HS2 marks completion of UK's largest rail bridge

A historic milestone has been reached in the ongoing construction of HS2. On September 5, contractors working on the Colne Valley viaduct in South Hertfordshire successfully lowered the final deck segment into place, solidifying its position as the longest rail bridge in the United Kingdom.

Stretching over 2.1 miles across the viaduct will carry high-speed trains at speeds of up to 200miles per hour. Its completion marks the end of the Tay Bridge's 137-year reign as the longest rail bridge in the country.

The construction of the Colne Valley viaduct has been a complex engineering feat, involving the use of a massive launching girder to lower 1,000 uniquely shaped deck segments into place. The viaduct's distinctive curved design was achieved by using pre-cast segments that were specifically shaped to fit the desired curvature.

It’s main contracting partner is Align JV – a team consisting of Bouygues Travaux Publics, Sir Robert McAlpine and VolkerFitzpatrick.

Once completed, the Colne Valley viaduct will form a vital part of the HS2 route, connecting London to Birmingham. The construction team will now move on from the viaduct’s construction and 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.

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.”

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.”