Granitzal Tunnel Chain

Carinthia, Austria

In the Austrian region of Carinthia HOCHTIEF built the shell construction for the Granitztal tunnel chain together with a partner. The project, which is almost six kilometers long, is part of the Koralmbahn railway between Graz and Klagenfurt. It consists of three tunnels (Deutsch-Grutschen Tunnel, Granitztal enclosure and Langer Berg Tunnel) and was constructed as a twin-tube tunnel system.

The Deutsch-Grutschen and Langer Berg Tunnel were built using the New Austrian Tunneling Method (NATM). In Granitztal we built the railway using the cut and cover method. Subsequently, the tunnel tubes were covered over and the site was landscaped to suit the typical surrounding countryside. In future there will be a centralized ventilation system with emergency exit and rescue area. Granitzbach is being traversed with a closed tunnel bridge. The North portal of the tunnel chain is located in Lavanttal, and the South portal is located in Jauntal.

The Granitztal tunnel chain is a central and component of the Koralmbahn railway, which together with the Semmering Base Tunnel Vienna main railway station, serves as a key project along the Baltic-Adriatic Corridor, running from Danzig in Poland to Ravenna in Italy.



  • Country: Austria
  • Client: ÖBB Infrastruktur AG
  • Construction time: 2015 – 2020
  • Contract volume: approx. EUR 140 million
  • HOCHTIEF share: 50%

Technical data:

  • Langer Berg Tunnel: 2.9 km
  • Granitztal enclosure: 0.6 km
  • Deutsch-Grutschen Tunnel: 2.6 km
  • Excavation volumes: approx. 1.3 million cubic meters, of this reintegrated material: approx. 800,000 m³