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GE "U18B" Locomotives: Specs, Roster, History

Last revised: January 2, 2025

By: Adam Burns

The U18B was a late model design the company marketed as a secondary, light branch service locomotive.  While GE did sell more than 150 U18Bs, overall it was not extremely successful.

By the 1970s, railroads had lost interest in specialized, non-switcher designs.  To make matters worse, the U18B drew complaints of being under-powered and suffering reliability issues. 

In addition, crews stated the locomotive featured a notoriously rough ride.  It was the Seaboard Coast Line that wound up acquiring the most "Baby Boats," purchasing 105 between 1973-1974.  

The Maine Central picked up 10, the Providence & Worcester a single unit, and Texas Utilities two units. 

Interestingly, Mexico's large Ferrocarriles Nacionales de México (NdeM) also acquired a  large batch of 45 units.  Today, you can still find a handful in operation in the United States, notably at short line Pickens Railway in South Carolina.

Photos

Maine Central U18Bs #403 and #404 are seen here in service at Northern Maine Junction on September 23, 1978. Warren Calloway photo.

Overview

The U18B was a late addition to the Universal line, beginning production in March, 1973.  It was equipped with GE's standard 4-cycle, 7FDL prime mover that could produce 1,800 horsepower.

The Maine Central was not the largest buyer of the U18B but its fleet was particularly interesting.  As Brian Solomon notes in his book, "GE Locomotives," the railroad acquired the model to replace its old Alco road-switchers (RS2, RS3, and RS11).

Since the locomotives were completed just prior to the nation's Bicentennial (1976) they were listed as part of MEC's "Independence Class."

The units were painted in yellow paint with green pinstriping and featured a massive eagle adorning the nose.  In addition, the railroad named each unit after a notable person or location involved in the Revolutionary War.

The MEC primarily assigned its U18B's to the legendary Mountain Division between Portland, Maine and St. Johnsbury, Vermont.

The remained in use for more than 25 years and some even made it into successor Guilford paint, as illustrated in the above photo.

General Electric offered the U18B with either General Steel Castings' (GSC) swing bolster, drop-side equalizer  (AAR Type B) or GE's own FB2 trucks.

In addition, Seaboard Coast Line had units #325-392 equipped with refurbished Blomberg trucks from  trade-in EMD units.

Data Sheet and Specifications

Production Roster

Sources

• Foster, Gerald. A Field Guide To Trains. New York: Houghton Mifflin, 1996.

• McDonnell, Greg. U-boats.  Toronto: Stoddart Publishing, 1994.

• Marre, Louis A. and Pinkepank, Jerry A. Contemporary Diesel Spotter's Guide, The: A Comprehensive Reference Manual To Locomotives Since 1972.  Milwaukee: Kalmbach Publishing Company, 1989.

• Solomon, Brian. GE Locomotives: 110 Years Of General Electric Motive Power. St. Paul: MBI Publishing, 2003.

A Maine Central freight, led by U18B #408 (named the "Battle of the Bagaduce"), rolls through Brunswick, Maine during the summer of 1976. Randy Kotuby photo.

Production on the U18B had ended by October, 1976. Apparently, the unsuccessful nature of the model convinced General Electric to scrap any plans to released a follow-up.

This unit would have been known as the B18-7 as part of the company's new "Dash 7" series (offering new electronics among other features).

Today, again, you can find a handful of U18Bs still in operation on short lines although there are none known to be preserved.