Can the inconvenience have been worthwhile? It all started rather more than six years ago in 1962, but they really got weaving in 1963. How They Dug the Victoria Line, BBC 1969
Today, the Tube is bursting at its seams. ibid.
To slash right across the existing system and bring the underground to a new region in the north-east. By any standard it was a hell of an undertaking. ibid.