EMD NW3

The EMD NW3 was a specialized diesel-electric switcher produced by General Motors' Electro-Motive Division at its La Grange, Illinois facility between November 1939 and March 1942. Only seven examples were ever constructed, and all of them were ordered by a single customer, the Great Northern Railway. The locomotives were originally assigned road numbers 5400 through 5406 before being renumbered 175 through 181 during their careers on the Great Northern. The small production total reflected the highly specific nature of the design, which was tailored to meet Great Northern's particular operational requirements rather than representing a broadly marketable product. In service, the NW3 locomotives wore Great Northern's black diesel paint scheme as originally delivered, though they were subsequently repainted in the railroad's striking orange and green Empire Builder livery. The first four units of the class were traded back to EMD in 1965 as part of transactions involving newer motive power. The remaining three locomotives were dispersed to other owners: one went to A.E. Staley Company in Morrisville, Pennsylvania, another was acquired by the Clinchfield Railroad as that road's number 361, and a third passed to Anaconda Aluminum as their number 100. The Clinchfield unit was eventually scrapped, while the former number 179 remained active in Morrisville until approximately 2019 before also being scrapped. The most enduring survivor of the NW3 class is the former Great Northern number 181, which went to Anaconda Aluminum as their number 100 and is preserved on display at the depot in Whitefish, Montana, restored to the Empire Builder color scheme it carried during its Great Northern years. This single preserved example stands as a reminder of a locomotive type that occupied a narrow and somewhat unconventional niche in early diesel development, built in too few numbers to have broad historical impact but notable for the originality of its configuration and its long association with one of the major western railroads.

The NW3 was built around a mechanical foundation similar to the EMD NW2 switcher, using the same hood assembly and prime mover arrangement, but mounted on a substantially lengthened frame to accommodate additional equipment. Power came from a twelve-cylinder EMD 567B diesel engine producing 1,000 horsepower, transmitted to the wheels through a direct current electrical system driving four traction motors arranged in a Bo-Bo wheel configuration using Blomberg B road trucks rather than the simpler switcher trucks more commonly associated with yard locomotives of this era. The use of road trucks rather than switcher trucks distinguished the NW3 mechanically from its closer relatives in the EMD switcher line and reflected the expectation that these locomotives would see service beyond purely confined yard environments. The most distinctive design feature of the NW3 was its enlarged cab and an additional full-width hood section forward of the cab, which housed a steam generator intended to provide passenger car heating during mixed or passenger service duties. The boiler exhaust was routed through the front of the cab structure, exiting at the center of the roof above the front windows, an arrangement that gave the locomotives an unusual appearance compared to conventional switchers. The short exhaust stacks fitted at the time of delivery were later replaced with the standard conical stacks typical of EMD switcher production, further altering the locomotives' external profile over the course of their service lives.

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