World record tunnel construction for Limberg II power plant
The tunnel was excavated at a rate of up to 24 meters per day.
The breakthrough of the new 3.5 km Schrahnbach tunnel was finally achieved on 12 January 2006 at the rear of the Kaprun Valley in the presence of VERBUND General Director Hans Haider.
The fast breakthrough was achieved, above all, due to the favourable rock properties. Speaking at a press conference, Herbert Schröfelbauer, Chairman of the Board of VERBUND-Austrian Hydro Power AG (AHP), explained: "This could well be a new world record as tunnels are normally only excavated at a rate of 15 metres per day." A tunnel system with a length of 5.8 kilometres has been built since the beginning of March last year. This is the third and last tunnel in the Alpine construction project.
Approximately 300,000 tons of rock had to be removed. 40% of this was used for the avalanche protection dam Griesbach which was constructed to protect the valley station of the Lärchwand funicular. A further 35% was used in the construction of access roads and only 25% ended up in the rock beds opposite the station for the glacier railway.
During the winter months, more than 100 specialists were involved in the development work for the Limberg II construction site. "The real work will commence at the end of April or the beginning of May, when the construction of the power plant gets under way. Approximately 250 workers will be on the site until December of next year," AHP Managing Director Michael Amerer explains.