The Feats of Precast Concrete

One of the most underrated aspects of precast concrete is the ingenuity it can bring to a project brief, offering solutions to difficult design problems on many schemes.

The HS2 Colne Valley Viaduct, completed in September 2025 a great example of how precast concrete can deliver an elegant design that will stand the test of time.

The 3.4km viaduct is now the UK’s longest railway bridge, and will carry high speed trains travelling at 321 kilometres per hour passing over the Colne Valley and water north west of London.

HS2’s senior project manager Billy Ahluwalia described the completed project as “a remarkable achievement”.

Designed by Grimshaw, the viaduct is formed of 1,000 distinct contoured precast concrete decks, raised 10 metres above the ground. Ibstock Anderton supplied our precast concrete cable troughs for use across the entire structure.

The project brief required a space saving system that would allow for low voltage and high voltage cabling to be safely installed and a drainage system that would ensure the viaduct track was not susceptible to water ‘ponding’.

Our concrete cable troughing units were specially adapted so that the units could be installed either side of the train line running across the viaduct.  
 
One trough carries high-voltage cables, another houses low-voltage cables, and a third serves as part of a drainage system. The three-trough concept was created so that the first two housed the electric cables, while rainwater would run off their lids into the third trough, acting as a drainage system.