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The "NW3": EMD's Early Testbed Road-Switcher

Published: August 12, 2024

By: Adam Burns

The NW3 marks a unique chapter in the history of the EMD's storied production. This rare model was built only between November 1939 and March 1942, with seven units produced during that time.

The model was essentially conceived as an experimental light-road switcher model equipped with a steam generator for passenger terminal work. 

It was built on the stretched frame of the NW2 and sported EMD's typical four-axle setup.  Interestingly, the La Grange builder chose not to offset the cab, which became common practice in road-switcher designs like Alco's RS1, giving the NW3 the odd appearance of a lengthened switcher.

The locomotive was powered by a 12-cylinder 567A prime mover capable of producing 1,000 horsepower.  The NW3 ultimately sold just seven examples to a single railroad, the Great Northern. Despite its limited production, the model set the stage for EMD's future road switcher designs, influencing subsequent models that would become more commonplace in the rail industry.

The NW3 stands as a pioneering example of innovation in locomotive design, combining the efficiency of a switcher with the robustness of a road locomotive. Its unique features and limited production run make it a notable, yet often understated, part of EMD's locomotive legacy.

A rare Elecro-Motive NW3, Clinchfield #361, is seen here in Erwin, Tennessee on March 30, 1971. This unit began its career as Great Northern #5405 in 1942. Warren Calloway photo.

Development

EMD's NW2 was one of the builder's best-selling switchers, witnessing 1,139 sales to both domestic and foreign buyers.  In an attempt to expand its market presence, the company elected to catalog a variant, the NW3.

While techincally a road-switcher in that it was designed for over-the-road assignments, the NW3 was intended to serve passenger terminals, utilizing its steam generator to switch passenger equipment.

Ultimately, there was little interest within the industry for this specialized locomotive with only Great Northern acquiring seven examples over a three year period; originally numbered #5400-5406, they were later renumbered #175-181.

The NW3 was constructed using the NW2 switcher’s hood, prime mover—a robust V12 EMD 567A diesel engine—and main generator, all mounted on a lengthened frame with road trucks (Blomberg Bs).

This extension in the frame accommodated a spacious cab and an additional full-width hood section that housed a steam generator for passenger service. The steam generator's exhaust was routed through the front center of the cab, positioned between the front windows and exiting at the middle of the roof front.

Delivered in Great Northern’s then-standard black paint scheme (sporting a large GN logo), the NW3s were later repainted in the eye-catching orange and green "Empire Builder" livery (Omaha orange and Pullman green). Initially, the locomotives featured short exhaust stacks, which were subsequently replaced with standard conical EMD switcher stacks.  The latter helped better direct diesel exhaust away from the crew cab, a common modification for diesel switchers of that era.

Purpose and Career

Though it was functionally advanced, the NW3's aesthetics were less appealing, with an added bulge on the hood near the cab to house the steam generator giving it a somewhat lumpy appearance. Despite this, the core mechanics and performance were standard, reliable EMD quality.

Interestingly, GN typically employed theirs in secondary passenger service, regularly assigned to trains 35 and 36; a 295-mile, six-day-a-week, two-car, all-stops local passenger service between Duluth, Minnesota, and Grand Forks, North Dakota, as late as the 1950s.

Later Years

The NW3's market viability became moot when the U.S. government’s War Production Board directed EMD to focus on building road locomotives during WWII, leaving switchers to other manufacturers. Post-war, EMD reentered the road switcher market with the BL2 and later the highly successful GP7 and GP9, solidifying its position in the industry.

Data Sheet

Production Roster

Disposition

In 1965, the first four locomotives were traded in by GN to EMD in exchange for new locomotives. The remaining three units found new homes:

• #179 was sold to A.E. Staley Co. in Morrisville, Pennsylvania, retaining its original number; it was later acquired by Locomotive Trouble Shooters from Fairless Hills, Pennsylvania, where its engine was replaced. 

• Locomotive #180 was sold to the Clinchfield Railroad as their #361, and #181 was purchased by Anaconda Aluminum, becoming their #100. The Clinchfield unit was eventually scrapped, while the Anaconda Aluminum locomotive is preserved and on display at the Whitefish, Montana depot, sporting its original Empire Builder colors. 

• Locomotive #179 remained in service in Morrisville, Pennsylvania, until it was scrapped in 2019, concluding its long and storied operational life.