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EMD "SD70ACe" Locomotives

Last revised: July 24, 2023

By: Adam Burns

Electro-Motive Diesel’s SD70ACe debuted in 2005 and was the main competition to General Electric’s Evolution Series™ of road-switchers.

Although the SD70 series, which was first cataloged by the company in 1992, has never been able to regain EMD's dominance as the number one locomotive builder it was nevertheless a very successful design with a few thousand different versions of the model operating around the country today.  

EMD's latest locomotive model is the SD70ACe-T4, which looks to carry on the success of its variants such as the original SD70ACe, SD70MAC, and SD70M (which sold more than 2,700 examples combined).


Today, the original SD70ACe can be found in operation on every Class I except Canadian National (which rosters the variant design, SD70M-2). Additionally, even regional Montana Rail Link has purchased sixteen of the locomotives. The price of these locomotives ranged from $1.5 million for DC traction motors, to nearly $2.5 million for AC traction motors.


91982537172612672189589268978.jpgA pair of Union Pacific SD70ACe's, led by #8464, roll west past historic Union Station in Kansas City with a string of autoracks in September, 2010. American-Rails.com collection.


The SD70ACe, as with General Electric's Evolution models, was born out of a requirement by the EPA that new locomotives meet the agency's then-"Tier II" standards for diesel admissions.

In the case of GE, its new GEVOs utilized a 12-cylinder prime mover that also captures diesel exhaust and captures it as energy in storable batteries to reuse later.

While EMD had not yet achieved such technological advances with its locomotives the SD70ACe held its own and is a fine design.

Rated at 4,300 hp, the SD70ACe was essentially a more environmentally friendly version of the builder’s SD70 series featuring EMD’s 16-cylinder model 710G3C-T2 engine, along with upgraded computer systems, electronics, and the builder’s famous self-steering trucks (the HTCR-II).

The HCTR-II has aided significantly in EMD's ability to continue strong sales despite continuing to lag behind GE in research and development.

The HTCR-II was created during the 1990s and first equipped on the original SD70 designs. It used computer software to steer itself into oncoming curves which greatly reduces the wear on both truck, axles, and the track itself.

While as successful as GE’s Evolution Series™ sales nonetheless were strong for the SD70ACe. Total sales for the model by the end of 2014 concluded at 1,034 units in North America.  

While the SD70ACe featured the same basic carbody of the SD70 series part of its design was inspired by Conrail's SD80MAC of 1995.

Although the '80MAC (also known as the "Conrail Cadillac" because it was the only railroad to purchase the locomotive) did not sell particularly well EMD rearranged some of its features on the longer frame.

Not only was it the first model to feature the flared rear radiator (common on GE models since the 1970s) but EMD also moved its dynamic brakes from directly behind the cab to the very rear of the locomotive. This new design feature was used on the later SD90MAC and kept with the SD70ACe.

EMD also offered one notable variant of the locomotive for North American lines, the SD70M-2. This locomotive was essentially the DC version employing General Motors' model AR20AB generator instead of the TA17/CA7A alternator.  

Ultimately, it sold to only three railroads; the Canadian National (#8000-8024, #8800-8964), Norfolk Southern (numbered #2649-2778), and Florida East Coast (#100-107).

Additionally, EMD's three demonstrators of this variant went to CIT Financial as leasing units. Dimensionally, the SD70ACe is 74 feet, 3 inches length or about six feet shorter than the SD80MAC and SD90MAC. 

Data Sheet and Specifications

Total Built (All Variants): 2,286

Entered Production (SD70ACe)4/2003 (Demonstrator GM70)
Years Produced (SD70ACe)4/2003 - 5/2015
Years Produced (SD70ACe-P4)7/2013 - 5/2014
Years Produced (SD70ACe-P4-T4)7/2016
Years Produced (SD70ACe TRC)2/2016 - 1/2020
Years Produced (SD70ACe-T4)9/2015 - 1/2020
Engine BuilderGM
Length74' 3"
Height (Top Of Rail To Top Of Cab)15' 11"
Width10' 3"
Weight408,000 Lbs
Fuel Capacity4900 Gallons
Air CompressorGardner-Denver
Air Compressor ModelWLASC
Air Brake ManufacturerWestinghouse
Air Brake Schedule26L
Truck TypeHTCR-II
Truck Wheelbase13' 7"
Wheel Size40"
Traction MotorsA3432 (6), GM
Primary GeneratorTA17, GM
Auxiliary GeneratorGM (A8589)
MU (Multiple-Unit)Yes
Dynamic BrakesYes
Gear Ratio70:17
Tractive Effort (Starting)191,000 Lbs at 35%
Tractive Effort (Continuous)157,000 Lbs at 12 mph
Top Speed70 mph

Production Rosters


Total Built = 1,946

Owner Road Number(s) Quantity Order Number Serial Number(s) Date Built
EMDX (Demonstrator)GM70-GM73*42002640420026404-1 thru 20026404-44/2003 - 5/2003
CSX4831-4850202003652020036520-1 thru 20036520-204/2004 - 9/2004
Union Pacific8309-84231152004661020046610-1 thru 20046610-1151/2005 - 7/2005
Kansas City Southern4000-4029302004662020046620-1 thru 20046620-3011/2005 - 1/2006
Montana Rail Link4300-4315162004662120046621-1 thru 20046621-165/2005 - 7/2005
Union Pacific8424-8523**1002004662120046621-1 thru 20046621-165/2005 - 7/2005
BNSF Railway9370-9399302005672920056729-1 thru 20056729-302/2006 - 4/2006
Union Pacific8521-8523 (2nd), 8524-86201002005675320056753-1 thru 20056753-1002/2007 - 7/2007
BNSF Railway9330-93691002005676620056766-1 thru 20056766-408/2006 - 10/2006
Kansas City Southern4030-4059302006685620066856-1 thru 20066856-308/2007 - 9/2007
BNSF Railway9130-9264***1352006686220066862-1 thru 20066862-13511/2007 - 9/2008
BNSF Railway9265-9304402006686220066862-146 thru 20066862-1754/2008 - 9/2008
Kansas City Southern4100-4129302006688720066887-1 thru 20066887-301/2008 - 4/2008
Union Pacific8621-8670502006688820066888-1 thru 20066888-505/2008 - 8/2008
BNSF Railway9305-9329, 9166-9167, 9184-9191352008602120086021-1 thru 20086021-351/2009 - 3/2009
Quebec, North Shore & Labrador501-50772008609420086094-1 thru 20086094-712/2009
Quebec, North Shore & Labrador508-51362010636420106364-1 thru 20106364-67/2011 - 8/2011
Union Pacific8671-8710402010637420106374-1 thru 20106374-407/2011 - 9/2011
Norfolk Southern1000-1024252010637720106377-1 thru 20106377-252/2011 - 5/2011
Ferromex4015-4058442010639520106395-1 thru 20106395-444/2011 - 6/2011
Ferromex4059-4096382011640220116402-1 thru 20116402-389/2011 - 12/2011
EMDX (Demonstrator)201212010645520106455-18/2011
Norfolk Southern1025-1064402011651220116512-1 thru 20116512-4010/2011
EMDX (Demonstrator)422312011652920116529-11/2012
Union Pacific8711-8773732011655720116557-1 thru 20116557-731/2012 - 6/2012
ArcelorMittal Canada9001-900552011659820116598-1 thru 20116598-510/2012
EMDX (Demonstrators)1205, 1201-1204****520116604A20116604A-1 thru 20116604A-55/2012
Kansas City Southern4130-41391020116604B20116604B-1 thru 20116604B-108/2012
EMDX (Demonstrators)1206-1210*****52011667620116676-1 thru 20116676-57/2012
BNSF Railway9050-9129702011668320116683-1 thru 20116683-707/2012 - 12/2012
Quebec, North Shore & Labrador514-5231020116688-20116688-1 thru 20116688-1012/2012
Union Pacific8784-8823402012674520126745-1 thru 20126745-401/2013 - 3/2013
Norfolk Southern1075-1099252012674620126746-1 thru 20126746-254/2013
Union Pacific8824-8896732012683720126837-1 thru 20126837-731/2014 - 7/2014
Norfolk Southern1100-1124252012683820126838-1 thru 20126838-252/2014
BNSF Railway8750-8799, 9000-90491002012686920126869-1 thru 20126869-1005/2013 - 12/2013
Montana Rail Link4400-440892013689520136895-1 thru 20136895-9
Kansas City Southern4140-4164252013693220136932-1 thru 20136932-2512/2013
BNSF Railway8520-8599, 8400-8499, 8990-89991902013692520136925-1 thru 20136925-1904/2014 - 12/2014
Kansas City Southern4175-4199252013695420136954-1 thru 20136954-259/2014 - 11/2014
Ferromex4100-4118192013696020136960-1 thru 20136960-191/2015 - 4/2015
Ferromex4119-4133152013698320136983-1 thru 20136983-154/2015 - 5/2015
Norfolk Southern1125-1174502013698820136988-1 thru 20136988-5011/2014
Union Pacific8897-89961002013699020136990-1 thru 20136990-10010/2014 - 12/2014
Kansas City Southern4165-4174102014699920146999-1 thru 20146999-103/2014 - 4/2014
Kansas City Southern de Mexico4200-4224252014602920146029-1 thru 20146029-252/2015 - 4/2015

*    Became Kansas City Southern #3997-3999.

**   Union Pacific #8521-8523 became heritage units #1989 (Rio Grande), #1995 (Chicago & North Western), and #1996 (Southern Pacific).

***  BNSF #9166, #9167, and #9184-9191 were canceled and resold to BHP (Australia) as #4324-4333.

**** #1201-1203 became Arkansas & Missouri #70-72.  #1204-1204 became Texas Utilities Mining Company #5308-5309.

***** #1206 and #1208-1210 became Canadian National #8100-8103.


Total Built = 22

Owner Road Number(s) Quantity Order Number Serial Number(s) Date Built
EMDX (Demonstrators)1211-1212*22012678020126780-1 thru 20126780-27/2013
BNSF Railway8500-8519202011658120116581-1 thru 20116581-204/2014 - 5/2014

* Became Tacoma Municipal Belt Line #7001-7002.


Total Built = 2

Owner Road Number(s) Quantity Order Number Serial Number(s) Date Built
EMDX (Demonstrators)1603-160422015626720156267-1 thru 20156267-27/2016

SD70ACe (T4C)

Total Built = 168

Owner Road Number(s) Quantity Order Number Serial Number(s) Date Built
Union Pacific8997-90961002014611520146115-1 thru 20146115-1002/2016 - 6/2017
Union Pacific9097-910482014611520146115-101 thru 20146115-10812/2018
Norfolk Southern1175-1224502017666220176662-1 thru 20176662-5011/2018 - 11/2019
EMDX (Demonstrators)2115-2124*102018664720186647-1 thru 20186647-1012/2019 - 1/2020

* Became Norfolk Southern #1225-1244.


Total Built = 148

Owner Road Number(s) Quantity Order Number Serial Number(s) Date Built
EMDX (Demonstrators)1501-1505*52014600620146006-1 thru 20146006-59/2015
EMDX (Demonstrators)1601-160222015620520156205-1 thru 20156205-212/2016
EMDX (Demonstrators)1605-160622015620620156206-1 thru 20156206-212/2016
EMDX (Demonstrators)1607-160822015620720156207-1 thru 20156207-26/2016
EMDX (Demonstrators)1609-161022015620820156208-1 thru 20156208-26/2016
Union Pacific3012-3099**882014614020146140-1 thru 20146140-35, 20146140-79 thru 20146140-88, 20146140-36 thru 20146140-7810/2016 - 10/2018
CSX8900-8909102017659020176590-1 thru 20176590-105/2019 - 6/2019
EMDX (Demonstrators)7201-7227272018668020186680-1 thru 20186680-1011/2019 - 1/2020
EMDX (Demonstrators)7233-7242102018666320186663-1 thru 20186663-1011/2019 - 1/2020

*  #1502-1505 became Union Pacific #3000-3003. 

** Union Pacific #3091, #3097-3099, and #3013 were returned to EMD, becoming demonstrators #7228-7232.

Tractive Effort

Its tractive effort ratings are very comparable to the GEVOs; 191,000 pounds starting (slightly more) and 157,000 pounds continuous (slightly less).  

There are also a few international variants of the model known as the SD70ACe/Ic and the SD70ACS. The former was purchased by BHP Billiton of Australia with a lower height profile to clear low hanging obstacles.

The latter design was developed for arid desert environments and has been purchased by Saudi Railway, Mauritania's Société Nationale Industrielle et Minière, and the Etihad Railway.   Alas, it seems foreign buyers will be the only customers for EMD's SD70 series moving forward. 


As the EPA increased its regulations on ever-cleaner diesel emissions it seemed the SD70ACe and its 710 prime mover were safe as the engine met later Tier III standards.  

However, when Tier IV standards went into effect on January 1, 2015 Caterpillar/Progressive Rail was unable to make the prime mover compliant and there is no way to do so according to Bill Badurksi,  a former EMD employee in his article "Closing A Chapter In History," from the January, 2015 issue of Trains Magazine.  

While EMD sat in the shadows as General Electric unveiled its all new, Tier IV-compliant model in August of 2012 the company continued working towards releasing its own design, especially after it became apparent the 710 prime mover would have to be retired for domestic sales.

At the Railway Interchange trade show in Minneapolis on October 4, 2015 the company, amid much secrecy, finally unveiled its own Tier IV locomotive, the SD70ACe-T4.  

While the model's name seems to indicate it is a variant of the original SD70ACe series, EMD states this is a brand new locomotive manufactured from the ground up.  

In place of the old 710 prime mover is the new 12-cylinder, 4,600 horsepower model 1010 diesel engine that was designed by Electro-Motive, Progressive Rail Services, and parent Caterpillar.  

During an interview with Trains Magazine at the show an EMD representative gave a confident and convincing interview of the SD70ACe-T4's capabilities.  

While they would not go into the specifics regarding how the engine can produce 4,600 horsepower and remain Tier IV compliant the representative did state they utilize technology similar to General Electric in that diesel exhaust is captured as energy and reused within the system.

Aside from the new engine several other design features went into the model using considerable feedback from railroads and employees.  

  • Riding on a new frame the SD70ACe-T4 is three inches shorter than the original SD70ACe to meet railroads' requests.

  • A larger interior cabin has been achieved by lowering the floor with a concave ceiling (high enough to offer plenty of clearance for hard hats).

  • An escape door on the conductor's side in the event of a rollover, and a return of EMD's classic notched windshield for better crew visibility.  

In addition to these features Electro-Motive debuted an all-new radial (self-steering) truck with independently controlled axles that is said to be much easier to maintain.  

The first demonstrator built was #1501, manufactured at Progress Rail’s Muncie, Indiana facility and EMD states there will be a total of five demonstrators in production draped in various paint schemes.  

The company goes on to state that SD70ACe-T4 will enter production in 2016.  Caterpillar and EMD have much riding on this locomotive.   If it proves troublesome and unsuccessful it appears the builder will never again compete against General Electric's now decades-long dominance in the locomotive marketplace.  

However, for the industry's sake having two competitive manufacturers offering high quality locomotives, one of which is the long-recognized name of diesel technology which almost single-handedly retired steam from main line service, would certainly be a good thing.   In any event, in the coming months and years we will find out what kind of product the SD70ACe-T4 is and how it performs.


  • McDonnell, Greg. Locomotives: The Modern Diesel & Electric Reference, 2nd Edition. Buffalo: Boston Mills Press/Firefly Books, 2015.
  • Solomon, Brian.  GE and EMD Locomotives:  The Illustrated History.  Minneapolis:  Voyageur Press, 2014.

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