ONE of Scotland's key roads has been forced to shut again a matter of days after it was claimed that 100,000 tonnes of debris is waiting to fall on it.

The infamous A83 at the Rest and be Thankful, has been closed since Thursday morning after an overnight downpour increased the risk of substantial amounts of debris sliding on to the road from the adjacent hillside.

Today it emerged that both the A83, and the official single track diversion, the Old Military Road (OMR) which runs through the centre of Glen Croe will remain shut throughout the day.

It is estimated around 250 tonnes of debris reached the OMR overnight.

That is despite £1m being spent on 175-metre long, 6.6 metre high barrier having been built next to the OMR to stop debris from a potential landslip.

Some locals have already complained at how the latest protection measures "haven't worked".

READ MORE: Race against time to stop 100,000 tonnes of debris falling on the A83 at the Rest and be Thankful

One said: "I thought the wall was supposed to stop stuff getting down to the OMR."

It comes as the stretch of road was being brought back into action last month as part of a strategy that was to see the the main road used during the day when weather conditions permit.

HeraldScotland:

Debris being cleared after latest episode.

The important Highlands route had been till then been barely open for three weeks in the previous five months since a landslip brought about by rain blocked the road in August. Drivers have faced 60-mile diversions when both routes are closed.

Before the A83 re-opening, Bear said a debris fence had been completed on hillside above A83 to provide further protection to road users.

But even the OMR had to shut in the early hours of Thursday for a few hours as a "safety precaution" after spell of intense heavy rain which led to around 20 tonnes of material sliding off the hillside, though it is said to have been captured in one of the debris nets.

And on Friday night persistent heavy rainfall meant the OMR relief road was shut again.  It re-opened on Saturday morning, before closing again late on Saturday afternoon.

Now it has emerged that with a fall of debris,  both the A83 and the OMR will remain closed on Sunday - leaving motorists with a 60 mile detour.

The Scottish Government's transport agency's route manager Neil MacFarlane recently told community leaders in the area that 2020 saw 20,000 tonnes fall onto the infamous A83 at the Rest and be Thankful – double what has fallen in nearly two decades.

And he said that Transport Scotland was looking at 12 options to prevent further calamity with "100,000 tonnes on the move on the hill"

Transport Scotland-appointed maintenance firm Bear Scotland said the reasons were that heavy rain contributed to "high saturation" on the hillside and significant surface water on parts of the OMR.

READ MORE: £80m 'wasted' over multiple failed fixes to iconic A83 Rest and Be Thankful

It said that around 130mm of rain had been recorded as falling at the Rest and Be Thankful since early Friday morning, with 280mm recorded in total throughout the week. It said the rainfall had contributed to an already saturated hillside following "significant snowmelt" brought on by milder temperatures.

HeraldScotland:

According to Bear Scotland around 250 tonnes of debris reached the OMR overnight

Overnight, debris was identified at multiple locations along the hillside above the A83, with the new barrier and two roadside catch-pits having caught nearly 700 tonnes of material between them, "preventing significant material" from inundating the trunk road, said Bear Scotland.

Around 250 tonnes of silt and debris has also been deposited on the OMR as a result of material being washed down the lower hillside channels by the substantial amount of surface water experienced. Teams are currently working in what Bear Scotland described as "challenging conditions" to assess the various sections and as clean-up operations get underway.

An inspection is due to take place at first light on Monday morning to consider if safe to reopen the local OMR diversion.

Western Ferries is providing an extra boat as necessary on their Gourock to Dunoon service as an alternative to the standard diversion route for road users.

Eddie Ross, Bear Scotland’s north west representative said: “The OMR and A83 were closed as a safety precaution late afternoon yesterday after conditions began to deteriorate in the area and significant surface water began to pose a risk to the operation of the local diversion in Glen Croe.

READ MORE: Rest and Be Thankful: Michael Matheson set deadline of five years for replacement of notorious landslip-prone road

“Overnight there has been various debris events across the hillside where mitigation measures are in place at the Rest. Initial assessments indicate that almost 700 tonnes of debris has been collectively prevented from inundating the A83 following the recent significant heavy rain fall. We now need to inspect these areas and establish the condition of the mitigation measures before we can begin to remove the debris safely.

“Whilst the new OMR bund has been successful in retaining debris, the OMR has been affected by a significant deposit of material, at a section not covered by the bund, which will require a full clear-up operation before we can open the route.

READ MORE: New bridges or tunnels could end A83 Rest and be Thankful chaos

“In the meantime, all traffic will be diverted via the standard diversion between Inveraray and Tarbet for safety.

“We’re continuing with a safety-first approach and we thank all road users as well as the local community for their continued patience while we work to address the ongoing situation at the Rest.”

HeraldScotland:

The A83 has been closed for safety due to a series of major landslips experienced throughout 2020.

Since August most traffic was being convoyed by an official vehicle on the OMR but even that has been frequently shut overnight because of fears that even it could be hit by landslides - leaving motorists with the 60-mile detours.

Ministers have previously been accused of wasting nearly £80 million on more than a decade of failed solutions to landslides on the road after the latest multiple slips in heavy rainfall.

Some locals have called for a public inquiry into the problems, with many saying a permanent solution must be found.

In September, Transport Scotland published 11 options for a new route to replace the landslip-prone section of the A83 include building up to three bridges or tunnels. But the choice of solution is not expected till next year.

The new solutions being considered include building new fixed link crossings at Loch Long, Gare Loch and the Firth of Clyde, which also include building a new road in the glen behind the current route.

Others include new crossings from near West Kilbride, North Ayrshire, to Bute via Little Cumbrae, and further crossings either over the Firth of Clyde from Rothesay to Toward, or from Rhubodach to Colintraive. Argyll and Bute Council is among those who have registered their concerns about the way the issues with the A83 have been handled.

Two weeks ago, the A83 opening hours were extended to 8.15am to 5pm each day with traffic being convoyed through the area when weather conditions allow. All traffic would then be switched to the single-track Old Military Road which runs through the centre of Glen Croe outwith daylight hours.