Included in the contract is the 16.3km twin-tube tunnelling through the Flachgau region (Tender 12656 and ENUW 1170) which comprises two sections: the Grafenholz Tunnel with a length of around two kilometres and the Seekirchner Tunnel, which has a total length of 14.3km. In the central section of the alignment, a swellable, locally disturbed flysch is expected, while sections with low overburden must penetrate water-bearing sediments, debris and molasse. A variety of tunnel construction methods are expected to be deployed given the locality’s complex geology and topography.
The consultants’ engineering studies will form the basis for the government approval of the project, expected to be granted in 2023/2024. The JV will also assist with the formulation of tender documents and provide consultancy services throughout the award procedure. Overall, the project aims to establish faster rail connections in the Austrian Westbahn of the Salzburg region, which currently has just one remaining slow-speed route.
