HS2 Viaduct Deck Slide Over M6 Achieves Major Milestone Near Birmingham Airport
Balfour Beatty VINCI has successfully completed the first phase of a major engineering feat, sliding the initial section of a 320-metre viaduct into position for HS2 over the M6 near Birmingham Airport. The operation marks a significant milestone in the construction of a twin-deck structure that will eventually carry high-speed trains across the motorway.
Over the weekend, the ‘East Deck’ of the M6 South Viaduct was launched 119 metres across a slip road adjacent to the motorway. To minimize disruption to traffic, the viaduct is being assembled to the side and gradually slid into place over three weekends. Each slide increases the total weight—from 1,300 tonnes for the first stage to a projected 3,290 tonnes for the final phase—due to the addition of more deck sections.
This progressive method allows for the viaduct to be launched with pre-cast concrete slabs already mounted on its steel structure, further limiting motorway closures. Once complete, the East Deck will carry two southbound tracks toward London, while a parallel West Deck will be installed next year to carry trains northbound to Birmingham and beyond.
Russell Luckhurst, Engineering Lead for Balfour Beatty VINCI, highlighted the significance of the achievement:
“This complex viaduct spanning the M6 and adjoining slip roads is really beginning to take shape. It’s a huge achievement for the dedicated team who’ve worked tirelessly over the past three years. We now look ahead to the next two launches later this year.”
HS2 Ltd’s Senior Project Manager, Liam Kenney, added:
“It’s great to see the first section of the East Deck in position. Once complete, this infrastructure will enhance journey times and ease capacity on the existing rail network. I’d like to thank everyone involved for completing the operation safely and reopening the road 11 hours ahead of schedule.”
The intricate launch process is led by Balfour Beatty VINCI with support from Victor Buyck Steel Construction (VBSC). The team is working in close coordination with National Highways and local stakeholders including the NEC and Birmingham Airport.
Victoria Lazenby, Regional Director for National Highways in the Midlands, praised the innovation:
“We know how vital it is to reduce disruption for motorists. The collaborative effort and smart engineering solutions here are a perfect example of how complex road and rail projects can be delivered with minimal impact.”
The deck was moved using strand jacks—industrial winches pulling the structure at 12 metres per hour—sliding it over Teflon-like pads to reduce friction. A 36-metre-long steel “launch nose” at the front of the structure helped guide and support the advancing viaduct section.
Temporarily supported by piers and restrained by custom equipment, the viaduct’s structure consists of hollow double-box girders made of weathering steel. This rust-colored steel forms a protective oxidized layer, minimizing the need for repainting and lowering long-term maintenance.
The four main viaduct spans are supported by concrete piers, the tallest standing at 9.9 metres. A 4.5-metre-high acoustic parapet will be added along the Chelmsley Wood-facing side to reduce noise for nearby communities.
The structural design was delivered by Balfour Beatty VINCI’s design joint venture of Mott MacDonald and SYSTRA. Tom Dutton, Senior Design Coordinator at Mott MacDonald SYSTRA DJV, noted:
“This launch marks a pivotal moment following years of design and planning. The collaboration between UK and French teams, along with Victor Buyck’s expertise, has overcome the immense challenges of both design and implementation.”
With the first deck in place, work now continues on assembling the next sections in preparation for two more slides later this year, as HS2 progresses towards reshaping the UK’s rail infrastructure.
