Case Studies

Cliff Stabilisation & Rockfall Analysis

Case Study Photo
Case Study Photo
Case Study Photo

The Gobbins Coastal Walkway

For the last few years Red Rock Geo have been Geotechnical consultants to Mid and East Antrim Borough Council leading the works to reopen the Gobbins Coastal Walkway in Northern Ireland.

This one mile long footpath comprises a man-made footpath that traverses along the base of spectacular 60m high sea cliffs.  Originally developed in the early 20th century, the path later fell into disuse as times changed and damage occurred to structures.  The path was reinstated to reflect as much of the original detail as possible. 

The cliffs are an environmentally protected ASSI with the rock ledges being important nesting sites for various seabirds. Recreating that early, untamed experience for the visitor within Health and Safety guidance was imperative for the attraction’s success. Any stabilisation works undertaken to minimise the risk to the public from natural hazards, in particular rockfalls, had to be sympathetic to the cultural heritage of the site and all aspects of the natural environment.

Red Rock Geo recommended that the level of rockfall risk to the public should be determined and considered in terms of other risks the public face in daily life utilising the HSE’s risk tolerability principles. This approach allowed the Council to make an informed decision on the risks people face using the footpath and to determine what measures are needed to further reduce and manage the hazards. 

A programme of environmentally proportionate stabilisation works were designed with rockfalls minimised by small field catch fences, localised sections of mesh and cable, rock anchoring of selected rock blocks, and controlled scaling to remove loose debris.

Vertical Technology Ltd won the main stabilisation contract and employed special measures to both access the main working areas and to undertake controlled scaling without incidental damage to the structures below.  Bespoke airbags and small catch fences were positioned over the footbridges and above working areas, respectively . 

The stabilisation works were undertaken outside the bird nesting season during the winter of 2017-18 and despite the storms and a very cold winter period, the programme was little affected.  Following the main works, a rockfall management plan was implemented to enable daily slope monitoring by tour guides with periodic roped access inspections by Red Rock consultants.

These measures, combined with daily monitoring, maintenance and progressive rockfall management, has allowed the path to be reopened for the visitor to experience this truly unique and breathtaking asset of Northern Ireland.

Fort Bovisand Redevelopment

Red Rock have been geotechnical consultants for the £14m redevelopment of the historic Victorian fort of Fort Bovisand lying on the eastern approaches to Plymouth Sound.

Dawlish, Devon

Red Rock undertook ground investigations and inspections of a section of cliff to provide a design for the slope stabilisation of a coastal cliff section.