Gemeinschaftskraftwerk Inn, Lot Maria Stein

The contract was the first alliance project in Austrian power plant construction. After the client had to part company with the original contractor, the work for further construction and completion was transferred to a consortium under STRABAG leadership.
The contract consisted of adapting the previously completed construction site equipment, including the two double-shield TBMs, and completing the headrace for the newly constructed power plant in Prutz. When the work was taken over, only approx. 3.0 km of a total length of approx. 22 km had been driven. In addition, both TBMs were stuck in geologically weak zones at the time, meaning that both machines had to be refloated by “overriding the shields” before driving could begin.

In addition, asbestos-containing rock was encountered in one of the two drives, as a result of which the work had to be carried out under special protective regulations.The associated components still to be constructed included the dismantling cavern in the intake area near Ovella, Switzerland, close to the Austrian border, grouting measures along the entire length of the headrace and the closure of the temporary access passage in the centre of the construction lot, which was used for all construction measures.