66306 EMD GP40 - Union Pacific #858 Diesel Locomotive - DCC SoundThe GP40 was considered the top of EMDS four axle line when first introduced in the late 1960s. It visually differed from earlier GP models, featuring three radiator fans on its long hood, but was otherwise similar in style to the GP38, which entered production around the same time. The locomotive was popular for its ease of maintenance and standardized features and remained in production until succeeded by the GP40 2 in the early 1970s. Today, many