EMD SD40-2W

The SD40-2W is a variant of the highly successful EMD SD40-2 road switcher, produced specifically for the Canadian market by General Motors Diesel, the Canadian manufacturing arm of General Motors located in London, Ontario. The defining characteristic that sets this variant apart from the standard SD40-2 is its widened North American Safety Cab, commonly referred to as the "W" cab, which provides improved crew protection and visibility compared to the conventional cab fitted to most domestic American SD40-2 production. Canadian National Railway was the primary customer for this variant, acquiring the locomotives to modernize and expand its motive power fleet during the latter half of the 1970s and into the early 1980s. Construction of the SD40-2W took place between 1975 and 1982, with approximately 450 units built during that period. Canadian National operated these locomotives across its extensive network, where they became a familiar and reliable presence on freight assignments ranging from heavy mainline service to general road switching duties. The wide safety cab design, which would eventually become standard on later North American locomotive production, gave Canadian operators early experience with the improved crew environment that the wider carbody afforded. The SD40-2W shares in the broader legacy of the SD40-2 family, which is widely regarded as one of the most dependable diesel-electric locomotive designs ever produced. The combination of the proven 3,000 horsepower 645E3 prime mover, the Dash 2 modular electronics, and the rugged HT-C truck arrangement gave the SD40-2W a long and productive service life on Canadian National. Many units accumulated millions of miles in service, and the type remained active for decades after its introduction, a testament to the fundamental soundness of the design.

The SD40-2W is powered by the EMD 645E3 turbocharged 16-cylinder prime mover, producing 3,000 horsepower and driving DC traction motors arranged in a C-C wheel configuration, meaning six powered axles on two three-axle trucks. This configuration provides excellent tractive effort and weight distribution, making the locomotive well suited for heavy freight service on the grades and curves common throughout the Canadian National system. The Dash 2 designation reflects the incorporation of modular electronic control systems derived from development work done on the experimental DDA40X, which improved reliability and simplified troubleshooting and maintenance compared to earlier EMD designs. The most visually distinctive feature of the SD40-2W is its widened cab structure, which extends further outboard than the standard SD40-2 cab to provide additional space and improved side-impact protection for the crew. This safety cab design was influenced by evolving Canadian operating practices and regulatory thinking that placed greater emphasis on locomotive cab crashworthiness than was common in the United States at the time. Aside from the cab configuration, the mechanical and electrical components of the SD40-2W are substantially identical to the standard SD40-2, sharing the same frame dimensions, hood structure, and running gear, which simplified spare parts provisioning and maintenance procedures across the broader locomotive fleet.

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Models by: Bowser · Intermountain