According to HS2 Ltd, installation of the Marston Box bridge represents the world’s longest box slide.
Around 450 people from Balfour Beatty Vinci (BBV) – HS2’s construction contractor in the Midlands – took part in the 40-hour operation between Christmas Eve and Boxing Day
The 12,600-tonne bridge was slid 163 metres at a speed of four metres per hour using hydraulic jacks.
This construction method minimised disruption to motorway traffic.
The 86 metre-long bridge structure was built on land next to the motorway over the last six months with a base, three walls and a top slab. The structure is designed for BBV by Mott MacDonald and Systra.
The M42 was closed for 10 days between junctions 9 and 10 for the actual slide but reopened in the new year.
The sliding mechanism, designed by Vinci subsidiary Freyssinet, allowed the box to be pushed into place over the motorway on a guiding raft.
On completion, the whole structure will be 190 metres long and will carry the HS2 railway over the M42 motorway.
Once built, the railway bridge will connect to Dunton Wood Embankment to the south and the Birmingham and Fazeley Canal Viaduct to the north.
HS2 Ltd’s civils delivery director, Mike Lyons said: “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. It’s fantastic to celebrate another big milestone for a project that is already providing work for almost 30,000 people today, and in the future, it will encourage people to use zero carbon public transport.”
BBV construction director Sasan Ghavami said: “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.
“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 with the aim of keeping disruption to an absolute minimum.”
The box slide operation was conducted out of HS2’s 550,000 sqm site at Kingsbury, where more than 1,000 people are currently working.