The alarm signal is a safety feature on all our trains. Any passenger or onboard staff member may pull the alarm in the event of danger—if, for example, there’s smoke inside the train, or a window breaks, or a passenger is ill. How does it all work?

On TGV high-speed trains, simply pull the alarm handle near the doors in your coach. The red handle is easy to spot and get to. Pulling the alarm sets off a light and sound signal in the driver’s cab and a ringing sound throughout the train.

The conductor determines which coach the alarm was pulled in and why.

• If it’s not a serious problem, the driver does not stop the train.
• If they determine there is a real danger or emergency, and if the onboard staff decides it is necessary, the train stops in a spot where the issue can be dealt with. 

When a train stops in response to an alarm signal, trains travelling behind it on the track also receive word to stop. This can back up traffic, especially on the most heavily travelled routes. Traffic is interrupted for at least 10 minutes in any case. How long the interruption lasts depends on why the alarm was pulled and whether or not SNCF employees or first responders need to intervene.

When it is safe for the train to resume its journey, those behind it resume theirs as well.

Pulling an alarm when there is no danger or apparent reason is considered vandalism. This kind of hoax is punishable by law:

• The law: “No person may activate an alarm or emergency brake provided for passengers to call company employees without a plausible motive.” (Article 74 of the Decree of 22 March 1942 providing public administration regulations for the policing, safety and operation of railways in the general and local interest)
• The penalty: “Any unlawful use of the alarm or braking system provided for passengers with the intent to prevent or hinder a train’s operation is punishable by six months in prison and a €3,750 fine.” (Article L 2242-4 of the Transport Code [2009])