A viaduct in Northamptonshire has officially become the first on the HS2 project to be completed as engineers installed the last stretch of parapet along the sides.

The 163m long Highfurlong Brook Viaduct, near the village of Aston le Walls, is one of more than 50 being built as part of the new rail project.

Consisting of seven spans, the viaduct crosses Highfurlong Brook’s floodplain at a height of around 9m.

Each span is made up of four beams weighing up to 56 tonnes and were lifted into position last year to form the backbone of the structure.

Each of the beams – which are up to 25m long - were manufactured off site before being delivered overnight to reduce disruption for local road users.

The deck – which will support the track and electrical systems – was poured in situ earlier this year, with the parapets along each side manufactured off site and installed over the last four months.

The viaduct is one of around 500 bridging structures on the HS2 project which range from small road bridges and drainage culverts to massive viaducts like the record-breaking Colne Valley Viaduct which will become the longest in the UK when its deck is completed.

Bill Price, HS2 project client, said: “The completion of our first viaduct is a major moment for the HS2 project and I’d like to thank everyone in our integrated project team and supply chain partners who have worked so hard to get us where we are today.

“It’s great to see Highfurlong Brook finished and I look forward to seeing many more of our viaducts, bridges, stations and tunnels come together over the next few years.”

Highfurlong Brook was delivered over two years by HS2’s main works contractor EKFB – a group made up of Eiffage, Kier, Ferrovial Construction and Bam Nuttall.

The design was done by EKFB’s design partner ASC working with architect Moxon.

With the viaduct now structurally complete, the next phase of construction will include delivering the earthworks that support the railway at either end before a separate set of contractors comes in to install the rail systems, including track, signalling, power and communications systems.

HS2 between London and the West Midlands is expected to start operation between 2029 and 2033.