Background knowledge The defence considerations remained decisive until the 1950s, When the missile age made it appear obsolete. The Channel Tunnel Study Group was formed and it published in 1960 a proposal for a rail tunnel from Folkstone to Calais n 1964 the two governments agreed to proceed with a rail tunneL. After frequent extensions of the estimated completion date, with costs constantly rising, the British government cancelled the project early in 1975, leaving two and a half kilometers of preliminary digging on both sides of the channel. In 1978 the matter of a channel crossing was again raisedBackground knowledge ▪ The defence considerations remained decisive until the 1950s, when the missile age made it appear obsolete. The Channel Tunnel Study Group was formed and it published in 1960 a proposal for a rail tunnel from Folkstone to Calais. In 1964 the two governments agreed to proceed with a rail tunnel. After frequent extensions of the estimated completion date, with costs constantly rising, the British government cancelled the project early in 1975, leaving two and a half kilometers of preliminary digging on both sides of the Channel. In 1978 the matter of a Channel crossing was again raised