ACS-64

ACS-64. The ACS-64 is a class of high-performance electric locomotives built by Siemens Mobility for passenger service in the United States. Primarily operated by Amtrak on the busy Northeast Corridor, these units were designed to replace aging electric locomotives and improve reliability and energy efficiency. The designation stands for "Alternating Current, Siemens, 64" referencing its power type, manufacturer, and horsepower in hundreds.

Overview and development

The development of the ACS-64 was driven by Amtrak's need to modernize its electric locomotive fleet, which included aging models like the EMD AEM-7 and the HHP-8. Following a competitive bidding process, Siemens Mobility was awarded the contract in 2010, with the design based on its proven EuroSprinter and Vectron locomotive families. The project represented a significant investment in the future of Amtrak and the Northeast Corridor, aiming to enhance service reliability and capacity. The first locomotive was unveiled at the Siemens plant in Sacramento, California in 2013, marking a new era for American passenger rail.

Technical specifications

The ACS-64 is a Bo-Bo wheel arrangement locomotive capable of a maximum speed of 125 miles per hour, making it ideal for high-density corridors. It generates 6,400 horsepower from its AC traction motors, providing high acceleration rates crucial for maintaining schedules on routes with frequent stops. Key features include regenerative braking, which feeds energy back into the overhead line, and compliance with the latest Federal Railroad Administration crashworthiness standards. The design also incorporates Head-end power to supply electricity to passenger carriages, and its modular construction aids in maintenance and serviceability.

Service history and operations

The ACS-64 entered regular revenue service with Amtrak in February 2014, initially operating on the Northeast Corridor and the Keystone Corridor. They are the primary motive power for Acela Express (non-tilting) and Northeast Regional services, hauling trains between Washington, D.C. and Boston. SEPTA also purchased a smaller fleet for its Regional Rail commuter services in the Philadelphia area. The locomotives have significantly improved on-time performance and operational flexibility compared to their predecessors, becoming a backbone of electrified passenger service in the Northeastern United States.

Fleet details and numbering

A total of 70 ACS-64 locomotives were built by Siemens Mobility between 2012 and 2016. Amtrak owns the majority, numbered 600–663, with their distinctive "Amtrak Phase V" or "Amtrak Phase VI" livery. The Southeastern Pennsylvania Transportation Authority (SEPTA) fleet consists of 15 units, numbered 901–915, painted in that agency's silver and green scheme. The locomotives are maintained at major facilities including Amtrak's Ivy City shop in Washington, D.C. and SEPTA's Fern Rock yard.

Accidents and incidents

The ACS-64 fleet has been involved in a few notable incidents. In March 2016, Amtrak train 185, led by ACS-64 603, struck a backhoe near Chester, Pennsylvania, resulting in fatalities and injuries among railroad workers. In January 2018, Amtrak train 501, operating as part of the new Cascades service in Washington (state) but led by an ACS-64, derailed on an overpass near DuPont, Washington due to excessive speed on a curve. This incident, which involved positive train control system issues, led to multiple fatalities and prompted investigations by the National Transportation Safety Board.

Category:Electric locomotives of the United States Category:Amtrak locomotives Category:Siemens locomotives