The Siemens Charger is a family of passenger locomotives built by Siemens Mobility for use in North America. The Charger family includes several variants developed for specific operators and service types including long-distance, inter-city and commuter rail, as well as different power sources including diesel, overhead wire, third rail, and batteries.
The diesel SC-44 model is used primarily for state-supported inter-city routes and commuter rail services. The SCB-40 variant was developed for Brightline in Florida, while the SCV-42 is used by Via Rail in Canada. Amtrak operates the ALC-42 for its long-distance routes and has ordered the ALC-42E, a dual-mode version capable of operating on externally-supplied electric power, for routes that travel over portions of the Northeast Corridor; Charger-family locomotives will eventually replace the aging GE Genesis fleet. A third rail dual-mode version, the SC-42DM, is also available, as well as a battery-electric model, the Charger B+AC.
The first production Charger locomotive, an SC-44, was unveiled on March 26, 2016, and began revenue service on August 24, 2017. Charger locomotives are often paired with Venture passenger cars, also manufactured by Siemens, as part of a trainset, such as Amtrak Airo.
Design Diesel models of the Charger are powered by a Cummins 16-cylinder QSK95 4-stroke high speed diesel engine, which meets United States Environmental Protection Agency's more stringent Tier 4 emissions standards that took effect in 2015. Power output varies by model: the SCB-40 produces , the SC-44 produces , and the ALC-42, SCV-42, SC-42DM (in diesel mode) produce . The maximum speed in service is .
The locomotive shares much of its overall design with the Siemens Vectron diesel and electric locomotives used in Europe and the Siemens ACS-64 electric locomotive built for Amtrak.
Four Insulated-gate bipolar transistor (IGBT) power inverters carry electric current to each of the four AC traction motors. A static inverter off of the main prime mover supplies head-end power (HEP). The locomotive also features dynamic braking with regenerative capability, allowing the locomotive to divert power generated by dynamic braking away from the resistor grids to HEP and onboard locomotive auxiliary power demands.
In response to a 2013 request for information from Metro-North Railroad, Siemens said they would be capable of producing a dual-mode variant capable of operating on third rail power with onboard energy storage for use by Metro-North and the Long Island Rail Road, as well as intercity service on Amtrak's Empire Corridor. This would become the SC-42DM.
California's SC-44s have aerodynamic "spoilers" on the rear of their roofs that match the height of bi-level California and Surfliner cars.
The diesel Charger series competes with other Tier 4 compliant diesel locomotives, such as the EMD F125 and the MPI MPXpress MP54AC. However, unlike the Charger series, both the F125 and MP54AC have struggled to find customers, selling fewer than 50 units each.
The B+AC Charger locomotives can operate on either overhead catenary wire or from a 3.1 mega-watt hour (MWh) on-board battery. The locomotive is capable of when running from overhead wires and on battery mode, and like other Chargers, has a top speed of . Claimed range on battery is , dependent on train configuration and route characteristics. The battery can be charged either en-route from overhead catenary wires, or from a 480V plug. Energy recovered from regenerative braking can also charge the battery.
Service history
The first production SC-44 unit was unveiled on March 26, 2016. The first two Charger locomotives to leave Siemens's factory in Florin, California, were transported to the Transportation Technology Center (TTC) in Pueblo, Colorado, in June 2016 and underwent testing of performance metrics such as acceleration and braking. The first Brightline SCB-40 locomotives were delivered in December 2016 to undergo testing in Florida.
In February 2017, Amtrak and the Washington State Department of Transportation began testing one of the Midwest-bound SC-44 locomotives along the Cascades corridor in the Pacific Northwest for federal certification. Additional test runs were conducted on the Midwest and Northern California routes in April and May. Testing at up to was conducted at TTC and on the Northeast Corridor in September 2016 which resulted in federal certification for operations.
Revenue testing on the Capitol Corridor and San Joaquins routes in Northern California began on May 25, 2017. During these tests, the trains operated with a second locomotive in case of failure. The Northern California units were formally accepted and approved for solo service on October 23, 2017. The SC-44 entered revenue testing on the Midwest routes in July 2017, with solo revenue service beginning on a Hiawatha train on August 24, 2017. Revenue service on the Cascades route began in November 2017.
Brightline began revenue operations with its SCB-40 locomotives on January 13, 2018. The first Chargers for MARC began testing that month, and revenue service began on April 5, 2018. Pre-revenue testing began on the Pacific Surfliner in October 2018; revenue service began later that year.
The first ALC-42 for Amtrak's long distance trains was put into service on the westbound Empire Builder on February 8, 2022, after extensive testing in the Midwest and on the Empire Builder route. Of the two units on the inaugural service, one was Amtrak's "Day 1" heritage unit No. 301.
Winter weather unique to the Americas has caused problems for the Charger series. An FRA spokesman said that "the light-dry snow of the midwest was not anticipated by Siemens." The air filters of the dynamic brake system allowed the snow to enter, causing ground faults that would stop the train. This issue was remedied in 2023.
Customers
+Siemens Charger customersOwnerModelALC-42ALC-42EEC-42SC-42SC-42DMSC-44SCB-40SCD-42ESCV-42Altamont Corridor Express—————6———6Amtrak12578———————233Brightline——————21——21California Department of Transportation—————24———24Coaster—————9———9Connecticut Department of Transportation————6————6Exo——10——————10Illinois Department of Transportation—————33———33Long Island Rail Road————44————44MARC—————8———8Metro-North Railroad————27————27Ontario Northland———3—————3Trinity Railway Express———————5—5Tri-Rail———7—————7Via Rail————————3232Washington State Department of Transportation—————9———11Total 125 77 10 10 77 89 21 5 32 467
Altamont Corridor Express
California regional commuter line Altamont Corridor Express ordered four SC-44 locomotives in April 2018, with deliveries beginning in December 2019. They entered revenue service in 2020.
Amtrak
National network On December 21, 2018, Amtrak ordered 75 ALC-42 locomotives with options for an additional 100. The first locomotive entered service in February 2022, with the last expected by 2024.
Compared with the SC-44, changes were made to the ALC-42 to make it more suitable for long-distance service: additional positive train control systems for nationwide service, a larger diesel fuel tank (instead of ), a larger diesel exhaust fluid tank, a larger sandbox, a more powerful 1,000-kilowatt head-end power generator (up from 600 kW), an extended nose section for easier repair in the event of minor front-end collision, and a prime mover de-rated to to lengthen maintenance intervals.
Assembly of the first ALC-42 began in March 2020. On August 5, 2020, Amtrak announced that one of the first six locomotives will be painted in a replica of the "Day 1" livery to commemorate 50 years of Amtrak service, while the other five will feature a preliminary "Phase VI" paint scheme. The remainder of the fleet will introduce a new "Phase VII" livery. By February 2021, 12 units had begun production, with the first locomotive, AMTK 300, delivered to Amtrak on June 17. The first ALC-42 locomotives entered revenue service on the Empire Builder on February 8, 2022. On the same day, Amtrak announced that they had ordered an additional 50 ALC-42s, bringing the total number of locomotives ordered to 125.
Amtrak Airo
Amtrak purchased 78 ALC-42E locomotives for 83 trainsets as part of its Amtrak Airo procurement, including 75 trainsets for Northeast Corridor and 8 trainsets for the Amtrak Cascades service.
Most Amtrak Airo trainsets are designed to operate on both electrified and non-electrified lines without the need to change locomotives. This is achieved through a hybrid configuration using a ALC-42E locomotive and either an Auxiliary Power Vehicle (APV) or a battery car. However, only three of the eight trainsets for the Amtrak Cascades service have been delivered with ALC-42E locomotives; while the five remaining trainsets will be operated using the existing fleet of SC-44 locomotives.
In diesel mode, the ALC-42E works like a typical diesel–electric locomotive, using its diesel engine to generate electricity for its motors. In electric mode, the ALC-42E uses either an APV or a battery car to send electricity to the locomotive, as it does not have its own pantographs to draw power from overhead lines.
The first locomotive with fleet number 7001 (initially numbered as 70001) for the Amtrak Cascades service entered into revenue service on September 30, 2026. As of August 2026, three ALC-42E locomotives with fleet numbers 7001, 7002 and 7004 have been delivered. The first dual-mode trainset, ALC-42E No. 7003 (along with APV No. 71301, and cab car No. 79001), was completed on May 28, 2026. The set has begun testing in Pueblo, CO in June 2026.
State-supported corridors
The Illinois Department of Transportation (IDOT), in conjunction with its counterparts in California, Michigan, Missouri and Washington, purchased 32 SC-44 locomotives for state-supported corridor services, operated by Amtrak under contract.
The $225 million order placed in March 2014 included options for an additional 75 corridor-configured locomotives In 2015, IDOT ordered 12 additional units for use on the upgraded Lincoln Service corridor. California ordered 16 additional units in November 2015 for use on the Pacific Surfliner beginning in 2018, plus two more units in 2016 for the Northern California services. Washington state ordered an additional unit to replace locomotive 1402, which was lost in the 2017 Washington train derailment and two more in connection with its purchase of new Siemens trainsets.
A total of 68 locomotives (32 base and 36 options) were ordered for Amtrak state corridors in this contract: 24 for California, 11 for Washington state, and 33 for the Midwest states. Another eight options were exercised by MARC, bringing total contract orders to 76.
Brightline
In September 2014, Brightline purchased ten SCB-40 locomotives with options for an additional eleven. The locomotives are used in pairs, bookending four passenger cars (expandable to seven) on Brightline's Miami–Orlando service. The SCB-40s have a streamlined front end that conceals the front coupler behind a removable nose cone and produce a maximum of instead of the on the SC-44. Brightline later ordered five additional trainsets and one extra locomotive (eleven locomotives total) for use on the extension to Orlando, with delivery between September 2021 and 2023. These locomotives have been able to reach speeds of up to 130 mph. As of February 19, 2023, all trainsets and the spare locomotive have been delivered to Brightline.
Coaster