Green Tunnels: High-Speed Trains Beneath Green Hills

A total of five of these green tunnel structures are being built between London and the West Midlands, through which high-speed trains will run in the future. They are situated at Copthall, Burton Green, Greatworth, Wendover and Chipping Warden. 

The Green Tunnels cover the new HS2 route where it runs through the countryside and close to urban areas. In doing so, they reduce noise, protect the surrounding environment and can be replanted with vegetation once construction is complete.

In July 2026, HS2 completed the tunnel structure of the Green Tunnel in Chipping Warden. The tunnel is almost two and a half kilometres long, making it one of the longest on the route. It consists of 5,020 prefabricated segments that were assembled on site to form an M-shaped double arch construction. To enable high-speed traffic without laying the route openly through the landscape, engineers opted for a cut-and-cover construction method, i.e., an open trench that is later covered again.

This is how the Green Tunnels are created. With the cut-and-cover method, a long, open trench is first excavated in which the concrete tunnel structure is built. Unlike with traditional deep tunnels, this does not require a tunnel boring machine to work its way through complex geology and groundwater for months on end. This reduces technical risks and makes construction easier to plan.

The prefabricated side and middle walls are placed on a concrete foundation, connected to the roof segments and assembled precisely. Because the elements are pre-produced in the factory, they can be installed more quickly and assembled with greater precision on site. This shortens the construction time, reduces personnel costs and reduces logistics costs.

The material created during the excavation will later be used to cover the tunnel and to plant the surface with bushes, trees and regional plants. The finished tunnel blends almost invisibly into the landscape. 

The modular concrete elements for several Green Tunnels along the HS2 route are supplied by SATEBA UK, which has been part of the Vossloh Group since 2025. The segments are manufactured and fully prefabricated at the company’s Stanton-by-Dale plant.

Compared with traditional construction methods, this approach halves the structure’s carbon footprint. The reduction is achieved through the structurally optimised double-arch design, which requires around 50 per cent less concrete and 20 per cent less steel than a heavy rectangular tunnel box. Manufacturing under controlled factory conditions also eliminates the need for weather-related material allowances and reduces waste on site, while the plant’s proximity to the construction site minimises transport emissions.

Once the first trains begin running through the tunnel, the rail and fastening systems become crucial. Vossloh supplies components including tension clamps, insulators and rail pads, which ensure stability, vibration damping and safety both inside the tunnel and along the entire route.

The systems are designed for speeds of up to 360 km/h and absorb the forces generated by high-speed rail operations. At the same time, they dampen vibrations and reduce noise.

Vossloh manufactures its components locally at its plant in Scunthorpe, UK. This shortens transport distances, reduces carbon emissions and contributes to the project’s sustainability. The durable, low-maintenance systems are also designed to operate reliably for decades.