The £15bn Crossrail project - linking Shenfield in
Essex to Maidenhead in Berkshire via London - is the largest engineering
project in Europe.
So far, two of the 26 miles of tunnel have been bored and BBC
London's transport correspondent Tom Edwards was the first to be allowed
to film deep under west London.
http://www.bbc.co.uk/news/uk-england-london-21196455