HS2 has successfully completed the first major phase of launching the Duddeston Junction Viaduct, marking a significant step forward in delivering high-speed rail services into Birmingham Curzon Street Station.
The engineering achievement marks the beginning of a complex operation to carry the new railway across six existing rail lines, comprising three freight routes and three passenger tracks. The programme is expected to continue until summer next year.
The Duddeston Junction Viaduct is the first and longest of five interconnected structures that form the Curzon Approaches, the series of viaducts that will bring HS2 services into Birmingham city centre. Stretching more than 700 metres, it is widely regarded as one of the most technically challenging structures on the entire approach.
Unlike the neighbouring Curzon 2 Viaduct, which is known for its distinctive appearance, Duddeston Junction stands out because of its engineering complexity. The structure follows a continuously changing horizontal curve while climbing on a three per cent gradient from ground level to approximately 12 metres above the existing railway.
This month, project teams successfully launched the first 170 metres of the viaduct over two critical freight lines that play a vital role in moving goods into Birmingham.
Tony Zakaria, HS2’s Senior Project Manager for the Curzon Approaches said:
"Launching the fifth and final viaduct on the Curzon Approaches is a clear sign of the progress we are making to bring high speed rail to Birmingham.
"This final mile stretch of the HS2 route into the city centre is extremely challenging and we’ve worked exceptionally hard, in conjunction with Network Rail, to plan the whole operation with minimum disruption to both passenger and rail freight services".
Years of Preparation
HS2’s construction partner, Balfour Beatty VINCI (BBV), began preparing the site in 2023. The work involved diverting major utilities, remediating contaminated land and undertaking significant rail infrastructure modifications.
A key element of the programme required two freight lines to be moved onto new infrastructure, creating sufficient space to construct the viaduct and its supporting structures safely.
To achieve this, BBV delivered the Duddeston Mill Road Underbridge before working with Network Rail to realign the freight routes. The newly configured railway created a 20-metre-wide corridor between operational lines, allowing construction to progress while maintaining railway operations.
The site remains one of the most constrained construction environments on the HS2 project. Teams of up to 90 engineers and operatives are working within a narrow corridor bordered by six live railway tracks and neighbouring industrial facilities.
Sliding Into Position
The weathering steel viaduct consists of 14 spans, each approximately 55 metres long, with a total structural weight of around 6,835 tonnes.
To cross the active railway, engineers are assembling the viaduct in sections before progressively launching it forward using a proven sliding technique. Seven spans will be launched across the railway corridor, with each new span added to the rear before the entire structure is pulled forward.
Once the structure has safely crossed the live tracks, the remaining spans will be installed on the far side using heavy lifting cranes.
Ross Rendell, Section Manager at Balfour Beatty VINCI said:
"Duddeston Junction Viaduct is hugely complex and a key section of the HS2 route that will take trains in and out of Curzon Street Station.
"The 705-metre-long structure is being built inside a narrow space next to a live railway, where it curves above Birmingham’s industrial heartland at an incline. The viaduct also crosses over six railway lines, adding further challenges to its construction. I’m incredibly proud of the way my team has overcome these hurdles, as this huge viaduct continues to take shape."
The viaduct is supported by one abutment, two steel piers, four portals and eight concrete piers. At more than 700 metres long, it is over 400 metres longer than Curzon 1, making it the largest structure within the Curzon Approaches programme.
Next Phase Planned for December
HS2, BBV and Network Rail are now preparing for the next stage of the operation, which will involve launching the viaduct across the three passenger railway lines. This phase is scheduled to begin in December.
John Emery, Senior Sponsor at Network Rail, said:
"We’re proud to play our part in enabling the impressive yet complex installation of the Duddeston Junction Viaduct across one of the region’s busiest rail corridors which is needed for our partners at HS2 to construct Britain’s new high-speed railway.
"The striking new structure will eventually span all six lines of the existing railway which carries a mixture of over 200 passenger and freight services daily.
"By working closely with HS2 and adopting innovative engineering solutions where construction effects the existing railway, we’re continuing to minimise disruption to passengers and freight as much as possible."
Birmingham Approach Taking Shape
The latest milestone highlights the rapid transformation of HS2's route through Birmingham. Once complete, trains will emerge from Bromford Tunnel and travel through Washwood Heath before climbing towards the city centre via retaining structures in Saltley and across the Duddeston Junction Viaduct.
From there, HS2 services will continue into Curzon Street Station, crossing six existing railway lines while maintaining the necessary clearance for one of the UK's busiest rail corridors.
Image and video credit: Network Rail
