By rosebell
The cut-and-cover tunnel is being constructed within a railway cutting alongside the A413, west of Wendover. Once sections of the structure are completed, excavated material is placed above the tunnel to restore the landscape and integrate the railway into its surroundings.
2,740 Segments Form Wendover Green Tunnel
The Wendover green tunnel comprises 2,740 precast concrete segments and has an ‘M’-shaped configuration, with separate tunnel sections for northbound and southbound trains.
Construction was divided into two sections so that excavation, preparation, tunnel construction and backfilling could progress simultaneously at different locations. The two sections have now been joined, with the final segment installed on Monday.
More than 1.2 million m³ of material, predominantly chalk, was excavated to create the tunnel formation. The material was stored on site and is now being placed and compacted above the structure, helping distribute the load evenly across the tunnel.
EKFB Advances Portal and Backfilling Works
With the central tunnel structure complete, EKFB will concentrate on the two portals, internal works and backfilling. A road currently carried across the construction area on a temporary bridge will also be realigned over the completed tunnel.
EKFB is the joint venture of Eiffage, Kier, Ferrovial Construction and Bam Nuttall responsible for HS2’s main works through Buckinghamshire and into South Warwickshire.
The Wendover tunnel is one of three green tunnels being delivered by EKFB. Construction teams are sharing lessons from the projects to improve productivity and accelerate construction.
Measures include prefabricating reinforcement cages for the base slab, improving concrete delivery through the tunnel and testing larger backfilling machinery.
Specialist Equipment Used Beneath Temporary Bridge
Most of the precast segments were lifted into position using cranes. However, segments beneath the temporary Ellesborough Road bridge required a different installation method.
A self-propelled modular transporter, supported by 16 sets of wheels, was used to lift the beams from underneath the bridge and position them precisely within the tunnel structure.
EKFB installed the first concrete segment in spring 2025 and subsequently placed more than 2,000 segments in less than 18 months to complete the central structure.
Five Green Tunnels Planned on HS2
The Wendover green tunnel is one of five green tunnels planned along the HS2 route between London and Birmingham. The Copthall tunnel on the outskirts of London was completed in summer 2026.
Once completed and landscaped, the Wendover structure will help integrate the high-speed railway into the surrounding Buckinghamshire landscape.
