Both machines are in the process of being dismantled, boxed up and transported from the Herrenknecht factory in Germany.
TBM 6, a slurry machine called Mary, will drill a tunnel under the Thames from Plumstead to North Woolwich alongside her sister machine Sophia, who started tunnelling at the start of January. Mary is specially equipped to deal with the chalk, flint and wet ground conditions that she will encounter in southeast London.
TBM 7, yet to be named, will be used on the drive from Pudding Mill Lane to Stepney Green, which will start in the summer. This is an earth pressure balanced machine designed for the London clay found north of the River.
All the machines’ components are expected to arrive at Crossrail’s sites within the next month where they will be reassembled.
TBM Mary is named after the wife of the Isambard Kingdom Brunel. She weighs 1,000 tonnes and is 110m long. TBM 7 is even bigger at 150m long.
Crossrail’s final tunnel boring machine, TBM 8, will complete factory testing this summer.
Crossrail programme director Andy Mitchell said: “Over 4km of tunnel has now been constructed on Crossrail. With tunnelling now well underway we are looking forward to welcoming our sixth and seventh tunnel boring machines to the project. Once we’ve unpacked and reassembled them, they’ll begin drilling yet more tunnels underneath the streets of the capital.”
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