Engineers working for the HS2 project have reopened the M6 ahead of schedule after sliding part of a huge new viaduct across the motorway.

Over the weekend, the 230-metre long East Deck was moved into position over the M6 during a planned closure of the northbound and southbound carriageways near Birmingham Airport.

For the first time on this project in the West Midlands, the team used a ‘fully restrained’ sliding technique on Friday (26 September) before the closure, allowing the viaduct to launch over the M6 Junction 4 slip road, while maintaining traffic on the carriageway below. This new approach was introduced in collaboration with National Highways, to reduce the time of the operation and further minimise the impact on road users.

The twin 320-metre viaducts, which are being constructed in phases, will ultimately carry HS2 trains over the motorway between London and Birmingham, with an identical West Deck due to be pushed into position next year

This was the second phase of the operation, following a successful first phase in June this year. Beginning on Friday, the team worked to complete the slide and reopen the road from 12.30pm on Sunday 28 September, nine-and-a-half  hours ahead of the schedule.  

Caroline Warrington, HS2 head of delivery, said: “This is a major feat of engineering over a vital section of the UK’s transport infrastructure, so to be able to reopen the road early is a fantastic achievement. These viaducts will be pivotal to the HS2 network, carrying high speed trains over the M6 and creating better journeys for people for many years to come.”

To reduce disruption for motorists, the viaducts are being built in stages. Each section is assembled to one side before being pushed out over the motorway, with the next section added behind it. This multi-stage process means that the weight of the concrete and steel deck will increase with each push, eventually reaching 4,645 tonnes.

The complex operation is being led by HS2’s main works contractor, BBV – a team made up of Balfour Beatty and VINCI, supported by specialist steelwork company Victor Buyck Steel Construction (VBSC).

The operation comes amid a comprehensive reset of the HS2 project. Mark Wild, HS2 chief executive, is leading the major overhaul of the programme to ensure the railway is built in the most efficient way possible and for the lowest reasonable cost.

Work on the M6 south viaduct will now continue, with the next phase of the operation due to take place later this year.