EMD SD80MAC
Model of diesel-electric locomotive built by EMD
title: "EMD SD80MAC" type: doc version: 1 created: 2026-02-28 author: "Wikipedia contributors" status: active scope: public tags: ["electro-motive-diesel-locomotives", "c-c-locomotives", "diesel–electric-locomotives-of-the-united-states", "freight-locomotives", "conrail", "conrail-locomotives", "standard-gauge-locomotives-of-the-united-states", "railway-locomotives-introduced-in-1995", "electro-motive-division-locomotives", "scrapped-locomotives"] description: "Model of diesel-electric locomotive built by EMD" topic_path: "geography/united-states" source: "https://en.wikipedia.org/wiki/EMD_SD80MAC" license: "CC BY-SA 4.0" wikipedia_page_id: 0 wikipedia_revision_id: 0
::summary Model of diesel-electric locomotive built by EMD ::
::data[format=table title="Infobox locomotive"]
| Field | Value |
|---|---|
| name | EMD SD80 Series |
| powertype | Diesel-electric |
| gauge | |
| trucks | EMD HTCR II |
| image | Conrail SD80MAC 4100.jpg |
| poweroutput | 80MAC: 5000 hp |
| 80ACe: 5300 hp | |
| aarwheels | C-C |
| uicclass | Co′Co′ |
| cylindercount | 20 |
| primemover | SD80MAC: EMD 20-710G3B-ES |
| SD80Ace: 20-710G3C-ES | |
| GT50AC: 20N-710G3B-EC | |
| enginetype | V20 diesel |
| transmission | diesel electric |
| height | 80MAC: 15 ft |
| 80ACe: 15 ft | |
| length | 80MAC: 80 ft |
| 80ACe: 76 ft | |
| wheeldiameter | 45 in |
| maxspeed | 75 mph |
| locoweight | 80MAC: 420000 lb |
| SD80ACe: 432500 lb | |
| tractiveeffort | SD80MAC: 185000 lbf starting, 147000 lbf continuous |
| 80ACe: 191000 lbf starting | |
| GT50AC: 125893 lbf starting, 91047 lbf continuous | |
| fuelcap | SD80MAC: 5800 usgal |
| SD80ACe: 4900 usgal | |
| GT50AC: 1981 usgal | |
| totalproduction | SD80MAC: 30 |
| SD80ACe: 7 | |
| GT50AC: 7 | |
| operator | SD80MAC: Conrail, Norfolk Southern and CSX |
| SD80ACe: Vale Mining | |
| GT50AC: Indian Railways | |
| disposition | VALE and Indian units in service, six NS units stored, remainder scrapped. |
| operatorclass | CSX 4590–4602 |
| NS 7200–7228 | |
| Vale 101-107 | |
| Indian Railways 50001-50007 | |
| builder | General Motors Electro-Motive Division (EMD) |
| buildmodel | SD80MAC, SD80ACe, GT50AC |
| builddate | SD80MAC: 1995–1996 |
| SD80ACe: 2011–2012 | |
| GT50AC: 2012-2018 | |
| :: |
| name = EMD SD80 Series | powertype = Diesel-electric | gauge = | trucks = EMD HTCR II | image = Conrail SD80MAC 4100.jpg | poweroutput = 80MAC: 5000 hp 80ACe: 5300 hp | aarwheels = C-C | uicclass = Co′Co′ | cylindercount = 20 | primemover = SD80MAC: EMD 20-710G3B-ES SD80Ace: 20-710G3C-ES GT50AC: 20N-710G3B-EC | enginetype = V20 diesel | transmission = diesel electric | height = 80MAC: 15 ft 80ACe: 15 ft | length = 80MAC: 80 ft 80ACe: 76 ft | wheeldiameter = 45 in | maxspeed = 75 mph | locoweight = 80MAC: 420000 lb SD80ACe: 432500 lb | tractiveeffort = SD80MAC: 185000 lbf starting, 147000 lbf continuous 80ACe: 191000 lbf starting GT50AC: 125893 lbf starting, 91047 lbf continuous | fuelcap = SD80MAC: 5800 usgal SD80ACe: 4900 usgal GT50AC: 1981 usgal | totalproduction = SD80MAC: 30 SD80ACe: 7 GT50AC: 7 | operator = SD80MAC: Conrail, Norfolk Southern and CSX SD80ACe: Vale Mining GT50AC: Indian Railways | disposition = VALE and Indian units in service, six NS units stored, remainder scrapped. | operatorclass = CSX 4590–4602 NS 7200–7228 Vale 101-107 Indian Railways 50001-50007 | builder = General Motors Electro-Motive Division (EMD) | buildmodel = SD80MAC, SD80ACe, GT50AC | builddate = SD80MAC: 1995–1996 SD80ACe: 2011–2012 GT50AC: 2012-2018 The EMD SD80MAC was a 5000 hp C-C diesel-electric locomotive. It was powered by a 20-cylinder version of EMD's 710G prime mover, and was the second diesel locomotive by GM-EMD to use a V20 engine, since EMD's SD45 series. It introduced a wide radiator housing similar to GE Transportation locomotives and the placement of dynamic brakes at the rear of the locomotive, which is a quieter location, features that were incorporated into the SD90MAC and SD70ACe models. Key spotting differences between the SD80MAC and SD90MAC include no external rear sandbox on the SD90MAC, no rear lighted number boards on the SD90MAC, and the placement of the front number boards (above the cab windows on the SD80MAC, on the nose on most SD90MACs). The SD80MAC also had recessed red marker lights in the nose, an identifying feature unique to Conrail (CR) locomotives, although Norfolk Southern (NS) had removed the lights on most of their former Conrail engines.
All 30 SD80MAC units built were delivered to Conrail, and the 28 production units were completed, tested, and painted at the former Pennsylvania Railroad shops in Altoona, Pennsylvania.
Prior to the 1995 merger with Union Pacific, Chicago and North Western Railway placed an order of 15 locomotives. Canadian Pacific placed an order as well but it was changed to SD90MACs. Conrail planned a second order of SD80MACs, but its new owners changed the order to SD70s and SD70MACs, all of which would be built at the Juniata Shops in Altoona.
Vale Mining of Brazil ordered a set of seven updated locomotives designated as the SD80ACe model. These locomotives feature Tier 1 compliant 20-710G3C-ES engines, with 5300 hp at 950 RPM. The design is currently for export only, and these specific locomotives will run on Vale Mining's broad gauge trackage.
Another broad gauge variant introduced in 2012 is the EMD GT50AC, also known as the Indian locomotive class WDG-5, a smaller and lighter 135-ton variant, with an up-tweaked EMD 20N-710G3B-EC engine, capable of producing 5500 hp at 910 RPM, to serve the Indian Railways, whose current tracks are weak to handle very heavy locomotives, just like how EMD GT46MAC WDG-4 was developed from SD70MAC by reducing the weight. The seven locomotives of the class were developed indigenously by Banaras Locomotive Works (BLW) of India. The locomotives are not a part of the SD80 series, but are completely based on it, making it the second International application of the V20-710 prime mover, after the Brazilian SD80ACe.
After the split of Conrail in 1999, the SD80MACs were split up between Norfolk Southern Railway and CSX Transportation. Norfolk Southern received 17 units (numbered 7200–7216) while CSX got 13 (800–812, renumbered to 4590–4602). The former Conrail units were the first AC traction locomotives owned by Norfolk Southern, with the railroad not ordering more until late 2008 with an order of General Electric's ES44AC. In late 2014, Norfolk Southern announced that they had reached an agreement with CSX Transportation to trade 12 EMD SD40-2 units (NS 3425–3447) for CSX's remaining 12 SD80MACs, leaving NS as the model's sole operator. They were delivered to the NS in April 2015.
In February 2020, following the beginning of COVID-19 pandemic, Norfolk Southern retired all 29 of its remaining SD80MACs, owing to their operational costs. Six units were sold to Canadian Pacific Kansas City (then Canadian Pacific Railway) as parts sources for their recent EMD SD70ACU rebuilds. The remainder of the NS fleet went to Progress Rail and were scrapped. As of January 2022, the Conrail Historical Society was in contact with Canadian Pacific Kansas City Limited hoping to have one SD80MAC set aside for preservation, after failing to make an agreement with Progress Rail. As of 2025, the six SD80MACs still remain in storage as the remainder were scrapped.
Incidents
CSX 4594, formerly CSX 804, and built as CR 4110, was scrapped in January 2014 after being used as a parts donor following a derailment in early 2009.
A Norfolk Southern South Fork crew was securing their engines for the night on November 18, 2016 when an electrical fire broke out in the cab of NS 7210 (built as CR 4118). There were no injuries, but the SD80MAC’s cab interior was completely destroyed. The unit was hauled to the Juniata Shops in Altoona where it was stored in the deadline until it was among the units that were sold off to Progress Rail. The unit was scrapped in December 2021.
SD80MAC technical details
The technical details of this locomotive model are as follows:
;Prime mover
- Electro-Motive Diesel V-20 710G3B-ES
- Displacement: 14200 cuin
- Idle: 200 rpm
- Full speed: 904 rpm
- Lube oil capacity: 510 gal
- Cooling water capacity: 342 gal
- Fuel capacity: 5800 gal
;Main alternator
;Traction motors
- 6 Siemens 1TB2830 AC motors mounted 3 each on 2 HTCR-2 Radial Self Steering trucks.
- Rated output: 638 kW
- Gearing: 83:16
- Wheel size: 45 in
- Max revolutions: 3,435 rpm
- Starting torque: 16300 N·m
- Continuous torque: 12900 N·m
- Maximum voltage: 2,183 V
;Performance
- Maximum speed: 75 mph
- Starting tractive effort: 185000 lbf
- Continuous tractive effort: 147000 lbf
- Braking effort: 96000 lbf)
- Weight: 210 ST; 420000 lb)
References
References
- (20 January 2022). "Rare SD80MACs Scrapped Despite Efforts to Preserve One".
- Siemens. "Diesel-Electric Locomotive SD80MAC with Three-Phase Drive".
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