Behind the scenes at HS2’s gigantic Colne Valley viaduct factory

Just inside the M25 motorway in northwest London is a huge worksite for the HS2 railway, building two tunnels heading north, but also the viaduct bridge that will span the Colne Valley as the railway heads towards London.
Colne Valley Viaduct (c) HS2
At the moment, it’s a vast construction site, but when all the mucky boots and hard hats have been hung up for the last time it will be landscaped into a nature reserve. But that’s a few years away yet and at the moment it’s a hive