[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 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.