Infrastructure

APS: Service-proven catenary-free tramway operations

APS

APS at a glance

  • Removes overhead line equipment from cities
  • High reliability, availability and safety
  • A simple service-proven concept
  • Built to endure temperatures as high as 55°C

APS™ (Aesthetic Power Supply) is a highly reliable power system that reduces the footprint of light rail lines and preserves the aesthetics of urban environments.

Preserving urban heritage with Alstom’s APS system

As cities worldwide seek to modernize public transport while preserving their architectural heritage, catenary-free tramway systems are emerging as a transformative solution. Alstom’s APS (Aesthetic Power Supply), a cutting-edge ground-level power supply system, offers a reliable and aesthetically sensitive alternative to traditional overhead wires.

Currently deployed in twelve cities across three continents, the APS system delivers safe, uninterrupted power to trams, whether over short catenary-free segments or along entire lines.

1/5 Citadis Tram in commercial service in Tours, France. Credit: Alstom / E. Lamperti

Effective and safe

Inspired by ‘third rail’ feeding systems present in metros, APS uses 11-metre segments set into the track bed between the guiding rails to supply ground-level power to vehicles. These segments automatically switch on and off according to whether a tram is passing over them, thereby eradicating any risk to other road users. This safety principle was certified by several competent bodies all over the world.

Tramway line equipped with SRS, in Nice, France. Credit: Alstom SA / TOMA - David Richard

Flexible and climate-resilient power supply

APS-powered trams can seamlessly switch between ground-level power, overhead lines, and onboard back-up batteries, ensuring uninterrupted service across varied routes. The system is easily extendable, making it ideal for expanding networks. APS is available in two versions: a standard model for temperate climates and a tropicalized version engineered for extreme conditions, capable of withstanding ambient temperatures up to 55°C. This adaptability makes APS a robust solution for cities seeking scalable, climate-resilient electric transport infrastructure.

  • > 85
    million kilometres travelled by trams on APS
  • 155
    km of single track fitted to date
  • 391
    Citadis trams equipped with APS technology

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