An EMD SD40X is a 6-axle experimental diesel-electric locomotive built by General Motors Electro-Motive Division between 1964 and 1965. 9 examples of this locomotive were built for test purposes to test the new 645-series prime mover 16-645E3. After testing, eight were sold to the Union Pacific Railroad and one example to the Gulf, Mobile and Ohio Railroad. This locomotive is an experimental testbed for the production SD40, but built on the shorter SD35 frame. This locomotive was also known as an SD35X.
The designation SD40X was also given to an experimental version of the SD50, built by EMD on an SD40-2 frame. 4 examples of this SD40X were built in 1979 and were delivered to the Kansas City Southern as KCS 700-703.
The EMD DDA40X is a 6,600 hp (4,943 kW) D-D locomotive, built by EMD from 1969 to 1971 exclusively for the Union Pacific Railroad. It is the most powerful diesel-electric locomotive model ever built on a single frame, having two 16-645E3A diesel prime movers. Union Pacific has marked DD40X on the cab exteriors, while EMD literature inconsistently refers to this model as either DD-40X or DDA40X.
The EMD SD40-2 is a 3,000-horsepower (2,200 kW) C-C diesel-electric locomotive built by EMD from 1972 to 1989.
The EMD DD35A, also known as the EMD DDA35, was a 5,000 hp (3,730 kW) diesel-electric locomotive of D-D wheel arrangement built by General Motors Electro-Motive Division exclusively for the Union Pacific Railroad. They were a cab-equipped variant of the previous, cabless booster EMD DD35. Fifteen DD35A locomotives were built between May and July 1965; they were assigned road numbers 70 through 84. This request also led to the introduction of the ALCO Century 855 and GE U50. A further development of the 8 axle, twin-engined locomotive produced the final, best known type, the DDA40X "Centennial".
The EMD SD50 is a 3,500-horsepower (2,610 kW) diesel-electric locomotive built by General Motors Electro-Motive Division. It was introduced in May 1981 as part of EMD's "50 Series"; production ceased in January 1986. The SD50 was a transitional model between EMD's Dash 2 series which was produced throughout the 1970s and the microprocessor-equipped SD60 and SD70 locomotives. A total of 431 were built.
The EMD SD24 was a 2,400 hp (1,800 kW) six-axle (C-C) diesel-electric locomotive built by General Motors' Electro-Motive Division of La Grange, Illinois between July 1958 and March 1963. A total of 224 units were built for customers in the United States, comprising 179 regular, cab-equipped locomotives and 45 cabless B units. The latter were built solely for the Union Pacific Railroad.
The GP40 is a 4-axle diesel-electric locomotive built by General Motors' Electro-Motive Division between November 1965 and December 1971. It has an EMD 645E3 16-cylinder engine generating 3,000 hp (2,240 kW).
An EMD SD35 is a 6-axle diesel-electric locomotive built by General Motors Electro-Motive Division between June 1964 and January 1966. Power was provided by an EMD 567D3A, 16-cylinder engine which generated 2,500 brake horsepower (1,900 kW). A 3,000-US-gallon fuel tank was used on this unit. This locomotive model shared a common frame with the EMD SD28, giving it an overall length of 60 feet 8+1⁄2 inches (18.504 m). 360 examples of this locomotive model were built for American railroads.
An EMD SDP35 is a 6-axle diesel-electric locomotive built by General Motors Electro-Motive Division between July 1964 and September 1965. Power was provided by an EMD 567D3A 16-cylinder engine which generated 2,500 horsepower (1.9 MW). Essentially this locomotive was an EMD SD35 equipped with a steam generator, located in the extended long hood end, for passenger use. 35 examples of this locomotive model were built for American railroads.
The EMD SD38 is a 6-axle diesel-electric locomotive built by General Motors Electro-Motive Division between May 1967 and October 1971. It had an EMD 645 16-cylinder engine generating 2,000 horsepower (1.5 MW), compared to the turbocharged EMD 645E3 V-16 engine that produced 3000 horsepower. Aside from the 3-axle trucks and a longer frame to accommodate them, the SD38 was identical to the GP38; the SD38 had the same frame as the SD39, SD40 and SD45. 52 were built for American railroads, one was built for a Canadian railroad, four were exported to a mining firm in Jamaica and seven were exported to a mining firm in Venezuela. The SD38 was succeeded by a Dash 2 version called the EMD SD38-2.
The EMD SD40 is an American 6-axle diesel-electric locomotive built by General Motors Electro-Motive Division between January 1966 and August 1972. 1,268 locomotives were built between 1966 and 1972. In 1972, an improved version with new electronics was developed and marketed as a new locomotive, the SD40-2.
An SDP40 is a 6-axle passenger diesel-electric locomotive built by General Motors Electro-Motive Division (EMD) between June 1966 and May 1970.
The SD45 is a six-axle diesel-electric locomotive built by General Motors Electro-Motive Division between 1965 and 1971. It has an EMD 645E3 twenty-cylinder engine generating 3,600 hp (2,680 kW) on the same frame as the SD38, SD39, SD40, and SDP40. As of 2022, most SD45s have been retired, scrapped or rebuilt to SD40-2 standards.
An EMD SD45X is a 6-axle experimental diesel-electric locomotive built by General Motors Electro-Motive Division between June 1970 and February 1971. Power was provided by an EMD 645E3A 20-cylinder engine which generated 4,200 horsepower (3,130 kW). 7 examples of this locomotive model were built for American railroads. 6 of these units would end up in service with Southern Pacific Railroad. One was rebuilt in 1980 by Morrison-Knudsen into an SD45Xm with a long hood from a scrapped DD35.
An SD39 is a 6-axle diesel-electric locomotive built by General Motors Electro-Motive Division between August 1968 and May 1970. 54 were built for American railroads.
An EMD GP50 is a 4-axle diesel-electric locomotive built by General Motors Electro-Motive Division (EMD). It is powered by a 16-cylinder EMD 645F3B diesel engine, which can produce between 3,500 and 3,600 hp. 278 examples of this locomotive were built by EMD between 1980 and 1985. BN 3110-3162 were all delivered with five cab seats, the final five of these having the cab lengthened 23 in (584 mm) vs. the standard EMD cab. The GP50 retains the same overall length of 59 feet 2 inches as the GP38, GP39, and GP40 series locomotives.
The EMD GP15-1 is a 4-axle diesel-electric locomotive built by General Motors Electro-Motive Division between June 1976 and March 1982. Intended to provide an alternative to the rebuilding programs that many railroads were applying to their early road switchers, it is generally employed as a yard switcher or light road switcher. This locomotive is powered by a 12-cylinder EMD 645E engine, which generates 1,500 hp (1,119 kW). The GP15-1 uses a 50-foot-9-inch (15.47 m) frame, has a wheelbase of 29 ft 9 in (9.07 m) and has a length over couplers of 54 ft 11 in (16.74 m). A total of 310 units were built for American railroads. A number of GP15-1s remain in service today for yard work and light road duty. The radiator section is similar to those found on the EMD SD40T-2 and EMD SD45T-2 "tunnel motors," leading some observers to incorrectly identify the units as such or as GP15Ts, and giving them the nickname "baby tunnel motors".
An EMD SD40A is a six-axle diesel-electric locomotive built by General Motors Electro-Motive Division between 1969 and 1970. 18 examples of this locomotive were built exclusively for the Illinois Central Railroad. The SD40A was basically an SD40 built on an SDP45 frame. The longer SDP45 frame allowed for a larger, 5000 gallon fuel tank. This locomotive is powered by a sixteen-cylinder EMD 645E3 diesel engine, which could provide 3,000 horsepower (2,240 kW). Illinois Central Railroad used the SD40A as a long-range road-switcher, utilizing the larger fuel tank found on the SDP45. The Soo Line Railroad eventually acquired five of these units and as of 2005 they are out of service. Six other units remain in service under Illinois Central, which is now a subsidiary of Canadian National Railway
An EMD GP40X is a 4-axle diesel-electric locomotive built by General Motors Electro-Motive Division between December 1977 and June 1978. Power for this unit was provided by a turbocharged 16-cylinder EMD 645F engine which could produce 3,500 horsepower (2,610 kW). 23 examples of this locomotive were built for North American railroads. This unit was a pre-production version meant to test technologies later incorporated into EMD's 50-series locomotives GP50 and SD50.
The EMD F40C is a 6-axle 3,200 horsepower (2.4 MW) diesel-electric locomotive built by General Motors Electro-Motive Division in 1974 for commuter service in Chicago. EMD only built 15 locomotives; the decline of the 6-axle design for passenger service led to the adoption of the 4-axle EMD F40PH as the standard passenger locomotive in the United States.
The EMD 710 is a line of diesel engines built by Electro-Motive Diesel. The 710 series replaced the earlier EMD 645 series when the 645F series proved to be unreliable in the early 1980s 50-series locomotives which featured a maximum engine speed of 950 rpm. The EMD 710 is a relatively large medium-speed two-stroke diesel engine that has 710 cubic inches displacement per cylinder, and a maximum engine speed of 900 rpm.