The Collaborative International Dictionary
Tube railway
Tube railway \Tube rail"way\, n. an electrically powered railroad with tracks running through a tunnel underground; a subway.
Wikipedia
Tube railway
The term tube railway may refer to:
- an atmospheric railway, a railway that uses differential air pressure to provide power for propulsion of a vehicle
- an underground railway constructed in a circular tunnel by the use of a tunnelling shield
- by extension of the previous definition, the London Underground, most (but not all) of whose lines are so constructed
Usage examples of "tube railway".
And all these within the central area are connected by either the Post Office tube railway or the London Transport Underground system.