Soon after Pafawag started the production of the universal EU07 locomotive, The Rolling-stock Industry Central Bureau of Construction (Polish: Centralne Biuro Konstrukcyjne Przemysłu Taboru Kolejowego) began to develop a new heavy Co-Co freight locomotive.
[2] PKP bought 1183 locomotives until the production was ceased in 1989 (numbered ET22-001 to ET22-1183, including two 201Ec type),[3] the last of which were delivered in 1990.
[4] This made the ET22 class the most numerous standard gauge electric locomotive built in Europe.
There are three basic types of locomotive bodies where the main differences are the size and placement of the side windows, air intakes and ventilation grids.
From ET22-282, big headlights, typical for Polish railways, were fitted in conical covers instead of hexagonal.
[4] In 1973 Pafawag built a prototype passenger locomotive of the building type 201Ea, which had a different gear ratio for top speed 160 km/h, with no other substantial changes.
[5] A modernization was considered successful, but in a view of an economical crisis in 1980s in Poland, the authorities of a planned economy lost interest in starting production of an improved locomotive.
They were fitted with main reservoir pipes required for the automatic door control of the passenger coaches.
[3] The only locomotives of 201E family built for export were 23 modified units of 201Eg type for Moroccan railways ONCF, delivered in 1976.
[2] Its maximum continuous power is 3,000 kW (4,000 hp) and it is the biggest single-box Co-Co locomotive in PKP service.