The Colne Valley Viaduct has officially become the UK’s new longest rail bridge at 3.4km( or 2.1 miles), after over two years of construction
The viaduct structure’s completion means that the 3.3km Tay Bridge linking Fife and Dundee has finally ceded the crown of Britain’s longest rail bridge to HS2, a record it had held since 1887.
With construction managed by main works contractor Align JV – a team consisting of Bouygues Travaux Publics, Sir Robert McAlpine and VolkerFitzpatrick, the gently-curved structure on London’s north-western edge stretches across the Colne Valley near the M25 motorway and the village of Denham.
It will carry high speed trains running to and from the capital at speeds of up to 320km/h (200mph).
The pre-cast segments were tailored to match the curve of the line
Construction work on the viaduct’s deck began in May 2022, where a massive launching girder was used to lower the bridge’s 1,000 uniquely-shaped deck segments into place.
The 160 metre long launcher used a balanced-cantilever method to lower deck segments into place to form half an arch either side of the 56 piers before moving to the next pier to complete the arch span by repeating the process, going from north to south.
The viaduct’s construction will next move into the rail systems installation phase as it progresses towards becoming an operational part of the new high speed railway between 2029 and 2033.
Once the main civil engineering phase of construction ends, the factory and surrounding buildings will be removed and the whole area between the viaduct and HS2’s 10-mile tunnel beneath the Chiltern Hills just to the north will be transformed into an area of chalk grassland and woodland as part of HS2’s ‘green corridor’ project.
“A historic achievement of which we can all be proud”
HS2 Ltd senior project manager Billy Ahluwalia said: “Lowering the Colne Valley viaduct’s final deck segment into place today marks the culmination of more than 10 years of planning, design and construction. I pay tribute to the dedicated team that has delivered a bridge that is both the longest on HS2 and has become the United Kingdom’s longest railway bridge – taking a record that had stood for nearly 140 years. That is a historic achievement of which we can all be immensely proud.”
Align project director, Loïc Menard said: “The Align team, along with our supply chain partners VSL who operated the launching girder, have worked very hard to get us to where we are today, ahead of plan. Working together and as a truly integrated team that includes HS2, Align, our design partners, our supply chain colleagues and the local community, we have built the Colne Valley Viaduct which will be the iconic feature of HS2.”
The milestone comes shortly after the completion of HS2’s first major viaduct, at Highfurlong Brook in Northamptonshire.
