The Arran Banner
Rock armour shipped in to save Pirnmill seawall
Urgent works have started to save a severely storm damaged seawall which has led to part of the main road round Arran crumbling into the sea.
The rock revetment works to the south of Pirnmill require 2,000 tonnes of rock armour shipped in from the mainland to shore up the seawall. Preparatory works started on Monday and the work is likely to last for four weeks. The project will cost £268, 800.
As a result of a heavy storm, large sections of the gabion basket seawall were swept into the sea or badly damaged leaving the main C147 road, on the west of the island, vulnerable to erosion by the sea in the future if left unattended. The Pirnmill Village Association has been pushing for this work to be carried out for some time.
A North Ayrshire Council spokeswoman said: ‘The coastal protection for the C147 road in this area currently consists of a length of masonry seawall, rock revetment and gabion basket seawall. The coastal protection works generally consist of the removal of the damaged gabion baskets and installing a further section of rock armour as an extension of the existing revetment. The project is being part-funded from the Crown Estate Net Revenue Allocation Scheme.’
The contractor for the project is W I & A Gilbert Ltd of Dalry, with John Thomson Construction of Lamlash sub-contracted to bring the materials to the island. The rock is being delivered from Hillhouse quarry in Dundonald to Troon where it is being loaded on to a landing craft, the Red Princess, and brought to Arran. Two shipments have already been made with a third due early next week.
‘This was considered the most favourable and long-lasting solution, with the least disruption and impact on the community,’ the council spokeswoman added.
The alternative would have been to use the main CalMac ferries for delivery of the rock supplies, which would have seriously affected island travel capacity, especially during Covid-19 restrictions. The rock would then have had to be trucked over The String to Pirnmill.
The landing site at Rubha Airigh was first used during the construction of the long sea outfall from the Isle of Arran Distillery at Lochranza four years ago and there have been claims that in the future
it could be used for timber extractions, as Red Princess is normally seen in Brodick transporting timber to the mainland, but these have been denied.
The site of the rock armour works is situated off road, so site traffic management will be to a minimum. However, there will be an increase in construction traffic for the duration of the works at certain times for the supply of materials. All foreshores will be returned to their natural conditions after the works, the council says.