The Evolution Series is a line of
diesel locomotive
A diesel locomotive is a type of railway locomotive in which the prime mover (locomotive), power source is a diesel engine. Several types of diesel locomotives have been developed, differing mainly in the means by which mechanical power is con ...
s built by
GE Transportation Systems (now owned by
Wabtec
Westinghouse Air Brake Technologies Corporation, commonly known as Wabtec, is an American company formed by the merger of the Westinghouse Air Brake Company (WABCO) and MotivePower in 1999. It is headquartered in Pittsburgh, Pennsylvania.
Wab ...
), initially designed to meet the
U.S.
The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 states and a federal capital district, Washington, D.C. The 48 contiguous ...
EPA's
Tier 2 locomotive emissions standards that took effect in 2005. The line is the direct successor to the
GE Dash 9 Series. The first pre-production units were built in 2003. Evolution Series locomotives are equipped with either AC or DC
traction motors
A traction motor is an electric motor used for propulsion of a vehicle, such as locomotives, electric or hydrogen vehicles, or electric multiple unit trains.
Traction motors are used in electrically powered railway vehicles (electric multiple u ...
, depending on the customer's preference. All are powered by the
GE GEVO engine.
The Evolution Series was named as one of the "10 Locomotives That Changed Railroading" by ''
Trains Magazine
''Trains'' is a monthly magazine about trains and railroads aimed at railroad enthusiasts and railroad industry employees. The magazine primarily covers railroad happenings in the United States and Canada, but has some articles on railroading e ...
'' and was the only locomotive series introduced after 1972 to be included in that list.
The Evolution Series locomotives are some of the best-selling and most successful freight locomotives in United States history.
These locomotives are equipped with
Nathan Airchime K5HL horns, with the reversed 2 configuration, making a K5HLR2. The horns are mounted backwards with the 2 bell only facing forward and the 4 bells facing back. All of the locomotives use these horns, except for the ET23DCM and international locomotives.
Models
Currently, six different Evolution Series models (seven including rebuilds), have been produced for the North American market. They are all six-axle locomotives and have
AAR wheel arrangement C-C (
UIC classification
The UIC classification of locomotive axle arrangements, sometimes known as the German classification''The Railway Data File''. Leicester: Silverdale, 2000. p. 52. . or German system,Kalla-Bishop P.M. & Greggio, Luciano, ''Steam Locomotives'', Cr ...
Co′Co′), except for the ES44C4 and ET44C4 which uses the
AAR A1A-A1A wheel arrangement and the
meter-gauge version developed for the Brazilian network ES43BBi which is
AAR B-B-B-B.
ES40DC (2004–2008)
The ES40DC (Evolution Series, 4,000 hp, DC traction) replaced the
Dash 9-40CW model in the General Electric catalogue and, like the former model, was delivered exclusively to
Norfolk Southern Railway
The Norfolk Southern Railway is a Class I freight railroad operating in the Eastern United States. Headquartered in Atlanta, the company was formed in 1982 with the merger of the Norfolk and Western Railway and Southern Railway. The comp ...
. ES44DCs owned by
CSX Transportation
CSX Transportation , known colloquially as simply CSX, is a Class I freight railroad company operating in the Eastern United States and the Canadian provinces of Ontario and Quebec. Operating about 21,000 route miles () of track, it is the lead ...
were also given this designation in 2009 after being de-rated to . However, high-horsepower demand on Norfolk Southern made a mandatory repowering of several ES40DC engines into their former ES44DC power.
ES44DC (2005–2010)
The ES44DC (Evolution Series, 4,400 hp, DC traction) replaced the
Dash 9-44CW model in the General Electric catalogue. Primary users are
BNSF Railway
BNSF Railway is the largest freight railroad in the United States. One of six North American Class I railroads, BNSF has 36,000 employees, of track in 28 states, and over 8,000 locomotives. It has three Transcontinental railroad, transcontine ...
,
CSX Transportation
CSX Transportation , known colloquially as simply CSX, is a Class I freight railroad company operating in the Eastern United States and the Canadian provinces of Ontario and Quebec. Operating about 21,000 route miles () of track, it is the lead ...
, and
Canadian National Railway
The Canadian National Railway Company () is a Canadian Class I freight railway headquartered in Montreal, Quebec, which serves Canada and the Midwestern and Southern United States.
CN is Canada's largest railway, in terms of both revenue a ...
.
Pilbara Iron
Pilbara Iron manages assets for Hamersley Iron Pty Ltd, a subsidiary of Rio Tinto (corporation), Rio Tinto, and Robe River Iron Associates, an unincorporated joint venture between Rio Tinto (53%) and Japanese steel companies Mitsui & Co, Mits ...
in
Australia
Australia, officially the Commonwealth of Australia, is a country comprising mainland Australia, the mainland of the Australia (continent), Australian continent, the island of Tasmania and list of islands of Australia, numerous smaller isl ...
ordered a lengthened, international version designated ES44DCi. The extra length is used for a larger radiator to increase cooling capacity in the Australian
outback
The Outback is a remote, vast, sparsely populated area of Australia. The Outback is more remote than Australian bush, the bush. While often envisaged as being arid, the Outback regions extend from the northern to southern Australian coastli ...
.
ES44AC (2003–present)
The ES44AC (Evolution Series, 4,400 hp, AC traction) replaced the
AC4400CW model in the General Electric catalogue. These locomotives have been ordered by every Class I railroad in North America:
Union Pacific Railroad
The Union Pacific Railroad is a Railroad classes, Class I freight-hauling railroad that operates 8,300 locomotives over routes in 23 U.S. states west of Chicago and New Orleans. Union Pacific is the second largest railroad in the United Stat ...
(who refers to these locomotives as the ''C45ACCTE''),
BNSF Railway
BNSF Railway is the largest freight railroad in the United States. One of six North American Class I railroads, BNSF has 36,000 employees, of track in 28 states, and over 8,000 locomotives. It has three Transcontinental railroad, transcontine ...
,
CSX Transportation
CSX Transportation , known colloquially as simply CSX, is a Class I freight railroad company operating in the Eastern United States and the Canadian provinces of Ontario and Quebec. Operating about 21,000 route miles () of track, it is the lead ...
,
Norfolk Southern Railway
The Norfolk Southern Railway is a Class I freight railroad operating in the Eastern United States. Headquartered in Atlanta, the company was formed in 1982 with the merger of the Norfolk and Western Railway and Southern Railway. The comp ...
,
Ferromex,
CPKC Railway, and
Canadian National Railway
The Canadian National Railway Company () is a Canadian Class I freight railway headquartered in Montreal, Quebec, which serves Canada and the Midwestern and Southern United States.
CN is Canada's largest railway, in terms of both revenue a ...
.
Union Pacific also bought the heavy ballasted variation of this model, the ES44AH, and refers to it as the C45AH. UP also uses this designation to refer to their ET44AH units.
CSX Transportation has bought these locomotives and they were always heavy ballasted, so they called these the ES44AH. The first set was 700-999, which was built from 2007-2011. Beginning 2023, CSX has repainted and renumbered the 3000 series locomotives to heritage units. The first heritage, 1827, was painted into Baltimore & Ohio and renumbered from 3059 on May 11, 2023.
BNSF Railway purchased 25 ES44AC locomotives in 2023, and they are all classified as ES44ACH. They were built between August and September of 2023 and were built concurrently with the ET44ACH. The numbers were 3282-3306, which officially ended the production of the ES44C4 in 2020. These units are Tier 4 credit units. In 2024, BNSF has bought 25 more ES44ACH locomotives, which are numbered from 3307-3331. These locomotives weigh 436,320 lbs.
ES44C4 (2009–2020)

The ES44C4 (Evolution Series, 4,400 hp, C to denote 3 axles per truck, 4 traction motors) was introduced in 2009. While similar to the ES44AC, the ES44C4 has two traction motors per truck, instead of the conventional three such as on the ES44AC. No ES44C4s with DC traction were built. The center axle of each truck is unpowered, giving an A1A-A1A wheel arrangement. BNSF Railway is the launch customer for this model, ordering an initial batch of 25 units numbered 6600–6624. The ES44C4 was initially only built for BNSF. The 4200s and units 7921-7999 are certified as Tier 4 Credit units, while the others are Tier 2 or Tier 3. On 30 January 2014
Florida East Coast Railway
The Florida East Coast Railway is a Class II railroad operating in the U.S. state of Florida, currently owned by Grupo México.
Built primarily in the last quarter of the 19th century and the first decade of the 20th century, the FEC was a p ...
announced that they would buy 24 ES44C4s, to be numbered 800–823, for heavy haul service and intermodal traffic. All were delivered by the end of 2014, in order to beat the EPA's deadline on exhaust-emissions standards for new-built Tier 3 locomotives.
A feature of these units is a variable traction control system in their computer systems. One of the differences between an ES44AC and an ES44C4 is the air cylinders and linkages on the truck sideframes of the ES44C4; these are part of the traction control system. Every time a variation in grade, traction, or wheel slip occurs, the computer adjusts the pressure in these cylinders to maintain sufficient adhesion, by varying the weight on the drive axles.
ES44DCi/ES44ACi

The ES44DCi (Evolution Series, 4400 horsepower, DC traction, international version) was built for the
Rio Tinto railway in Australia. The ES44ACi was built for the
Roy Hill and
Rio Tinto Group
Rio Tinto Group is a British-Australian multinational company that is the world's second largest metals and mining corporation (behind BHP). It was founded in 1873 when a group of investors purchased a mine complex on the Río Tinto, in Hu ...
.
The ES44ACi/DCi is essentially an ES44AC/DC in a
GE AC6000CW
The AC6000CW is a diesel locomotive, diesel electric locomotive built between 1995 and 2001 by GE Transportation. It is among the world's most powerful single-engined diesel locomotives. The locomotive was designed for extremely high horsepower ...
's body, with the radiator at the end protruding out over the rear deck in the same way the AC6000CW does. The locomotive's large radiator allows it to handle the Australian outback's extreme temperatures.
Roy Hill has ordered 21 ES44ACi locomotives, and is currently in possession of all 21 locomotives (numbered 1001 "Ginny"-1021). Rio Tinto ordered 100 ES44DCi locomotives and has all 100 (numbered 8100–8199) and 21 ES44ACi locomotives (numbered 9100–9120) and more are on order. Rio Tinto's units can be remotely driven, meaning nobody has to be in the cab as they can be controlled from a control center.
Ferromex also acquired 50 ES44ACi. As the construction of these locomotives was subsequent to the new environmental laws of the US, GE cataloged them only as ES44ACi, although in the external technical specifications of the locomotives say ES44AC). These locomotives can no longer reenter the US operating.
In Brazil, the Rumo, Suzano and MRS Logística railways purchased 25 units, manufactured at Wabtec of Brazil with broad-gauge trucks.
ET44AC/ET44C4 (2012–present)

The ET44AC (Evolution Series Tier 4, 4,400 hp, AC traction) replaces the
ES44AC model. These locomotives have been ordered by every US and Canadian Class I railroad, including
BNSF Railway
BNSF Railway is the largest freight railroad in the United States. One of six North American Class I railroads, BNSF has 36,000 employees, of track in 28 states, and over 8,000 locomotives. It has three Transcontinental railroad, transcontine ...
,
Canadian National Railway
The Canadian National Railway Company () is a Canadian Class I freight railway headquartered in Montreal, Quebec, which serves Canada and the Midwestern and Southern United States.
CN is Canada's largest railway, in terms of both revenue a ...
,
CPKC,
CSX Transportation
CSX Transportation , known colloquially as simply CSX, is a Class I freight railroad company operating in the Eastern United States and the Canadian provinces of Ontario and Quebec. Operating about 21,000 route miles () of track, it is the lead ...
,
Norfolk Southern
The Norfolk Southern Railway is a Class I freight railroad operating in the Eastern United States. Headquartered in Atlanta, the company was formed in 1982 with the merger of the Norfolk and Western Railway and Southern Railway. The comp ...
, and
Union Pacific
The Union Pacific Railroad is a Class I freight-hauling railroad that operates 8,300 locomotives over routes in 23 U.S. states west of Chicago and New Orleans. Union Pacific is the second largest railroad in the United States after BNSF, ...
. BNSF also ordered similar ET44C4 locomotives, which have a dynamic weight management system instead of a traction motor on the middle axle of each truck. UP and CSX designate their ET44ACs as ET44AH although UP calls these C45AH, and BNSF calling them ET44ACH as their locomotives are ballasted to 436,320lbs.
ET23DCM (2023–present)

The ET23DCM (Evolution Series Tier 4, 2350 hp, DC traction), sometimes called the SD23T4, is a modernized locomotive using
EMD's
SD40-2 platform and the Wabtec Inline 6-cylinder Tier 4 diesel engine.
CSX Transportation
CSX Transportation , known colloquially as simply CSX, is a Class I freight railroad company operating in the Eastern United States and the Canadian provinces of Ontario and Quebec. Operating about 21,000 route miles () of track, it is the lead ...
ordered 15 of these locomotives, with most being built at their Huntington Heavy Repair Shop. Wabtec also built one locomotive as a demonstrator from ex-NS SD40-2 3259.
TE33A
The TE33A is an export 1520 mm gauge locomotive in the GE Evolution Series.
3TE25K2M
The 3TE25K2M is an export 1520mm gauge locomotive in the GE Evolution Series for
Russian Railways
Russian Railways or RZD () is a Russian fully state-owned vertically integrated railway company, both managing infrastructure and operating freight and passenger train services and has a near-monopoly on long-distance train travel in Russia.
...
.
Identifying features
The Evolution Series locomotives are visually similar to the
AC4400CW and
GE Dash 9 Series, although small differences are evident. The most noticeable difference is the
radiator
A radiator is a heat exchanger used to transfer thermal energy from one medium to another for the purpose of cooling and heating. The majority of radiators are constructed to function in cars, buildings, and electronics.
A radiator is always a ...
section at the rear of the locomotive is larger to accommodate the GEVO's air-to-air intercoolers. As with the
AC6000CW, the radiators project beyond the end of the hood. On the ES44ACi and ES44DCi models, the radiator extends in the same way as the AC6000CW, protruding out over the rear deck. For the other Evolution Series locomotives, the radiator does not protrude completely over the rear deck, but rather sits nearly flush with the rear of the engine hood. Unlike previous GE locomotives, the grills under the radiator are at two different angles. The increase in radiator size is due to the necessity for greater cooling capacity in the locomotive in order to reduce emissions. The other major difference between the Evolution Series and earlier models is the vents below the radiators, which are larger than those on previous GE locomotives. Also, all Evolution Series units have air conditioners mounted below the cab on the conductor's side.
Operators
Licensed production
Australia
In 2002, GE and
UGL launched the Evolution Series locomotive, and in 2009, continued their partnership for another 10 years for UGL to distribute and sell GE locomotives in Australia.
India
In November 2015, it was announced Indian Railways and GE would engage in a 11-year joint venture in which GE would hold a majority stake of 74%, to provide a mix of 1,000 diesel locomotives of type
ES43ACmi which are 4,500 horsepower and type
ES57ACi which are 6,000 horsepower each. Indian Railways designated these 1,676 mm (broad gauge) locomotives as the
WDG-4G class and
WDG-6G class respectively.
General Electric
General Electric Company (GE) was an American Multinational corporation, multinational Conglomerate (company), conglomerate founded in 1892, incorporated in the New York (state), state of New York and headquartered in Boston.
Over the year ...
has invested ₹2,052 crore (US$305 million) for its construction. In the $2.6 Billion deal, Indian Railways would purchase 1,000 goods locomotives a year for ten years beginning in 2017; the locomotives would be modified versions of the
GE Evolution series.
/sup> Diesel Locomotive Factory, Marhowrah was built by GE for the manufacture of the locomotives.
/sup>
South Africa
Transnet Rail Engineering, Transnet Engineering in South Africa
South Africa, officially the Republic of South Africa (RSA), is the Southern Africa, southernmost country in Africa. Its Provinces of South Africa, nine provinces are bounded to the south by of coastline that stretches along the Atlantic O ...
has a license to manufacture 233 ES40ACi locomotives for Transnet Freight Rail, with core components including GEVO-12 engines supplied from the United States.
The first six of these Class 44-000 locomotives were built in Erie, Pennsylvania
Erie is a city on the south shore of Lake Erie and the county seat of Erie County, Pennsylvania, United States. It is the List of municipalities in Pennsylvania, fifth-most populous city in Pennsylvania and the most populous in Northwestern Pen ...
, in April and July 2015. In October 2015, the first of the 227 South African-built locomotives was nearing completion at Transnet Engineering's Koedoespoort shops in Pretoria
Pretoria ( ; ) is the Capital of South Africa, administrative capital of South Africa, serving as the seat of the Executive (government), executive branch of government, and as the host to all foreign embassies to the country.
Pretoria strad ...
.[Railways Africa, 11 Feb 2015: New Transnet Diesel-Electric Locomotives](_blank)
(Accessed 22 Nov 2015)
See also
* EMD SD70 series, a similarly powerful locomotive produced by EMD in response to GE's predecessor of the Evolution Series, the Dash 9 Series.
* Wabtec FLXDrive, a battery-electric locomotive built by Wabtec
Westinghouse Air Brake Technologies Corporation, commonly known as Wabtec, is an American company formed by the merger of the Westinghouse Air Brake Company (WABCO) and MotivePower in 1999. It is headquartered in Pittsburgh, Pennsylvania.
Wab ...
based on the Evolution Series design.
References
Notes
Bibliography
*
*
*
*
*
*
*
External links
* GE Transportation Systems. '.
* NorthEast Rails.
GE AC4400-6000 Diesel Railroad Locomotives
'. Retrieved on 23 February 2005.
* GE Evolution Locomotives. Published by Voyageur Press 2007
{{DEFAULTSORT:Ge Evolution Series
General Electric locomotives, Evolution Series
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Diesel–electric locomotives of the United States
A1A-A1A locomotives
EPA Tier 2-compliant locomotives of the United States
Railway locomotives introduced in 2003
Standard-gauge locomotives of the United States
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