|Type and origin|
|Builder||GE Transportation Systems|
|Build date||April 1959 – February 1966|
|AAR wheel arr.||B-B|
|Gauge||4 ft 8 1⁄2 in (1,435 mm)|
|Prime mover||GE FDL-16|
|Power output||2,500 hp (1,900 kW)|
|Disposition||most scrapped, a few in preservation|
The GE U25B was General Electric's first independent entry into the United States domestic Diesel-electric locomotive railroad market for heavy production road locomotives since 1936. From 1940 through 1953, GE participated in a design, production, and marketing consortium (Alco-GE) for diesel-electric locomotives with the American Locomotive Company. Starting in 1956 GE launched its Universal Series of diesel locomotives for the export market. The U25B was the first attempt at the domestic market since its termination of the consortium agreement with Alco.
The U25B (nicknamed U-Boat) was the first commercially successful domestic diesel electric road locomotive designed, built, and sold by General Electric after its split with the American Locomotive Company (Alco), a company dating back to the steam era. Along with Ingersoll-Rand, GE built the first viable American diesel-electric locomotive in 1928. GE had previously produced a number of prototype diesel switchers, in part with Alco. The GE Universal Series started production in 1956 and some 400 export locomotives were sold before the U25B was offered in the United States.
The U-Boat put GE on the road to becoming the top locomotive producer in the U.S., much to the chagrin of EMD. It introduced many innovations to the U.S. diesel locomotive market, including a pressurized car body and a centralized air processing system that provided filtered air to the engine and electrical cabinet, thus reducing maintenance. The U25B was also the highest-horsepower four-axle diesel road locomotive in the U.S. at the time of its introduction, its contemporaries being the GP20 (2000 hp) and the RS27 (2,400 hp or 1,800 kW).
Though many were produced and sold, the only remaining U25B locomotives are in museums, as many were retired or scrapped at the end of their service life by the end of the 1980s.
Only one remains in operating condition. Southern Pacific 3100 is now on permanent exhibit at the Orange Empire Railway Museum in Perris, California. Built in 1963, this locomotive was first numbered SP 7508. Later numbered SP 6800, it became a goodwill ambassador for the railroad in 1976 when it was painted in an elaborate red, white, and blue color scheme in celebration of the nation's bicentennial; it was later renumbered and repainted in standard SP livery and was donated to the museum. The 3100 is fully certified to run on any of the nation's railroads and is frequently used as motive power for offsite work trains.
A second U25B locomotive is currently undergoing restoration efforts at the Illinois Railway Museum in Union, IL. Former Milwaukee Road engine number 5056 (built in 1965) is being both cosmetically and mechanically restored for operation on the museum grounds.
A third U25B locomotive is on display at the Western Pacific Railroad Museum in Portola, CA. Former Milwaukee Road engine number 5057 can be made operable. It was purchased by Cascade Rail Foundation to eventually be displayed at the South Cle Elum Rail Yard.
Conrail 2510 was to be preserved by The Great Northeastern Rail Road Foundation, but the plans fell through and the engine is sitting in rough shape, in Glenmont,NY. It is currently owned by the NRHS. It was built as New York Central 2510 in May of 1964.
New York, New Haven & Hartford #2525 has been preserved by the Railroad Museum of New England of Thomaston, CT. It wears its original New Haven colors, however it is not currently operational.
|General Electric (XP-24 testbed)||2||751–752||Never sold, retained by GE|
|General Electric (demonstrator)||4||753–756||High short hood; to Frisco 804–807|
|4||2501–2504||to Union Pacific 633–636|
|Atchison, Topeka and Santa Fe Railway||16||1600–1615||renumbered 6600–6615|
|Chesapeake and Ohio Railway||38||2500–2537||renumbered 8100–8137|
|Chicago, Burlington and Quincy Railroad||6||100–105||to Burlington Northern 5424–5429|
|Chicago, Milwaukee, St. Paul and Pacific Railroad ("Milwaukee Road")||12||380–391||380 retired 1966; remainder renumbered 5000–5010; renumbered 5050–5060|
|Chicago, Rock Island and Pacific Railroad||39||200–238||225–238 to Maine Central Railroad 225–238|
|Erie Lackawanna Railroad||27||2501–2527||to Conrail 2570–2596|
|Great Northern Railway||24||2500–2523||to Burlington Northern 5400–5423|
|Louisville and Nashville Railroad||27||1600–1626|
|New York Central Railroad||70||2500–2569||to Penn Central 2500–2569; to Conrail 2500–2569|
|New York, New Haven and Hartford Railroad||26||2500–2525||to Penn Central 2660–2685; to Conrail 2660–2685|
|Norfolk and Western Railway||1||3515||renumbered 8138|
|Pennsylvania Railroad||59||2500–2548, 2649–2658||renumbered 2600–2658; to Penn Central 2600–2658; to Conrail 2600–2658|
|St. Louis – San Francisco Railway ("Frisco")||28||800–803, 808–831||804–807 ex GE. Numbers 800–807 were high short hood units in black and yellow scheme; The next set (808–815) were low short hood units in black and yellow. The last 16, 816-831, were low hoods and delivered in the orange and white scheme. To Burlington Northern 5210–5233.|
|Southern Pacific Company||68||7500–7567||renumbered 6700–6767|
|Union Pacific Railroad||12||625–632, 637–640||633–636 ex GE demonstrators 2501-2504. The only railroad, other than the Frisco, to have high short hood U25Bs.|
|Wabash Railroad||15||500–514||to Norfolk and Western 3516–3529; renumbered 8139–8152|
- Marre, Louis A. (1995). Diesel Locomotives: The First 50 Years: A Guide to Diesels Built Before 1972. Railroad Reference Series (Book 10). Waukesha, WI, USA: Kalmbach Publishing. ISBN 0890242585.
- Komanesky, John. General Electric U25B Roster. Retrieved January 27, 2005. States data from Extra 2200 South.
Jerry Pinkepank, "The Diesel Spotter's Guide," Milwaukee: Kalmbach, 1973.