Construction of the major project in Forbach, Baden-Württemberg, started in autumn 2023. PORR Tunnel Construction is responsible for the cavity construction of caverns, water reservoirs and tunnels using mining tunnelling, the shell construction of the power plant cavern and the construction of two pressure shafts. Since then, the tunnel construction specialists have been working tirelessly to blast and excavate enormous cavities and tunnels in the rock.

Rapid progress in tunnel construction

Work on the former Rudolf Fettweis plant is progressing rapidly. In the meantime, the access tunnel, which leads from the factory premises into the mountain, has passed under the federal highway 462. A spectacle wall adjoins the tunnel. As the tunnel splits in two directions here, the access tunnel now runs to the left and the energy discharge tunnel to the right.
Half of the excavation work in the direction of the power station cavern has already been completed from the intersection of the Schutter, secondary and access tunnels. At the same time, excavation work is being carried out in the secondary tunnel 5 towards the water storage cavern and in the energy discharge tunnel. The total excavated length of the project is around 5,300 meters, of which around 4,700 meters is accounted for by the tunnels.
The cavern of the power plant extends over a length of around 123 meters, 20 meters wide and 42 meters high. The two pressure shafts comprise 357 meters of SBW (Schwarzenbachwerk) and 153 meters of MuW (Murgwerk). In total, the excavated volume amounts to around 400,000 cubic meters of solid mass. Of this, around 200,000 cubic meters are intended for water storage in the main and secondary tunnels. Completion of the pumped storage power plant is planned for 2027.