The EMD SD18 was the builder's third entry of its six-axle, "Special Duty" locomotive line. The model proved to be one of EMD's big disappoints of the era, on par with the BL2, although its lackluster sales performance can partly be contributed to the fact that most railroads at the time still preferred the four-axle Geeps, like the phenomenally successful GP7 and GP9. Ironically, the SD18 sold better to foreign lines than domestic railroads. The locomotive was also the first of the Electro-Motive Division's six-axle models to be offered in a low nose version (similar to the GP20 being the first offered with the feature). Interestingly, despite the SD18's poor sales performance a few models still roam the rails today on shortlines. Additionally, at least three SD18s are known to be officially preserved including; Chesapeake & Ohio #1810 at the Southern Appalachian Railway Museum, C&O #1818 at the Hoosier Valley Railway Museum, and Duluth Missabe & Iron Range #193 at the Lake Superior Railroad Museum.