HS2 goes modular with ‘green tunnels’
By Catrin Jones12 January 2022
HS2 has revealed the first images of the green tunnel in Northamptonshire - the longest out of three precast modular tunnels planned. Two more tunnels will be built off site, shipped and then installed at Wendover in Buckinghamshire and Chipping Warden in Northamptonshire.
The 2.4km tunnel will be built off site in a factory in Derbyshire before it will be shipped to the site and assembled. Once it has arrived, it will be covered with earth and landscaped to ensure that it fits in with the surrounding countryside.
HS2’s main contractor, EKFB - a team made made up from Eiffage, Kier, Ferrovial Construction and BAM Nuttall - took inspiration from the construction of recent French high speed lines to create an offsite modular build solution.
The Greatworth tunnel, designed as an ‘m’ shape double arch, will have two seperate halves with one for northbound and the other for southbound trains.
The design of the modular tunnels reduces the amount of concrete and steel used - both of which are significant sources of carbon emissions - therefore halving the amount of carbon embedded into the lighter-weight modular structure. Other benefits include less people and less equipment on site therefore reducing disruption for nearby residents.
Rohan Perin, HS2 Ltd’s project client, said, “The Greatworth green tunnel is a great example of what we’re doing to blend the new railway into the landscape and protect communities living close to the line. By adopting an ‘off site’ approach to manufacturing, we’re also cutting embedded carbon from the design, improving efficiency, safety and making the whole construction process less disruptive for the community.”