By Ashley Karen
HS2 Ltd has delivered the world’s longest box slide to carry a 12,600t bridge into place through a motorway in Warwickshire.
A team of 450 people from HS2 Ltd.’s construction contractor in the Midlands, Balfour Beatty Vinci (BBV), has slid the Marston Box bridge into position across the M42.
A specifically designed sliding mechanism drove the box into place on a guiding raft over a distance of 165m – acknowledged as the world’s longest box slide.
This method of maneuvering the bridge was used to decrease disruption to road users and is a part of HS2’s plan to relieve the impact of building on local communities.
The operation was done during the Christmas period, as this was the calmest time on the roads. HS2 and BBV worked in partnership with National Highways to deliver the operation.
The 86m-long structure with a base, three walls and a top slab were constructed on land next to the motorway during the last six months. It was designed by a JV containing Mott MacDonald and Systra, working as the representative of BBV.
The specialist civil and structural engineering company, Freyssinet, has designed this sliding mechanism for maneuvering the bridge.
Once operational, the entire structure will be about 190m long and carry HS2 trains through the motorway towards Crewe in the north or Birmingham Curzon Street in the south.
The bridge will also be employed by HS2 trains headed for Interchange Station in Solihull, Old Oak Common Station and London Euston.
Mike Lyons, HS2 Ltd.’s civils delivery director, claimed: “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.”
In addition, Sasan Ghavami, Balfour Beatty Vinci’s construction director for the project pointed out: “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.”
The bridge was driven into place at a speed of 4m per hour and took 40 hours during a 10-day closure of the motorway between Junctions 9 and 10. The motorway opened to traffic again on 3 January.
BBV finished preparation work to install the Marston Box bridge, containing making a 3m deep cutting, installing and linking new drainage, and making foundations in February last year.
