TBM delivery heralds HS2 London launch date

17 December 2021

UK tunnelling activity is forging ahead following the recent delivery of two giant Herrenknecht EPB TBMs to HS2 main works civil contractor Skanska Costain Strabag JV in West London.

Delivering the 9.82m-diameter machines to the West Ruislip site required a huge effort of logistical coordination involving 260 deliveries, including 110 abnormal loads. The largest components were transported by road from Essex ports on wide-bodied vehicles.

Tunnelling for HS2 in London is set to begin in 2022 following the delivery of the 1,900t machines from Germany earlier in November. They are the first of six TBMs that will bore 13 miles (20.8km) of twin-bored tunnels underneath London where HS2 services will run.

“The HS2 team at West Ruislip has been preparing the site for over two years to ensure it is ready to launch the first two London TBMs in 2022,” said Malcolm Codling, Client Director for HS2. “This will be an exciting step as we begin our four-year programme of tunnelling under London, showcasing the best of British engineering, and building Britain’s newest low-carbon transport network.”

The two TBMs will reach depths of 30m below ground, boring mainly through Lambeth Group gravels, sands, silts and clays, as well as chalk and London Clay. For every five miles of tunnel (8km), each machine will install 4,220 tunnel segment rings, working 24/7 for two years and stopping only at Christmas and Easter.

In total, 10 TBMs will work on Phase One of the HS2 project between London and the West Midlands, excavating 64 miles (102km) of tunnels for the high-speed railway.