Scotland TranServ, on behalf of Transport Scotland will begin repair works on the A77 Marchburn landslip north of Cairnryan on the 30th October.
In order to establish the working site and install supportive piling, it will be necessary to completely close the A77 between Stranraer and Girvan for the duration of the weekend beginning 8pm Friday 3rd until 6am Monday 6th November. A fully signed diversion will be in place over the weekend.
Charles Macklin, Scotland TranServ’s Principal Engineer said: “We have been carrying out painstaking assessment of the landslip and intricately assessing the unique geography of the area in order to identify and design the best long-term solution. The complexity of the location is intensified by the high, steep embankment towards Loch Ryan on the downslope.
“Delivering this solution will require a large, complex project that we expect will take a number of months to complete. Initial forecasting from our contractors suggests that the works will be completed, the traffic lights lifted, and the road fully reinstated by early 2018.”
Winter storms in November 2014 caused the failures on both sides of the A77 trunk road. This meant that the embankment supporting the carriageway was compromised, while the upslope embankment deposited debris directly onto the trunk road carriageway.
Early in 2015, Scotland TranServ was able to carry out temporary repairs to backfill the upslope side with rockfill. Unfortunately, it wasn’t possible to carry out similar short-term remediation on the downslope side, and we had to keep the traffic lights in place protect the public.
Due to the size of the failure and the 40m (130 feet) high steep embankment between the road and Loch Ryan (see Fig 1below) it was not possible to carry out temporary repairs on the downslope side in early 2015. Scotland TranServ required a careful geotechnical assessment of the area in order to determine a long-term solution to the issue.
The health and safety of our workers and the travelling public is of utmost importance to Scotland TranServ, and therefore the decision was taken to keep traffic safely distanced from the unstable slope.
Following the weekend closure to establish the working site, the existing traffic lights will be reinstated, providing our contractors with the required lane space from the flow of trunk road traffic to work as safely and efficiently as possible.
In order to minmize the disruption of this closure, we are also proposing an additional resurfacing project for the A77 in the area, the resurfacing of 1km of the carriageway at Altimeg, approximately five miles south of Ballantrae.
Andy Fraser, Scotland TranServ’s Operating Company Representative added: “The A77 is an important economic artery for the region, with many communities and businesses along the route. Throughout, we have scheduled this significant programme to be delivered with maximum efficiency and minimal disruption. Across South West Scotland, we are working on behalf of Transport Scotland to prioritise such road maintenance issues and deliver our road surface improvement projects as quickly, efficiently and safely as possible.”