 The electrical equipment for these trains was manufactured by Metropolitan Vickers (later license-built by the Dynamo factory in Moscow), and the mechanical equipment was made by the Mytischi Railroad Machinery Plant.After World War II, the entire production was transferred to the Riga Railroad Machinery Plant, which continued producing these trainsets until 1958.The many versions of the S-series trains produced included 1500-V and 3000-V versions, dual-current versions and some versions fitted with dynamic brakes.