HS2 celebrating a world-first as 450 workers complete a box ‘bridge slide’ in Warwickshire


Balfour Beatty VINCI, bridge construction, HS2, UK,


HS2’s contractor Balfour Beatty VINCI (BBV) delivers world’s longest box slide to move a 12,600 tonne bridge into place over the M42 in Warwickshire.

HS2 Ltd is today celebrating a world-first as around 450 people from HS2’s construction contractor in the Midlands – Balfour Beatty VINCI (BBV) – slid a 12,600 tonne bridge a record 165 metres to position it across a motorway in Warwickshire.

The site team worked around the clock to move HS2’s Marston Box bridge into place over the M42 during the Christmas period. The dramatic operation took 40 hours, at a speed of 4 metres per hour, from Saturday, 24 to Monday, 26 December, during a 10-day closure of the motorway between Junctions J9 and J10 (northbound and southbound). The motorway is scheduled to reopen at 0500 on Tuesday, 3 January 2023.

“This is yet another astonishing achievement by HS2 – a project which is already changing lives through employment and regeneration and will completely transform the way we live and work once trains hit the tracks,” says Rail Minister Huw Merriman. 

“Thank you to the 450 people working over the Christmas period on this incredible operation, who are playing their part in bringing this pioneering project to life. What a way to end the year,” says Rail Minister Huw Merriman.


“This is the first box slide of its kind over a motorway in the UK, and we believe it’s also the world’s longest slide, so it’s a great achievement for HS2 as we quickly approach peak construction. Celebrating another big milestone for a project already providing work for almost 30,000 people today is fantastic. In the future, it will encourage people to use zero carbon public transport,” says HS2 Ltd’s Civils Delivery Director, Mike Lyons. 

Over the last six months, the giant 86 metre-long structure was built on land next to the motorway. The structure, developed by a Design Joint Venture of Mott MacDonald and Systra, working on behalf of BBV, has a base, three walls and a top slab.

The sliding mechanism, designed by specialist civil and structural engineering company Freyssinet, allowed the box to be pushed into place over the motorway on a guiding raft over a distance of 163 metres – believed to be the world’s longest box slide.

On completion, the whole structure will be around 190 metres in length. They will carry HS2 over the motorway as it heads north to Crewe or on its southward journey as it loops into Birmingham Curzon Street or continues straight on to Interchange Station in Solihull, Old Oak Common Station and London Euston.

Once built, the railway bridge will connect to Dunton Wood Embankment to the south and the Birmingham and Fazeley Canal Viaduct, which crosses the heritage canal, to the north.

This construction method, which allowed it to be moved into place in one movement, meant only two one-week motorway closures over 12 months, dramatically reducing disruption for road users.

“We’re extremely proud to have successfully delivered the world’s longest box slide. It’s a huge achievement for our project team and everyone connected with Balfour Beatty VINCI,” says Balfour Beatty VINCI’s Construction Director, Sasan Ghavami. 

“We’ve used innovative construction techniques and worked tirelessly throughout the Christmas period to move this 12,600 tonne bridge over the M42 motorway – all done to keep disruption to an absolute minimum,” says Balfour Beatty VINCI’s Construction Director Sasan Ghavami. 

The box slide operation is part of HS2’s 550,000 square metre site at Kingsbury, where over 1,000 people are working. Around 6,800 people are already employed in HS2’s construction in the West Midlands, with thousands more jobs supported through the wider supply chain.

HS2 and its contractor Balfour Beatty VINCI (BBV), have partnered with National Highways to deliver this complex operation.

“We’d like to thank motorists for their patience during the closure of the M42. It’s never easy to close a busy motorway such as the M42 for an extended period, but it has been vital to ensure the safety of the workforce and motorists while this work is taking place,” says National Highways Senior Network Planner Frank Bird. 

“We’ve been working collaboratively with HS2 for the past 18 months to ensure the operation ran smoothly and to help keep disruption to a minimum for drivers. The installation of the new Marston Box bridge is a significant milestone in the HS2 project, and it’s great to see it finally in place,” says National Highways Senior Network Planner Frank Bird. 

Source: © High Speed Two Ltd 2023

Image source: © High Speed Two Ltd 2023

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