27.3 kilometers long. According to ÖBB, the tunnel will be built from five points and 14 simultaneous drives, five drives have already been completed. Work on the interior of the tubes also began in 2020: the tunnel will be lined with a concrete inner shell, and around seven kilometers have already been covered. The last step is the technical railway equipment (tracks, lines, etc.). The tunnel reduces the travel time between Vienna and Graz to one hour and 50 minutes. According to ÖBB, there is an “extremely complicated mountain structure” with completely different rock layers (hard, soft, water-bearing, dry). The tunneling work was interrupted for a long time, the mountain had to be stabilized first. However, tunneling using excavators and blasting was recently resumed. 900 meters are still missing. Construction costs increase to almost four billion euros. The current assumption is the turn of the year 2029/30. The projected construction costs also rose to 3.9 billion euros.
source site-12