EMD GP40 Diesel Locomotive - UNION PACIFIC #508 (without dynamic brakes) - N Scale. The EMD GP40 diesel locomotive was built by General Motors Electro-Motive Division between November 1965 and December 1971. Powered by an EMD 645E3 16-cylinder engine which generated 3000 horsepower the GP40 has proven itself as a standard freight engine on railroads throughout North America. This model features; operating directional dimming (Rule 17) headlights, All-wheel electrical pickup and drive, Skew wound motor with bronze bearings, Die-cast chassis, Performs best on 11. 25" radius curves or greater.