HS2 engineers have installed the final roof segment on the 700-metre Burton Green tunnel, marking structural completion on the West Midlands section of the new railway.
The 16-metre-wide twin-box tunnel will carry high-speed trains beneath the village of Burton Green, near Kenilworth, with an internal wall separating northbound services to Birmingham, Manchester and Scotland from southbound trains to HS2’s London stations at Old Oak Common and Euston.
With the main civils now complete, attention turns to the tunnel’s 500-metre ‘green roof’, designed to blend the structure into the surrounding landscape and provide green space for local communities.
Doug Barnett, senior project manager for HS2 Ltd, said: “With the main civil engineering complete, thanks to the hard work and dedication of the 150-strong team on the ground, we can now begin the next phase of this exciting project. We look forward to working with local communities to bring the bold design vision for Burton Green tunnel to life, maximising the potential of this new green space.”
Once complete, the Kenilworth Greenway will be reinstated close to its original alignment above the tunnel, providing a link from Balsall Common to Kenilworth, via Burton Green, for walkers, cyclists and horse-riders.
Tim Akers, design manager from the Mott MacDonald/SYSTRA design joint venture, said: “A range of techniques were incorporated into the design to enable construction through this narrow corridor within the village. The end result will be a railway within a landscape, where the original character of the Kenilworth Greenway and ecological connectivity to the wider landscape are restored over the buried tunnel.”
Excavated material from the tunnel is being reused in wider landscaping works, with native trees and shrubs planted to create habitats and re-establish vegetated links to Black Waste Wood and Little Poors Wood.
HS2’s construction partner, Balfour Beatty VINCI (BBV), is working with community groups and schools on plans for the Greenway.
Rupert Blake, project manager for BBV, said: “The structural completion of Burton Green tunnel is a huge moment for BBV and our supply chain partners, who’ve worked tirelessly over the last five years to get us here. A range of construction techniques have been used to deliver this complex engineering project, showcasing the team’s skill, expertise and resilience. The next step is to install a 500-metre green roof on top of the structure, so it integrates into the natural landscape.”
BBV’s civils team is now working on the tunnel’s remaining elements, including the escape walkway to the south of the structure and the application of fire-proof protection to the upper tunnel walls.
Cromwell Lane, which links both sides of the village and was temporarily diverted during construction, is due to reopen on its original alignment in October, following completion of utilities works. A temporary route for the Kenilworth Greenway has run throughout construction from the site of Burton Green Village Hall, following field boundaries to Berkswell station in the north-west.
Galldris Group was the main civils subcontractor on the project, with a direct workforce of over 100 people on site.
Ibrahim Arshad, senior project manager from Galldris Group, said: “From start to finish, we have provided engineering expertise, detailed planning and self-delivery capabilities to safely deliver this complex section of HS2. Working collaboratively with Balfour Beatty VINCI, the design joint venture and the wider supply chain, we are proud to have contributed to the structural completion of one of HS2’s most significant green tunnels.”
Burton Green is one of five green tunnels being built on the HS2 route. Their cut-and-cover design makes them shallower than deep twin-bore tunnels, with each finished with trees, plants and shrubs on top. The other four are Copthall in outer London, Wendover in Buckinghamshire, and Chipping Warden and Greatworth, both in Northamptonshire.
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