GE Evolution Series

The **Evolution Series** is a line of diesel locomotives built by GE Transportation Systems (now owned by Wabtec), initially designed to meet the U.S. EPA's Tier 2 locomotive emissions standards that took effect in 2005. The first pre-production units were built in 2003. Evolution Series locomotives are equipped with either AC or DC traction motors, 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" in the January 2009 issue of *Trains Magazine*. It was the only locomotive introduced after 1972 to be included in that list.

The Evolution Series, mainly the ES44DC, ES44AC, and ET44AC, are some of the best-selling and most successful freight locomotives in United States history.

Currently, six different Evolution Series models have been produced for the North American market. They are all six axle locomotives and have the wheel arrangement C-C (AAR classification) or Co′Co′ (UIC classification), except for the ES44C4 which has an A1A-A1A wheel arrangement and the meter-gauge version developed for the Brazilian network ES43BBi which is B-B-B-B. All North American Evolution Series locomotives are equipped from the factory with a Nathan-Airchime K5HL-R2 "Evolution" airhorn, and most later models are equipped with a Graham-White 373 electronic bell.

### ES40DC[edit]

A Norfolk Southern ES40DC powering an intermodal freight train
The **ES40DC** (**E**volution **S**eries, **40**00 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. ES44DCs owned by CSX Transportation were also given this designation in 2009 after being de-rated to 4,000 hp (3,000 kW). However, high-horsepower demand on Norfolk Southern made a mandatory repowering of several ES40DC engines into their former ES44DC power.

### ES44DC[edit]

A pair of CSX ES44DCs
The **ES44DC** (**E**volution **S**eries, **44**00 HP, **DC** traction) replaced the Dash 9-44CW model in the General Electric catalogue. Primary users are BNSF Railway, CSX Transportation, and Canadian National Railway. Pilbara Iron in Australia ordered a lengthened, international version designated ES44DCi. The extra length is used for a larger radiator to increase cooling capacity in the Australian outback.

### ES44AC[edit]

Canadian National Railway 2869 EF-644p in Quesnel, British Columbia
Citirail (CREX) ES44AC no.1203 in March 2014.
Union Pacific C45ACCTE #7767 in Denton, Texas
The **ES44AC** (**E**volution **S**eries, **44**00 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 (who refers to these locomotives as the *C45ACCTE*), BNSF Railway, CSX Transportation, Norfolk Southern Railway, Kansas City Southern Railway, Kansas City Southern de Mexico, Ferromex, Canadian Pacific Railway, and Canadian National Railway.

The Class II Iowa Interstate Railroad ordered 14 ES44ACs (IAIS 500-513) in 2008 to handle an expected traffic growth resulting from new ethanol plants coming on line. An additional 3 locomotives (IAIS 514-516) were delivered in 2016 and three more (IAIS 517-519) were delivered in late 2019. As a result of the delivery of the final six locomotives, the Iowa Interstate will retire its SD-38 fleet. The IAIS 513 is painted in a Rock Island, Route of the Rockets heritage paint scheme, and the IAIS 516 is painted in a Rock Island inspired scheme celebrating the 30th anniversary of the start-up of the railroad.

CSX began receiving an order of 200 ES44ACs (referred to by CSX as the *ES44AH*) in December 2007. The A is for A.C power The "H" in the class CW44AH and ES44AH units refers to the HTE ("high tractive effort") adhesion-management software with which those units are equipped. The reason CSXT has assigned specific classes to units equipped with that software is that the software allows the units to have increased tonnage ratings and is in reference to a combination of subsystems that produce high levels of tractive effort at low speeds. In order to be classified as an "AH" by CSX, a locomotive has to have not only an increased nominal weight (currently to 432,000 pounds or 196 tonnes), but also (1) steerable trucks, (2) TM3 adhesion control software, (3) software that extends to 33,000 pounds-force (150 kN) from 30,000 pounds-force (130 kN) the maximum amount of tractive effort that each traction motor is permitted to produce, and (4) GE's Rail Cleaner, which directs high-pressure air onto the rails in front of the sand nozzles forward of axle number one.

In September 2008, Norfolk Southern purchased 24 ES44ACs numbered 8000-8023, and began receiving the first of these units in October 2008. Ordered to be used on long haul coal trains, they were the first new AC locomotives ever purchased by NS.[*citation needed*] An additional 65 units were ordered in 2011, numbered 8025-8090. 24 more units, numbered 8091-8115, were ordered at the beginning of 2012. 10 of these units: 8025, 8098-8105 & 8114 were painted in predecessor company "heritage" paint schemes for NS's 30th anniversary. All NS ES44ACs are built to CSX specifications, with the exception of the Hi-Ad trucks & headlight placement.

In March 2008 Cemex took delivery of one ES44AC, number 81, built to the specifications of CSXT units 700-839 as an add-on to that order.[*citation needed*]

Canadian National's first order of ES44ACs was in January 2012, and as of 2018 they roster about 236 units, numbered in the 2800-2999 and 3800-3835 series. With the introduction of the United States Environmental Protection Agency's **Tier 4** locomotive emission regulations, CN's newest Tier 3 GE ES44AC's are restricted to Canadian use only.

Citirail/CREX acquired 100 ES44ACs for lease service. They are painted silver with blue & yellow nose striping and blue numbers. Most, if not all of these units,[*weasel words*] are leased to BNSF Railway.[*citation needed*]

In 2013, General Electric built one ES44AC, GECX 3000, as a test bed for their NextFuel natural gas power kit.[*citation needed*] The engine runs on liquefied natural gas from a fuel tender. The unit has since been converted to a battery-electric locomotive to be tested on BNSF trains in California.

### ES44C4[edit]

BNSF Railway #8013, an ES44C4, at Dallas, Texas, 20 May 2014, awaiting re-crew.
Rear view of brand new BNSF Railway ES44C4 no. 8270, at Ashland, Nebraska, on October 19, 2014.

The **ES44C4** (**E**volution **S**eries, **44**00 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. As of 2020, BNSF Railway currently rosters over 1200 ES44C4 units. The 4200's and units 7921-7999 are certified as Tier 4 Credit units, while the others are Tier 2 or Tier 3. It is speculated that as many as 288 more units are on order, to be numbered 5547-5599, 6439-6499, 8292-8317, and 8600-8748. On 30 January 2014 Florida East Coast Railway 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 unique feature of these units is that there is a variable traction control system in their computer systems. One of the differences between an ES44AC and an ES44C4 are 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 will adjust the pressure in these cylinders to maintain sufficient adhesion, by varying the weight on the drive axles.

### ES44DCi/ES44ACi[edit]

An ES44DCi of Rio Tinto on an iron ore train in Western Australia
The **ES44DCi** (**E**volution **S**eries, **44**00 horsepower, **DC** traction, **i**nternational version) was built for the Rio Tinto railway in Australia. The **ES44ACi** was built for the Roy Hill and Rio Tinto Group.

The ES44ACi/DCi is essentially an ES44AC/DC in a GE AC6000CW'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.

**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.

### ET44AC/ET44C4[edit]

Union Pacific 2668 ET44AC (C45AH designation)
The **ET44AC** (**E**volution Series **T**ier 4, **44**00 HP, **AC** traction) replaces the ES44AC model. These locomotives have been ordered by most of the Class I railroads in North America, including Union Pacific, CSX Transportation, Norfolk Southern and Canadian National Railway. BNSF Railway will be receiving similar ET44C4 locomotives, which have no traction motor on the middle axle of each truck. CSX designates their ET44ACs as **ET44AH**, due to their locomotives being **H**eavy-ballasted.

In the summer of 2012, GE unveiled its first Tier 4 emissions-compliant locomotive, now officially named the **ET44AC**. The prototype demonstrators, as well as current production units, are visually quite different from previous models. First, the "ET" is 74 feet 6 inches (22.71 m) long - an increase of 16 inches (0.41 m) from the 73-foot-2-inch (22.30 m) length of all previous GE 6-axle models beginning with the "DASH 9" series in 1993. While the front third of the locomotive, including the control cab, is unchanged, the rear two-thirds is noticeably different. On Tier 4 demonstrator units the entire midsection above the prime mover is raised to accommodate an advanced exhaust treatment system; it is seen as a "hump" that rises above the rest of the locomotive considerably. Production units have this hump only over the exhaust manifold directly ahead of the radiator, rather than encompassing the entire midsection. Also, the radiator section is much larger than that of earlier "ES" units, featuring a two-fan split-cooling system located inside a very large, angular compartment. Grilles under the radiator section have been smoothed out, and there are two extra air intakes on the rear of the locomotive hood. ET44ACs are all equipped with Graham-White electronic bells (E-bells). Tier 4 demonstrator units are equipped with two airhorns: a three-chime horn – facing forward – located behind the cab and a rear-facing two-chime horn protruding from the back of the radiator. Production units feature the now-standard Nathan-Airchime model K5HL-R2 "Evolution" airhorn mounted on the hood slightly forward of the placement location used on previous models.

A DC variant of the ET44AC has not been cataloged by General Electric.

### TE33A[edit]

Main article: TE33A

The TE33A is an export 1520 mm gauge locomotive in the GE Evolution Series.