With over one million man-hours invested to date and almost two years of construction work completed, the 14.7km dual carriageway scheme between Castledawson and Randalstown on the A6 in Northern Ireland is making significant progress.
2.2km of new carriageway, three bridges and one footbridge have already opened to the public. A further 7.2km of carriageway, three additional bridges and four underpasses are expected to open this summer.
The £140million scheme involves the on-line/off-line improvement of the A6 trunk road from single carriageway to dual 2-lane carriageway (D2AP) between Randalstown and Toome and between Toome and the Castledawson roundabout.
It comprises 14.7km of mainline, a park and ride facility for 150 cars, 9 side roads and 18 structures, including one river bridge, 11 overbridges and three footway bridges.
Roughan & O’Donovan-ARUP design team
Roughan & O’Donovan (ROD), in 50:50 design joint venture with ARUP, delivered the detailed design for the scheme and now have a full-time designers site team working closely with the design offices and contracting team to monitor construction of the works.
The contractor, a joint venture of Graham Construction and Farrans Construction, has made significant progress in the area between the Toome bypass and Deerpark Road, with one bridge completed and a large portion of the earthworks already undertaken.
This comes in spite of the challenges presented by soft ground to significant depth and various environmental constraints, including the presence of whooper swans.
Structures and groundwork
Significant surcharge embankments have been constructed at the new junction near Toome, with mainline being constructed to the west.
A 400m section of the existing road was excavated to almost 6m deep and then reconstructed during a series of weekend closures.
In the Randalstown to Toome section (zone 2), all of the structures have been constructed, with only finishing works remaining.
In the Castledawson to Toome section (zone 1), three structures have been constructed, with three under construction. A further three are due to commence this summer.
Scheme opening in 2021
When open, the scheme will improve safety, reduce journey times and improve journey reliability for the estimated 23,000 motorists using the route between Belfast and Derry each day.