24 May 2021

Rest and Be Thankful: an update on the landslide mitigation works

Posted by Dave Petley

Rest and Be Thankful: an update on the landslide mitigation works

Yesterday, The Scotsman newspaper posted a long and detailed article about the ongoing attempts to manage the landslide problem on the A83 at Rest and Be ThankfulI have posted frequently in recent years about the landslide problems at this site, which is undoubtedly the most challenging landslide location in the UK at the moment.

The article describes the new engineering works that have been completed to protect the diversion route lower down the hillside, the Old Military Road, which is brought into use when the main A83 route is unusable.  The latest attempt to protect this road has involved the construction of a huge bund, 6 metres high and 180 metres long, on the upslope side of the Old Military Road, to capture debris from the slope above.  The article includes images of this remarkable structure:-

The newly constructed bund to create a retention space for debris flows above the Old Military Road at Rest and Be Thankful.

The newly constructed bund to create a retention space for debris flows above the Old Military Road at Rest and Be Thankful. Image by John Devlin via The Scotsman.

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From the perspective of the road the structure looks like this:-

Detail of the newly constructed bund  above the Old Military Road at Rest and Be Thankful. Image by John Devlin via The Scotsman.

Detail of the newly constructed bund above the Old Military Road at Rest and Be Thankful. Image by John Devlin via The Scotsman.

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Meanwhile on the main A83 road itself, catch pits are being built on the upslope side of the road to try to retain mobilised debris, and multiple flexible barriers have been constructed.  At one location a flexible barrier has been constructed along the centreline of the road itself to try to protect a part of the carriageway.  I have not seen that approach previously:-

One of the catch pits and a flexible barrier on the A83 at Rest and Be Thankful.

One of the catch pits and a flexible barrier on the A83 at Rest and Be Thankful. Image by John Devlin via The Scotsman.

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The scale of these engineering works, and the construction of increasingly large structures in an area that is protected, illustrate the enormous magnitude of the challenges on the A83 at Rest and Be Thankful.  Plans are progressing for the construction of an alternative alignment, but this will take several years to bring to completion.  In the meantime, protecting the roads against landslides will be a mighty battle.