HS2 has reached another significant construction milestone in the West Midlands after engineers successfully installed the final viaduct spans over the M42 during a planned weekend motorway closure.
The complex operation, completed in the early hours of Monday morning, saw teams lift the last of six huge viaduct spans at the Water Orton viaduct site, allowing the motorway to reopen on schedule at around 4am.
At the same time, a separate HS2 construction team working three miles south near the NEC completed the installation of the final beams for the project's distinctive "twin box" structure, which will carry high speed trains across the motorway.
The work marks the culmination of four carefully coordinated weekend closures across the summer, delivered by HS2's West Midlands construction partner, Balfour Beatty VINCI (BBV).
With the structural elements now complete, engineers will move into the final stages of construction, including parapet installation on the Water Orton viaducts and concrete finishing works on the twin box ahead of track installation.
The achievement comes as HS2 enters what it describes as the peak of construction activity nationwide, while Chief Executive Mark Wild continues a programme-wide review aimed at improving delivery efficiency and managing costs.
Precision Planning Delivers Major Milestone
The extensive programme of works required detailed planning and coordination, with teams working simultaneously on multiple structures to minimise disruption to motorists and reduce the number of motorway closures required.
Agnes Usciak, HS2 Ltd's Senior Project Manager, said:
"I'd like to thank motorists and local residents for their patience during this huge programme of work – our biggest yet over the motorway network.
"Splitting a huge construction programme into four separate weekends requires meticulous planning, and our engineers executed the entire operation with pin-point precision, ensuring the motorway reopened on time, every time.
"Structural completion of the Water Orton viaducts and the twin box means the end is in sight for our bumper programme of motorway works this year."
The closures also enabled National Highways to undertake its own maintenance and infrastructure activities, including demolition work on Bickenhill Bridge near M42 Junction 6.
Twin Box Structure Takes Shape Near NEC
One of the most technically challenging elements of the weekend's work involved the completion of the twin box structure near the NEC.
The 300-metre-long bridge is formed of two large box structures designed to carry HS2 across the motorway at an angle. During the latest closure, a 150-strong workforce installed the final 44 roof beams above the southbound carriageway.
The completed roof consists of 175 precast beams weighing between 56 and 92 tonnes each. Using a 300-tonne crawler crane, crews carefully lifted the 23-metre-long beams into position between supporting walls, columns and the motorway central reservation.
Once complete, the structure stands 10 metres high and comprises two 145-metre-long walls, supported by 46 internal columns carrying a roof weighing approximately 9,800 tonnes.
Water Orton Viaducts Span Strategic Delta Junction
Meanwhile, work at Water Orton focused on completing the viaduct structures forming the upper section of HS2's triangular delta junction, which connects Birmingham to the main line heading north.
The twin viaducts cross several key transport and environmental corridors, including the M42, A446, Birmingham to Peterborough railway line and the River Tame.
A team of 75 engineers and construction specialists installed the final two 45-metre-long spans on Water Orton Viaduct 2 above the southbound carriageway, following the successful completion of similar works on Viaduct 1 in August.
Each span was constructed using 18 precast concrete segments manufactured at BBV's Kingsbury facility. Once assembled into 1,000-tonne structures, the spans were transported into position using self-propelled modular transporters before being secured with post-tensioning cables.
The design of the structures has been developed by BBV's Design Joint Venture, comprising Mott MacDonald, SYSTRA and WW+P Architects.
Team Effort Praised Following Summer Programme
Oliver Shore, Project Director for Balfour Beatty VINCI, said:
"The twin box and Water Orton Viaducts are three major structures that cross the busy M42 motorway. In just four weekends, we've completed the bridging works on each of them, closing the gap over the north and southbound carriageways.
"This was a huge engineering challenge and I'm so proud of the way our teams have responded. Their skill, dedication and hard work throughout the summer means we can move forward to the next exciting phase of our work."
Next Steps
Engineers will shortly extend Water Orton Viaduct 2 by a further 40 metres, closing the remaining gap above Gilson Road.
A further M42 closure is scheduled from 9pm on Friday 23 October until 5am on Monday 26 October, when teams will install parapets on the viaduct sections directly above the motorway.
During the same closure, contractors will also undertake the fourth and final launch of the M6 South Viaduct West deck. While the M6 main carriageway will remain open, the M42 North to M6 North connector road will be closed.
Elsewhere on the HS2 programme, progress continues with platforms now installed at Old Oak Common, completion of the project's first green tunnel and installation of the Curzon 2 Viaduct approaching Birmingham Curzon Street station.
Image and video credits: HS2
