Blog: SECBE Awards 2023 Finalist HS2 Colne Valley Viaduct Temporary Jetty (by VolkerStevin)

25 April 2023

Project of the Year over £10m sponsored by Hill Dickinson

HS2 Colne Valley Viaduct Temporary Jetty (submitted by VolkerStevin)

Building Project of the Year over £10m SECBE Award 2023 finalist

VolkerStevin delivered a technically challenging package which is enabling the Align JV to construct HS2’s iconic two mile long permanent viaduct crossing the Colne Valley to the north west of London.

The project team overcame technical and environmental challenges by developing an innovative ‘traveller’ piling gate. This allowed the team to complete the temporary jetty early, 7% below target cost, sustainably and with zero accidents, whilst leaving a collaborative working legacy that Align is using as a blueprint to manage other subcontract packages.

HS2 will construct over 500 bridges, with Colne Valley Viaduct (CVV) being the most notable due to its length, design and prominence. Colne Valley is a SSSI and boasts diverse countryside, including parks, green spaces, and reservoirs, making it a popular recreational destination. In November 2020, VolkerStevin was awarded the contract for the temporary jetty and cofferdams project required for the construction of the CVV. The viaduct is part of the Central 1 (C1) section of HS2 Phase One that Align JV is delivering. Align is a joint venture of VolkerFitzpatrick, Bouygues Travaux Publics and Sir Robert McAlpine.

The project involved building nearly 1km of temporary jetty to support a 200t crane and ancillary equipment to service the main viaduct construction, and 56 sheet pile cofferdams for the viaduct's piers. After extensive planning, work started in spring 2021 and finished in September 2022.

VolkerStevin worked collaboratively with Align through 2020 to develop the right technical solution. The standard method of building a piled jetty, using floating plant or driving temporary piles, was not feasible due to site constraints. The shallow water made it impossible for conventional barges to operate and limited space for barge moorings and tugs.

Most important was sustainability and the environmental constraints. An aquifer in the underlying chalk meant that driving and extracting temporary piles would create a flow path between the aquifer and the lake water. Significant depths of sediment and the risk of disturbing this meant that end bearing ‘legs’ were also not viable.

VolkerStevin brought in its in-house temporary works experts and consultant Tony Gee and Partners to address the challenges. They have a successful history of developing innovative solutions together on the projects to work over water. The integrated team evaluated multiple options and ultimately chose a ‘traveller’ type gate that ‘jacks’ itself forward similarly to the permanent viaduct's launching girder. Pre-fabrication of the jetty’s steelwork and concrete deck units meant a 12m-long cycle of new jetty could be safely and sustainably installed per day at peak performance.

The extent of collaboration between Align and VolkerStevin also stood out. VolkerStevin adopted Align’s Perform C1 initiative to integrate its teams and processes, avoid ‘man-marking’ and eliminate unnecessary tasks. This contributed to £2m of savings and went beyond a traditional main contractor-subcontractor relationship.

Key achievements:

• VolkerStevin delivered the project on time and 7% below target cost. The temporary jetty is now meeting its function of providing the Align JV with the access it needs to safely and sustainably construct HS2’s Colne Valley Viaduct, which is the UK’s longest rail bridge.

• VolkerStevin avoided the environmental harm that the driving and extraction of a traditional piling gate’s temporary piles would cause by instead using a large ‘traveller’ style gate. VolkerStevin's pre-fabrication of the jetty’s steelwork and deck units, and the piling gate’s ability to smoothly traverse forward, allowed the team to complete a full 12m cycle of new jetty every day at peak production.

• VolkerStevin adopted Align’s Perform C1 initiative to integrate the teams and processes, avoid ‘man-marking’ and eliminate unnecessary tasks. This contributed to £2m of savings and went beyond a traditional main contractor-subcontractor relationship.

Client: Align Joint Venture

Project Partners: VolkerStevin, Tony Gee and Partners, Taziker Industrial

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Find out who wins at the Constructing Excellence SECBE Awards 2023 Ceremony on Thurs 29th June 2023.

About the Building Project of the Year Award (sponsored by  Hill Dickinson):  

Project of the Year delivers outstanding outcomes for all those involved in a construction project.  It showcases the benefits achieved through the application of many of the principles described in the other award categories. More info.

>> Find out more about the other Constructing Excellence SECBE Awards 2023 finalists here