Fanciful scheme for the Tube?

Wikipedia Word definitions in Wikipedia
Pipe Dream is a 2002 romantic comedy film, starring Mary-Louise Parker and Martin Donovan . The film was directed by John C. Walsh , who previously wrote and directed the film Ed's Next Move .

Douglas Harper's Etymology Dictionary Word definitions in Douglas Harper's Etymology Dictionary
1870; the sort of improbable fantasy one has while smoking opium; from pipe (n.1) + dream (n.). Old English pipdream meant "piping."

WordNet Word definitions in WordNet
n. a fantastic but vain hope (from fantasies induced by the opium pipe); "I have this pipe dream about being emperor of the universe" [syn: dream ]

Wiktionary Word definitions in Wiktionary
n. (context idiomatic English) A plan, desire, or idea that will not likely work; a near impossibility.