EMD SD80MAC

The EMD SD80MAC was a 5,000 horsepower diesel-electric locomotive produced by Electro-Motive Diesel between 1995 and 1996. A total of 30 units were built, all of which were delivered exclusively to Conrail. The 28 production units were completed, tested, and painted at the former Pennsylvania Railroad shops in Altoona, Pennsylvania. The SD80MAC was notable for being only the second EMD diesel locomotive to employ a 20-cylinder engine configuration, the first having been the earlier SD45 series. Other railroads had expressed interest in the model during its development period, including Chicago and North Western Railway, which placed an order for 15 units prior to its 1995 merger with Union Pacific, and Canadian Pacific, which ultimately redirected its order toward the related SD90MAC instead. When Conrail was divided between Norfolk Southern Railway and CSX Transportation in 1999, the SD80MAC fleet was split accordingly. Norfolk Southern received 17 units, numbered 7200 through 7216, while CSX took possession of 13 units, initially numbered 800 through 812 and later renumbered 4590 through 4602. The SD80MACs represented the first AC traction locomotives to enter Norfolk Southern's roster. In late 2014, Norfolk Southern arranged a trade with CSX, exchanging 12 EMD SD40-2 locomotives for CSX's remaining 12 SD80MACs, with those units arriving on Norfolk Southern in April 2015 and making the railroad the sole operator of the class. In February 2020, Norfolk Southern retired all 29 of its remaining SD80MACs, citing operational costs. Six units were subsequently sold to Canadian Pacific Railway to serve as parts donors for that railroad's SD70ACU rebuild program, while the remainder were sent to Progress Rail and scrapped. As of 2025, the six units held by Canadian Pacific Kansas City remained in storage. Efforts by the Conrail Historical Society to secure at least one example for preservation had not yet resulted in a confirmed outcome.

The SD80MAC was powered by an EMD 710G3B-EC 20-cylinder prime mover, operating at a full speed of 904 rpm and producing 5,000 horsepower. The locomotive rode on two HTCR-2 radial self-steering trucks, each carrying three Siemens 1TB2830 AC traction motors, for a total of six motors in a C-C wheel arrangement. Each motor was rated at 638 kilowatts and could produce a starting torque of 16,300 newton-meters. The locomotive weighed 210 short tons and was capable of a maximum speed of 75 miles per hour, with a starting tractive effort of 185,000 pounds-force and a continuous tractive effort of 147,000 pounds-force. Fuel capacity was 5,800 US gallons, and the main alternator was an EMD TA22-CA8A unit capable of a maximum output of 2,600 volts DC. Several of the SD80MAC's design elements were forward-looking and influenced subsequent EMD products. The locomotive introduced a wide radiator housing and positioned its dynamic brakes at the rear of the carbody, a quieter arrangement that was later carried over to both the SD90MAC and the SD70ACe. The Conrail units also featured recessed red marker lights set into the nose, a styling detail characteristic of Conrail's locomotive orders. The SD80MAC's 20-cylinder engine architecture was later revisited in an export variant designated the SD80ACe, built for Vale Mining of Brazil in broad gauge configuration with an upgraded 5,300 horsepower rating.

Models by: Athearn