Strabag begins Karawanks Tunnel refurbishment

24 September 2020


Austrian construction group Strabag is continuing work on the €68.4m (US$79m) contract awarded in July 2020 by ÖBB-Infrastruktur for the rehabilitation and modernisation of the Karawanks Railway Tunnel (Lot KRT 1 Karawankentunnel – Construction Technology).

Straddling Austria and Slovenia, the 100 year-old, eight kilometre-long tunnel opened in 1906 with a two-track configuration. But it must be reconfigured to single track to comply with modern safety standards. This will allow the tunnel to operate for another 30 years with trains running at faster speeds.

In a statement, Strabag said construction had started with the cleaning of the tunnel interior, to be followed by the removal of previous renovation layers to allow the installation of a new shotcrete lining. The tunnel vault will be partially renovated with the addition of new anchors and other reinforcement measures. Future drainage will take place via laterally-laid drainage pipes.

The entire floor of the tunnel will be dismantled and rebuilt and the space resulting from the conversion will be used for an emergency escape corridor. Some existing chambers are to be converted and remodelled into technical rooms. The historically-listed portal structures will remain in place and will also be renovated as part of the project.

To date, the Karawanks Tunnel has been heavily used for freight traffic between Austria and Slovenia. Work is expected to last one year, which includes a period of full closure lasting nearly seven months. The reopening is scheduled for September 2021.