EMD AEM-7

EMD AEM-7

Now-retired #919 leads the Silver Meteor through Odenton, Maryland, in 2010

Type and origin Power type Electric Builder General Motors Electro-Motive Division Build date 1978–1988 Total produced 65 Rebuilder Alstom Transport Rebuild date 1999-2002 Number rebuilt 29

Specifications AAR wheel arr B-B UIC class Bo'Bo' Gauge 4 ft 8 1⁄2 in (1,435 mm) standard gauge Wheel diameter Minimum curve 245 ft (75 m) / 23.4° (single unit) 265 ft (81 m) / 21.6° (coupled) Wheelbase (between truck centers) Length (over coupler faces) Width (over handrails) Height (pan locked down) (pan fully extended) Axle load 51,225 lb (23,235 kg) Adhesive weight 100% Loco weight 204,900 lb (92,941 kg) max Sandbox cap 10.6 cubic feet (300 L) Power supply Catenary Electric system(s) 11-13.5 kV 25 Hz AC 11-13.5 kV 60 Hz AC 25 kV 60 Hz AC Current collection Dual pantographs Traction motors ASEA LJH 108-5 (DC) Alstom 6 FXA 5856 (AC) Head end power 500 kilowatts (670 horsepower) (DC) 1,000 kilowatts (1,300 horsepower) (AC) Transmission 85:36 MU working yes Train heating Locomotive-supplied head-end power Loco brake Dynamic / Regenerative / Electropneumatic Train brakes Electropneumatic Safety systems ACSES II

Performance figures Maximum speed 135 mph (217 km/h) (design) 125 mph (201 km/h) (operational) Power output AEM-7DC and AC: 5,100 kilowatts (6,800 horsepower) maximum at rail 4,320 kilowatts (5,790 horsepower) continuous at rail Tractive effort Starting Tractive Effort: 53,924 lbf (239.9 kN) (DC) 51,700 lbf (230.0 kN) to 43 mph (69 km/h) (AC) Continuous Tractive Effort: 30,000 lbf (133.4 kN) @ 77 mph (124 km/h) (DC) 39,500 lbf (175.7 kN) @ 65 mph (105 km/h) (AC) Factor of adh ~ 3.85 Loco brakeforce 15,600 lbf (69.4 kN) (DC) 20,000 lbf (89.0 kN) (AC)

Career Numbers Amtrak: 900–953 MARC: 4900–4903 SEPTA: 2301–2307 Nicknames Toasters; Meatballs Locale Northeast Corridor, Keystone Corridor

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. EMD manufactured 65 locomotives between 1978–1988; the majority of these were for Amtrak, other operators included MARC and SEPTA. Amtrak has been phasing out its fleet in favor of the newer Siemens ACS-64, which entered service in 2014; MARC and SEPTA plan to replace theirs between 2017–2019.

Background

Green Cargo Rc4 no. 1290 in original livery

See also: PRR GG1

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. 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). Amtrak favored the Swedish design, which became the basis for the AEM-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.

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. These remanufactured AEM-7s are designated as "AEM-7AC"s. Between 1999 and 2002, 29 AEM-7s were converted to AEM-7ACs.

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.

ALP-44

New Jersey Transit No. 4416 at Hoboken Terminal in 2005

Main article: ABB ALP-44

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). 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." Between 1980 and 1982, 46 AEM-7s (900-946) 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. SEPTA ordered seven in 1987.

In 2010 Amtrak ordered 70 Siemens ACS-64 locomotives to replace both the AEM-7s and the newer but unreliable Bombardier/Alstom HHP-8s. The ACS-64s began entering revenue service in February 2014. The final use of the AEM-7 on Amtrak will be on a special excursion train on June 18, 2016, which will run between Washington, DC and Philadelphia. The planned train consist includes two AEM-7 locomotives, seven Amfleet-I coaches and two Amfleet-I food service cars.

MARC ordered the Siemens Charger locomotive to replace their fleet of AEM-7s and HHP-8s. Replacement is expected between 2017 and 2018.

SEPTA will replace their AEM-7s and single ALP-44 with the ACS-64 between 2018 and 2019.

External links

• 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