HS2 engineers have completed the first major stage of launching the Duddeston Junction Viaduct, sliding the first 170 metres of the new structure over live freight railway lines in Birmingham. At 700 metres long, it is the longest of the five interconnected Curzon Approaches viaducts carrying HS2’s final mile into Curzon Street Station, with the full launch across six active rail lines expected to be completed by mid-2027.

Sliding a 6,835-Tonne Structure Over Live Track

The viaduct comprises 14 spans, each approximately 55 metres long, with a combined weight of around 6,835 tonnes. HS2’s construction partner, Balfour Beatty VINCI (BBV), is assembling each span at the rear of the structure before sliding it forward across the railway tracks below, a method selected specifically to avoid extended closures of the rail network. The final seven spans, located beyond the existing rail corridor, will instead be lifted into position by crane once the launched sections have moved clear of the tracks.

The structure follows a 3 percent gradient and curved alignment, both of which HS2 said increase the complexity of the launch operation. Working within a constrained urban site bordered by an industrial estate and live rail operations, BBV has up to 90 engineers and operatives on site at any one time. Tony Zakaria, HS2’s Curzon Approaches senior project manager, described it as “an extremely challenging” final stretch into the city centre, saying the team worked closely with Network Rail “to plan the whole operation with minimum disruption to both passenger and rail freight services.”

Years of Preparation Before the First Span Moved

BBV began preparatory work at the Duddeston Junction site in 2023, relocating major utilities and addressing ground contamination long before construction of the viaduct itself began. To create sufficient working space, the team diverted two of the three affected freight lines onto a newly constructed bridge and embankment, a realignment delivered jointly with Network Rail that created a 20 metre-wide corridor for assembling and launching the viaduct.

That preparatory diversion enabled this month’s crossing of the freight lines. The next and more sensitive phase, which involves launching the viaduct over three passenger lines, is scheduled to start in December, with the full operation not expected to conclude until mid-2027. HS2 and Network Rail have also highlighted more immediate disruption: work near Duddeston over the August bank holiday weekend to install the adjoining Saltley viaduct section will affect rail services, and passengers are being advised to check National Rail Enquiries before travelling.

The Last of Five Viaducts Feeding One Station

Duddeston Junction is the fifth and final viaduct in the Curzon Approaches sequence, joining a group of structures Construction Review has tracked as they have progressed over the past year. Curzon 2, the tallest structure in the sequence at more than 40 metres and informally known as the Bellingham Bridge, completed its own 4,200-tonne bridge assembly in May 2026 ahead of a 180 metre launch. While Curzon 2 features a prominent steel arched truss designed as a visible addition to Birmingham’s skyline, Duddeston Junction is a longer, lower-profile concrete structure whose principal engineering challenge is navigating a live freight and passenger rail corridor rather than achieving significant clearance height.

Once finished, the viaduct will connect the Bromford Tunnel area through Saltley to Curzon Street Station, carrying HS2’s tracks 12 metres above the existing railway. The station itself reached a separate construction milestone in March 2026, when HS2 completed a 2,011-pile foundation across the 400 metre city-centre site, moving the station from groundwork towards viaduct integration and above-ground construction. Curzon Street Station’s design was finalized earlier in May 2025, when Birmingham City Council approved revised plans from construction partner Mace Dragados Joint Venture, clearing the way for the structural works now progressing alongside the approach viaducts.

Visible Progress Against a Backdrop of Rising Costs

The Duddeston milestone comes amid continued scrutiny of HS2’s wider budget and schedule. Construction Review reported in May 2026 that the project’s construction cost had risen to £102.7 billion, with the first passenger services between Old Oak Common and Birmingham Curzon Street now expected between 2036 and 2039, more than a decade later than originally planned. Visible progress on structures such as Duddeston Junction and Curzon 2 provides HS2 with tangible evidence of construction progress even as the programme’s overall cost and timetable remain under public scrutiny.

What Happens Next

The freight-line crossing completed this month represents only the first half of Duddeston Junction’s launch. HS2 and BBV must still move the viaduct across three active passenger lines beginning in December, a more sensitive phase given the volume of passenger traffic through the corridor, before the structure is expected to be fully launched by mid-2027.

Project Fact Sheet

• Project Name: Duddeston Junction Viaduct, Curzon Approaches
• Location: Duddeston/Saltley, Birmingham, West Midlands, United Kingdom
• Project Value: Part of HS2 Phase One, London to Birmingham, budgeted overall at roughly £102.7 billion as of May 2026
• Client/Owner: HS2 Ltd
• Main Contractor: Balfour Beatty VINCI (BBV)
• Key Components: 700 metre viaduct comprising 14 spans of approximately 55 metres each, with a combined weight of about 6,835 tonnes; launch over six active railway lines, including three freight and three passenger lines; supporting freight-line diversion bridge and embankment constructed with Network Rail
• Construction Start: Preparatory works began in 2023; first major freight-line launch phase completed in August 2026
• Expected Completion: Passenger-line launch phase begins in December 2026; full viaduct launch expected to conclude by mid-2027

Project Team

• Client/Owner: HS2 Ltd
• Main Contractor: Balfour Beatty VINCI (BBV)
• Infrastructure Partner: Network Rail
• Senior Project Manager, Curzon Approaches: Tony Zakaria, HS2 Ltd