Two large power cables, each weighing 48 tons and measuring 3.3 kilometers in length, had been lying on the lake bed between Wädenswil and Männedorf for over 80 years. These have now been successfully recovered and replaced with a new, more powerful 16-kilovolt cable.

On behalf of Elektrizitätswerke des Kantons Zürich (EKZ), Willy Stäubli Ing. AG was commissioned to replace the existing medium-voltage cables with more powerful ones. The project started with so-called flushing drillings from the shore out into the lake. On the Wädenswil side, empty conduits were drilled at a depth of approx. 10 meters from the shore into the lake and even approx. 150 meters underground on the Männedorf side.

After completing the preparatory work in the shore zone, our company began recovering (including hanging up) the old cable in mid-June 2020. The old submarine cable was retrieved from Lake Zurich from a platform. The challenge was to ensure that no oil (impregnating compound) got into the lake during the cuts.

The laying of the new, high-performance submarine cables was completed on August 12, 2020. A Lake Zurich ferry was hired to transport the four bobbins and lay the cables. The ferry, which had been loaded the day before, set off from Horgen at 5 a.m. and the 3.3 kilometers of submarine cable were laid by 4 p.m.

We would like to thank the client and the other companies involved in the project, as well as our employees, for their constructive cooperation.