Green tunnels

What is a green tunnel?

A green tunnel consists of two parallel tunnels, each containing a single rail track, constructed using a cut-and-cover technique.

This involves digging a trench, building the tunnel structure, then covering it with soil and planting trees and shrubs. We call these ‘green tunnels’.

This simple construction method works well for shallow tunnels and helps us reduce the impact on people and nature.

We’re building five main green tunnels between London and the West Midlands.

Building tunnels in three stages

First, we dig a cutting where we need the green tunnel. We keep the earth nearby because we’ll need it later.

In the second stage, we lay a concrete floor then install concrete walls to form the tunnel structure.

In the final stage, after we install the tunnel segments, we return the earth to fill the area. We plant new trees and shrubs so the tunnel blends into the landscape, connecting wildlife habitats along the route.