Major components of the first machine called Emily have now been lifted into the 25m deep ancillary shaft at the HS2 site in Ealing to prepare for the launch. The other new machine Anne will follow for the Northolt East Drive.

James Richardson, managing director of SCS joint venture, said: “The London Tunnels programme is reaching its peak delivery stage and we’re excited to name our next two TBMs, Emily and Anne.

“They will join our first two TBMs, 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 TBMs that will tunnel between Old Oak Common and Euston.”

The earth pressure balance TBMs, designed specifically for London clay, will begin the 3.4-mile journey at the start of 2024.

They will dig under Ealing from the Victoria Road Crossover Box, near to Old Oak Common in West London 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.

This section of tunnelling will complete the 8.4mile 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 TBMs 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.

The first TBM lowered into the shaft has been named after Emily Sophia Taylor who lived between 1872 and 1956. Emily 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 co-operative school which provided education for the working classes, in an era when it was mainly for the wealthy.