The first huge viaduct has been completed at HS2’s Delta Junction in North Warwickshire, marking a major milestone as construction ramps up on the high-speed line in the region.
A team of 40 people working for HS2’s contractor in the Midlands, Balfour Beatty VINCI, used a giant cantilever structure to build the 472 metre single-track River Tame West Viaduct.
It is the first time in the UK that the technique has been deployed - moving the concrete segments into place span-by-span, making it an efficient and flexible construction process.
Work started on the viaduct’s piers in 2023, followed by the concrete deck construction starting in early 2024. Since then, 190 pre-cast concrete viaduct segments have been lifted into place using the specialist cantilever technique.
The River Tame West Viaducts will carry three rail tracks in total, made up of one single track viaduct and one double-track viaduct. Work is now underway on the double-track viaduct.
These precast segmental viaducts are located at the northern tip of the Delta Junction – the triangular section of the railway that enables trains to run between London, Birmingham and the north. In total, Delta Junction is made of 13 viaducts and more than 10kms of track to carry HS2 over rivers, existing rail lines, local roads and motorways.
Sam Hinkley, Lead Senior Project Manager for Delta Junction at HS2 Ltd said:
“The completion of the River Tame West single-track viaduct is a big milestone for the Delta Junction team. In this very complex construction area, we’re building a network of 13 viaducts to carry new high-speed trains over motorways, existing rail lines, rivers and floodplains.
“Nearly 10,000 people in the West Midlands are delivering this world-class engineering, which will lay the foundations for Britain’s future rail network.”
In this location HS2 is also building the single-track River Tame East Viaduct. In addition, two Water Orton Viaducts are being built on either side of the River Tame West Viaducts, making it one of the most complex sections of the HS2 railway.
Used in the UK for the first time, the specialist cantilever method is being used to build nine of the 13 viaducts in Delta Junction, totalling 6,500 metres in length. The process installs pre-cast concrete segments produced at HS2’s nearby factory at Lea Marston.
Nicolas Gallone, Pre-cast Segmental Viaducts Project Manager at Balfour Beatty VINCI said:
“This is the first time in the UK we’ve used this innovative technique to build segmental viaducts. It’s an efficient and flexible process using cable stays from the cantilever structure to keep the viaduct in place, while a mast and swivel crane are used to place each segment in place.
“It’s a great achievement for the whole team and work now continues using this technique on the other eight pre-cast segmental viaducts in the Delta Junction.”
The two River Tame West Viaducts cross the River Tame near Water Orton and join the Curdworth Box, which will take high speed trains over the existing Birmingham to Derby railway.
Construction of the 20 piers to support the two viaducts started in 2023, with the first spans of the three-track section completed in Spring 2024. This initial phase involved placing the segments onto two 42 metre truss beams, moving them into place with a skidding trolley, and securing them by post-tensioning techniques.
Since then, the giant cantilever structure was built, using a 22-metre-high mast, including temporary post-tensioning cable stays and a 14-metre-high swivel crane.
The crane lifts and installs one concrete segment into place at a time, eventually completing each 45-metre span length. The permanent post-tensioning tendons are then stressed to allow the removal of the temporary cable stays, leaving the permanent structure securely in place. The same process is repeated between each pier until all the spans are complete.
The process was initially developed by Campenon Bernard, later becoming part of VINCI Construction. The mast and the swivel crane deployed on the River Tame West Viaducts are designed and manufactured by the company BERD.
A team of 40 people are currently involved in the operation, and a total of 2,742 concrete segments in total will be moved into place for all nine viaducts using this specialist technique. All the deck segments are due to be in place by late 2026.
When complete, HS2 will provide more reliable and faster services between London and the West Midlands, with trains reaching destinations further north via the existing railway. It will relieve pressure on the most congested southern end of the West Coast Main Line – creating extra capacity for local and freight services.
ENDS
