The GE U33B is a diesel-electric locomotive that was offered by GE between 1966 and 1970, featuring a 16-cylinder motor. It is part of the GE Universal Series It is 60 ft 2 in (18.34 m) long. From the U30B, the U33B gave an additional 300 horsepower to the traction motors. In doing so, a larger rear radiator assembly was required. This "winged" look became a trademark of GE locomotives, and continues today under successor Wabtec Freight. The units were distinguished by their wider rear radiators, needed to support the higher horsepower output. It was dubbed the "U-Boat" at the time it was released.