Crossrail work at Connaught Tunnel gathers pace
16:00 28 April 2012
Work to prepare the Connaught Tunnel for the Crossrail era is now well under way.
Engineers started to dig wells last week in a bid to lower water levels, allowing them to the deepen and widen the 130-year-old Royal Docks structure.
This will allow it to accommodate Crossrail’s larger trains, when the scheme launches in 2018.
By the time they have finished, the structure’s pump house shaft will have been deepened to hold modern equipment that will work to keep the tunnel dry.
Over the next month, Head House, a Victorian building on the site, will be removed brick by brick and donated to Newham Council.
Crossrail said it is too small to hold the modern pumping equipment that will be installed as part of the tunnel’s major refurbishment.
Project manager Linda Miller said: “Works are progressing extremely well and we are on track for turning this Victorian railway tunnel into modern infrastructure that will service London well into the next century.
“Major works will begin early next year after the London Boat Show, which will include placing coffer dams in the passage between Royal Victoria and Royal Albert docks, pumping out the water and performing open heart surgery to widen and deepen the central section of the tunnel.”
The Connaught Tunnel was built in 1878 and was part of the North London Line until 2006.
In 1935, larger ships scraped the bottom of the Royal Victoria Dock - which sits above the tunnel - causing structural problems.
As part of previous work to deepen the dock, the central section of the tunnel was narrowed with brickwork removed and steel segments installed.
Crossrail originally planned to strengthen the section by removing the existing steel linings and filling the section with concrete foam.
But concerns over its structural condition led the Crossrail engineering team to opt to dig down into the tunnel to carry out the enlargement work.
This will be the first time the tunnel has been exposed from above ground since its construction in the 1870s.