Construction of HS2’s longest 'green tunnel' takes major step forward following realignment of road near Banbury
The construction of HS2’s longest ‘green tunnel’ took a major step forward this week with the realignment of a key local road near Banbury, freeing up space for the next phase of excavations.
Set to stretch for 2.7km, the tunnel is being built inside a shallow cutting near Greatworth, West Northamptonshire, using a ‘cut-and-cover’ technique, with the earth put back on top afterwards. HS2 hopes that this will help "blend the railway into the landscape".
Engineers working for the high-speed rail project have already assembled the first kilometre of the structure and the temporary realignment of the B4525 will allow work to begin on the next stage of the tunnel.
Assembled from precast concrete segments, the tunnel is in an ‘M’ shape, with separate halves for northbound and southbound trains.
The nearby Chipping Warden green tunnel uses a similar design and the teams at the two tunnels said they have been able to learn lessons from each other.
HS2 Ltd’s Project Manager, Sam Arrowsmith, said: “I’m really pleased to see the temporary realignment of the B4525 open to drivers. This major milestone means that we can keep local traffic moving while we deliver the next stage of the Greatworth green tunnel.
“Once complete, the tunnel will help protect the rural landscape and reduce disruption for people living nearby. We’ve still got a long way to go, but the lessons from Chipping Warden have helped us significantly increased productivity and I’d like to thank everyone who’s worked so hard to get us to this point.”