First 170-Meter Launch Completed on UK HS2 Duddeston Junction Viaduct

en.Wedoany.com Reported - Engineering teams on the UK's HS2 high-speed rail project have completed the first major phase of the launch of the Duddeston Junction Viaduct over the Birmingham to Derby railway line, pushing the first 170 meters of the 700-meter-long structure over two important freight lines leading into Birmingham city centre.

The viaduct is the first and longest of five interconnected viaducts on the Curzon Approaches, which wind through Birmingham's industrial heartland along the approach to Curzon Street Station. The full viaduct will span six railway lines—three freight and three passenger—with all launching works expected to be completed by next summer. The viaduct follows a varying horizontal curve with a 3% gradient and stands 12 meters above the existing tracks below, making construction, logistics, and alignment particularly challenging.

In 2023, construction partner Balfour Beatty Vinci (BBV) began extensive preparatory works for the viaduct, relocating major utilities and treating heavily contaminated soil, before diverting two of the three freight lines onto new bridges and embankments. To complete the diversion, BBV built the Duddeston Mill Road Underbridge and worked with Network Rail to realign the two railway lines, creating a 20-meter-wide corridor between the existing tracks and providing the necessary clearance and safe working space for viaduct construction.

The weathering steel viaduct comprises 14 spans, each approximately 55 meters long, with a total weight of 6,835 tonnes. Under the construction plan, the team is assembling and launching seven of the spans in sequence: each span is added to the rear of the structure once completed, then pulled forward using proven sliding techniques; once the assembled spans have safely crossed the railway lines, the remaining seven spans will be lifted into place by crane on the other side of the railway. The site is tight and severely constrained, with up to 90 operatives and engineers working at any one time between six operational railway lines and a busy industrial area.

The Duddeston Junction Viaduct is supported by one abutment, two steel piers, four portal frames, and eight concrete piers, making it the longest viaduct on the Curzon Approaches, at over 400 meters longer than the Curzon 1 Viaduct, which is approximately 300 meters long.

Tony Zakaria, Senior Project Manager for HS2's Curzon Approaches, said the launch of the fifth and final viaduct on the Curzon Approaches is a clear sign of the progress the project is making in bringing high-speed rail to Birmingham. He said the final mile of HS2's route into the city centre is extremely challenging, and the project team is working with Network Rail to plan the entire operation in detail to minimise disruption to passenger and freight rail services.

Ross Rendell, BBV Section Manager, said the Duddeston Junction Viaduct is highly complex and a critical section of the HS2 route that will carry trains into and out of Curzon Street Station. The 705-meter-long structure is being built in a tight space alongside a live railway line, above Birmingham's industrial heartland, on an inclined curve, and must cross six railway lines, adding further challenges to construction. He said he is proud of the way the team has overcome these construction obstacles, and that the large viaduct is taking shape.

HS2 and BBV are now working with Network Rail to plan the next phase of works—the launch over the passenger railway lines—which is scheduled to begin in December. John Emery, Senior Project Manager at Network Rail, said the company has played a role in the complex installation of the viaduct over one of the busiest rail corridors in the region; the new structure will ultimately span all six lines of the existing railway, which operates more than 200 passenger and freight services every day. Through close collaboration with HS2 and the use of innovative engineering solutions where construction affects the existing railway, the project is minimising disruption to passengers and freight.

HS2's route through Birmingham city centre is taking shape. Upon completion, trains will emerge from Bromford Tunnel, travel through the Washwood Heath cutting, then climb via retaining walls at Saltley to join the Duddeston Junction Viaduct. At that point, the high-speed line sits approximately 12 meters above ground level, providing safe clearance over the six railway lines below.