KFS SIL2 Currently being tested on the Rhonexpress, Lyon’s new tramway


Lyon’s new “Rhonexpress” tramway, is equipped with the KFS SIL2 system, an Automatic Train Stop Mechanism (ATS), currently being tested by night, holding off passengers in its SIL2 version.

Lyon’s “Rhonexpress” tramway has the characteristic of having a single track on which trains will be able to reach the speed of 100km/hr in order to get from the station in Lyon to Saint Exupéry airport in under 30 minutes. It is this special feature which motivated the implementation of an automatic train stop system in the event that signals are passed through wrongly.

In this way, KFS SIL2 (SIL2 certified by Certifer under reference ECI_1462_0005 – 26/07/2010 and developed by ClearSy), will soon be in use on the tramways of the Rhone Express network. For the time being, this system is currently undergoing testing and the initial trials have been conclusive.

Operating principles of the KFS SIL2 (ATS)

The KFS system operates from three elements:

  • an onboard KFS sensor
  • a KFSI beacon installed on the ground on the track
  • an onboard KFS processing block or framework

The principle behind it is simple: the onboard KFS sensor detects an electro-magnetic (or magnetic) field, emitted by a KFSI beacon, installed on the ballast between the running rails via the intermediary of an external chassis, and relayed to the manoeuvre protection signal. The KFS sensor sends the information picked up at the KFS processing block, which is responsible for decoding it and passing on the information for the emergency braking or the driver’s alarm, which in turn triggers the halting of the tramway.

Find out more about KFS SIL2