Once built, the tunnel will carry HS2 trains through the village of Burton Green, near Kenilworth, and will feature a green space above for use by the local community. It is one of five ‘green tunnels’ being built on the project. These are shallower tunnels which will be finished with planting on top to help them blend into the natural landscape.
As well as Burton Green, green tunnels will be constructed at Copthall in Hillingdon, Wendover in Buckinghamshire, and Chipping Warden and Greatworth – at 2.7km, the longest of the green tunnels – both in Northamptonshire.
Delivered by HS2’s main works civils contractor for the West Midlands, Balfour Beatty Vinci (BBV), and designed by Mott MacDonald engineers from the Mott MacDonald SYSTRA Design Joint Venture (DJV), the Burton Green structure is being built using a ‘top down’ construction method which involves building the structure from existing ground level. This includes initially building the side walls and roof of the tunnel, with large openings to ease excavation. The tunnel is then excavated and the tunnel base is constructed.
In the last year, work on the tunnel has included completion of the 200m-long southern portal entrance and a series of underground structural elements, including retaining walls and more than 1,300 piles, using 33,000m3 of concrete in total.
An onsite team of 150 people will now focus on the next phase of the build ahead of full completion in autumn 2026. This includes further tunnel excavation work – with excavated soil being reused as part of wider landscaping plans – and the installation of roof slabs, base slabs and internal structures.
“We’re incredibly proud to have achieved the 50% completion mark at Burton Green Tunnel and to be celebrating this milestone moment,” said HS2 senior project manager Doug Barnett. “Delivering a complex structure of this scale requires a huge amount of expertise and energy, which is thanks to everyone involved – from onsite engineers and machine operators, to design and support colleagues working behind the scenes.”
BBV project manager Rupert Blake said it was hugely rewarding to lead the delivery of the tunnel.
“This is a fascinating structure both in terms of scale and complexity, but its green characteristics are what really sets this tunnel apart,” he said.
A key feature of the Burton Green Tunnel for people in the local area is the realignment of the Kenilworth Greenway, which provides a link from Balsall Common to Kenilworth via Burton Green for walkers, cyclists and horse-riders. Once construction and landscape work is complete, the Greenway will be restored close to its original alignment, running across the top of the new tunnel.
While the railway is being built, HS2 has created a temporary route for the Kenilworth Greenway.
Tim Akers, engineering manager for Mott MacDonald Systra Design Joint Venture, described the tunnel as “a railway within a landscape” where the original character of the Kenilworth Greenway and ecological connectivity to the wider landscape were restored.
In recent weeks in the West Midlands, work started on the 2,000 underground columns that will support Birmingham’s Curzon Street Station, as well as the foundation work for a new bridge designed to carry HS2 trains under a section of the A38 near Lichfield.
