HS2 has announced a significant breakthrough in its construction, with the Long Itchington Wood Tunnel becoming the first deep tunnel on the high-speed rail route to complete its civil engineering phase.
The one-mile-long, twin-bore tunnel, a crucial part of the line connecting London to the West Midlands, has seen the completion of key structural elements. These include three cross passages, concrete finishing works, base slabs, and emergency and maintenance walkways. This marks a pivotal step before the installation of complex operating systems, such as power, track, and signalling.
This achievement is particularly notable as it represents the first of five twin-bore tunnels on the HS2 project to reach this stage, with 27.4 miles of the route between London and the West Midlands being constructed in deep tunnels.
Work on the Long Itchington Wood Tunnel commenced in June 2020. The tunnel boring machine, affectionately named ‘Dorothy’ after Nobel Prize-winning chemist Dorothy Hodgkin, was launched in December 2021 and completed excavation in March 2023. The excavation process produced approximately 750,000 tonnes of material, which has been repurposed for embankments along the route.
Since the breakthrough, efforts have focused on fitting the tunnel with its essential structural components. The project, led by HS2’s main works contractor Balfour Beatty VINCI (BBV), has seen 380 individuals contribute to its completion.
Doug Barnett, Senior Project Manager for HS2 Ltd, said: “Long Itchington Wood Tunnel is a tremendous feat of engineering and would not have been possible without a huge amount of continuous work put in over the past five years – I’d like to thank everyone involved working both onsite and behind the scenes for their support.”
“It’s a small part of HS2 but it’s been four and a half years of my life in which I’ve seen this construction go from its very embers to nearing completion – a really proud moment for me personally.
The project has also provided valuable opportunities for young engineers, such as Alfie Ward, a recent graduate who contributed to the successful completion of the tunnel’s cross passage work. Alfie said: “Working as a young engineering graduate on the Long Itchington Wood Tunnel was the perfect platform to launch my career from. This experience at such an early stage in my career meant I was able to learn lots of new skills, which I’m now applying at Bromford Tunnel, as a site engineer.”
Jules Arlaud, Tunnelling Director for Balfour Beatty VINCI, highlighted the scale of the accomplishment, noting the installation of 1,582 concrete rings across both tunnels.
Jules said: “The scale of this achievement is enormous. A dedicated workforce of around 380 people have worked tirelessly over the past five years to reach this latest phase of construction, where the tunnels are now fitted with three cross-passages and the concrete finishing works, base slabs, and walkways are also complete.
“Throughout this project, our expert tunnelling team have installed a total of 1,582 concrete rings across both tunnels, with each ring made from eight two-metre-wide segments, each weighing up to 8 tonnes.”
The Long Itchington Wood Tunnel was designed to minimise environmental impact, built 30 metres below ground to preserve ancient woodland and avoid local villages.
Construction of HS2 continues across the West Midlands and London, with the project now supporting over 31,000 jobs. Recent progress includes the completion of the first viaduct at HS2’s Delta Junction in North Warwickshire and advancements on a new green bridge near Kenilworth.
Other HS2 tunnel projects include:
- The 3.5-mile Bromford Tunnel, expected to complete excavation this year.
- The 10-mile Chiltern Tunnel, with internal works ongoing.
- The 8.4-mile Northolt Tunnel, with the first drive completed.
- The 4.5-mile Euston Tunnel, in advanced preparation.
When fully operational, HS2 will provide high-speed services between London and the West Midlands, freeing up capacity on the existing West Coast Main Line and boosting economic growth.
