Lyon–Moutiers DC transmission scheme
The Lyon–Moutiers DC transmission scheme was the most powerful mechanical high voltage direct current electric power transmission scheme ever built. Designed by Rene Thury, it was used between 1906 and 1936 for power transmission from a hydroelectric power plant at Moûtiers to Lyon, France.
Source: Wikipedia — Lyon–Moutiers DC transmission scheme (CC BY-SA 4.0)