The line of locomotives were powered by the 16-cylinder 645-series prime mover. A total of 1,145 units were produced between 1966 and 1972. These turbocharged 3,000hp locomotives were used primarily in road freight service. The GP40 was a versatile locomotive that could be found across the US hauling drag freights over mountain passes and leading high-speed intermodal trains across flat terrain. Three rooftop radiator fans at the rear of the long hood differentiate a GP40 from its lower horsepower counterpart, the GP38, which has two fans. The Atlas EMD GP40 comes equipped with a dual-mode ESU LokSound Select sound and DCC dual-mode decoder for operation on DCC and DC layouts, and features a five-pole skewed-armature motor with dual flywheels, directional LED lighting and AccuMate(R) magnetic knuckle couplers. The EMD GP40 features accurate decoration, roadname-appropriate details and has plenty of applied details. Note that although the dual-mode decoders will operate on DCC and DC layouts, DC and DCC units will not operate together in a consist.