Eurostar. What are the yellow doors for that close when you go through the channel tunnel.?

Question

Just before the train enters the channel tunnel an extra set of doors closes at each end of each carriage. Is it a safety feature?

Answer 1

Keep's a fire in one place, your place.

Everyone elses safety feature.

Feeling sacrificial?

Answer 2

Fire Doors, They are designed to be opened to allow passengers to get out in a fire, before being closed to contain a fire until the train is either out of the tunnel, or an evacuation can be performed