Major components of the first machine due to launch have now been lifted into the 25m deep ancillary shaft at the HS2 site in Ealing to prepare for the launch. HS2's London tunnels contractor, Skanksa Costain STRABAG joint venture completed the lift as it prepares for the next stage of tunnelling under the capital.
The first TBM lowered into the shaft has been named after Emily Sophia Taylor who lived between 1872 and 1956. She was a midwife who provided services for women who could not afford maternity care. She helped establish the Perivale Maternity Hospital in 1937 before becoming Ealing's first female mayor in 1938.
The second TBM's namesake is Lady Anne Byron, an educational reformer and philanthropist who lived between 1792 and 1860. She established the Ealing Grove School in 1834 - England's first cooperative school which provided education for the working classes in an era when it was mainly for the wealthy.
Made in Germany
The two TBM were manufactured by Herrenknecht in Germany and weigh 1700t each. After being lowered underground into the launch chambers in pieces, they will be reassembled. Each part of the TBM is lifted using a crane, including the 316t front shield and 336t middle shield. Eight back gantries for each machine will also be lifted into place to provide all the systems required for the tunnelling operations underground.
Speaking about the preparations for the next set of TBMs to be launched in London, Richard Crathern, head of delivery for HS2 said: "We are proud that the TBM have been given names from women with a connection to the local area who made a difference to previous generations of young people. This next set of TBM will be contributing to important infrastructure for generations to come as they build Britian's new high-speed railway."
The machines are earth pressure balance TBM, designed specifically for soft ground conditions, specifically London clay.
Under London
The machines will begin the 3.4-mile journey at the start of 2024, travelling under Ealing from the Victoria Road site towards Greenpark Way in Greenford, taking around one year to complete the journey. At Greenpark Way, the machines will be disassembled and removed via another 35m deep shaft.
The London Tunnels programme is reaching its peak delivery stage
James Richardson, MD of Skanksa Costain STRABAG joint venture, said: "The London Tunnels programme is reaching its peak delivery stage and we're excited to name our next two TBM, Emily and Anne. They will join our first two TBM, Sushila and Caroline, who are already one year into constructing the section of tunnel between West Ruislip and Victoria Road.
"We are well on the way to delivering the high-speed tunnels into London. Next year we'll be assembling our final two TBM that will tunnel between Old Oak Common and Euston."
Northolt tunnel
This section of tunnelling will complete the 8.4-mile long Northolt tunnel. The tunnel is being built in two sections. Two TBMs are already boring the western end of the tunnel beginning in West Ruislip working towards Greenford with almost two miles completed so far. The two new TBM will bore the eastern section. The final section of tunnel from Victoria Road Crossover Box to connect to Old Oak Common Station will be constructed using spray concrete lining.
Before the launch of the TBM, a blessing ceremony conducted by a local priest will be held - a longstanding tunnelling tradition. A statue of St Barbara, the Patron Saint of tunnelling, will be blessed and placed at the entrance of the tunnel.
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