Many of these mining engineers have already worked on projects like the Channel Tunnel and the Jubilee line extension so they're not easily impressed.

BBC: Crossrail: Passion deep below west London

And investments, including the Underground's current star project, the Jubilee Line extension, have sometimes been guided more by political considerations than by careful cost-benefit analysis.

ECONOMIST: The end of the tunnel

This setback came a week after the announcement of further delays on one of Britain's largest construction projects, the extension of London Underground's Jubilee Line from Westminster to Stratford in east London.

ECONOMIST: Are British builders uniquely awful?