'Elizabeth' lowered down 120ft hole to burrow underground for Crossrail
PUBLISHED: 12:00 30 October 2012
Crossrail has reached a milestone in constructing the new 'super tube' by lowering a 550-tonne tunnelling machine they've named 'Elizabeth' into a shaft 120ft deep.
The operation on the banks of the Lea River near the Canning Town Bridge took place last Thursday, ready to start tunnelling under east London towards Canary Wharf and the City.
The operation needed one of the largest cranes in Europe to lift the equivalent of 280 London taxis in one go.
Perfect weather conditions, light wind and no rain allowed the 1,350-tonne crane to lower ‘Elizabeth’ underground without mishap.
The team will shortly repeat the operation with its sister machine, ‘Victoria’.
‘Elizabeth’ starts tunnelling later this year, burrowing under the Lea towards Canary Wharf, then on to Whitechapel, Liverpool Street and the City, with ‘Victoria’ following, creating a second twin tunnel.
The two machines will use large shove frames to push themselves forward into the earth.
A conveyer system is being put together to take the earth from the bottom of the shaft onto nearby ships on the Lea.
A jetty is being built to berth ships that will take 1.2 million tonnes of earth to Wallasea Island out in the Thames Estuary to create a new RSPB bird nature reserve. It will also be used to dock barges bringing 120,000 concrete segments from Chatham in Kent to line the tunnels, avoiding transporting them by road which would create congestion.
Work has also started at Crossrail’s Canary Wharf station to get ready for ‘Elizabeth’ and ‘Victoria’ to arrive, some time next year. Construction workers are breaking out the hard concrete which will be the tunnel ‘eyes’ for the twin boring machines.
Maintenance on the machines will then be carried out in the large station box, before tunnelling resumes on the next six-miles to Farringdon where the twin machines link up with the western section of Crossrail’s 15-miles of tunnelling.