ABSTRACT
When the design for the Channel Tunnel project started there was a general assumption that all three tunnels would be fully lit all the time; it was not long before people began to ask why. This led to initial studies of safety and ergonomic aspects, which indicated a strong operational preference, on safety grounds, for the rail tunnels to be virtually dark. Reliance on locomotive headlights avoids the issue of flicker from the tunnel lighting, and also helps drivers to recognise trackside signs. It should be remembered that railway signalling within the Eurotunnel operation is of the' cab signal' type, where all advisory information to the driver is displayed on a video terminal in the cab.
