Industry NewsTransportationTunnel Boring

Fourth tunnel boring machine launched for HS2 Northolt Tunnel

The fourth and final tunnel boring machine (TBM) for HS2’s Northolt Tunnel has been launched. HS2 reported that the 13.5 km (8.4-mile) Northolt Tunnel will run from Victoria Road in Ealing to West Ruislip in Hillingdon.

The fourth TBM is named Lady Anne Byron. The name was chosen by the local community around Ealing through a public vote.

Lady Anne Byron was 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.

TBM Anne will bore 5.4 km (3.4 miles) from Victoria Road in Ealing, near HS2’s Old Oak Common station, to Greenpark Way in Greenford, alongside TBM Emily which launched in February.

The other 8 km (5 miles) of twin-bored tunnels has been under construction since 2022, with TBMs Sushila and Caroline both more than halfway through their journey between West Ruislip, on the outskirts of London, and Greenpark Way. The quartet of TBMs are all set to complete their journeys in 2025, when they will be extracted from the ground through giant shafts at Greenpark Way.

HS2’s London tunnels contractor, Skanska Costain STRABAG joint venture, has delivered an extensive program of work for the TBM to launch at the Victoria Road Crossover Box, excavating the caterpillar shaped box where eventually the trains will cross tracks on their way in and out of Old Oak Common station.

‘Anne’ is the eighth TBM that has been launched to date across the HS2 project between London and the West Midlands to build the mined tunnels for the trains. In all, almost half of the 104 km (65 miles) worth of twin-bored tunnels needed for the route has now been excavated.

When complete, HS2 will improve connections between London and the West Midlands, with trains running further north on existing lines.

The TBM was manufactured by Herrenknecht in Germany. It is one of 10 machines specially designed for HS2 and the ground through which they will bore. Two remaining TBMs, which will eventually be used to dig HS2’s final tunnel between Old Oak Common and Euston, in central London, are still being built.

SCS JV worked collaboratively with Herrenknecht on a cutting-edge design that maximizes productivity and achieves the highest standards in a tunneling environment.

The TBM weighs 1,700 t (1,873 st) and is 170 m (560 ft) in length. The cutterhead is 9.11m (30 ft) in diameter.

TBM Anne was lowered in parts into the 25 m (82 ft) deep crossover box at the end of last year, where she was reconstructed and prepared for launch.

HS2 has reached peak tunneling activity as we focus on delivering the HS2 route between London and Birmingham. The launch of Anne is the culmination of many years of work for the London Tunnels team and a further triumph in British engineering,” said Malcolm Codling, HS2’s Project Client Director for the London Tunnels.

“The launch of TBM Anne is a milestone moment in this year of peak activity for the HS2 London Tunnels project. With a quartet of TBMs and over 20 construction sites all making significant progress, we are on course to deliver the high-speed line into central London, creating economic growth and opportunities at every step of the way,” James Richardson, manager for Skanska Costain STRABAG joint venture said.

The two final TBMs will construct the Euston Tunnels, taking HS2 trains into central London. They are set to be delivered to the UK later this year and lowered into the underground station box at Old Oak Common ready for launch.

Related Articles

Back to top button