Press Release

Balfour Beatty VINCI engineers have reopened the M6 ahead of schedule after sliding part of a huge new HS2 viaduct across the busy 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 the HS2 project in the West Midlands, the team used a ‘fully restrained’ sliding technique on Friday 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 26 September, the team worked tirelessly to complete the slide and reopen the road from 12.30pm on Sunday 28 September, 9.5 hours ahead of the schedule.   

Russell Luckhurst, the Balfour Beatty VINCI engineer leading the delivery of the works, said: “This weekend, we successfully delivered the second phase of a complex operation to launch a huge viaduct over the M6 motorway. Thanks to the team’s hard work and engineering expertise using new techniques, we were able the reopen the northbound carriageway on Saturday evening and then the full motorway was open again from Sunday lunchtime – which was great news for road users in the area.

“Assembly of these viaduct decks is taking place offline next to the motorway, and are being launched in three phases, to reduce disruption on the road network. Our focus is now on the third and final launch of the East Viaduct, which is planned for later this year.”

Caroline Warrington, HS2 Ltd’s 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 team worked closely with National Highways to consider the impact of the closure on other planned traffic management in the area, as well as other key local stakeholders including Birmingham Business Park, the NEC and Birmingham Airport.

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

Kamaljit Khokhar, National Highways’ Head of Planning and Development for the Midlands, said: “Our focus with any scheme is to minimise the impact on people using or living near our roads while ensuring the work is carried out safely and efficiently. We have worked closely with HS2 and their construction partners to do all we can to limit the disruption this huge infrastructure project will inevitably bring.

“We are pleased to see how well the work went at the weekend and applaud the innovative techniques HS2 has introduced which have significantly reduced traffic restrictions on this key route by constructing the structure next to the road.”

The team moved the viaduct using a series of winches, known as strand jacks, at an average speed of ten metres per hour. To reduce friction, the structure was slid across non-stick pads, using a material usually found on the surface of a household frying pan.

The viaduct was guided by a number of rollers placed on the piers, which ensured the deck remained on course for the full duration of the operation.

Each viaduct is formed of a hollow double-box structure made of weathering steel. The steel boasts a natural protective layer of oxidisation which gives it a characteristic ‘rusty’ appearance and reduces maintenance by eliminating the need for regular repainting.

Four pairs of concrete piers support the viaducts with the tallest one measuring 9.9m in height. A 4.5m high parapet will be installed on the side facing Chelmsley Wood to reduce noise and disturbance from passing trains.

ENDS