Bridging the Precast Challenge

Custom designed precast concrete beams have been manufactured and supplied for the construction of a new bridge that forms part of the Highways Agency’s major M6 road extension scheme between Carlisle and Guards Mill, Cumbria.

136 M10 bridge beams, each measuring 30.5 metres, have been specially designed and supplied by Tarmac Precast, the UK’s leading suppliers of precast concrete. They have been used to create the new Mossband railway viaduct, a key part of works to upgrade the A74 to a dual, three-lane motorway from the M6 Junction 44 near Carlisle.

The precast beams have been manufactured over a four-month period, as part of a major contract between Tarmac Precast and Carillion Construction Ltd, the leading national contractor appointed by the Highways Agency to deliver the £174 million scheme.

With high load-bearing capacity, the precast concrete M10 beams - each with a depth of 1.36 metres - are the largest in Tarmac’s M beam range. The use of precast methods has reduced installation costs, helped to accelerate the build programme and will ensure lower maintenance levels over the project’s lifetime.

Carillion’s Project Director, Chris Hayton, said:
“The precast solution has been developed by Tarmac Precast, working as part of the integrated ECI team who focussed on cost savings by shortening the time taken to construct the bridge, whilst maintaining the highest levels of safety of the West Coast main line railway. In addition, benefits have been realised by reducing the cost of the overall design and maintenance whilst improving durability of the structure.

Commenting on the contract, Alistair Carter, senior estimator at Tarmac Precast said: “By working closely with Carillion, the high volume order of M10 beams has been specially developed by our engineers and cast at our Tallington site. This is a clear example of our ability to co-ordinate the manufacture and supply of a bespoke, high load bearing product.”

January 2008