The GE U18Bdiesel-electric locomotive was introduced by GE Transportation as a branch line road switcher locomotive in 1973.[1] It was the only North American locomotive powered by the 8-cylinder 7FDL engine.[2] The U18B was not a popular seller with GE only making about 150 of them, and they were mostly purchased by Maine Central and Seaboard Coast Line.[1] Railroads lost interest in specialized road units entering the 1970s.[1] The U18Bs were noted for having reliability issues and being underpowered.[1] The Maine Central referred to their U18Bs as the Independence class and named their units after revolutionary war heroes.[3][1] GE included information about a B18-7 locomotive (which would have followed the U18B) in its 1978 "Series-7 Road Locomotives" service manual, but none of these updated units were ordered, sold, or built.[4][5]