GE U50

The GE U50 was an eight-axle, 5,000 horsepower diesel-electric locomotive built by GE Transportation, a twin-engined unit that combined two 2,500 horsepower diesel engines on one frame. It rode on four two-axle trucks with a B+B-B+B wheel arrangement, reusing trucks and bolsters from scrapped Union Pacific turbine locomotives. Union Pacific wanted a 15,000 horsepower three-unit locomotive to replace its turbines, and the U50 was effectively two U25B locomotives on one frame. Three went to Union Pacific in October 1963, three to Southern Pacific in 1964, and Union Pacific ordered 20 more. Union Pacific units were nicknamed U-Boats and the Southern Pacific ones Baby Hueys. None was preserved, although a nose door from Southern Pacific 9950 survives at the Southern California Railway Museum.