Works update on the major Rhigos mountainside repair scheme

The Council has received the contractor Alun Griffiths’ latest progress update for the major Rhigos Mountain Road repairs. The final phase of work has proven extremely challenging, with a further 700 tonnes of rock needing to be removed and transported from the site, which was unexpected in the initial work programme. 

Despite the best efforts to bring the target completion date forward, the latest projection indicates the work will continue until Friday, November 22. This will ensure the safe and full completion of this major scheme.

The mountain road between Treherbert and Rhigos was closed from July 22 as an absolutely necessary measure to ensure safety throughout the large remediation scheme. This is essential to rectify damage from a previous wildfire at the Treherbert end of the road, which caused major damage across a significant area of the mountainside, as well as its netting and fencing.

The repair scheme is critical to future-proofing this key route. Overall, the work has made considerable progress since the summer in a very challenging environment – and it is now entering its final stages with a series of intricate works. While the first two phases of work were completed on programme, the third and final phase has evolved into a much larger operation than expected.

Without this work being completed thoroughly and fully, the rockface could deteriorate further. In this scenario, it is possible that an emergency closure would be needed over a much longer period of time. The full progress update from the contractor is included at the bottom of this article – including what has been achieved since the last update in October, and the plans to demobilise the site from next week with the removal of the heavy plant.

Rhigos Mountain Road closure – Frequently Asked Questions

A spokesperson for Rhondda Cynon Taf Council said: “From the outset, the Council has been very clear that the Rhigos Mountain Road remediation work is a complex project, dealing with huge infrastructure in a challenging mountainside environment – that has needed to engage specialist contractors. For such complex and lengthy projects, it is very difficult to accurately predict completion timescales from the start, due to the number of potential variables.

“At the start of the project, we had hoped the work could be completed by the end of October, based on all of the information available.

“The new estimated completion date of November 22 is down to several contributing factors – including weather conditions, very complex drilling conditions due to the nature of the geology, the quantity of loose material on the one phase of the rock-face, and limited site access. Maintaining the rockface’s stability during drilling work requires a steady approach, ensuring the risk of rockfall is safely controlled and that the contractor’s workforce is kept safe at all times.

“We’d like to thank local communities for their continued patience and cooperation, and we absolutely understand the disruption caused by the closure. However, we must get this project fully-completed to ensure the mountain road is available and safe into the future, which is what we all want.”

Works progress update – week commencing Monday, November 4

All historical fire damaged, plastic-coated rockfall netting within zones one to three has now been removed from the slopes. These have been replaced with improved measures, consisting of either passive or active rockfall netting and rockfall attenuators. All new equipment is galvanised steel, which is resistant to fire and does not possess the same fire as the former plastic-coated mesh.

Installation of the rockfall attenuators in zones one and two is substantially complete, along with the structure of the attenuator in zone three – where the mesh installation is around 80% complete. Earthworks and excavation work in both zones two and three is also now complete. Installation of the rockfall barrier foundations has been finished with the anchors around half complete – the remainder of these and the barrier structure will be installed imminently.

Overall works are nearing completion. Final anchor testing and commissioning work will follow completion of the GBE barrier installation. Site demobilisation works are planned to start from next week, with much of the large plant and equipment to be removed in stages until the new completion date.