The former NBA basketballer Charles Barkley once said “sometimes the light at the end of the tunnel is a train”. We did see a light at the end of the Crossrail tunnels; however it wasn’t a train as they won’t be running until 2018.
Good progress has been made on the warren of tunnels burrowing through the capital and Londonist was on-hand as Crossrail kindly invited us on-site to see the only part of the route that will pass under the Thames.
This section of tunnel, or should we say tunnels (there are two, one for each direction of travel) pass from Plumstead to North Woolwich near the ferry terminal and reach for almost two miles. The section under the Thames itself runs for 460m.
The tunnelling in this section was faster than through other parts of London due to the chalk and flint near the river, rather than the sticky London clay elsewhere. As they bore under the Thames, the tunnelling machines convert waste chalk and flint to slurry which is then made into ‘cakes’ to be used for land reclamation.
In total, this section of Crossrail has seen 500,000 tonnes of material removed by the two tunnelling machines, Mary and Sophia — named after the wives of Isambard and Marc Brunel who constructed the first ever Thames tunnel over 150 years ago.
Twenty three tunnels now pass under the Thames fulfilling a whole host of functions — from carrying communication cables to providing routes for vehicles and tube/DLR trains.