PENNSYRR.COM by Jerry Britton


GE U25B, Class GF25

The GE U25B was General Electric's first independent entry into the United States domestic road switcher 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. In 1956 the GE Universal Series of diesel locomotives was founded 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. GE had developed internal combustion-electric generating, control, and drive systems in the early 1920s, which provided the foundation for the use of internal combustion engines in railroading. Early applications were in motorized railcars and switch engines. The 1930s saw that technology adapted to high speed mainline locomotives. In 1940 GE partnered with Alco, who by that time were well-established as a manufacturer of diesel switch engines and were introducing their first diesel road locomotives. They were successful in building locomotives for switching and short-haul applications, having introduced the first road-switcher design in 1941 (which would supplant the carbody design developed by the Electro-Motive Corporation by the mid-1950s) and gained a 26% market share as of 1946. Alco-GE's efforts in main line road locomotives had not been successful at breaking into EMD's dominant position in that market, although they introduced a successful gas turbine-electric locomotive to market in 1952. In 1953 GE went independent from Alco in locomotive production, with their new subsidiary GE Rail taking over the gas turbine-electric venture while they sought a supplier of more reliable diesel engines suitable for road locomotives. Production of Cooper-Bessemer powered Universal Series locomotives began in 1956 and some 400 export locomotives were sold before the U25B was offered in the United States. The U25B was announced by General Electric as a domestic model on April 26, 1960. It was the first locomotive powered by GE's highly successful FDL-16 engine.

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).

Road Numbers Delivery HO Scale Model

Bowser (2501, 2502, 2506, 2519, 2526, 2641, 2647, 2651, 2656)

Oriental Limited

Precision Scale


prr ge u25c

GE U25C, Class GF25a

The U25C was General Electric's first six-axle road switcher intended for the United States domestic market. Launched in September 1963, it remained in production until December 1965. It was replaced by the U28C.

The origin of the U25C grew out of the need for six axle locomotives to operate on a 12-mile heavy haul railroad to construct Oroville Dam. The General Electric salesman to Oro Dam Constructors offered essentially a U25B riding on six axle trucks. When the salesman got back to GE's Erie Plant it was discovered that no six axle U25 was available, nor did GE wish to construct a domestic six axle road switcher until the horsepower threshold reached 3000 horsepower. Rather than lose the four unit sale GE quickly began a design of a six axle U25 that relied heavily on the U25B for engineering. The U25C was longer than the U25B by four feet four inches. The extra length was needed to accommodate the improved Trimount trucks. Completed in September 1963 the U25C was the first six axle unit of the second generation of dieselization. 


The following are normally identified as U25C phases:

Phase I
Phase I units were built from September 1963 to May 1964. These units featured a 2900-gallon fuel tank with the air tanks on the ends of the tank. The early U25Cs had louvers on the equipment boxes under the engineer's side of the cab. Oro Dam Constructors #8010-8016 and Atlantic Coast Line #3000-3003 were the only examples.

Phase II
Phase II units were built from May 1964 to November 1964. These units had a 3500-gallon fuel tank. The air tanks were relocated to inside the carbody behind the cab. Louvers were placed in the long hood behind the cab for ventilation of the air tanks. There were 24 Phase II units. They were built for Northern Pacific #2500-2514, Lake Superior & Ishpeming #2500-2501, and Atlantic Coast Line #3004-3010

Phase III
Built from April 1965 to July 1966. The Phase III units were the most numerous and included the Upgraded U25Cs. A total of 78 U25Cs were built with this carbody. The Phase III U25C carbody overlapped into early Phase I U28C production. A total of 28 Phase I U28Cs used this same carbody. The Phase III had screened panel openings in the carbody behind the cab. Louvers were eliminated from the left side of the carbody, but kept on the engineer's side. A rectangular box opening on the roof provided fresh air for ventilation and cooling the air tanks. Pennsylvania and L&N U25Cs also had an extra equipment box and third handrail stanchion on the raised part of the walkway next to the radiator intake. The extra equipment box was for extended range dynamic brake contactors. In later Phase III production screened doors replaced the screen panels behind the engineer's side of the cab. The louvers behind the engineer's side of the cab were also removed in late production Phase III units.

Road Numbers Delivery HO Scale Model
6500-6519  1965

Korea Brass





prr ge u28c

GE U28C, Class GF28a

The U28C locomotive was developed by General Electric from the U25C, with a slight increase in power of 300 hp.

General Electric built ten uprated U25Cs in 1965. Facing the competitive pressure of the second generation horsepower race, GE built these units with increased horsepower. The competitive 2750 horsepower Alco C628 had more horsepower and the 3000 horsepower Alco C630 was announced in July 1965. General Motors had the 3000 horsepower EMD SD40 demonstrators testing on several railroads. The increase in unit horsepower was happening that year. The uprated units were built for three railroads that were already operating the U25C. The first uprated units were built for the Northern Pacific between May and July 1965. These were NP #2518-2520 and were rated at 2750 horsepower. Three more uprated U25Cs were built as Atlantic Coast Line #3011-3013 in December 1965. The ACL units were rated at 2800 horsepower. The last four uprated U25Cs were rated at 2800 horsepower and were built for the Pennsylvania Railroad in December 1965. These were PRR #6516-6519. Six additional PRR U25Cs were uprated to 2800 horsepower: 6500-6503, 6510-6511. In early 1966 General Electric began offering the 2800 horsepower U28C. A total of 28 look-a-like U28Cs were built between February 1966 and July 1966 as Chicago Burlington and Quincy #562-577 and Northern Pacific #2800-2811. These early Phase I U28Cs shared the 64 foot 4 inch frame that was standard with the predecessor U25C.

A drawing of the proposed longer frame U28C is in the November 1965 issue of Trains Magazine. Starting in May 1966 GE began producing the U28C on a longer frame. The new length for these U28Cs was 67 feet 3 inches. These are the 43 Phase II units built for Louisville and Nashville, Pennsylvania, Southern Pacific and Union Pacific. The Phase II units used either the General Electric GT 598 Generator or the GTA 9 Alternator. The 10 Santa Fe U28CGs were also built on this longer frame. Starting in November 1966 and through mid 1967 GE built 24 look a like Phase I U30Cs that used the same carbody as the Phase II U28Cs.

Road Numbers Delivery HO Scale Model
 6520-6534 1966

Atlas (6527, 6529, 6534)

Rivarossi (6514, 6519)


Korea Brass (6513, 6516, 6518)


prr ge u30c

GE U30C, Class GF30a

The GE U30C was one of the earliest successes from General Electric in the diesel locomotive market. With 600 units sold, the U30C proved to be a viable alternative for customers who were unable to purchase SD40s from Electro-Motive Diesel (EMD) due to production backlog. Throughout its ten-year production span, the U30C was known for reliability issues concerning its electrical system. However, most railroads were assured of the reliability of the GE Model 752 DC traction motor, and began to place orders for U30Cs starting in 1966. When production ended, the last U30Cs carried pre-Dash 7 specifications, which would be carried in its replacement, the GE C30-7.

Road Numbers Delivery HO Scale Model
6535-6539  1967

Atlas (6536, 6537, 6539)



pc ge u33c

GE U33C, Class GF33a

The GE U33C is a 6-axle diesel-electric locomotive built by GE Transportation Systems between January 1968 and January 1975. 375 examples of this locomotive were built for 11 North American railroads and one construction contractor.

Although ordered by the Pennsylvania Railroad, the U33c's were delivered in Penn Central livery.

Road Numbers Delivery HO Scale Model
6540-6559  1968  Atlas