Acela Express (first-generation)
Amtrak Acela Express train, led by power car #2009, at Old Saybrook, Connecticut
Business Class car interior
ManufacturerBombardier, Alstom
Entered service2000
Number built20 sets
Number in service20 sets
SuccessorAvelia Liberty
Formation8 cars (two power cars, six coaches)
Fleet numbers2000–2039 (power cars)
Capacity304 (44 in First Class, 260 in Business Class)
Line(s) servedNortheast Corridor
Car body constructionStainless steel
Train length663 ft 8+34 in (202.30 m)
Car length
  • 69 ft 7+38 in (21.22 m) (power car)
  • 87 ft 5 in (26.64 m) (coach)
  • 10 ft 5 in (3.18 m) (power car)
  • 10 ft 4+12 in (3.16 m) (coach)
  • 14 ft 2 in (4.32 m) (power car, rail to roof)
  • 13 ft 10+58 in (4.23 m) (coach)
Floor height4 ft 3 in (1.30 m)
DoorsSingle leaf sliding plug doors:
  • 4 per side (intermediate coaches)
  • 2 per side (end coaches)
Wheel diameter
  • 40 in (1,016 mm) (power car)
  • 36 in (914 mm) (coach)
  • 35 ft 3 in (10.74 m) (power car)
  • 59 ft 6 in (18.14 m) (coach)
Maximum speed
  • 165 mph (266 km/h) (design)
  • 150 mph (240 km/h) (service)
  • 1,246,000 lb (565,000 kg) (trainset)
  • 204,000 lb (93,000 kg) (power car)
  • 142,000 lb (64,000 kg) (end coach)
  • 139,000 lb (63,000 kg) (intermediate coach)
  • 137,000 lb (62,000 kg) (bistro coach)
Axle load
  • 51,000 lb (23,000 kg) (power car)
  • 35,750 lb (16,220 kg) (coach)
Traction systemAlstom GTO-VVVF inverter control
Traction motorsAlstom 4-FXA-4559C 3-phase AC asynchronous motor
Power output4,600 kW (6,200 hp) (per power car), 1,150 kW (1,540 hp) (per motor)
Tractive effort49,500 lbf (220.2 kN) (per power car, starting)
Power supply2850 V DC (PWM rectified) voltage regulated from mains re-inverted to three-phase, frequency and voltage controlled AC waveform
Electric system(s)Single-phase AC from overhead catenary: 25 kV at 60 Hz, 12.5 kV at 60 Hz, 12 kV at 25 Hz
Current collection methodPantograph, 2 per power car
UIC classificationBo'Bo'-2'2'-2'2'-2'2'-2'2'-2'2'-2'2'-Bo'Bo'
Braking system(s)
Safety system(s)Advanced Civil Speed Enforcement System (ACSES)
Track gauge4 ft 8+12 in (1,435 mm) standard gauge

The first-generation Acela Express trainset is a unique set of vehicles used on the Acela, Amtrak's flagship high-speed service along the Northeast Corridor (NEC) in the Northeastern United States. When they debuted in 2000, the sets were the fastest in the Americas; reaching 150 mph (240 km/h) on 33.9 mi (54.6 km) of the route. They were built between 1998 and 2001 by a consortium of Alstom and Bombardier. Each set has two power cars derived from units that Alstom built for the TGV, and six passenger cars derived from the LRC that Bombardier built for Via Rail.

While the Acela sets were based on TGV equipment, the power cars and passenger cars are much heavier in order to meet the Federal Railroad Administration's crash standards. The extra weight leads to the Acela's power-to-weight ratio being about 22.4 hp per tonne, compared to 30.8 hp for a SNCF TGV Réseau trainset. Unlike the TGV, the Acela sets employ active tilting technology, which helps control lateral centrifugal force, allowing the train to travel at higher speeds on the sharply curved NEC without disturbing passengers.

Bombardier later used the Acela carriage design and a diesel/gas turbine variant of the power car for its experimental JetTrain.

The present Acela Express equipment will be replaced by new Avelia Liberty sets, beginning in 2021. The new trains will have greater passenger capacity and an enhanced active tilt system that will allow faster speed on the many curved sections of the route. Amtrak plans to retire all current Acela trains by the end of 2022.


Building and development

Acela Express trainset undergoing testing at Transportation Technology Center in 2000
Acela Express trainset undergoing testing at Transportation Technology Center in 2000

In the early 1990s, Amtrak tested several different high-speed trains from Europe to explore the possibility of adding a high-speed rail service along the Northeast Corridor. An X 2000 train was leased from Sweden for test runs from October 1992 to January 1993, followed by revenue service between Washington DC and New York City from February to May and August to September 1993. Siemens showed the ICE 1 train from Germany, organizing the ICE Train North America Tour which started to operate on the Northeast Corridor on July 3, 1993.[3]

This testing allowed Amtrak to define a set of specifications that went into a public tender in October 1994.[4] Requirements for the trainset included the ability to reach 150 miles per hour (240 km/h) and withstand a collision with a freight train at speed without collapsing.

Most manufacturers which bid on the Acela were unable to meet the structural requirements, due to increased costs and complications for the manufacture of the trains, and the need for manufacturers to make significant engineering changes to their standard designs. In the end, only three qualified bidders remained: ABB (manufacturer of the X 2000 train), Siemens (manufacturer of the ICE), and a consortium of Bombardier (manufacturer of the LRC trains) and GEC Alsthom (manufacturer of the French TGV).[5]

The consortium of Bombardier (75%) and GEC Alsthom (now Alstom) (25%) was selected in March 1996.[4][6][7]

A pilot trainset was completed by early 2000, and sent to Transportation Technology Center for testing in June 2000. An inaugural VIP run of the Acela occurred on November 16, 2000,[8] with the VIP train being led by power car number 2020 with no. 2009 at the opposite end, followed by the first revenue run on December 11, 2000, a few months after the intended date.[9][10]

Amtrak's original contract was for the delivery of 20 sets (6 coaches each, with power cars at front and rear) for $800 million.[11] By 2004, Amtrak had settled contract disputes with the consortium, paying a total of $1.2 billion for the 20 sets, plus 15 extra electric locomotives, and the construction of maintenance facilities in Boston, New York, and Washington.[12]


In August 2002, shortly after their introduction, Acela sets were briefly removed from service when the brackets that connected truck (bogie) dampers (shocks) to the powerunit carbodies ("yaw dampers") were found to be cracking.[13][14] The Acela returned to service when a program of frequent inspections was instituted. The damper brackets have since been redesigned and old brackets replaced by the newer design.

On April 15, 2005, the Acela was removed from service when cracks were found in the disc brakes of many passenger coaches.[15] The Bombardier-Alstom consortium replaced the discs under warranty. Limited service resumed in July 2005, as a portion of the fleet operated with new brake discs.[16] Metroliner trains, which the Acela Express was intended to replace, filled in during the outage. Amtrak announced on September 21, 2005, that all 20 trainsets had been returned to full operation.

In October 2012, Acela service was cancelled immediately before, during, and after Hurricane Sandy,[17] which damaged the North River Tunnels causing lasting delays and reliability problems.


The Acela trainsets underwent minor refurbishments between mid-2009 and 2010 at Penn Coach Yard, next to 30th Street Station in Philadelphia, Pennsylvania. These refurbishments included new blue leather seats throughout the trainset.[18]

By 2011, the Acela fleet had reached half of its designed service life. Amtrak proposed several replacement options, including one as part of its A Vision for High-Speed Rail in the Northeast Corridor.[19] In 2011, Amtrak announced that forty new Acela coaches would be ordered in 2012 to increase capacity on existing trainsets. The existing trains would have received two more coaches, lengthening the trainsets from a 1-6-1 configuration to 1-8-1 (power car — passenger cars — power car). The longer trainsets would have required the modifications of the Acela maintenance facilities in Boston, New York and Washington. The first of the stretched trainsets was to have entered service in fiscal year 2014.[20] This plan was cancelled in 2012 in favor of replacing, rather than refurbishing, the Acela fleet.[21]

In May 2018, Amtrak announced a 14-month program to refresh the interiors of the Acela sets, including new seat cushions and covers, new aisle carpeting, and a deep clean. This refurbishment program has been completed as of June 2019.[22]


In January 2014, Amtrak issued a request for proposals on 28 or more new model Acela sets, in a combined order with the California High-Speed Rail Authority. These bids were due May 17, 2014.[23] After discussions with manufacturers, Amtrak and the California High Speed Rail Authority concluded their needs were too disparate for common rolling stock and decided not to pursue the joint option.[24] The present Acela Express equipment will be replaced by new Avelia Liberty sets, beginning in 2021. The new trains will have greater passenger capacity and an enhanced active tilt system that will allow faster speed on the many curved sections of the route. Amtrak plans to retire all current Acela trains by the end of 2022.[25]


Overhead view of an Acela power car in Boston; an MBTA Orange Line subway train is also visible in the background.
Overhead view of an Acela power car in Boston; an MBTA Orange Line subway train is also visible in the background.


The sets use identical 6,200 horsepower (4,600 kW) power cars at each end which operate on a voltage of 11,000 volts AC, and either 25 or 60 Hz frequency, derives several components from the TGV,[26] such as the third-generation TGV's traction system (including the four asynchronous AC motors per power car, rectifiers, inverters, and regenerative braking), the trucks/bogies structure (a long wheelbase dual transom H frame welded steel with outboard mounted tapered roller bearings), the brake discs (although there are only three per axle, versus four on the TGV), and crash energy management techniques to control structural deformation in the event of an accident.[2][26]

The tilting carriages are based upon Bombardier's earlier LRC trains used on Via Rail rather than the TGV's non-tilting articulated trailers. Acela power cars and passenger cars are much heavier than those of the TGV in order to meet the FRA's crash standards.[27] French and Canadian crews testing the Acela referred to it as "the pig" due to its weight.[28][29] The extra weight leads to the Acela's power-to-weight ratio being about 22.4 hp per tonne, compared to 30.8 hp for a SNCF TGV Reseau set.[26] The Tier II crash standards, adopted in 1999, have also resulted in the passenger cars being designed without steps and trapdoors, which means that the sets can only serve lines with high-level platforms such as the Northeast Corridor. Acela trains are semi-permanently coupled (but not articulated as in the TGV) and are referred to as sets.

Operating speeds

With a 71:23 gear ratio, the Acela is designed with a top speed of 165 mph (266 km/h) and reaches a maximum speed of 150 mph (240 km/h) in regular service on three sections of track totaling 33.9 miles (55 km) in Rhode Island and Massachusetts.[30] The Acela achieves an average speed (including stops) of 82.2 mph (132.3 km/h) between Washington and New York,[31][32] and an average speed of 66 mph (106 km/h) from New York to Boston.[33][34] The average speed over the entire route is a slightly faster 70.3 mph (113 km/h).[33][35]

In practice, the Acela's speed depends more on local restrictions along its corridor than on its set. In addition to speed restrictions through urban areas, the Acela's corridor includes several speed restrictions below 60–80 mph (97–129 km/h) over older bridges, or through tunnels a century old or more. Altogether, Amtrak has identified 224 bridges along Acela's route that are beyond their design life.[36]

To prepare for the Acela launch, Amtrak upgraded the track along the Connecticut shoreline east of New Haven to allow maximum speeds in excess of 110 mph (177 km/h).[37] West of New York City, the Acela's top speed is 135 mph (217 km/h).[30] One limiting factor is the overhead catenary support system which was constructed before 1935 and lacks the constant-tension features of the new catenary east of New Haven.[19] The Pennsylvania Railroad ran Metroliner test trains in the late 1960s as fast as 164 mph (264 km/h) and briefly intended to run the Metroliner service at speeds reaching 150 mph (241 km/h). Certification testing for commercial operation at 160 mph (257 km/h) involving test runs at up to 165 mph (266 km/h) began between Trenton and New Brunswick in September 2012.[38]

Acela Express's fastest schedule between New York and Washington, DC was 2 hours and 45 minutes in 2012. $450 million was allotted by President Barack Obama's administration to replace catenary and upgrade signals[39] between Trenton and New Brunswick, which will allow speeds of 160 mph (257 km/h) over a 23 mi (37 km) stretch. The improvements were scheduled to be completed in 2016, but have been delayed; the project is now scheduled to be finished in 2020.[40] This section of track holds the record for the highest speed by a train in the US, which is 170.8 mph (274.9 km/h), achieved in a test run by the U.S./Canada-built UAC TurboTrain on December 20, 1967.[19][41]


The production sets are formed as follows:[2]

Car no. 1 2 3 4 5 6 7 8 Total
Designation Power Business Class Business Class Cafe Business Class Business Class
(quiet car)
First Class Power
Weight (US ton) 102.0 71.0 69.5 68.5 69.5 69.5 71.0 102.0 623.0
Weight (Long ton,
Metric ton)
91.1 long tons; 92.5 t 63.4 long tons; 64.4 t 62.1 long tons; 63.0 t 61.2 long tons; 62.1 t 62.1 long tons; 63.0 t 62.1 long tons; 63.0 t 63.4 long tons; 64.4 t 91.1 long tons; 92.5 t 556.2 long tons; 565.2 t
Capacity 0 65 65 0 65 65 44 0 304

The Acela Express trainset consists of two power cars, a café car, a First Class car, and four Business Class cars, semi-permanently coupled together. Acela offers two classes of seating, Business Class and First Class. Unlike most other Amtrak trains, Business Class is the de facto standard class on Acela trains; there is no coach service.[42]

The First Class car has 44 seats, being three seats across (one on one side, two on the other side), four seat tables and assigned seating. There are 260 Business Class seats on each set; these cars have four seats across (two on each side) and four-seat tables.[43] Baggage may be stowed in overhead compartments or underneath seats. Trains are wheelchair-accessible. Each car has or two toilets, with one being ADA compliant. Automatic sliding doors between cars reduce noise.

Acela maintenance is generally taken care of at the Ivy City facility in Washington, DC; Sunnyside Yard in Queens, New York; or Southampton Street Yard in Boston.


  1. ^ "High-Speed Trainsets" (PDF). Bombardier Transportation.
  2. ^ a b c "Acela Express". February 2001. Retrieved June 18, 2012.
  3. ^ "ICE Train North America Tour". Eisenbahntechnische Rundschau (in German). 42 (11): 756. 1993.
  4. ^ a b Dao, James; Wald, Matthew L.; Phillips, Don; Dao (April 24, 2005). "Acela, Built to Be Rail's Savior, Bedevils Amtrak at Every Turn". The New York Times. Retrieved March 4, 2008.
  5. ^ Black, Clifford R. (March 2005). "The Acela Express" (PDF) (40). Japan Railway & Transport Review. Archived from the original (PDF) on June 13, 2011. Retrieved August 29, 2009. Cite journal requires |journal= (help)
  6. ^ For high speed, a big step. For Amtrak, a giant leap Railway Age April 1996 page 14
  7. ^ Equipment Railway Age September 1998 page 8
  8. ^ "U.S. Transportation Secretary Slater celebrates inaugural run of Acela Express high-speed rail service". M2 Presswire. November 17, 2000. Archived from the original on October 26, 2012. Retrieved August 29, 2009.
  9. ^ "Amtrak postpones debut of high-speed rail line". Business Courier Serving Cincinnati – Northern Kentucky. March 3, 2000. Retrieved August 29, 2009.
  10. ^ A coming-out party for Acela Express Trains February 2001 pages 24-27
  11. ^ "Amtrak Sues Train's Manufacturer Over Design Flaws". Los Angeles Times. November 22, 2002. Retrieved December 23, 2017.
  12. ^ "Two equipment makers settle dispute with Amtrak". Brotherhood of Locomotive Engineers & Trainmen. March 18, 2004. Retrieved December 23, 2017.
  13. ^ "Discovery of hairline cracks causes more problems for Amtrak's Acela Express". USA Today. August 20, 2002. Retrieved August 29, 2009.
  14. ^ Daniel, Mac (August 14, 2002). "Flaws Shut Down Amtrak's Acela Express Line". Boston Globe. Retrieved August 29, 2009.
  15. ^ Hauser, Kristine (April 15, 2005). "Amtrak Suspends Acela Trains After Finding Brake Problems". The New York Times. Retrieved April 15, 2005.
  16. ^ Reed, Keith (June 10, 2005). "Acela's return expected in July". The Boston Globe. Retrieved August 29, 2009.
  17. ^ "Sandy: Amtrak impacts - Storms of 2012".
  18. ^ Grynbaum, Michael (January 13, 2010). "Amtrak Introduces Blue, if Not Corinthian, Leather". The New York Times.
  19. ^ a b c "The Amtrak Vision for the North East Corridor 2012 Update Report" (PDF). Amtrak. July 2012. Archived from the original (PDF) on December 1, 2017. Retrieved November 20, 2017.
  20. ^ "Amtrak To Add 40 Coach Cars To Acela Express Under FY 2012 Budget Plan" (PDF). Amtrak. February 14, 2011. Retrieved April 7, 2013.
  21. ^ O'Toole, James (December 13, 2012). "Amtrak to replace high-speed Acela trains".
  22. ^ "Amtrak Refreshes Interiors of Acela Express Trains" (Press release). Amtrak. May 14, 2018. Retrieved April 26, 2019.
  23. ^ "Amtrak and California Request Bids for High-Speed Trainsets" (PDF). Amtrak. January 24, 2014. Archived from the original (PDF) on December 1, 2017. Retrieved November 20, 2017.
  24. ^ "Amtrak and California drop joint high-speed train tender". Global Rail News. June 24, 2014. Retrieved November 20, 2017.
  25. ^ "Next-Generation High Speed Trains". Amtrak. Retrieved November 11, 2017.
  26. ^ a b c Perren, Brian (April 1998). TGV Handbook, Including Eurostar (2nd ed.). Harrow Weald: Capital Transport Publishing. p. 156. ISBN 9781854141958. OCLC 47037025.
  27. ^ McCaughrin, Eric (March 5, 2007). "How the FRA is Regulating Passenger Rail Out of Existence". East Bay Bicycle Coalition.
  28. ^ Philips, Don (January 2010). "Now it seems to be official: Freight rail is the future". Trains. Vol. 70 no. 1. p. 10. When the train was being tested at the technology center in Pueblo, Colo., I had lunch one day out on the ballast with the French and Canadian crews doing the testing. The conversation turned to the weight of the Acela, which the crews considered laughably too heavy. At one point, a French engineer confided that the crews called the train "le cochon", meaning "the pig". The man and his supervisor immediately realized he had said too much. They asked me to keep that a secret, and I did for many years until I was sure everyone on the program had moved on to other jobs.
  29. ^ Dao, James; Wald, Matthew L.; Phillips, Don; Dao (April 24, 2005). "Acela, Built to Be Rail's Savior, Bedevils Amtrak at Every Turn". The New York Times. Retrieved March 4, 2008. Before the first train was built, the Federal Railroad Administration required it to meet crash safety standards that senior Amtrak officials considered too strict. That forced the manufacturers, Bombardier Inc. of Canada and GEC Alstom of France, to make the trains twice as heavy as European models. Workers dubbed the trains le cochon – the pig.
  30. ^ a b "Northeast Corridor Employee Timetable #5" (PDF). National Railroad Passenger Corporation (Amtrak). October 6, 2014. p. 110. Archived from the original (PDF) on November 12, 2020. Retrieved December 24, 2017 – via National Transportation Safety Board.
  31. ^ "Northeast Corridor New York–Washington Timetable" (PDF). Amtrak. March 4, 2019. Archived from the original (PDF) on April 26, 2019. Retrieved April 26, 2019.
  32. ^ The timetable gives 2 hours and 45 minutes, minimum, between Washington and New York. Dividing that into the distance traveled, 226 mi (364 km), gives an average speed of 82.2 mph (132.3 km/h).
  33. ^ a b "Northeast Corridor Boston–Washington Timetable" (PDF). Amtrak. March 4, 2019. Retrieved April 26, 2019.
  34. ^ The timetable gives 3 hours and 30 minutes, minimum, between New York and Boston. Dividing that into 231 mi (372 km) gives an average speed of 66 mph (106 km/h).
  35. ^ The timetable gives 6 hours and 30 minutes, minimum, between Washington and Boston. Dividing that into 457 mi (735 km) gives an average speed of 70.3 mph (113.1 km/h).
  36. ^ "The Acela Story Part 2: Planning for the Not-So-Distant Future — Northeast Alliance for Rail". Northeast Alliance for Rail. July 27, 2011.
  37. ^ "The Northeast Corridor Infrastructure Master Plan" (PDF). Amtrak. March 24, 2010. Archived from the original (PDF) on December 1, 2017. Retrieved November 20, 2017.
  38. ^ "High-Speed Testing in New Jersey" (PDF). Amtrak Ink. Amtrak. August–September 2012. p. 4. Archived from the original (PDF) on May 10, 2015. Retrieved August 1, 2012.
  39. ^ Nusca, Andrew (May 20, 2011). "Amtrak lands $450 million to boost Acela to 160 mph". ZDNet. Retrieved December 23, 2017.
  40. ^ Higgs, Larry (September 14, 2017). "160 mph trains will speed from Trenton to New Brunswick by 2020". New Jersey On-Line. Retrieved December 27, 2017.
  41. ^ "High Speed Rail Transportation in North America". June 14, 2007. Retrieved December 23, 2017.
  42. ^ "Acela Train, Accommodations". Amtrak. Retrieved September 1, 2021.
  43. ^ "Acela Express, United States of America". Railway Technology. Retrieved September 3, 2014.