HS2 completes foundation work for UK’s longest railway bridge.

The final concrete piles for the foundations for the UK’s longest railway bridge have been installed this week at the site of HS2’s Colne Valley Viaduct. 

Once complete, the 3.4km railway bridge will carry the new high-speed rail line across a series of lakes and waterways near Hillingdon.

The viaduct will stretch for more than 2 miles across a series of lakes and waterways between Hillingdon and the M25.

The railway bridge will be almost a kilometre longer than the Forth Rail Bridge.

Foundations

It has taken almost two years to install the 292 concrete piles. The construction of the foundations, the 56 huge piers and the deck on top, have all been happening in parallel. This meant separate teams working from north to south. Deck assembly began last year, with more than 500m of the viaduct structure now complete.

In order to deliver the 66 piles in the lakebed, the team first had to construct over a kilometer of temporary jetties. Cofferdams were created to hold back the water around each set of foundations. The jetties are also used to transport materials and equipment during the construction of the piers and viaduct deck.

HS2 Ltd project client David Emms said: “Once complete, HS2 will transform journeys across the UK, help to boost the economy and support the UK’s transition to net zero.

Achievement

“The completion of the piling for the Colne Valley Viaduct is a major achievement for our whole team and marks the end of almost two years of hard work. With pier construction and deck assembly also well underway, the viaduct is fast becoming one of the most impressive and recognisable parts of the project.”

Set low into the landscape, the widest spans are reserved for where the viaduct crosses the lakes. This design was chosen to enable views across the landscape, minimise the viaduct’s footprint and complement the natural surroundings.

The design was inspired by the flight of a stone skipping across the water. It features a series of elegant spans, some up to 80m long. The viaduct will carry the railway around 10m above the surface of the lakes, River Colne and Grand Union Canal.

Commitment

This coincides with Chancellor Jeremy Hunt denying reports claiming a planned HS2 terminus at London Euston could be mothballed.

Committing the government to the rail line reaching the central London station, Hunt said that HS2 would terminate at Euston as originally planned.

Hunt was asked following a speech at Bloomberg’s headquarters whether HS2 would go ‘all the way’ to central London. He replied that he did not ‘see any conceivable circumstances in which that would not end up at Euston’. He added: ‘And, indeed, I prioritised HS2 in the autumn statement.’

In a separate statement, the Department for Transport said that it was committed to HS2’s link with Manchester. The connection could start being built in 2027 and be up and running by 2036.

HS2 Ltd project client David Emms said:

“Once complete, HS2 will transform journeys across the UK, help to boost the economy and support the UK’s transition to net zero.

“The completion of the piling for the Colne Valley Viaduct is a major achievement for our whole team and marks the end of almost two years of hard work. With pier construction and deck assembly also well underway, the viaduct is fast becoming one of the most impressive and recognisable parts of the project.”