A milestone in a £14.8 billion rail scheme was reached today with the breakthrough of a 1,000-tonne tunnel boring machine.
Named Elizabeth, the machine broke through 90ft down at the new Canary Wharf station in London which is being created as part of the Crossrail project.
With its sister machine, Victoria, Elizabeth is creating more than five of the 26 miles of tunnelling beneath central London that are being dug for Crossrail.
The 73-mile long route runs from Maidenhead in Berkshire in the west, through London to Shenfield in Essex in the east.
Passing through 37 stations, Crossrail will be ready by 2018.
Transport Secretary Patrick McLoughlin said: "This Government knows that by investing in transport projects like Crossrail we are investing in Britain.
"Over the past few years Crossrail has let contracts worth more than £6 billion, more than half going to small and medium-sized businesses, which are supporting jobs across the country."
London Mayor Boris Johnson,said: "Many thought it would never happen, it seemed almost unimaginable. But now, with the arrival of this gigantic tunnelling machine in the heart of Canary Wharf, grubby with mud and rubble, we can be in no doubt it's on its way."