Third machine tunnels for Crossrail
By Sandy Guthrie29 November 2012
Elizabeth, the third tunnel boring machine (TBM) for London’s massive Crossrail project, is underway as work has begun on the longest tunnel section.
Manufactured by Herrenknecht and weighing in at 1,000 tonnes, Elizabeth has begun the 8.3km tunnelling journey to create the eastern section of the new rail line between Docklands to the east of the city and Farringdon in central London.
Elizabeth and sister tunnelling machine Victoria were lowered 40m underground into a shaft at Limmo Peninsula, next to Canning Town station, last month. Victoria will also begin work on the eastern tunnels later this year.
As the 150m long tunnelling machines advance, precast concrete segments are put in place to form concrete rings to line the tunnels. Elizabeth has now placed the first of 110,000 concrete segments that will line the eastern tunnels.
All of the concrete segments are being manufactured at a new facility in Chatham in Kent, before being delivered by barge to the east London site. Crossrail said this helped prevent thousands of lorry journeys through Kent and east London.
Ships will also being used to transport excavated material from the eastern tunnelling work to Wallasea Island in Essex, where it be used to create a new 607ha Royal Society for the Protection of Birds nature reserve.
Andrew Wolstenholme, Crossrail’s chief executive, said, “With the start of work on Crossrail’s eastern tunnels, we are seeing the biggest construction project in Europe now tunnelling on both sides of the capital. This is a significant step towards the huge transport improvements Crossrail will deliver, creating much needed additional capacity and faster new links with London’s major employment areas.”
Across the whole Crossrail project, eight tunnelling machines will construct 21km of twin tunnels under London. The Crossrail route will pass through 37 stations and run 118km from Maidenhead and Heathrow in the west, to Shenfield and Abbey Wood in the east.