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EMD SD70 series
EMD SD70M demonstrator #7004
Power type Diesel-electric
Builder General Motors Electro-Motive Division (EMD)
Model SD70, SD70M, SD70I, SD70MAC, SD70M-2, SD70ACe
Build date 1992 – current
Total production SD70: 120
SD70M: 1,646
SD70I: 26
SD70MAC: 1,124
SD70ACe: 185
SD70ACe/lc: 46
SD70M-2: 130
AAR wheel arr. C-C (UIC: Co'Co' )
Gauge 4 ft 8+12 in (1,435 mm) for the North American market; 1600 mm (5 ft 2 in) for Brazil
Prime mover EMD 16-710-G3
Cylinders 16
Transmission Siemens AC alternator, Siemens AC traction motors (SD70MAC/SD70ACe), DC traction motors (SD70/SD70I/SD70M/SD70M-2)
Career See Article
Number See Article
Disposition In service as of 2008

The EMD SD70 is a series of diesel-electric locomotives produced by the Electro-Motive Division of General Motors beginning in 1992. Over 4000 locomotives in this series have been produced, mostly of the SD70M and SD70MAC models. All locomotives of this series are hood units with C-C trucks. All SD70 models up to the SD70ACe and SD70M-2 have the HTCR Radial truck, rather than the HT-C truck; the self-steering radial truck was designed to allow the axles to steer in curves, reducing wear on the wheels and railhead. With the introduction of the SD70ACe and SD70M-2, in an effort to reduce cost EMD introduced a new bolsterless non-radial HTSC truck as the standard truck for these models. The radial truck, now the HTCR-4, is still an option.





Norfolk Southern Railway 2561.

The SD70 carriers the smaller standard cab or spartan cab, common on older locomotives, instead of the larger new comfort cab. This model also has DC traction motors, which simplifies the electrical system by cutting out the need for computer-controlled inverters. One hundred twenty examples of this model locomotive were produced, for Norfolk Southern Railway, Conrail, Illinois Central and Southern Peru Copper. (Conrail was partly absorbed by Norfolk Southern Railway in 1999, and all 24 of Conrail's SD70 engines went to NS. These SD70s were ordered to NS specifications, as NS and CSXT modified CRs SD80MAC order for SD70s for NS and SD70MACs for CSX)

Production of the standard cab at London ended in 1994. The 24 CR SD70s were assembled from kits at Juniata, and the IC and SPC SD70s were assembled from kits at Super Steel Schenectady. Nearly all SD70s are still in service with Norfolk Southern Railway and Canadian National, which merged with the Illinois Central in 1999.

Numbers: NS 2501-2556 [1], 2557-2580 (Ex-Conrail), IC 1000-1039 (IC 1006, 1013, 1014, 1023 wrecked & retired).


A comparison of the various versions of the SD70s as operated by Union Pacific Railroad

The SD70M has a wide nose and a large comfort cab (officially known as the "North American Safety Cab"), allowing more crew members to ride comfortably inside of the locomotive than the older standard cab designs. There are two versions of this cab on SD70Ms, the Phase I, which was introduced on the SD60M, and is home on the SD80MAC & SD90MAC's and the Phase II, which made a return to a more boxy design a la the original 3 window SD60M cabs. Though the Phase II cab has a two piece window matching the Phase I cab windows, the lines of the nose are boxy, with a taller square midsection for more headroom. The SD70ACe/SD70M-2 line has what is considered the Phase II cab, but it is actually more so a Phase III cab, as the windows went from the teardrop design to a rectangular window. Like the SD70, the SD70M also uses DC traction motors. Starting in mid-2000, the SD70M was produced with SD45-style flared radiators allowing for the larger radiator cores needed for split-cooling (split-cooling is a feature that separates the coolant circuit for the prime mover and the circuit for the air pumps and turbocharger). There are two versions of this radiator, the older version with two (2) large radiator panels per side, and the newer style with four (4) square panels per side. This was due to the enactment of the EPA's Tier I environmental regulations. Production of the SD70M was replaced by the SD70M-2 in late 2004, as the EPA's Tier II regulations went into effect on January 1, 2005. 1,646 examples of this model locomotive were produced. SD70M models were produced with 4000 horsepower (2,980 kW) EMD Model 710 prime movers. Purchasers included CSX, New York Susquehanna & Western (part of EMDX order #946531[2]), Norfolk Southern, Southern Pacific (now UP), and Union Pacific.

EFC (CVRD) #714, in Maranhão, Brazil.

This locomotive model is also built for export, and is still catalogued by EMD (at 4300hp). CVG Ferrominera Orinoco has 6 SD70Ms that were built as an add-on order to UPs FIRE cab equipped SD70Ms. Companhia Vale do Rio Doce (CVRD) in Brazil has ordered 27 of this model for service in Carajas pulling trainloads of iron ore. Since CVRD track is gauged at 1600 mm, a wider bogie, the HTSC2, was designed for these units by EMD.[3]

Numbers: UP 2001-2002, 3778-5231 (4687 Withdrawn), EMD 7000-7024 to CSXT 4675-4699, NS 2581-2648


The SD70I is a version of the SD70M which has been fitted with a cab that is isolated from the frame of the locomotive with rubber gaskets (officially known as a "WhisperCab"). The isolation reduces noise and vibration from the prime mover. A seam is visible across the nose and on the long hood where the cab connects with the body. 26 examples of this model locomotive were produced, all for Canadian National. The WhisperCab feature was incorporated into some SD70MAC and later models.

Numbers: CN 5600-5625


The SD70MAC (colloquially known as a "Mac" or a "Mac 70") is very similar to the SD70M and SD70I (the SD70I's WhisperCab feature was a build-to-order option), the main difference being that the SD70MAC uses AC traction motors. AC motors, while simpler and more reliable than DC motors, require expensive inverters to generate a variable-frequency AC signal, raising the locomotives purchase cost substantially. The majority of SD70MAC models were produced with 4000 horsepower (2,980 kW) EMD Model 710 prime movers[4], while later-production SD70MACs are rated at 4300 horsepower (3,210 kW) and feature SD45-style flared radiators. They were also offered with a head-end power generation system for passenger trains. (The SD70MAC is no longer produced due to EPA regulations and has been replaced by the SD70ACe.) Over 1500 examples of this locomotive model were produced. Purchasers include Burlington Northern (now BNSF Railway), Conrail (engines now owned by CSX Transportation), CSX, TFM/Kansas City Southern Railway and the Alaska Railroad.

Numbers: ARR 4001-4016, 4317-4324 (these 8 units have Tier 1 flared radiators and are equipped with HEP generators for passenger service), BNSF 8800-8989 (8876 retired), 9400-9499 (Ex BN), 9504-9999, CSXT 4500-4574, 4575-4589 (Ex Conrail), 4701-4830, TFM 1600-1674 [5]


KCS 4034 SD70ACe sits at CN Nichoals Yard.

The SD70ACe is similar to the SD70MAC; however, it has been updated to meet the latest EPA regulations for road locomotives. Several other changes were included as well. The radiator on the locomotive is nearly as wide as the cab, and looks similar to the radiator on the SD80 and SD90 series of locomotives. The nose has been modified, producing a much more angular nose than previous models. The cables and brake lines have been routed beneath the walkways, allowing for easy access by maintenance workers. SD70ACe models are rated at 4,300 horsepower (3,200 kW). As of 2005, 185 examples of this model locomotive have been produced. Purchasers include BNSF Railway, CSX Transportation, Ferromex, Kansas City Southern Railway, Montana RailLink, CVG Ferrominera Orinoco and Union Pacific Railroad.

Numbers: BNSF 9130-9329 (all ordered) 9330-9399, CSXT 4831-4850, FXE 4000-4019, KCS 3997-3999 (ex EMD demonstrators), 4000-4029, 4030-4059, 4060-4129, MRL 4300-4315, UP 1982, 1983, 1988, 1989, 1995, 1996 (Heritage Fleet), 4141 (Bush unit), 8309-8665.


SD70ACe/lc[6] is a low clearance, export version of the SD70ACe.

In 2004, BHP Billiton of Australia ordered 14 SD70ACe/lc locomotives for use in iron ore hauling; the "lc" in the model designation stands for "low clearance" as these locomotives are designed to negotiate the tight clearances under the mine equipment.

Certain external differences between the SD70ACe & SD70ACe/lc models include the addition of marker lights, number boxes lower in the body rather on top of the cab, windscreen protector panels (to deflect abrasive iron ore when in mid train position), fire suppression canisters, louvre style vents, different horn and subtle differences with handrails.

Of the first batch of SD70ACe/lc (Numbers 4300-4313), 4301-4313 are named[7] after sidings on the BHP system. 4300 is used for spare parts and has never seen service. The second batch of locomotives (Numbers 4313-4323), have a newly designed isolated cab. An order for a third batch of 13 SD70ACe/lc's (Numbers 4334-4346) was placed with EMD in August 2007. But such was the demand for locomotive power in the Pilbara region, ten SD70ACe destined for BNSF were purchased before this third batch was constructed, becoming numbers 4324-4333. These ten ex-BNSF locos (ex-9166, 9167, 9184-9191) are in the BNSF Orange with white BHP Billiton lettering and are standard North American SD70ACe units. Some modifications have been made to bring them inline with the rest of the fleet. A fifth batch of SD70ACe/lc (Numbers 4347-4355) was recently delivered to BHP Billiton in July 2009, bringing the total of SD70ACe type locomotives to 55 + 1 for spare parts.


The SD70M-2 is a DC traction version of the SD70ACe, and the two models are nearly identical in every other respect. SD70M-2 models are rated at 4,300 horsepower (3,200 kW) each. As of 2007, 180 examples of this model locomotive have been produced. Examples are owned by Norfolk Southern Railway, CIT Financial, Canadian National and eight units for the Florida East Coast Railway.

Road Numbers: CITX 140-142(currently on lease to the Florida East Coast Railway), CN 8000-8024 and 8800-8849, FEC 100-107, NS 2649-2778,

Like the SD70ace, all SD70M-2's are equipped with the Airchime model K5LLA air horn and an electronic bell.

Original Buyers

Owner SD70 SD70I SD70M SD70MAC SD70M-2 SD70ACe SD70ACe/lc
Alaska Railroad 28
BHP Billiton Iron Ore 10 46
BNSF Railway 594 270
Burlington Northern Railroad 315
CIT Financial (CITX) 3
CSX Transportation 25 245 20
CVG Ferrominera Orinoco 6 7
Canadian National Railway 26 140
Companhia Vale do Rio Doce (CVRD) 27
Conrail 24 15
EMD 25 3 4
Ferromex (FXE) 20
Florida East Coast Railway 8
Illinois Central Railroad 40
Kansas City Southern Railway 133
Montana Rail Link 16
Norfolk Southern Railway 80 68 130
Southern Pacific 25
Southern Peru Copper 2
Transportacion Ferroviaria Mexicana (TFM) 75 15
Union Pacific Railroad 1452 365



  1. ^ The Diesel Shop,, All Rosters Unless Otherwise Noted
  2. ^ The Unofficial EMD Homepage, Order # 946531. Retrieved June 2, 2009.
  3. ^ Electro-Motive Diesels, SD70M for CVRD. Retrieved December 1, 2005.
  4. ^
  5. ^ KCS Historical Society,, TFM Roster
  6. ^ SD70ACe/LC Product Brochure from Downer EDI Rail,
  7. ^ BHP Billiton Loco Roster,


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