• Temporary bridge crosses lakes near Hillingdon, Denham, and Harefield
  • Download images showing the temporary access bridge and construction of the record-breaking Colne Valley Viaduct

HS2 today confirmed that a temporary access bridge – put in place during the construction of the 3.4km Colne Valley Viaduct – has already taken more than 10,000 vehicle journeys off local roads in its first year of operation.

Running alongside what will become the UK’s longest viaduct, the temporary bridge allows construction vehicles to cross a series of lakes and waterways near Denham on the outskirts of London.

Construction of the HS2 project, which is designed to improve rail links between London, Birmingham and North, help level-up the economy and provide a low carbon alternative to car and air travel, is ramping up across the UK with almost 30,000 jobs now supported by the project.

As well as taking vehicles off local roads, the 800m long temporary bridge, completed in February 2022, is also used to get equipment out to where the viaducts piers are being built in the lake.

Lorries making deliveries to site all arrive from the M25 and follow a 6km internal access route via HS2’s South Portal construction site, and the temporary bridge, instead of using local roads – significantly reducing the impact on the local community during construction.

It was built by HS2’s main works contractor Align JV – a team made up of Bouygues Travaux Publics, Sir Robert McAlpine and VolkerFitzpatrick, working with specialist subcontractors KVJV, Kilnbridge, VSL, Tarmac, VPH and Volker Stevin, who are constructing the Colne Valley Viaduct.

HS2 Ltd’s Senior Project Manager, Billy Ahluwalia said:

“The Colne Valley Viaduct will form a key part of the HS2 route – helping to deliver better connections across the UK, free up rail capacity on the existing train network, and offer passengers zero carbon travel options.

“But it is also essential that we work to reduce the impact on communities during construction. That’s why I’m delighted to see that the temporary access road has taken so many vehicle journeys off local roads in it’s first year of operation.”

Construction of the Colne Valley Viaduct is now well underway, with all the foundation pilling for the 56 piers and 2 abutments now complete.

The main deck of the viaduct is being built using a ‘launching girder’. The 160m long bridge-building machine is the only one of its kind operating in the UK and is used to lift the giant concrete deck segments that form the viaduct’s arches into position which are being cast in purpose-built temporary factory at the nearby South Portal site. The girder moves from pier to pier constructing the deck as it goes.

Almost 200, out of a thousand deck segments, have now been installed, with each one weighing up to 140 tonnes. To allow for the gentle curve of the viaduct as it crosses the valley, each segment is unique.

Align’s Surface Operations Director, Derek van Rensberg said:

“We are making good progress constructing the Colne Valley Viaduct, and by completing the temporary access road with bridges over the lakes, I am delighted that it has resulted in a significant number of vehicles being taken off local roads, thereby minimising the impact of our activities on the local community.”