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Positive start to major mountainside repairs at Treherbert side of Rhigos Mountain

Rhigos grid

The Council has provided an update on the essential ongoing work to rectify fire damage to the hillside (Treherbert side) at A4061 Rhigos Mountain Road. Positive progress has been made in the first four weeks, taking advantage of the good weather.

The route between Treherbert and Rhigos has been closed since July 22, as an absolutely necessary measure to ensure public safety while the complex remediation scheme takes place. A significant area of the mountainside was damaged in a previous fire, along with wire netting, plastic netting and fencing.

It is essential that the work is carried out now to ensure the road remains available for communities into the future, to avoid the risk of a longer emergency closure that is possible if the rockface is left to further deteriorate.

Rhigos Mountain Road closure – Frequently Asked Questions

The road cannot remain open while the work goes ahead to ensure safety. Heavy machinery and specialist access equipment are being used to reach the rockface’s full height, while there is a risk of debris falling onto the road.

The final, agreed-upon design to rectify the hillside damage incorporates a combination of specialist geotechnical solutions. These include an attenuator system, a rock fall barrier, and active and passive rock netting systems.

Progress update – week commencing Monday, August 19

Council contractor Alun Griffiths (Contractors) Ltd began initial work from July 22 to fully-mobilise the site, including setting up the site fencing and security. The work area stretches across approximately 375-metres of the hillside.

This early work included installing the anchors, that has enabled workers to access all areas of the rockface via rope. The slope exceeds 50-metres in length and 30-metres in height, requiring safe systems to be put in place.

Vegetation has been removed across the work area, to allow the construction of the new rockfall protection infrastructure. This clearance work focused on essential locations – for example, around the damaged areas of rock netting.

Key activity to drill and test the rock bolts has also been completed. This work has verified the design work for the wider scheme, and has provided detailed information about rock strength and the structure’s performance under load.

Drilling of the main rock bolts is ongoing – being installed throughout the site in various length and diameter. The bolts will serve to secure the new rockfall protection equipment – including netting, catch fences and attenuators.

The Council has previously indicated the overall scheme is aiming to complete by the end of October 2024. The positive progress made to date has ensured the scheme is currently on that schedule. Timescales are continually being assessed, with fair weather being relied upon to maintain this good progress.

A spokesperson for Rhondda Cynon Taf Council said: “The construction phase for the Rhigos Mountain Road repairs has started well. The nature of the work to the rockface means the work is heavily reliant upon fair weather, which is why the summer months are key to make good progress. Work to date has moved from the initial site setup to vegetation clearance at key damaged areas of the mountainside, and testing and installing the rock bolts.

“We’d like to thank residents and road users for their continued patience while the work is undertaken within this necessary road closure. We absolutely recognise the significant inconvenience it is causing – but this work needs to be done, as we have a responsibility to ensure the key route is available into the future, which is something everyone wants. Doing nothing isn’t an option, as we risk a longer emergency closure if the condition of the hillside worsens.

“Our contractor is making as quick and efficient progress as possible – even changing work shift timings based on the nature of the site activity, and to avoid periods where poor weather is forecast. Please also be assured that with the new school year approaching, we’ve consulted the RCT Home to School Transport team for the period of work beyond September – with alternative travel arrangements being put in place with local schools.”

Posted on 19/08/2024