The 27.3 km long new Semmering Base Tunnel is the key structure of the new Austrian Südbahn line. On 30 June 2017, tunnelling works started on the third and last tunnel section, Grautschenhof. The two 1000 m deep shafts have already been sunk on this approx. 7 km long section between Spital am Semmering and Mürzzuschlag in Styria. The two tunnels are being excavated with excavators and blasting both in the direction of Mürzzuschlag and in the direction of Gloggnitz.
The joint venture Marti GmbH/Marti Tunnelbau AG Work has already been working on the contract for ÖBB-Infrastruktur AG at the tunnel site in Grautschenhof since May 2016 – starting with preliminary works such as noise protection walls and water treatment – with shaft sinking from September 2016. The total investment for the new Semmering Base Tunnel is 3.3 billion euros. After the planned opening in 2026, trains will be able to travel from Vienna to Klagenfurt in two hours 40 minutes and in 45 minutes from Graz to Klagenfurt.