The crown of the Hengsberg Tunnel, part of the Koralmbahn between Graz and Klagenfurth was broken through after 10 months’ construction at the end of April 2009. In the Styrian part-section of the route between Weitendorf and Wett-manstätten the single-tube,
2-track Hengsberg Tunnel, which is 1,695 m long, represents a key part of the Koralm-bahn. Following the breakthrough the bench and base will now be tackled and the inner shell subsequently concreted. This work is scheduled to be completed by the end of January 2010.
Various construction methods were applied to build the Hengsberg Tunnel: mainly drill+blast but also cut-and-cover with the top cover method being used for the southern portal section. The tunnel is being provided with 3 emergency exits set 500 m apart.
The first stage of the new part of the route is scheduled to be opened in 2011. In this way, it can be assured that the Koralm Tunnel construction site in the neighbouring section can be supplied by track according to schedule.
Tunnelling operations are being carried out by Wayss & Freytag Ingenieurbau AG with its partners Habau und Held & Franke. The contract is worth 74.2 mill. euros.