Operating as part of a project to extend the Barenwerk hydropower plant in Fusch, Austria, Herrenknecht deployed a Gripper S-800 TBM specialising in fast tunnelling in hard rock conditions to get the job done.
With the S-800 boasting a powerful 1400kW high-performance drive capable of creating a diameter of 3830mm, combined with a competent tunnelling team, the project advanced in the fast lane – excavating up to 322m of tunnel per week with a route gradient of 4.8%.
Lead contractor, construction company Marti Tunnelbau AG, celebrated the successful breakthrough on September 10, 2013 – just 5.5 months after works commenced at the end of March 2013.
The S-800 TBM dug persistently through phylite slate, quartzite, limestone mica slate and green slate with carboniferous banded limestone to achieve the milestone.
“In terms of design, manufacture and jobsite installation, Herrenknecht engineers have achieved best times once again,” Herrenknecht said in a statement.
In operation since 1924, the Barenwerk extension will increase the capacity of the hydropower plant by almost a third, to 14.96 megawatts.
Upon completion, Barenwerk operator Salzburg AG will supply close to 19,000 households with electricity from environmentally friendly hydropower.
Environmental upgrading measures are also underway, with the decommissioning of old pressure pipelines providing local agriculture with new grazing areas.
