Pumped-Storage Plant Limmern
Access Tunnel I and Funicular 1
To ensure the supply of peak energy from storage power plants, Kraftwerke Linth-Limmern AG (KLL) built a new pumped-storage plant with a turbine output of 1,000 megawatts between the Limmernboden reservoir and the Muttsee in the Canton of Glarus. The heart of the plant is the central power station Limmern, which includes an underground machine and transformer cavern 1,700 meters above sea level. The plant is accessible via an access tunnel from the valley floor at Tierfehd, which was equipped with a funicular (special load 220 t).
The inclined tunnel was excavated by means of a tunnel boring machine. This began boring in the specially designed 100-m-long starter tunnel at the cavern "valley station" located about 200 m in the mountain. The inclined tunnel is characterized by a length of approximately 3,700 m and a gradient of approximately 24%. Halfway to the mountain station, a passing point is necessary for the crossing of vehicles of the Funicular 1.
The planning included the following elements:
• Access valley station: L = 220 m, A = 60 m2; drilling and blasting with complete eruption
• Cavern valley station: L = 35 m, A up to 300 m2; drilling and blasting with partial eruptions
• Inclined tunnel: L = 3,760 m, A = 50 m2, gradient 24 %; TBM tunneling
• Passing point in the inclined tunnel: L = 220 m, A = 94 m2; expansion via blasting
• Excavation preliminary cut with a max. depth of 18 m
• Portal structure and cut-and-cover tunnel as reinforced concrete frames
• Access structure und access road
• Tunnel drainage and retaining structure
Project period: 2007 - 2014
Services: Representative overall project management, project management underground works and technical specialist geotechnics / rock mechanics for the phases design, tendering incl. tender evaluation, implementation planning, documentation
Learn more about the Pumped-Storage Plant Limmern.