A83 Rest and Be Thankful: Explosion for boulder goes ahead

A controlled explosion has been carried out in a bid to break up a huge boulder that was a threat to safety on the A83 at the Rest and Be Thankful in Argyll.

The 150-tonne rock was deemed unsafe by experts after being loosened on the hillside, 175m above the carriageway, during Storm Frank last week.

The blast to remove the boulder went ahead at about 16:30 despite low cloud on the slope delaying earlier efforts.

Engineers broke it up using explosives inserted into 30 holes in the rock.

Road maintenance firm Bear Scotland said that, due to the limited daylight, teams had been unable to complete a full safety assessment of the slope or the remaining rock fragments.

They said a full assessment of the slope would be carried out on Thursday.

Bear said that due to the size of some of the larger pieces of boulder debris, the biggest of which is about a third of the size of the original boulder, the Old Military Road would be closed overnight as a precaution.

The huge boulder is about 175m above the A83

A large section of the A83 remains closed around the Rest and Be Thankful.

The A83 connects the Central Belt, via the A82 from Glasgow, to the Kintyre peninsula, all the way down to Campbeltown.

The road, which starts in Tarbet on the banks of Loch Lomond, is almost 100 miles long.

The Rest and Be Thankful is a pass about 10 miles from Tarbet between Glen Kinglas from Glen Croe.

Bear Scotland's Eddie Ross said: "Despite the poor weather conditions, the low cloud lifted just in time for geotechnical teams to carry out the blast on the rock this afternoon.

"The boulder is now broken apart however one large section remains which requires a full assessment, and the Old Military Road will be closed overnight again as a precaution.

"We will continue the work to assess the slope tomorrow and will resume at first light.

"The continued patience of the public is very much appreciated by our team and we will continue to do all we can to get the A83 open as quickly and safely as possible."

Bear initially closed the A83 at the Rest and Be Thankful after about 200-300 tonnes of debris crashed on to the carriageway during Storm Frank on Wednesday 30 December.

It reopened but then closed again on Monday after geotechnical assessors highlighted safety concerns.

The Old Military Road diversion was in use on Tuesday between 09:00 and 16:30, but closed overnight, with an alternative, longer, diversion via Dalmally.