GE Dash 9-40CW

The GE Dash 9-40CW emerged from General Electric's Transportation Systems division in Erie, Pennsylvania, as part of the broader Dash 9 locomotive family. Production ran from January 1996 through December 2004, during which time 1,444 units were constructed. The locomotive was conceived under a philosophy similar to that of its standard-cab predecessor, the Dash 9-40C, namely that operating at a reduced power rating relative to the platform's maximum capability would extend engine longevity and reduce fuel consumption. Norfolk Southern Railway became the dominant customer for the type, acquiring 1,090 units numbered 8889 through 9978, making the Dash 9-40CW a fixture of that railroad's motive power fleet for decades. CSX Transportation also received examples of the type, though their order carried some distinctions from the Norfolk Southern units. The early CSX locomotives were built with carbodies visually similar to the preceding Dash 8-40CW, and the first three units of that order were assembled on Dash 8 frames before transitioning to standard Dash 9 construction. These units were initially designated C44-8W and built to a 4,400 horsepower rating before being downrated to 4,000 horsepower, occupying an unusual transitional position between the two locomotive generations. CSX's units were also fitted with GSC Floating Bolster 3 trucks rather than the Hi-Ad trucks that became standard on later production. When GE introduced its Evolution Series in 2005, the ES40DC effectively replaced the Dash 9-40CW in the product catalog. Norfolk Southern continued ordering 4,000 horsepower units in the form of the ES40DC, maintaining the same conservative power philosophy that had characterized its Dash 9-40CW fleet. Beginning around 2015, Norfolk Southern undertook a rebuilding program to convert portions of its C40-9W roster into AC44C6M locomotives, extending the mechanical service life of the underlying platforms while upgrading them to alternating current traction technology.

The Dash 9-40CW is a six-axle diesel-electric locomotive arranged in a C-C wheel configuration and rated at 4,000 horsepower. It shares its principal mechanical components with the more widely produced Dash 9-44CW, including the same frame, Hi-Ad trucks, 16-cylinder GE FDL engine, and 752AH-31 traction motors. The power difference between the two models is not a matter of mechanical configuration but rather of electronic governance. Software within the engine control unit limits output to 4,000 horsepower, though the arrangement reportedly allows an engineer to override this restriction under certain operating conditions. The traction system employs direct current, distinguishing it from later AC-traction designs that would follow in GE's product line. The narrow-gauge BB40-9W variant, produced exclusively for the Brazilian carrier EFVM, represents a notable adaptation of the basic design. All 141 of these units, numbered 1113 through 1253, ride on four B trucks rather than the two C trucks of the standard North American configuration. This arrangement was necessitated by the 1,000 millimeter track gauge of the EFVM system and the lower axle load limits of approximately 25 tonnes imposed by that railway's infrastructure, compared to the roughly 32.4 tonne axle loads permissible on North American standard gauge lines.

Models by: Athearn