The company started organizing its main 330-kV power network in 1965. The Vostochnaya, Chudovo, and Yuzhnaya substations with 330-kV lines were commissioned, providing connection of the Lenenergo power system to the United Central Power System. New developments included construction of a 750-kV high-voltage line, adoption of 10-kV and 220-kV oil-filled cables, construction of 1,400 mm heating lines, complex automation of production processes, adoption of management telemechanics, and many others.