EMD E3A/E3B

The EMD E3 emerged from Electro-Motive Corporation's La Grange, Illinois facility in September 1938 as the fourth model in the company's growing line of E-series passenger diesel locomotives. The demonstrator unit, numbered 822, departed La Grange on September 12, 1938, and was subsequently modified before being delivered to the Kansas City Southern Railway. Production of the cab-equipped A units ran from September 1938 through June 1940, with 17 examples eventually built for revenue service. The booster B units were fewer in number, produced in two small batches during March and September of 1939, yielding only a handful of units for railroad customers who needed additional unpowered cab-less power in their consists. The E3 represented a meaningful step forward in the development of reliable diesel passenger power in North America, most notably because it introduced the EMD 567 prime mover to the E-unit line. Earlier E-series locomotives had relied on the Winton 201A engine, which had proven troublesome in regular service due to its origins as a marine powerplant rather than a purpose-built railroad engine. The transition to the 567 gave railroads a significantly more dependable locomotive, and the engine family itself would remain in production until 1966, underpinning much of EMD's subsequent success. The E3 and its immediate successors, the E4, E5, and E6, share a visual characteristic that distinguishes them from later E-units, namely a pronounced slant to the nose when viewed from the side, earning them the informal designation of slant-nose units among enthusiasts and historians. Only one E3 is known to survive into the present era. The former Atlantic Coast Line Railroad E3A numbered 501 passed through several hands over the decades following its retirement, eventually coming under the care of the North Carolina Transportation Museum in Spencer, North Carolina. In January 2013 ownership was formally transferred to the North Carolina Department of Cultural Resources, the parent organization of Spencer Shops, and the locomotive has been maintained in operational condition, occasionally operated for museum purposes.

The E3A and E3B units each developed 2,000 horsepower through the use of two twelve-cylinder EMD 567 engines mounted in the locomotive's engine compartment, each producing approximately 1,000 horsepower at 800 revolutions per minute. The 567 is a two-stroke, mechanically aspirated diesel arranged in a 45-degree V configuration, with each cylinder displacing 567 cubic inches, a figure from which the engine took its name. Each prime mover drove its own direct current generator, and the electrical output from both generators was used to power four traction motors distributed across the locomotive's two trucks. The wheel arrangement, designated A1A-A1A, placed two powered axles and one unpowered center axle on each truck, a configuration chosen to distribute the locomotive's weight adequately over the rail while keeping the axle loading within acceptable limits for passenger main lines. The nose profile of the E3 differed in a subtle but notable way between the demonstrator and production units. The original demonstrator 822 was built with a nose closely resembling those of the earlier EA and E1A units, featuring a flush-mounted headlamp. Later production E3s incorporated an elevated headlamp housing mounted in a raised nacelle, giving the front end a slightly different appearance. The demonstrator was itself modified to match this arrangement prior to its delivery to the Kansas City Southern. By the time EMD moved into later E-unit production, the slant-nose profile shared by the E3 through E6 gave way to the more upright bulldog nose that would become characteristic of the F-unit cab cars and later E-series locomotives.

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