Balfour Beatty VINCI’s work to build HS2’s 700-metre-long Burton Green Tunnel in Warwickshire has reached the halfway mark.

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 – shallower tunnels which will be finished with trees, plants and shrubs on top, helping 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, both in Northamptonshire.

Delivered by Balfour Beatty VINCI, and designed by Mott MacDonald engineers from the Mott MacDonald SYSTRA Design Joint Venture, the Burton Green structure is being constructed 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 ramped up and has seen the completion of the 200-metre-long southern portal entrance and a series of underground structural elements, including retaining walls and over 1,300 piles – concrete pillars built underground – using 33,000 cubic metres 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.

Rupert Blake, Project Manager for Balfour Beatty VINCI, said:“As an engineer, it’s hugely rewarding to lead the delivery of the 700-metre-long Burton Green Tunnel in Warwickshire.

“This is a fascinating structure both in terms of scale and complexity, but its green characteristics are what really sets this tunnel apart. When it’s complete, the roof will be finished with trees, plants and shrubs, so it blends in seamlessly with the existing landscape.”

Doug Barnett, Senior Project Manager for HS2 Ltd, said: “We’re incredibly proud to have achieved the 50% completion mark here at Burton Green Tunnel and to be celebrating this milestone moment.

 “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.”

 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 which starts at the site of the Burton Green Village Hall and then follows the existing field boundaries linking with Berkswell Station in the northwest.

In recent weeks, HS2 construction progress in the West Midlands has seen work start on the 2,000 underground columns that will support the flagship Birmingham Curzon Street Station, as well as the beginning of foundation work for a new bridge designed to carry HS2 trains under a section of the A38 near Lichfield.