The 220m-long structure is the last of five “double composite” viaducts on the central section of HS2 to be installed using the technique.

Delivered by main works contractor EKFB – Eiffage, Kier, Ferrovial and BAM – the steel and concrete deck was slid into place over three days using PTFE-covered pads to reduce friction.

Once in place, it will be lowered 60cm onto permanent bearings before work begins on the concrete deck and parapets.

The weathering steel viaduct spans a floodplain and Banbury Lane and is designed to blend with the surrounding countryside while managing local drainage.

EKFB technical director Janice McKenna said the “double composite” system – using hollow steel sections with reinforced concrete slabs – helped slash embodied carbon by up to 59% compared to traditional solid concrete beams.

HS2 project manager Sam Arrowsmith said the three-day slide was the culmination of four years of work, with final touches now underway across the five viaducts between the Chilterns and South Warwickshire.

Westbury is the most advanced, where cantilever formwork travellers are being used to build concrete decks span-by-span without cranes, boosting safety and efficiency.