General Motors purchased EMC (Electro Motive Corporation) and Winton Engine in 1930.
EMC was a subsidiary of GM until 1941 when it became a full division (EMD). Switchers
built prior to February 1939 were powered by the 201A engine, after that the 567 series
followed by the 645 series engines were used.
Transfer Units TR - pre-war NW2 based cow/calf TR1 - FT/NW3 based cow/calf TR2 - NW2 based cow/calf TR3 - NW2 based cow/calf/calf TR4 - SW7 based cow/calf TR5 - SW9 based cow/calf TR6 - SW8 based cow/calf TR12 - SW1200 based cow/calf