Construction of the Colne Valley Viaduct, which is set to carry HS2 across the Colne Valley viaduct near Denham in Buckinghamshire, has passed the half-way mark.

At over two miles long, when complete, it will be Britain’s longest railway bridge, and will carry HS2 trains at speeds of up to 200 mph between the line’s London and Chiltern tunnels.
Construction of the viaduct began in December 2021 and, when complete, will have 56 main piers that carry the bridge deck across both land and water.

A huge launching girder is being used to facilitate construction, with it working south across the Colne Valley from one pier to the next to lower and fix the viaduct’s deck segments into place.

In total there are 1,000 deck segments to be installed, each weighing up to 140 tonnes each, more than 500 of the Colne Valley Viaduct’s, Each segment has an individual shape that allows the structure to gently curve and blend into the landscape as it carries the railway 2.1 miles over land, lakes, and the Grand Union Canal. So far, over 500 segments have been installed.

The latest publication of HS2’s Construction Review shows since the main construction started in August 2020, progress at 350 worksites between London and the West Midlands has seen work started on two-thirds of the railway’s 55 viaducts, over 20 miles of single-bore tunnels have been driven, which is more than a third of the total, and these are supported by 160,000 tunnel segments.

HS2 Ltd’s main civil works contractor for construction of the Colne Valley Viaduct is being led by Align JV, which consists of a team made up of Bouygues Travaux Publics, Sir Robert McAlpine and VolkerFitzpatrick.

Sir Jon Thompson, HS2 Ltd’s Executive Chair, said: “HS2 is by far the biggest and most ambitious infrastructure project in the UK and it’s fantastic to see phenomenal feats of civil engineering like the Colne Valley Viaduct taking shape.

“The enormous progress made in the last three years along the length of the route between London and the West Midlands is testament to the skill and dedication of the thousands of people who work on this transformational project every day.”

HS2 Ltd senior project manager Billy Ahluwalia said: “I pay tribute to the teamwork, professionalism and dedication of everyone involved in getting this landmark viaduct to its halfway mark.

“There’s still a long way to go to complete the viaduct; which I know will be achieved with the same dedication of everyone in the Align JV and its supply chain partners.”

Align’s Surface Operations Director, Derek van Rensburg said: “To have manufactured and installed over 500 segments, which equates to over one mile of the viaduct deck, is another great achievement for the Align team involved, working with our supply chain partners and in particular VSL.

“It is also important to note that we have delivered this work safely and in the process we have endeavoured to minimise any disruption for the local community.”