GE U25B

GE U25B

Milwaukee Road GE U25B at Bellingham, Washington 1972.

Type and origin Power type Diesel-electric Builder GE Transportation Systems Model U25B Build date April 1959 – February 1966 Total produced 478

Specifications AAR wheel arr. B-B Gauge 4 ft 8 1⁄2 in (1,435 mm) standard gauge Prime mover GE FDL-16 Transmission Diesel electric

Performance figures Power output 2,500 hp (1,900 kW)

Career 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 (2,000 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.

Four Southern Pacific U25Bs were rebuilt by Morrison-Knudsen with a Sulzer V-12 prime mover. These locomotives, designated M-K TE70-4S, operated from 1978–1987.