The EMC E3 was a 2,000 horsepower (1,500 kW), A1A-A1A passenger train locomotive that was manufactured by Electro-Motive Corporation of La Grange, Illinois. The EMC demonstrator #822 was released from La Grange for test on September 12, 1938. The cab version, or E3A, was manufactured from September 1938 to June 1940, and 17 were produced. The booster version, or E3B, was manufactured in March 1939 and September 1939, and 2 were produced. The 2,000 hp (1,500 kW) was achieved by putting two 1,000 horsepower (750 kW), 12-cylinder, model 567 engines in the engine compartment. Each engine drove its own electrical generator to power the traction motors. The E3 was the fourth model in a long line of passenger diesels of similar design known as EMD E-units.
Compared with passenger locomotives made later by EMD, the noses of the E3, E4, E5, and E6 cab units had pronounced slants when viewed from the side. Therefore, these four models have been nicknamed "slant nose" units. Later E models had the more vertical "bulldog nose" of the F series. E3 demonstrator 822 was built with a nose identical to earlier EA and E1A units, but later locomotives in the series featured an elevated headlamp mounted in a nacelle, distinct from the flush profile mounting of the earlier units. 822 was modified in a similar fashion prior to delivery to the Kansas City Southern Railway.
