GE "U18B" Locomotives: Specs, Roster, History

Last revised: January 2, 2025

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

Entered Production	12/1973 (Seaboard Coast Line #250)
Years Produced	12/1973 - 10/1976
GE Class	U18B
Engine	7FDL (8 cylinder)
Engine Builder	General Electric
Horsepower	1800
RPM	1050
Length	54' 8"
Height (Top Of Rail To Top Of Cab)	14' 14 1/2"
Width	10' 3"
Weight	220,000 Lbs
Fuel Capacity	1,200 Gallons
Air Compressor	3CDC (Westinghouse)
Air Brake Schedule	26NL (Westinghouse)
Trucks	B-B
Truck Type	Swing Bolster, Drop-Side Equalizer (GSC) or FB2 (GE)
Truck Wheelbase	9' 3"
Wheel Size	40"
Traction Motors	752-E6 (4), GE
Traction Generator	GT581, GE
Auxiliary Generator	GY27, GE
MU (Multiple-Unit)	Yes
Dynamic Brakes	Optional
Gear Ratio	74:18
Tractive Effort (Starting)	70,000 Lbs
Tractive Effort (Continuous)	57,500 Lbs at 10.7 mph
Top Speed	70 mph

The SCL was quite fond of the U18B, which replaced its aging fleet of RS2's and RS3's. They were primarily used in branch and light duty service all across the railroad's network.

In addition, three units #390-392, were assigned to phosphate service in Florida according to Greg McDonnell's book, "U-Boats."

Production Roster

Owner	Road Number	Serial Number	Order Number	Completion Date	Quantity
Seaboard Coast Line	300-309	38847-38856	2801	3/1973 - 5/1973	10
Seaboard Coast Line	310-324	38857-38871	2802	3/1973 - 5/1973	15
Seaboard Coast Line	325-343	39388-39406	2807	11/1973 - 12/1973	19
Seaboard Coast Line	250-261	39407-39418	2807	12/1973	12
Texas Utilities	101-102	39506-39507	2826	2/1974	2
Ferrocarriles Nacionales de México (NdeM)	9000-9011	39641-39652	2810	1/1974 - 2/1974	12
Ferrocarriles Nacionales de México (NdeM)	9012-9019	39653-39660	2810	3/1974 - 4/1974	7
Ferrocarriles Nacionales de México (NdeM)	9020-9037	39661-39678	2810	7/1974 - 9/1974	18
Ferrocarriles Nacionales de México (NdeM)	9038-9044	39679-39685	2810	10/1974	7
Seaboard Coast Line	344-392	39852-39900	2900	8/1974 - 11/1974	49
Maine Central	400 ("General Henry Knox")	40720	2824	5/1975	1
Maine Central	401 ("Hannah Weston")	40721	2824	5/1975	1
Maine Central	402 ("General John Stark")	40722	2824	5/1975	1
Maine Central	403 ("Peleg Wadsworth")	40723	2824	5/1975	1
Maine Central	404 ("Kenneth Roberts")	40724	2824	5/1975	1
Maine Central	405 ("Arundel")	40725	2824	6/1975	1
Maine Central	406 ("Colonel John Allan")	40726	2824	6/1975	1
Maine Central	407 ("Unity")	40727	2824	6/1975	1
Maine Central	408 ("Battle of the Bagaduce")	40728	2824	6/1975	1
Maine Central	409 ("Ethan Allen")	40729	2824	6/1975	1
Providence & Worcester	1810	41482	1408-1	10/1976	1

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.

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