HS2 engineers have completed a major milestone in the construction of the new high-speed railway in the West Midlands, lifting the final viaduct spans into position over the M42.
The complex operation at the Water Orton viaduct site was completed during a planned weekend closure of the motorway, with the M42 reopening at around 4am on Monday morning as scheduled.
The work was led by HS2’s West Midlands construction partner, Balfour Beatty VINCI (BBV), as part of a carefully coordinated programme designed to make the most of motorway closures and minimise disruption.
At Water Orton, a team of around 75 people installed the final two 45-metre spans of Water Orton Viaduct 2 over the southbound carriageway. Each span comprises 18 precast concrete segments, manufactured locally at BBV’s concrete batching plant in Kingsbury.
Once assembled, the approximately 1,000-tonne spans were transported into position using self-propelled modular transporters before being secured with tensioning cables within the hollow structure.
The two Water Orton viaducts form part of the ‘delta junction’ connecting Birmingham with the main HS2 route heading north. Together, they cross the M42, A446, the Birmingham–Peterborough railway line and the River Tame.
Final beams installed on ‘twin box’ structure
The same weekend also saw engineers complete another significant piece of HS2 infrastructure around three miles away, near the NEC.
A 150-strong team installed the final 44 beams forming the roof of the 300-metre-long ‘twin box’ structure, which will carry HS2 trains over the M42.
The structure consists of two large concrete boxes, a design adopted because of the angle at which the railway crosses the motorway. Its roof is formed from 175 individual beams, each weighing between 56 and 92 tonnes.
A 300-tonne crawler crane was used to lift the 23-metre-long beams into position, spanning the supporting walls and columns on either side of the carriageway and within the central reservation.
The completed structure is around 10 metres high, with two 145-metre-long walls and 46 internal columns supporting the 9,800-tonne beamed roof.
With the major lifting operations now complete, construction teams can move on to the final stages, including installing the remaining parapets on the Water Orton viaducts and completing the final concrete pours on the twin box ahead of track installation.
The programme has been carefully sequenced across a series of motorway closures, with engineers working simultaneously across the three structures to reduce the overall number of closures required.
National Highways also used the latest closure to carry out its own programme of works, including demolition of Bickenhill Bridge on the northern side of the M42 Junction 6 roundabout.
The progress at Water Orton and the NEC highlights the scale and complexity of the engineering now taking place as HS2 reaches the peak of construction activity in the West Midlands. It also demonstrates the importance of coordinating major infrastructure projects to minimise disruption while maintaining momentum on delivery.
The structural design for the Water Orton viaducts has been undertaken by Balfour Beatty VINCI’s Design Joint Venture, comprising Mott MacDonald and SYSTRA, with WW+P Architects.