M6 extension: Carlisle to Guards Mill, Cumbria

Liverpool canal link
Project Information
  • Client: Highways Agency
  • Principal designer: Capita Symonds
  • Principal engineer: Scott Wilson
  • Principal contractor: Carillion plc
  • Contract value: £154 million

About the project

This extension has upgraded the A74 dual carriageway (the Cumberland Gap), completing the motorway network from London to Glasgow. The route carries 42,000 vehicles a day.

The project incorporated 9km of new dual three-lane motorway. The new Esk Bridge was constructed, spanning 180 metres over a fast-flowing river. A new viaduct was built at Mossband over the West Coast mainline railway, and the old viaduct was demolished.

Environmental and conservation challenges included relocating hundreds of adders and lizards; consideration for the habitats of birds, badgers, otters and bats; and making sure process run-off water did not pollute or overwhelm local drainage systems.

The project achieved a cost-saving of over £20 million, through excellent design and efficient procurement. Some materials were recycled, including 160,000 tonnes of locally sourced stone and the Systema parapet from the old viaduct.

The project has exceeded all success criteria, was delivered three weeks early and achieved over 1.25 million safe hours worked without a reportable accident. The scheme has already won six industry awards.

Judges' comment

"This road upgrade presented engineers and contractors with major environmental and conservation challenges – all successfully met."

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