Soviet Railways series С (1929)

From 1929 onwards, the Russian Northern Railway (Severnaya Zheleznaya Doroga) had multiple units manufactured for suburban traffic, which got the designation С (S). This letter stood for the railway administration mentioned. The sets normally consisted of three cars, each of which had a motor car at one end, a trailer in the middle and either a control car or another trailer at the other end.

The oldest vehicles had received electrical equipment from Metropolitan-Vickers until they switched to domestic equipment. Initially, operation only took place under 1,500 volts direct current, but when the first lines were converted to 3,000 volts, vehicles were built that could operate under both voltages. This was achieved by connecting the traction motors in series or parallel. After most of the lines had been converted, the last series were only designed for 3,000 volts.

Until 1958, a total of almost 1,000 three-car sets had been created. The vehicles, which were only built to operate under 1,500 volts, were subsequently converted to 3,000 volts. Some motor cars were used individually as locomotives and pulled cars with a total weight of up to 300 tonnes. In the 1960s, two sets were converted into battery-powered vehicles that could be recharged while running under the overhead line and were used in the Baltics. Most were retired in the 1980s, but some were in use in Yaroslavl until 1997.