EMD AEM-7

Background

Amtrak took over most private intercity passenger rail in the United States on May 1, 1971, inheriting 300 locomotives and 1190 passenger cars, many from the 1940s–1950s. On the electrified Northeast Corridor, operations relied on Budd Metroliner EMUs and aging PRR GG1 locomotives restricted to 85 mph.

No US manufacturer offered a replacement electric passenger locomotive, and importing a European design required a three-year lead time. Amtrak turned to GE to adapt the E60C freight locomotive, but the resulting E60CP and E60CH proved unsuitable above 90 mph. In 1976–77, Amtrak tested two European designs: the Swedish SJ Rc4 and the French SNCF Class CC 21000, favoring the Swedish model as the basis for the AEM-7.

History

Amtrak planned 53 locomotives at an estimated $137.5 million, but limited funding led to a September 1977 plan for 30 at $77.8 million. Five groups bid; the EMD/ASEA partnership won the contract in January 1978. Amtrak ordered 17 more in February 1980, totaling 47.

The first locomotive, No. 900, was delivered in February 1980 and tested at the Transportation Test Center in Pueblo, Colorado, from April 1980 to May 1981, covering 156200 mi. Revenue service began on May 9, 1980, with No. 901 departing Washington Union Station. The Swedish influence earned the nickname 'Meatball', while railfans called them 'toasters'. By 1982, 47 AEM-7s were in service.

Amtrak retired its last GG1s on May 1, 1981, and sold most GE E60s. MARC ordered four in 1986, and SEPTA ordered seven in 1987. Amtrak also used AEM-7s on the Keystone Corridor as Budd Metroliners were retired.

Design

The AEM-7 was significantly smaller than the PRR GG1 and GE E60, measuring 51 ft long, 10 ft wide, and 14 ft tall, with a weight half that of the E60CP or GG1. It was the smallest and lightest high horsepower locomotive in North America at introduction. The Budd Company built carbodies for the initial Amtrak order, while Simmering-Graz-Pauker built those for MARC and SEPTA. The locomotive could operate at three voltages: 11 kV 25 Hz AC, 12.5 kV 60 Hz AC, and 25 kV 60 Hz.

Power was collected by Faiveley DS-11 two-stage pantographs at each end. Thyristor converters stepped down high-voltage AC to DC for four traction motors. As built, it had 7000 hp, starting tractive effort of 51710 lbf, continuous tractive effort of 28100 lbf, and a maximum speed of 125 mph. A static converter supplied 500 kW 480 V head-end power for 8–10 Amfleet cars.

The rebuilt AEM-7ACs used AC traction with water-cooled IGBT technology, providing about 5000 kW traction power plus 1000 kW HEP, and were the world's first passenger locomotives with IGBT.