Colne Valley Viaduct


LOCATION: Thames Valley
VALUE: £55M to £65M
SECTORS: Major projects and infrastructure, Rail
SERVICES: Building and Civil Engineering

Scope of works:

The Colne Valley Viaduct is a bridge, currently under construction, which will carry the High Speed 2 railway over the Colne Valley Regional Park and the Grand Union Canal. With a length of 2.1 miles (3.4 km) and a weight of 116,000 tonnes, this will be largest railway bridge in the UK, as well as one of the largest single civil engineering works of this phase of HS2.

Kilnbridge are engaged to construct the foundations and 58 reinforced concrete piers for the iconic viaduct. Producing high quality patterned concrete in a challenging location amongst highly sensitive natural habitats, works include:

  • Design development of the ‘V-pier’, a large mock-up of one of reinforced concrete piers which supports the viaduct
  • Construction of individual pile cap bases, each up to 500m3 of concrete within cofferdams, associated pile cropping and capping beam construction
  • Establishment and operation of a precast concrete facility nearby which is delivering over 775 precast concrete bridging planks, some weighing up to 21.6t and measuring up to 11m in length, with a total concrete volume in excess of several thousand cubic metres.


  • The 11 V-piers will be constructed, to a specified architectural finish, above water solely accessible via the jetty.
  • Bespoke high quality visual concrete


  • Formwork for this project was designed and fabricated in-house by Kilnbridge
  • Over 200 Kilnbridge employees are embedded within the wider project team