Nacionales de Mexico GE U18B 9026 at Empalme, Sonora, January 10, 1997. Photographer: Paul Wester.

(Craig Garver, Public domain,



The GE U18B diesel-electric locomotive was introduced by GE Transportation as a branch line road switcher locomotive in 1973. It was the only North American locomotive powered by the 8-cylinder 7FDL engine. 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. Railroads lost interest in specialized road units entering the 1970s. The U18Bs were noted for having reliability issues and being underpowered. The Maine Central referred to their U18Bs as the Independence class and named their units after revolutionary war heroes. 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.


Seaboard Coast Line No. 1982, a GE U18B, at Tampa, FL, June 1983.

(Gary Todd from Xinzheng, China, CC0, via Wikimedia Commons)


Original Owners

Railroad Quantity Numbers Notes
Maine Central Railroad 10 400–409 Blomberg trucks; part of a cancelled SCL order
Ferrocarriles Nacionales de México 45 9000–9044 AAR type-B trucks
Providence and Worcester Railroad 1 1801 FB-2 trucks
Seaboard Coast Line Railroad 105 250–261, 300–392 325-392 with Blomberg trucks, all others FB-2. All to CSX. 10 additional units on order but cancelled
Texas Utilities 2 101–102 AAR type-B trucks


Empalme, near Guaymas, was the system general shops for the Ferrocarril del Pacifico and the Sud Pacifico de Mexico before that. FCP was 100% Alco, GE and MLW, and the shop forces are quite familiar with keeping GE's well content, happy and healthy.

General Electric built just 163 U18B's, mostly for two customers: 105 for Seaboard Coast Line and 45 for NdeM. Maine Central took 10, went to the Providence & Worcester and two went an electric power company in Texas. Production lasted from 1973 until 1976.

These units were intended for use on branchlines, and had a small 8 cylinder 7FDL engine. At the time, most railroads were filling this need with either rebuilding programs for GP7/GP9's, or EMD's 2000 hp GP38-2. - Craig Garver


View of Winslow Junction on the Southern Railroad of New Jersey in Winslow Township, New Jersey.

View of Winslow Junction on the Southern Railroad of New Jersey in Winslow Township, New Jersey.

SRNJ locomotive No. 1801, a model U18B built by General Electric, is on a siding, with rolling stock acquired by SRNJ from various railroads.

(Caseyjonz, Public domain, via Wikimedia Commons)


GE U18B Overview

Type and origin
Power type: Diesel-electric
Builder: General Electric
Model: U18B
Build date: March 1973 – October 1976
Total produced: 163
​• AAR B-B
• UIC Bo′Bo′
Gauge: 4 ft 8+1⁄2 in (1,435 mm) standard gauge
Length: 54 ft 8 in (16.66 m)
Prime mover: GE 7FDL
Engine type: V8 4-stroke diesel
Aspiration: Turbocharger
Displacement: 5,344 cu in (87.57 L)
Cylinders: 8
Cylinder size: 9 in × 10.5 in (228.6 mm × 266.7 mm)
Transmission: DC generator, DC traction motors
Locomotive brake: Straight air, Dynamic
Train brakes: 26-L Air
Performance figures
Power output: 1,800 hp (1.34 MW)
Locale: North America