HS2 engineers build UK's longest railway bridge over a road

We're standing here on the Colne Valley Viaduct, here at Pier 54 where  behind me we are installing the last   pair of segments to allow us to complete  our viaduct over the A412 (in Denham).  Essentially the process is the launching  girder lifts a segment into position. We   apply epoxy to the face of the segment,  which essentially is a very strong glue.   And then after a few hours of carefully  installing strands through the segments,   we post-tension the cantilever. The permanent post tensioning   is essentially what strengthens the  cantilever and holds the viaduct up.  Over the last couple of months we've  been installing the segments overnight,   with the aid of a closure of the A412. That's to  allow us to lift the segments overnight safely,   with minimal disruption to the local community. We have about 20 people on site, with a range   of skills from operators of the launching  girder, to engineers, to superintendents,   so we've got a good team here who have allowed  us to build the viaduct safely over the road.  We started construction of the viaduct  super structure back in May. Since   then we've installed 99 segments and  completed four spans. So the viaduct,   as it stands today is just over 300 metres long.  Ahead of the launching girder we've  constructed a series of piers,   from here at the North Embankment all the way  down to the south embankments, through the lakes.   It's critical to ensure that the piers have been  constructed in time for the launching girder.  The Colne Valley Viaduct consists of 1,000 unique  segments. They're all unique in nature to account   for the curvature of the viaduct. To date we've cast 180.   Tonight we've installed the 99th segment,  so there's only 901 segments to go.

Channel: HS2 Ltd

Views: 75,772

Keywords: high speed railway, united kingdom, HS2, tunnelling, train, engineering, construction, infrastructure, project, rail, railways, uk, civil engineering, buckinghamshire, bucks, viaduct, colne valley, mega project

Id: ohip-tBu_TU

Length: 2min 13sec (133 seconds)

Published: Wed Nov 16 2022