The Edgcote Viaduct will be a crucial part of the railway in the West Midlands (Image: HS2)
Across the country, major projects are being worked on to upgrade the UK’s ageing railway network.
HS2 is the largest infrastructure project in Europe. Despite the section between Birmingham and Manchester being axed in 2022, engineers are still working to finish significant milestones on the remaining route.
One of these is the huge half-kilometre long Edgcote viaduct.
Set low into the landscape of West Northamptonshire, the 515m-long bridge will carry the new railway across the floodplain of the River Cherwell, south of Chipping Warden.
The structure was redesigned last year, copying the approach used at HS2’s Thame Valley, near Aylesbury.
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A lighter weight design cuts the amount of concrete and steel in the viaduct, with the piers, beams, deck planks and parapet manufactured off site at a facility in Kent, officials say.
The section is designed to ‘free up space’ on the most crowded part of the existing West Coast Main Line and ‘boost economic growth’.
HS2 says that, instead of five beams per span, secured with concrete poured on site, the twin viaducts use just two larger ‘u’ shaped beams per span. These are secured directly to the neighbouring beams.
This was inspired by viaducts on the Spanish high speed rail network, and will ‘reduce the number of lorry movement and speed up construction by removing the in-situ concrete work’.
It is between six and eight metres high, and the viaduct will be supported by 20 pairs of pre-cast concrete piers.
The Edgcote Viaduct is now being constructed (Image: HS2)
These must be lifted into position with their steel reinforcing rods slotted into pre-prepared sleeves within the pile caps.
The gaps are then sealed with grout.
Officials say: “As well as changes to the beams, the piers will also be narrower and extended to almost connect with the parapet edge, helping to enhance the appearance of a light and narrow structure.
“From a distance, it will be largely hidden by existing hedgerows and woodland.
“Two major new wildlife sites will also be created where the viaduct crosses the floodplain, with new and enhanced fen, marshland and meadow alongside new woodland planting.
“The schemes – which total 7.6 ha – will create valuable new habitats for insects, bats, newts and other amphibians.
“The viaduct passes close to the site of the medieval Battle of Edgcote. Fought on July 26, 1469, during the Wars of the Roses, the battle is thought to have taken place on the nearby Danesmoor and archaeological investigation has not found any evidence of the battle at the viaduct construction site.”
The estimated cost of the HS2 line from London to Birmingham is thought to have ballooned to as much as £66billion.