HS2 has announced the start of construction on the UK’s longest railway bridge with the launch of a 700 tonne bridge-building machine at an event attended by HS2 minister Andrew Stephenson
The Colne Valley Viaduct will be the UK’s longest railway bridge, stretching for more than two miles across a series of lakes and waterways between Hillingdon and the M25.
The railway bridge 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.
‘A landmark moment for HS2 and a feat of British engineering’
HS2 Minister, Andrew Stephenson said: “HS2 began construction on what’s set to be Britain’s longest railway viaduct, a landmark moment for HS2 and a feat of British engineering, taking the HS2 line from London, and into Hertfordshire and Buckinghamshire.
“Infrastructure is the backbone of HS2 and this viaduct will be integral to delivering faster journeys and an increased capacity rail network.”
The 160m long bridge-building machine is known as a ‘launching girder’, and is the only one of its kind in the UK. It will be used to lift the giant concrete deck segments that form the viaduct’s arches into position. Once each section is complete, the machine will inch itself forward into position to build the next stage.
A total of one thousand deck segments will be needed, with each one weighing up to 140 tonnes. To allow for the gentle curves of the viaduct as it crosses the valley, all the segments are slightly different shapes and made on site at a purpose-built temporary factory close to the north abutment.
‘Yet another big milestone for HS2’
Welcoming the milestone, HS2 Ltd chief executive Mark Thurston commented: “I’m absolutely delighted that we have started work to assemble the giant deck segments that will form the Colne Valley Viaduct.
“It is yet another big milestone for HS2 Ltd, as we work to deliver the UK’s new high speed railway. Once complete, this record-breaking structure will form a key part of the HS2 railway – helping to deliver better connections across the UK, free up rail capacity on the train network, and offer passengers a zero carbon travel option.
“I’d like to thank all those involved in getting us to this exciting stage and look forward to seeing the whole viaduct come together over the coming years.”
The construction of the UK’s longest railway bridge is being led by HS2’s main works contractor Align JV – a team made up of Bouygues Travaux Publics, Sir Robert McAlpine and VolkerFitzpatrick.
The design of the viaduct is set low into the landscape, to enable views across the surroundings and to minimise the viaduct’s footprint on the lakes.
The construction team have also completed the construction of three of four jetties across the lakes to get equipment into position to support the construction and help take construction vehicles off local roads.
Where the viaduct crosses the lakes, the piles are being bored directly into the lakebed, using a cofferdam to hold back the water while the pier is constructed.
