EMD AEM-7

The AEM-7 is a twin-cab B-B electric locomotive that is used in the United States on the Northeast Corridor between Washington DC and Boston and the Keystone Corridor between Philadelphia and Harrisburg in Pennsylvania. They were built by Electro-Motive Division from 1978 to 1988. There are two versions of the AEM-7 as of 1999: the original AEM-7DC which has DC propulsion equipment and the newer, modified AEM-7AC which uses AC propulsion equipment. EMD manufactured 65 locomotives between 1978–1988; the majority of these were for Amtrak, other operators included MARC and SEPTA. Amtrak is phasing out its fleet in favor of the newer Siemens ACS-64, which entered service in 2014.

Background

Green Cargo Rc4 no. 1290 in original livery

Amtrak had inherited high-speed operations on the Northeast Corridor from the bankrupt Penn Central in 1971. Electrified passenger services between New York and Washington were handled by the new if unreliable Budd Metroliner electric multiple units and the aging PRR GG1s, originally built for the Pennsylvania Railroad in 1934–1943.^[5] Amtrak's first attempt at replacing the GG1 was the General Electric E60, delivered in 1974. The E60s proved unable to safely exceed 100 miles per hour (160 km/h) and Amtrak relegated them to hauling slower long-distance services. Amtrak turned to existing European high-speed designs, and two were brought over for trials in 1976–77: the Swedish Rc4 (numbered X995), and the French CC 21000 (X996).^[6] Amtrak favored the Swedish design, which became the basis for the AEM-7.^[7]

Design

The AEM-7 weighs 101 short tons (90 long tons; 92 t), whereas the GG1 weighs 238 short tons (213 long tons; 216 t). With all the weight on eight drivers, the AEM-7 has a high horsepower to weight ratio (70 hp/short ton) and needs a sophisticated wheelslip control (Pressductor) system.

The locomotive's head end power (HEP) was sufficient for 8-10 Amfleet cars.^[8]

AEM-7AC

In 1999, Amtrak and Alstom began a remanufacturing program for Amtrak AEM-7s. Alstom supplied AC propulsion equipment, electrical cabinets, transformers, HEP, and cab displays. The rebuild provided Amtrak with locomotives that had improved high end tractive effort and performance with longer trains. Amtrak workers performed the overhauls under Alstom supervision at Amtrak's shop in Wilmington, Delaware.^[9] These remanufactured AEM-7s are designated as "AEM-7AC"s. Between 1999 and 2002, 29 AEM-7s were converted to AEM-7ACs.^[10]

The power modules use water-cooled IGBT technology and provide about 5,000 kilowatts (6,700 horsepower) of traction power plus 1,000 kilowatts (1,300 horsepower) of HEP, an improvement over the 500 kilowatts (670 horsepower) HEP capacity of the original DC units, and enough for 18 Amfleet or Viewliner coaches. The traction motors (model 6 FXA 5856) are from Alstom's ONIX family of propulsion components, and have a maximum rating of 1,250 kilowatts (1,680 horsepower)-1,275 kilowatts (1,710 horsepower) and a continuous rating of 1,080 kilowatts (1,450 horsepower). Locomotive electric brake ratings are ~4,300 kilowatts (5,800 horsepower) in regenerative mode and ~2,200 kilowatts (3,000 horsepower) in rheostatic (resistor-only) mode. As such, the remanufactured AEM-7 is the world's first passenger locomotive with IGBT in service.^[1][11]

ALP-44

New Jersey Transit No. 4416 at Hoboken Terminal in 2005

The ABB ALP-44 is an electric locomotive built by ASEA Brown Boveri (Sweden) between 1990 and 1996. It was designed specifically for New Jersey Transit. At first glance, the two locomotives might look the same to a casual observer. Both the ALP-44 and AEM-7 are based on the same line of locomotives from ABB; the AEM-7 from the Rc4, and the ALP-44 from the Rc6 and Rc7 models.

ABB provided one ALP-44 to SEPTA in part settlement of claims for late delivery of the N-5 Norristown High Speed Line cars. The engine (numbered 2308) operates interchangeably with SEPTA's AEM-7 fleet. SEPTA'S AEM-7 and ALP-44 fleet will be retired and replaced by the ACS-64 by 2018-2019.

History

Amtrak ordered 30 AEM-7s in 1977 (Order Number: 776073) and 17 more in 1980 (Order Number: 806004).^[12] By 1978, the Electro-Motive Division of General Motors (EMD), now Electro Motive Diesel, began production. The bodies came from the Budd Company, with electrical, trucks and mechanical parts imported from Sweden. The first AEM-7 (900) went into service in 1979. The Swedish influence led to the nickname "Meatball", after Swedish meatballs. Railfans nicknamed the boxy locomotives "toasters."^[13] Between 1980 and 1982, 46 AEM-7s (901-946) went into service. This helped retire the GG1s from regular service. Amtrak ordered seven more AEM-7s in 1987 (Order Number: 876006), which were completed by 1988. Two commuter operators in the Northeast ordered AEM-7s. MARC ordered four in 1986 for use on its Penn Line service on the Northeast Corridor between Washington, D.C. and Perryville, Maryland.^[14] SEPTA ordered seven in 1987.^[15]

In 2010 Amtrak ordered 70 Siemens ACS-64 locomotives to replace both the AEM-7s and the newer but unreliable Bombardier/Alstom HHP-8s.^[16] The ACS-64s began entering revenue service in February 2014.^[17]

Current status

In 2015, Amtrak started the process of retiring its entire AEM-7 fleet with the arrival of the new Siemens ACS-64. All AEM-7DCs have been retired. The last units active were 909, 926, 931, and 945; all were retired on April 14, 2015.

Notes

References

• Cudahy, Brian J. (2002). Rails Under the Mighty Hudson (2nd ed.). New York: Fordham University Press. ISBN 0-8232-2190-3. OCLC 48376141. 
• Middleton, William D. (1994). North American commuter rail 1994. Pasadena, CA: Pentrex. OCLC 32665882. 
• Simon, Elbert; Warner, David C. (2011). Amtrak by the numbers: a comprehensive passenger car and motive power roster, 1971-2011. Kansas City, MO: White River Productions. ISBN 978-1-932804-12-9. OCLC 837623640. 
• Soloman, Brian (2003). Electric Locomotives. Saint Paul, MN: MBI Publishing. ISBN 978-0-7603-1359-6. 
• Solomon, Brian (2014). GE and EMD Locomotives: The Illustrated History. Minneapolis: Voyageur Press. ISBN 978-0-7603-4612-9. OCLC 868039631. 

External links

Wikimedia Commons has media related to EMD AEM-7 locomotives.

• AEM-7DC power, tractive effort, and braking curve graphs on page 11-27 (figures 11.2.10 - 11.2.12).
• AEM-7AC Completion Dates and Data by On Track On Line