Harefield route reopened after HS2 span lifted into place

Timed for the school summer holidays, to reduce disruption, the closure allowed HS2 to safely bring in cranes to lift 11 huge segments into position over the road.

These were then strengthened with internal steel cabling to complete the span.

Once complete, the viaduct will be the longest railway bridge in the UK, stretching for more than two miles across the Grand Union Canal, River Colne, roads and a series of lakes.

To allow for the gentle curve of the viaduct, each of the 1,000 segments that form the arches and deck are slightly different. All are manufactured at a temporary factory set up close by, with direct access to the M25.

Most of these segments are slotted into place by a giant 700-ton ‘launching girder’ – the only one of its kind in the UK.

But the engineers used a different approach at Moorhall Road, to allow the closure to coincide with the school holidays when traffic is lighter. 

The viaduct’s design was inspired by the flight of a stone skipping across the water.

Moorhall Road reopened on Friday (18).