Alstom APS
| Company type | Technology / System |
|---|---|
| Industry | Electric transportation |
| Predecessor | Innorail (division of Spie Enertrans) |
| Founded | 2003 |
| Founder | Innorail (division of Spie Enertrans) |
| Headquarters | France |
| Products | Ground-level power supply system for trams, buses, and electric vehicles |
| Parent | Alstom |
Alstom APS, an acronym for Alimentation par Sol ("ground-level power supply"), represents an innovative system that delivers electrical power to street trams and similar vehicles directly from the track surface. Originally developed by Innorail, a division of Spie Enertrans, the technology became part of Alstom's portfolio following Spie's acquisition by Amec. The inaugural deployment of APS occurred on the Bordeaux tramway, which commenced operations in 2003. Since 2011, this technology has been adopted in multiple cities worldwide.
Chosen mainly for its visual appeal, APS serves as a ground-level alternative to traditional overhead lines, competing with other power delivery methods such as ground-based systems and battery energy storage. In 2015, Alstom launched a variant called Alstom SRS (Système de Recharge statique par le sol), designed to allow battery-powered trams and buses to recharge while stationary.
Alstom has also customized APS for application in buses and various other vehicles, performing comprehensive safety evaluations under harsh conditions including snow removal, ice accumulation, road salting, brine exposure, and vehicle skid scenarios. A public demonstration of its electric road system (ERS) is scheduled on the RN205 highway in the Rhône-Alpes region from 2024 through 2027. This initiative aims to provide up to 500 kW of power suitable for electric heavy-duty trucks, utility vehicles, and passenger electric cars.
Technology
The APS system incorporates a third rail installed centrally between the running rails, segmented electrically into 11-meter sections that activate and deactivate automatically as a tram passes overhead. According to the manufacturer, this design eliminates hazards for other road users. Each tram is equipped with two power-collecting shoes fitted with antennas that emit radio signals to energize the corresponding rail segments beneath the vehicle. At any given moment, two adjacent segments underneath the tram are energized.
APS is distinct from the older conduit current collection technique, which supplied electricity via third and fourth rail conductors housed within an underground conduit between running rails. Historically utilized in cities such as Washington, Manhattan, Paris, Berlin, Vienna, Budapest, and London, conduit systems gradually declined due to their higher operational costs and complexity relative to overhead wiring.
Safety
In contrast to conventional trackside third rails commonly used by many metro systems and some mainline railways—which present electrocution risks—APS is designed to be safe for pedestrians and animals alike. This capability allows its deployment in pedestrian zones and urban streets without danger. According to French government records, there have been no reported incidents involving electrocution or electrical accidents on any French tramway from 2003 through December 31, 2022.
Bordeaux
During the late 19th and early 20th centuries, conduit current collection systems were implemented in several cities including Bordeaux but encountered significant maintenance difficulties and safety concerns. Bordeaux maintained its conduit system until 1958. Later developments in ground-level power supply technologies emerged, with solutions like the Ansaldo Stream serving as early examples; however, Alstom's APS became the first commercially operational system when introduced in 2003. This breakthrough encouraged wider adoption of ground-level power supply methods.
The construction of Bordeaux’s catenary-free tram network began in February 2000. A contract for tram procurement was finalized with Alstom in May of that year, followed by track installation starting in October. After extensive construction and testing phases throughout 2001–2003, line A officially opened on December 21, 2003. The inauguration was attended by President Jacques Chirac and Mayor Alain Juppé. Line A linked Lormont-Lauriers and La Morlette with Mériadeck.
Additional Cities
| System | City | Country | Inaugurated | Notes |
|---|---|---|---|---|
| Angers tramway | Angers | France | 2011 | Incorporated APS technology to modernize urban transit. |
| Reims tramway | Reims | France | 2011 | Adopted APS to eliminate the need for overhead cables. |
| Orléans tramway | Orléans | France | 2012 | Employs a catenary-free system using APS technology. |
| Tours tramway | Tours | France | 2013 | Utilizes Citadis trams fitted with APS equipment. |
| Dubai Tram | Dubai | United Arab Emirates | 2014 | Equipped entirely with APS along passenger routes; pantographs are restricted to depots. |
| VLT Carioca | Rio de Janeiro | Brazil | 2016 | Mainly relies on APS, complemented by Alstom’s supercapacitor energy storage where necessary. |
| CBD and South East Light Rail | Sydney | Australia | 2019 | Uses APS within Sydney’s central business district; conventional overhead wiring elsewhere. |
| Cuenca tram | Cuenca | Ecuador | 2020 | Combines selective APS use with overhead wiring. |
| Istanbul T5 tramway | Istanbul | Turkey | 2021 | Incorporates APS technology on the Golden Horn route. |
| Lusail Tram | Lusail | Qatar | 2022 | Features around 19 kilometers of APS on elevated sections. |
| Barcelona tram | Barcelona | Spain | 2024 | Deploys APS on segments of the Trambesòs line; overhead wires remain in other areas. |
Standardization
Since 2020, companies such as Alstom and Elonroad have been collaborating on developing a standard for electric roads utilizing ground-level power supply. The French Ministry of Ecology has identified rail-based ground-level power supply as the foremost technology for electric road systems. In late 2022, CENELEC Technical Standard 50717 was ratified, establishing the first standard for vehicle electrical equipment compatible with rail electric road infrastructure. Further standards are anticipated by the end of 2024, aiming to ensure "complete interoperability" and create a "unified and interoperable solution" for ground-level power supply systems, including detailed protocols for communication and conductive rail power delivery embedded within roadways.