Crossrail recycling lost heritage under London
Underneath east London, the capital's lost industrial heritage is being recycled for Crossrail.
The last time I visited the 1.2 mile (2km) long Connaught Tunnel was a year ago.
Then it was full of weeds, graffiti and had been derelict for years. Not anymore.
Now it looks like a construction site.
The tunnel was built in 1878 and Crossrail are going to use it as part of the route to Abbey Wood.
The bottom of the tunnel has been lowered to make room for the larger Crossrail trains.
And the major part of the project is a huge dam called the Cofferdam, which has been built to hold back the water from the docks.Soot-stained brickwork
Engineers have now pumped out the water and can now get to the tunnel beneath and renovate the tunnels.
What's interesting about this part of the project is they are using and embracing the industrial heritage.
Huge brick struts across the line have been preserved. The engineers have been pleasantly surprised at the condition on the soot-stained brickwork.
Embracing the heritage and using the tunnel has cost £50m.
The work is in stark contrast to the relatively quick and modern techniques which we have filmed being used with the Tunnel Boring Machines at the other end of the line.
The big question now is will we continue to see these techniques ?
Will we get "Crossrail 2" from the north to the south of the capital ?
London's campaign arguing for "sustained investment" in transport is just starting. Expect much much more of it.
But is the Treasury listening or has City Hall had its lot?