The Nizhne-Svirskaya Hydroelectric Plant, the world’s first power plant constructed on floating Devonian clays, was launched with a ceremony on December 19, 1933. The facilities were constructed on a massive continuous concrete slab to avoid possible deformation. This engineering solution was used for the first time in the world. Energy from the hydroelectric plant was transmitted to the Chesmenskaya Leningrad substation via a 240-kilometre-long, 220 kV power line. This line was the first of its kind in the USSR. The Dubrovskaya State District Power Station was the first power station to be constructed without foreign specialists and furnished with equipment produced by domestic manufacturers.