A LANDSLIP-PLAGUED iconic trunk road has been shut yet again - just a week after it was re-opened after the latest round of safety repairs.

It means the A83 at the Rest And Be Thankful has been open for just 12 days since the first of two landslides hit the vital route nearly two months ago.

Maintenance firm BEAR Scotland has said the A83 has been shut again "as a safety precaution" due to the forecast of heavy rain.

It was re-opened last Wednesday under traffic light control after it was hit by a second landslide in just over a month on September 13.

Now the road has shut again, with motorists diverted onto the mainly single track Old Military Road (OMR) "as a safety precaution" due to a forecast of sustained heavy rain throughout the day.

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

Geotechnical specialists are on site monitoring conditions on the hillside and in the area.

BEAR Scotland said engineers are continuing to work on further mitigation measures on the hillside following two major landslips in recent months.

Eddie Ross, BEAR Scotland’s north west representative said: “Heavy rain has been impacting the area since early morning and with more forecast throughout the day we’ve taken the decision to divert all road users via the Old Military Road local diversion route as a precaution.

“Our geotechnical experts have advised that the rain could have an impact on the hillside so we’ve taken a safety-first approach and our teams will continue to carefully monitor the area throughout the day.

“Safety of road users remains our top priority and we’ll do everything we can to ensure any disruption is minimised as much as possible.”

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.

Last week Transport Scotland published details of the 11 "corridor 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 landslide on August 4 came as 100mm of rain fell in the Argyll area blocking the A83.

The source of the landslip was located around 200m high above the A83, which split into two main channels as it spread out in a “fan effect” down the hillside.

One of the channels filtered into one of the landslip mitigation catch-pits which prevented around 2,000 tonnes of material from reaching the road, with around 1,500 tonnes of debris reaching the carriageway at the second channel. Car-sized boulders also reached the roadside in the debris. A further 2,000 tonnes of material was washed onto the OMR.

In total, the landslide is thought to have moved around 10,000 tonnes of debris on the hillside following detailed geotechnical calculations of the hillside, making it one of the largest landslips in recent times. Earlier estimates put the original figure at 6,000 tonnes.

On August 6, a further 100 tonnes of material reached the carriageway overnight via the steep channel scoured out by Tuesday’s landslip, exposing large boulders. Teams worked to make these boulders safe using water-bags dropped into position from a helicopter as well as using a high-pressured hydraulic ‘jack’ to force the boulders into a new, safer position further down the steep channel.

READ MORE: 'Unprecedented' - Public inquiry call as A83 Rest and be Thankful remains closed after another landslip 'disaster'

Teams completed the clear-up of 2,000 tonnes of debris from the OMR on August 7 and began work to construct a protective bund and channel parallel to the roadside.

The A83 reopened under traffic light control at around 10.25am on September 7. But the A83 and OMR were closed on September 12 due to forecast intense rain. This triggered a landslide which brought over 2,000 tonnes of material to the A83 with some reaching the OMR the following day.

The clearance of the debris started on September 14 as 5,000 tonnes of material had reached the A83 and OMR.