Crossrail has unveiled the first of eight 1,000 tonne, tunnel boring machines (TBM) that will burrow under London excavating the tunnels for the new west to east rail link.
The 140 metre long, fully assembled tunnel boring machine is currently undergoing factory testing in Germany. The machine will then be dismantled and shipped to London where it will be re-assembled at Westbourne Park. Tunnelling should commence from Royal Oak in March.
Eight tunnel boring machines will be used to drill 13 miles of twin-bore tunnels. The TBMs will undertake ten individual tunnel drives as they excavate the 6.2 metre diameter tunnels. Building Crossrail is a round-the-clock operation and the TBMs will run 24 hours a day, 7 days a week stopping only for scheduled maintenance.
As the TBMs advance forward, precast concrete segments will be built in rings behind the TBMs. Construction of the concrete segment factory for the western running tunnels between Royal Oak and Farringdon is now complete at Old Oak Common. The plant will begin manufacturing over 70,000 segments for the western tunnels from January.
Says Chris Dulake, Crossrail’s Chief Engineer, ‘Crossrail tunnelling will get underway in March 2012 when the first of eight tunnel boring machines will begin burrowing below the streets of London. Work is continuing across the Crossrail route to prepare for construction of the major new rail tunnels.
‘The new Tunnelling and Underground Construction Academy has welcomed its first students and will train at least 3,500 people with the skills required to work below ground while the first of the tunnel segment manufacturing plants will shortly commence full operations.’
The eight Crossrail TBMs are being manufactured by Herrenknecht AG, Germany which also manufactured tunnel boring machines for the Jubilee Line Extension and the Docklands Light Railway (DLR) Extension to Bank.