GE "U23C" Locomotives: Specs, Roster, History

Last revised: January 1, 2025

The U23C, developed in the latter 1960s, was a late model U-boat manufactured by General Electric for use in yard, transfer, and heavy drag service.

It featured a variation of GE's 7FDL prime mover and was meant to compete with similar models offered by the Electro-Motive Division (EMD), notably the SD38 and SD39.

In this case, neither GE or EMD saw particularly strong sales; the SD38/SD38-2 series sold just 198 examples and the U23C saw just 53 domestic sales.

Ironically, GE's variant outsold EMD's thanks to a large order for Rede Ferroviária Federal, the Federal Railways Of Brazil, which acquired 170 examples alone.

The specialized nature of the U23C was not of particular interest to many by the late 1960s, especially considering that other models could perform the very same tasks, notably EMD's SD40 series or even the U30C.

Railroads that tended to buy the U23C were either strapped for cash (Penn Central) or merely testing the waters (GE products at the time tended to come with a lower price tag).

Today, there is one U23C preserved Lake Superior & Ishpeming #2300 (in its original colors and number, the first U23C to roll out of Erie) located at the Arkansas Railroad Museum.

Photos

Lake Superior & Ishpeming U23C #2300 (built new for the railroad in February, 1968) and a few other units are running eastbound through Negaunee, Michigan on January 3, 1983. Brian Rackley photo.

History

The U23C began production in March, 1968 using a 12-cylinder version of the company's 4-cycle 7FDL prime mover, which could produce 2,250 horsepower.

The model was almost identical to the U30C save for six access doors in place of the standard eight found on most other U-boats equipped with the 7FDL16 prime mover.

GE's six axle Universal locomotives offered far greater tractive effort than their four axle counterparts. The U23C featured ratings of 90,000 pounds of starting effort and 85,800 pounds while in motion at 7.3 mph.

The company cataloged the model as a slow-speed, heavy drag locomotive. As Brian Solomon notes in his book, "GE Locomotives," the Penn Central used their small fleet in yard service.

Reception

The U23C was essentially a transfer locomotive, which other builders, like Baldwin and Alco had attempted to market more than a decade earlier. Once again many systems found little interest in this specialty locomotive type.

The U23C's sales appeared stronger due to the 170 units acquired by Brazil's Rede Ferroviária Federal. Greg McDonnell points out in his book, "U-boats," its initial fleet of 20 units (3901-3920) was completed at Erie without trucks.

The locomotives were then transferred to GE's plant in Sao Paulo where Brazilian trucks and GE traction motors were applied. The remaining 150 examples were all completed in Brazil.

The US railroads that purchased the U23C included the Santa Fe (20); Chicago, Burlington & Quincy (9), Lake Superior & Ishpeming (5), and Penn Central (19).

Data Sheet and Specifications

Entered Production	3/1968 (Lake Superior & Ishpeming #2300)
Years Produced	3/1968 - 9/1970
GE Class	U23C
Engine	7FDL12 (12 cylinder)
Engine Builder	General Electric
Horsepower	2250
RPM	1050
Length	67' 3"
Height (Top Of Rail To Top Of Cab)	15' 4"
Width	10' 3 1/2"
Weight	348,000 Lbs
Fuel Capacity	2,900 Gallons
Air Compressor	3CDC (Westinghouse)
Air Brake Schedule	26L (Westinghouse)
Trucks	C-C
Truck Type	Trimount/Adirondack
Truck Wheelbase	13' 9"
Wheel Size	40"
Traction Motors	752 (6), GE
Traction Generator	GT581, GE
Auxiliary Generator	GY27, GE
MU (Multiple-Unit)	Yes
Dynamic Brakes	Optional
Gear Ratio	74:18
Tractive Effort/Starting	90,000 Lbs
Tractive Effort/Continuous	85,800 Lbs at 7.3 mph
Top Speed	70 mph

Production Roster

(Total Built = 223)

Owner	Road Number	Serial Number	Order Number	Completion Date	Quantity
Lake Superior & Ishpeming	2300-2301	36706-36707	2500	3/1968-4/1968	2
Burlington	460-468	36988-36996	2510	4/1969	9
Santa Fe	7500-7519	37098-37117	2515	6/1969-7/1969	20
Lake Superior & Ishpeming	2302	37138	2509	9/1969	1
Penn Central	6700-6718	37540-37558	2525	10/1970-11/1970	19
Lake Superior & Ishpeming	2303-2304	37572-37573	2509	9/1970	2
Rede Ferroviária Federal (Federal Railways Of Brazil)	3801-3880	2500247-2500326	-	12/1972-8/1974	80
Rede Ferroviária Federal (Federal Railways Of Brazil)	3901-3920	2500603-2500622	-	11/1975-1/1976	20
Rede Ferroviária Federal (Federal Railways Of Brazil)	3921-3990	2500623-2500692	-	1974-1976	70

Sources

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.

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

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

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

While the historic LS&I purchased the fewest, it found the locomotives well suited in heavy drag service hauling loads of iron ore through Wisconsin and Michigan's Upper Peninsula.

The company continued to use the six-axle locomotives through the 1990s before finally replacing them with newer motive power.