HS2 has started production of 2,742 huge concrete segments which will be used to build the Delta Junction, a triangle-shaped series of viaducts that will take high-speed trains between London, the Midlands and the North.

The deck segments – which each weigh up to 80 tonnes – are being made on site at a purpose-built outdoor factory at Kingsbury, Warwickshire.

The 55,000 square metre site employs around 1,000 people in total, with a team of 200 tasked with building the network of 9 viaducts at Water Orton and Coleshill, crossing motorways, roads and footpaths.

The site also hosts a Skills Academy to support local people into employment or further training.

Panos Psathas, HS2 senior project manager for Delta Junction, said: “We’re pleased to see this next milestone on the Midlands section of HS2, as the first segments come off the production line, ready for the BBV team to start building the viaducts next year.

“The Kingsbury pre-cast segment factory is a major HS2 site in the Midlands, supporting around 1,000 jobs. Importantly, it’s also home to BBV’s Skills Academy, providing training opportunities across a whole range of disciplines for people in the region.”

The pre-cast yard will turn out up to eight segments per day, with a variable weight between 50 and 80 tonnes. The segments are 3.5m high and come in two different widths - 7m or 11m, to support single track and double track sections of the railway.

A 54 metre-long gantry crane lifts each segment during the manufacturing cycle, ahead of their onward transport to nearby Water Orton and Coleshill ready for on-site assembly.

Pascal Albertelli, project manager at Balfour Beatty VINCI oversees the construction of the 9 viaducts, from the substructures works to deck erection, including segment precast production at the Kingsbury site.

He said: “Watching the first segments roll off the production line recently at our pre-cast yard in Kingsbury was a really proud moment for me and my team, who’ve worked tirelessly over the past two years to get us to this point.

“It’s a fascinating phase of the project to be involved in, because of the sheer scale and the innovative production methods we’ve introduced here. It’s incredible to think that this open-air factory will help to build HS2’s Delta Junction, located just a few miles down the road.”

HS2’s Delta Junction forms two spurs which branch off the main HS2 line between London and the North. Trains will travel between the Birmingham Curzon Street Station terminus and the North, and between Curzon Street and the South, accounting for around 10km of HS2 tracks.

The project is being delivered by HS2’s main works contractor for the West Midlands, Balfour Beatty VINCI (BBV) who are constructing 90km of HS2 between Long Itchington in Warwickshire to the centre of Birmingham and on to Staffordshire.

The first segments made at Kingsbury will be used to build the 500 metre River Tame West viaduct near Water Orton. This viaduct crosses the River Tame valley and joins the Watton House Embankment to the Faraday Embankment for trains on the journey from London to the North. Construction of the substructures supporting the viaduct deck started earlier this year, with deck construction starting by the end of 2023.

Teams are employing a ‘match-casting’ technique, which involves casting each segment against the following segment in a production line, creating a seamless viaduct deck when installed.

Each segment is uniquely precise and adjustable by as little as 5mm. This approach - where each segment is poured against the previous one - ensures the whole arch fits perfectly when assembled on site.