A556 clearance
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A556 Knutsford to Bowden Improvement Scheme

Client: Costain/Highways England

Value: £15m


  • 1.1 million m3 cut-and-fill
  • 20,000 m3 of Japanese knotweed remediated
  • 6.5km greenfield construction
  • Lime modification techniques used
  • Huge fleet used including dozers, loaders and articulated dumpers


The  Knutsford to Bowden improvement scheme (A556) is a £102 million project connecting the M6 at Junction 19 near Tabley / Knutsford with the M56 at Junction 7 near Bowdon – a distance of 7.5km. The aim of the scheme is to improve links between Greater Manchester and the West Midlands, whilst improving the local environment, road safety and journey reliability.

Walters UK were invited to join the Costain and Highways England Team as strategic partner for this major project at pre-qualification stage and were integral in providing specialist earthworks advice and design input throughout the entire ECI process.

Early ground investigation work by the client suggested that 250,000m3 of lime modification works would be required due to the wet and variable nature of the material on site. This process has been largely avoided through the use of alternative drying and engineered modification methods.

The Project also had significant ecological constraints due to the presence of Great Crested Newts, bats, badgers and nesting birds in the local environment.

Walters worked closely with the on-site ecological team to ensure the local protected species and their habitats suffered minimal impact while the 1.1 million cubic metres of material were moved.
The extensive ecological constraints prevented the team from commencing construction until almost halfway through the 2015 earthworks season. Through utilising a fleet of plant including 70t & 56t excavators, 40T articulated dump trucks and D8 dozers, the team were able to reach production rates of over 10,000m3 per day, completing the movement of all 1.1 million cubic metres of material in a single season.

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