The Bombardier-Alstom HHP-8 locomotive is a 8,000 horsepower electric locomotive, constructed by Bombardier and Alstom in 2000, and were utilized by Amtrak and MARC.
In the early 1990s, Amtrak was in the midst of experimenting with various types of high speed train-sets for its densely trafficked Northeast Corridor. After much negotiation, Bombardier-Alstom won the American Flyer contract, which consisted of an order of twenty high speed trainsets (Acela) and fifteen high speed, high horsepower electric locomotives (HHP-8). Maryland Area Regional Commuter (MARC) followed suit, and placed an order for six HHP-8’s for its Penn Line between Washington D.C. and Perryville, Maryland.
Delivered in 2001, the HHP-8 (High Horsepower 8000), was delivered in tandem with the high speed Acela Express train sets after an agreement with Bombardier-Alstom for fifteen high speed locomotives to supplement the current AEM-7 fleet, and replace the aging GE E60 locomotives. Bombardier and Alstom also agreed in the contract to rebuild 29 of Amtrak’s AEM-7s from direct current (DC), to alternating current (AC) traction.
Upon delivery, the HHP-8 locomotives were fraught with computer and wheelslip issues, which unfortunately, would plague the locomotives their entire operating life. The locomotive’s computers malfunctioned in extreme weather and were oftentimes set awry do to various voltage issues pertaining to surges in the overhead wires. Furthermore, the locomotives required constant software upgrades throughout their operating life.

Soon after delivery, the locomotives were removed from service due to cracks in the truck frame, however, the issue was quickly repaired and the locomotives reentered service. Furthermore, lack of support by the locomotive’s manufacturers further hindered the fleet. Additionally, the locomotives had a outdated computer system developed by manufacturers that had merged into larger entities such as Wabtec. As a result of these issues, the locomotives experienced unscheduled maintenance an average every 12 days, which cost the railroad an exponential amount of capital and resources.
Wheelslip was another prevalent issue that plagued the fleet, as the units often encountered this issue when operating in less than ideal conditions. The wheel slip system was on a per truck basis instead of per axle, as if wheelslip was detected, the entire truck would shut down instead of just one axle, making it increasingly difficult to set into motion from a complete stop with wet leaves, rain, or various other types of debris on the rail head.
Perhaps one of the most prevalent issues plaguing the HHP-8 was the size of the fleet. Amtrak only acquired fifteen examples of the type, making spare parts sparse. Furthermore, Bombardier failed to give Amtrak ample maintenance support, equating to expensive parts and labor. Interestingly, although the locomotive is strikingly similar to the Acela power cars, few parts are interchangeable.

The locomotives were delivered in a paint scheme similar to the “American Flyer”, later known as the Acela Express, and operated regional and long distance trains on the corridor. From 2001-2003, the locomotives had a Acela logo applied to the sides of its cab, as it oftentimes hauled the Acela Regional, however, when the service was renamed Northeast Regional, the logos were removed.
In 2010, an order of 70 ACS-64 locomotives were ordered from Siemens to replace the AEM-7 and HHP-8 locomotives. These locomotives were based on the highly successful Vectron locomotive utilized throughout Europe, and was adapted for the North American market. With delivery beginning in early 2014, the HHP-8 locomotives were soon retired by December 2014, and lay in storage at Amtrak’s shops in Bear, Delaware, after only a decade of service.
The MARC examples continue to operate on the Penn Line, despite rumors that the commuter railroad was eliminating electric motive power, due to a dispute with Amtrak over catenary usage. The MARC HHP-8’s have recently entered an extensive rebuild program, which was deemed successful, as various updates have been performed to prolong their operating life.
Technical
Built in a coalition between Bombardier and Alstom, the HHP-8 locomotives produced 8,000 horsepower, have a maximum speed of 135 mph, and has 71,240 lbf of tractive effort. The locomotive is powered by a voltage of 60 Hz AC from overhead catenary, and has dual pantographs. The locomotive’s carbody, constructed from stainless steel, includes extensive crash-worthiness implications set forth by the FRA, including the 6 MJ crash energy absorbance structure.

Originally, the locomotives were known as HHL-8 (high horsepower locomotive 8,000), but were later changed to HHP-8. Although the locomotive has the capability of reaching 135 mph, the locomotives are limited by the FRA’s Tier 1 standard of 125 mph. The locomotives utilize an electric traction system derived from the Alstom BB 36,000 Astride locomotives, operated by French rail operator, SNCF. The locomotives are also equipped with regenerative and dynamic braking capabilities.
Upon arrival on Amtrak property, the locomotives were numbered 650-664, however, when the ACS-64’s were delivered and the HHP-8s entered storage, they were renumbered 680-694, as to prevent conflicting numbers. The MARC units were numbered 4610-4615, and retained those numbers throughout their service life.
Builder | Alstom-Bombardier |
Number Produced | Amtrak:15 MARC: 6 |
Horsepower | 8,000 (downrated to 7,100) |
Tractive Effort | Starting:71,240 lbf Continuous: 56,200 lbf |
Wheel Configuration | B-B |
Wheel Diameter | 40 in |
Minimum Curve | 76 m |
Wheelbase | 9 ft 4 in |
Length | 67 ft 1 in |
Width | 10 ft 4 in |
Height | 14 ft 2 in |
Weight | 222,000 lbs |
Electric Voltage | 12 kV 25 Hz AC 12.5 kV 60 Hz Ac 25 kV 60 Hz AC |
Electrical Pickup | Dual Pantograph |
Traction Motors | 4 x 1.5 MW Alstom 4-FXA-4559C 2,000 hp |
Numbers | Amtrak: 650-664 (formerly) 680-694 (current) MARC: 4910-4915 |