HS2 creates first of 56 giant piers

The construction of the UK’s longest railway bridge is progressing with work starting on the first of 56 giant concrete piers that will support the Colne Valley Viaduct as it crosses a series of lakes on the outskirts of London.

Stretching for 3.4km, the viaduct being built as part of the HS2 rail project will carry high speed trains travelling at speeds of up to 200mph between the outskirts of Hillingdon and the M25 on their way to Birmingham and the north.

The first pier was cast by engineers from HS2’s main works contractor Align JV, a team made up of Bouygues Travaux Publics, Sir Robert McAlpine, and VolkerFitzpatrick and working in partnership with Kilnbridge.

Weighing in at around 370 tonnes, the 6m tall reinforced concrete pier was cast on site by a team of engineers who used a specially-designed formwork to create the shape of the structure. This was then removed after 4 days to reveal the final product.

Each pier is designed to support the full weight of the deck above and rests on a set of concrete piles going up to 55m into the ground. This foundation work began last year and will require the construction of 292 piles and 56 pile caps across the whole length of the viaduct.

In another visible sign of progress on the project, the team have also completed the construction of the first of four jetties across the lakes to get equipment into position to support the construction, thereby taking construction vehicles off local roads. Where the viaduct crosses the lake, the piles will be bored directly into the lakebed, using a cofferdam to hold back the water while the pier is constructed.

I have no doubt that the viaduct will become one, if not the most striking element of HS2 phase 1 once complete. The way it will be constructed is going to be equally fascinating for engineers young and old. The sections for the deck will be fabricated at our main construction site to the west of London just inside the M25, and using a huge launching girder, the deck will be formed from north to south, along the line of the route, thereby keeping unnecessary construction traffic off the roads.
Daniel Altier Align Project Director

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

Set low into the landscape, wider spans will carry the viaduct crosses the lakes, and narrower spans for the approaches. This design was chosen to enable views across the landscape, minimise the viaduct’s footprint on the lakes and help complement views across the natural surroundings.

The main deck of the viaduct which supports the railway line will be built in 1000 separate unique segments at a temporary factory nearby before being assembled from north to south, starting this year.

As part of a push across the whole HS2 project to cut carbon in construction, the design and construction teams working on the viaduct have also cut the amount of embedded carbon in the viaduct by around a third, by narrowing the width of the structure and applying lessons for the design of highspeed railway bridges in Europe.

HS2 has worked closely with Affinity Water and the Environment Agency to monitor water quality and agree working methods. These are being monitored by a team of specialist engineers during construction in order to protect the natural environment.

HS2 starts first of 56 giant piers for UK’s longest rail bridge HS2 Ltd 31.8K subscribers Subscribe

We're standing today at the South Portal which is part of

the HS2 alignment going from London to Birmingham and behind

me you can see we're constructing the first pier of

what will be 56 piers, which will form part of the Colne

Valley Viaduct. This is a big milestone because it's the

first concrete pour that's taking place for the piers. The

overall construction process will take about two and a half

years for the viaduct. They'll be supporting the deck segments

which are the precast deck segments which eventually will

be carrying the railway for HS2. It's a very special

project because HS2 and Align are utilizing a variety of

cutting-edge technology and construction techniques. For

example, they'll be using a launching gantry to launch the

precast segments. The use of a launching gantry is a very

sophisticated and complicated construction method that's used

around the world and it allows you to build your structure

faster, cheaper, and with a much better quality control and

efficiency. Everything we're doing on site here today and

everyday is governed by strict agreements and

regulated. These agreements govern everything we do in

terms of the construction on site including the plant and

machinery allowed to use. The hours of operation that those

plants and machinery can work. One of the key mitigations we

we do implement very strongly and very regularly is in terms

of letting people know exactly what's happening on site. For

warning the local residents about likely impacts of those

works is is crucial.

Find out more about HS2

HS2 Colne Valley Viaduct wins design award
26 Nov 2024

Colne Valley Viaduct named winner in the 'engineering' category  of the Royal Fine Art Commission Trust’s Building Beauty Awards - 2024 

Read more about
Last segment of Colne Valley Viaduct installed
06 Sept 2024

The Colne Valley Viaduct becomes Britain's longest rail bridge after Align JV reaches this major milestone for HS2.

Read more about
Sector profile: Mike Hickson, Managing Director of Defence
01 Jul 2024

Mike Hickson, Sir Robert McAlpine’s newly appointed Managing Director of Defence, shares his vision for the sector and his ambitions for the year ahead.

Read more about

Latest Infrastructure news

Green Apple award for project with sustainability at its core
27 Nov 2024

The sustainable approach to delivery taken by our AmeySRM JV team on the A533 Expressway Replacement Bridge Scheme has seen the project honoured with an international Green Apple Environment Award.

Read more about
HS2 Colne Valley Viaduct wins design award
26 Nov 2024

Colne Valley Viaduct named winner in the 'engineering' category  of the Royal Fine Art Commission Trust’s Building Beauty Awards - 2024 

Read more about
A19 named England’s No1 road
08 Nov 2024

The Strategic Roads User Survey by Transport Focus highlights the remarkable success of the A19 DBFO Project.

Read more about

Latest news

Raptor cranes at 2 Finsbury Avenue
10 Jan 2025

Raptor cranes enhance productivity at 2 Finsbury Avenue, British Land’s iconic dual-tower project redefining Broadgate’s skyline.

Read more about
2 Finsbury Avenue celebrates bottoming out ceremony
10 Dec 2024

Guests gathered at the lowest point of the structure’s foundations, just over 50m below ground.

Read more about
ONE Station Hill reaches practical completion
06 Dec 2024

Congratulations to all those who have worked on ONE Station Hill in Reading as the project completes.

Read more about