Christmas works deliver major HS2 viaduct milestone

Construction of one of the most technically demanding sections of the UK’s high-speed rail programme advanced over the Christmas period with the completion of two critical viaduct spans near Water Orton in Warwickshire. The works form part of the Delta Junction, a large triangular rail intersection east of Birmingham that will enable high-speed services on HS2 to connect Birmingham with the main north–south route. The junction is comparable in complexity to major motorway interchanges, comprising flyovers, underpasses and multiple viaducts arranged to maintain operating speeds of up to 360 km/h on the mainline.

The Water Orton viaducts sit at the northern end of the Delta Junction and will carry southbound trains towards Birmingham Curzon Street and the Washwood Heath depot. During a planned five-day Christmas rail closure, engineers from Balfour Beatty VINCI safely installed two parallel spans over the existing Birmingham to Peterborough railway. This sequencing minimised disruption while allowing uninterrupted progress on a live railway corridor.

Each viaduct is constructed using a precast segmental cantilever method. Individual concrete segments are erected sequentially from each pier using temporary stays, followed by permanent post-tensioning through internal ducts once a span is complete. The supporting structure comprises 32 in-situ reinforced concrete piers, some reaching heights of 20 m, with segments manufactured at a dedicated facility near Lea Marston.

With the rail crossing complete, works will progress next to spans over the A446 and M42 motorway. Once finished, the two single-track viaducts will extend approximately 1.4 km across railways, roads, rivers and floodplains. The milestone demonstrates how careful planning, off-site fabrication and specialised erection techniques can deliver complex infrastructure safely within constrained operational windows.