Agree with Pieface - giving someone a rail network for a couple of years is hardly an open invitation for investment in the rolling stock.
Oh, and don't forget the Victorians built our current rail network. I'd like to see what the current shambles will make of it:-
building company: "we can do that for £25 and a bag of crisps by next week. (chat to you later about the job on the board"
government: "sold to the lowest bidder"
building company: "ah, now we've signed the contract we've noticed you actually want some work doing. We need 1000 billion. Oh, and twenty five years"
goverment: "here's the open cheque. After 30 years we'll write you out another one to stop your (non) work and declare everything a wonderful success in bringing Manchester only 7 hours train ride away from the centre of the world (London)."
public "erm, it only took 2 hours before you started work, and it now takes me 5 hours to drive into the centre of Manchester to get the high speed link to London"