Project summary

Notable for the achievement of 25% cost savings (£42m) at the Early Contractor Involvement (ECI) stage, we are responsible for the completion of the A6 Randalstown – Castledawson Dualling Scheme as part of a Joint Venture (JV) with Farrans. Valued at £135m, the four-and-a-half-year project involves the design and construction of 14.7km of dual carriageway through a predominantly rural landscape and the extension of the M22 north.

As traffic levels continue to grow towards 20,000 vehicles per day, this vital highways infrastructure project will improve road safety, reduce journey times and congestion on this strategically important North West transport corridor, connecting Belfast and Derry/Londonderry.

The detail

Since breaking ground in summer 2017, significant progress has been made by the GRAHAM/Farrans JV with work on 15 of 21 structures underway, six borrow pits are in operation, a considerable amount of earthworks are complete and the laying of pavement has commenced.

The successful implementation of ECI on the A6 project has enabled our expert team to contribute to the development of the design and provided us with the opportunity to consider construction issues at an early stage. Importantly, it also created the conditions for the delivery of significant cost savings, resulting from the exploitation of a range of efficiency avenues, including earthworks (securing borrow pits with local landowner agreements to win Class 2 material), drainage/culverts (VE opportunities in shortening/combining/straightening culverts), structures (designed as a family of structures, elimination of retaining walls) and programme (reduction of overall programme as a result of ECI logic development).

A6 Bridges

Adopting a “family of structures” approach and standardisation of design, we developed and constructed 21 major structures in the completion of the A6 Randalstown – Castledawson Dualling Scheme. Valued at £135m, this vital infrastructure project has improved road safety and reduced journey times and on a strategic transport corridor, connecting Belfast and Derry/Londonderry.

The A6 is notable for the achievement of 25% cost savings (£42m) at the ECI stage. From the outset, we developed a sufficient level of design detail which meant we were able to procure high cost items, such as pre-cast concrete bridge beams, that were installed in the construction of seven new overbridges, one new underbridge, seven accommodation works overbridges and underpasses, and two footway and cycleway overbridges.

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