One for each direction and the middle tunnel is an emergency escape route.
The Channel Tunnel (or Chunnel) is the undersea railway tunnel under the Dover Strait. It connects Folkstone, Kent in the United Kingdom with Coquelles, Pas-de-Calais in the north of France. A link...
The Channel Tunnel connects England and France, and it is located underneath the English Channel.
Three; two 7.6 metre running tunnels and a service tunnel between them.
an English term for the tunnel is 'the chunnel' (a new word coined from 'channel' and 'tunnel')