HS2 begins construction of UK's largest railway bridge near Denham
The HS2 project is designed to improve rail links between London, Birmingham and the North.
Work has begun on what will be the UK's longest railway bridge - which is set to be built near Denham in Buckinghamshire.
HS2 Ltd have revealed an enormous 700 tonne bridge-building machine at an event attended by the HS2 Minister, Andrew Stephenson MP, just outside London.
Stretching for more than two miles (3.4km) across a series of lakes and waterways between Hillingdon and the M25, the Colne Valley Viaduct will be the longest railway bridge in the UK.
The HS2 project 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.
HS2 Minister, Andrew Stephenson said:
“Today, 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.”
Known as a ‘launching girder’, the 160m long bridge-building machine is the only one of its kind in the UK and 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.
Welcoming the milestone, HS2 Ltd Chief Executive Mark Thurston said:
“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.”
Originally built in 2004, the launching girder was first used during the construction of the Hong Kong East Tsing Yi Viaduct.
56 piers each weighing around 370 tonnes are being constructed along the Colne Valley ahead of the girder, with the girder moving from one pier to the next, installing the deck segments as it goes. Steel tensioning cables will be threaded through the segments to strengthen the bridge.
Once construction is complete, the factory and surrounding buildings will be removed and the whole area between the viaduct and the Chiltern tunnel will be transformed into an area of chalk grassland and woodland as part of HS2’s ‘green corridor’ project.