HS2’s first giant London tunnelling machine switched on

Press release 06/10/2022 17:45 CET

Our Skanska Costain STRABAG joint venture launches first tunnel boring machine on HS2’s largest section of tunnels through London.

Sushila Hirani, local school teacher after whom the TBM was named, turned the machine on

HS2 Ltd and our Skanska Costain STRABAG joint venture today [06/10/2022] celebrated the start of the next phase of tunnelling on the enormous infrastructure project, launching the first of six tunnel boring machines (TBMs) that will dig over 26 miles of tunnels under the capital.  

The launch of the first TBM, called Sushila, marks the start of tunnelling in London, one of the busiest cities in the world. In total, our Skanska Costain STRABAG joint venture is constructing 13 miles of twin bore tunnels between West Ruislip and Euston (26 miles of tunnels in total).

HS2 Ltd’s CEO, Mark Thurston was joined by local teacher, Sushila Hirani, after whom one of the tunnel boring machines at the West London site is named, as it begins its five-mile journey.  

'Sushila' is the fourth of 10 HS2 tunnel boring machines across the project to be launched to date. The milestone highlights the progress being made on building Britain’s new high speed rail network, creating jobs and providing contracts for businesses now.  

Later this year a second TBM, named after 18th century astronomer Caroline Herschel, will also be launched from the West London site to build the second of HS2’s twin-bore tunnels towards central London.  

Launching the TBM, HS2 CEO Mark Thurston said: “The launch of the tunnel boring machines on the longest section of tunnels through London is a significant moment for HS2, and one that demonstrates the momentum that has built behind Britain’s flagship levelling-up project. The construction of 170 miles of new high speed railway between London and Crewe is now in full swing, supporting 27,000 jobs, nearly 1,000 apprenticeships and contracts for over 2,500 businesses.”  

James Richardson, Managing Director of Skanska Costain STRABAG JV said: “Today we start one of the most complex parts of HS2, tunnelling from here at West Ruislip towards Euston beneath one of the busiest cities in the world. The huge team effort has enabled some of the most advanced TBMs ever built to be launched. Our team has brought together world class skills along with developing many new people to the industry working on this crucial national infrastructure project.” 

Each weighing over 2,000 tonnes and measuring 140 metres in length, both TBMs will bore five miles non-stop for 22 months, except Christmas Day and bank holidays, to Green Park Way in Greenford, where they will be dismantled and lifted from the ground.  

Separately, two other equally massive tunnel boring machines will set off towards Green Park Way from HS2’s Victoria Road site in 2023 to build a further 3.4mile twin-bore tunnel. Together the quartet of TBMs will build 8.4miles of twin bored tunnels between West Ruislip and the new high speed rail super hub station at Old Oak Common.     

Another tunnel 4.5 mile twin-bore tunnel extending from Old Oak Common to Euston will complete HS2’s journey to its London terminus.  

Each TBM is operated by 15 people, working in shifts. A team of around 40 people assembled the TBMs, with 56 companies involved in getting the site ready and machines launched. 

In total the 10 TBMs will create 64 miles of tunnels on HS2 between London and the West Midlands.  

Sushila and Caroline will be operated by our Skanska Costain STRABAG JV. The machines are manufactured by worldwide TBM specialist Herrenknecht in Germany.    

Further facts about the TBMS: 

  • Each machine is 140 metres in length, one and a quarter times the length of a football pitch 
  • Each has a cutter head that is 9.84m in diameter, slightly smaller than the machines boring through the Chilterns  
  • They each weigh approximately 2,050 tonnes, roughly the weight of 20 blue whales 
  • 2 million cubic metres of excavated material will be removed, weighing 2.46 million tonnes