HS2 green tunnel receives planning approval

The design responds to community feedback calling for bigger and better green spaces around the railway.

The plans for the southern end of the structure have already been approved by Warwickshire District Council, where the railway will travel in a 400m-long green tunnel. The roof will be covered with landscape planting and new footpaths to integrate the railway into the surrounding landscape.

Solihull Council’s approval of the northern section of the structure, where the railway exits the tunnel north portal in a 1.4 km cutting with retained walls, completes the planning approvals for this stretch of HS2.

A key feature for this 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. The new Greenway will cross under Cromwell Lane and then cross the roof of the green tunnel and run alongside the railway cutting.

HS2 senior project manager Alan Payne said the organisation was committed to maximising green space around the high-speed railway.

“[We] have worked with residents and authorities to ensure our tunnel design conserves, enhances and transforms the landscape in this area,” he said.

“The design for the permanent realignment for the Kenilworth Greenway and the landscape infrastructure created over the green tunnel is central to how we deliver this, linking the local community and railway with the wider landscape.”

The green tunnel in Burton Green was designed by the Mott MacDonald Systra Design Joint Venture working for HS2’s main works contractor for the West Midlands, Balfour Beatty Vinci (BBV), which is constructing 90km of HS2 between Long Itchington in Warwickshire to the centre of Birmingham and on to Staffordshire.

It is one of five green tunnels on the project. As well as Burton Green, there are green tunnels at Copthall in Hillingdon, Wendover in Buckinghamshire and Chipping Warden and Greatworth, both in Northamptonshire.

Construction of the underground elements of the tunnel is under way, including widening of the historic railway cutting to the width of the new tunnel, construction of the wall panels to the north of Cromwell Lane, and completion of the diversion of Cromwell Lane to enable construction of the tunnel’s southern section.

The south portal and tunnel wall panels have been constructed, along with the solid tunnel roof to the north of the original Cromwell Lane bridge, and work is progressing on the Cromwell Lane underpass to allow the diversion of Cromwell Lane.

The tunnel roof slab to the north of Cromwell Lane and excavations in this section have started. Over the coming months, work includes continuation of the main tunnel excavation, construction of the tunnel base slab and internal mid-wall, demolition and removal of Cromwell Lane bridge, work to join the northern section to the south portal, and construction of the tunnel roof slab to the south of Cromwell Lane.

The bowl-shaped landscape around the south tunnel portal and the portal services building will be planted with trees and shrubs so the structures are not easily visible from the surrounding area and have been designed to guide bats around the portal and away from the trains.

Once the tunnel is built, the cutting will be back filled with soils as the basis for recreating the landscape, and soil will conceal the tunnel roof to support planting and public footpaths.