Engineers working on HS2 in the West Midlands are preparing to launch the next phase of a major viaduct installation over the M6 near Chelmsley Wood.
The first section of the M6 South viaduct’s west deck, which will carry high-speed trains towards Birmingham, is scheduled to be moved into position on 11 April 2026.
Complex operation set for April
The 107-metre section, weighing around 1,250 tonnes, will be slid into place over the M6 junction 4 southbound slip road using a hydraulic jacking system. The operation is expected to take two days to complete.
A 45-strong engineering team from Balfour Beatty VINCI (BBV), HS2’s main contractor in the West Midlands, will carry out the work. The slip road will close from 5am on 11 April, with reopening planned for 10pm on 12 April following final safety checks.
The viaduct is being assembled in four sections due to site constraints, including limited space, staggered abutments and the curvature of the road layout.
Building on previous milestone
The west deck will sit alongside the east deck, which was installed in 2025 in three stages. The final phase of that operation marked a UK-first, with the viaduct successfully slid into place while traffic continued to flow beneath on the motorway.
Ian Clarke, HS2 Ltd’s project manager for the M6 works, said:
“After safely completing the first viaduct on time, our engineers have wasted no time in forging ahead with the second installation.
“Thanks to the world-class engineering techniques we’re adopting on HS2, we’ve once again been able to reduce the number of temporary closures on the motorway while we carry out these essential works.”
Engineering challenges and preparation
The west deck presents additional complexity compared to the earlier installation, requiring an extra stage due to the shorter launching platform available on site.
Ahead of the launch, engineers have fitted a launching nose to guide the structure and are completing installation of the propulsion system, including cables and hydraulic jacks.
BBV civil engineer Russell Luckhurst, who is leading the works, said:
“Building on the success of installing the East deck viaduct last year, we’re gearing up for the first launch of the neighbouring West deck in April.
“We’re using the same sliding technique, where a giant hydraulic jack will push the viaduct across the motorway in multiple stages throughout the year. The previous launches provided the team with invaluable experience, which they’re eager to apply to future works on this eye-catching structure spanning the M6.”
Minimising disruption
HS2 Ltd is working closely with National Highways to manage the impact of the works, with a focus on keeping disruption to road users to a minimum.
Kamaljit Khokhar, National Highways Midlands Head of Planning and Development, said:
“The impact of these major construction works on the people who use our roads is always our focus and we will continue to work with HS2 and their partners to ensure both the safety of road users and that disruption is kept to a minimum while this second viaduct is put into place.
“We are very supportive of any initiatives which will reduce disruption for drivers and local communities and welcome the innovation being displayed by HS2 to keep the number of closures required to a minimum.”
Further works planned
The installation of the west deck marks the start of a wider programme of viaduct construction across the West Midlands motorway network throughout 2026.
While the M6 will remain open during later phases, further works are expected on both the M6 and M42 during the summer, with detailed schedules to be confirmed.
