Geotechnical specialists scale Brighton’s chalk cliffs to tackle rockfalls

A specialist team from CAN Geotechnical has been using rope access to work at a height of 30 metres (ten storeys) on Brighton’s chalk cliffs, between the marina and Saltdean, making the area safe after repeated rockfalls affected use of the Undercliff Walk.

CAN Geotechnical Project Manager Andy Pope said: “Our work here involves a two-pronged approach. The first priority is to make the area safe by identifying and removing any loose material (chalk and flints), which we are achieving by using light hand-scaling tools on an area of about 5000 metres. Once this has been completed, we will be carrying out a geotechnical inspection, which will provide a detailed report on the condition of the chalk face to give an informed assessment of the area.”

Andy said it had been challenging to evaluate the scale of the project until the six-person team could access and examine the cliff face. The work on the cliff began on 20 February and was paused on 7 April with 50% of the project complete. This is to avoid intrusive work on the chalk cliffs during the bird-nesting season. The project will resume in September.

He said: “In terms of technical and safety considerations for a project like this, we’ve had to align our rigging at the crest to allow for the constant movement of ropes (two 50-metre ropes for each operative), which is essential to hand scale the cliff face. For our rigging, we are using 4×4 vehicles and 8T excavators. This means that, instead of installing anchors 660 millimetres deep into the chalk cliff tops, CAN operatives have used purposely immobilised 4×4 vehicles and the excavators to create rigging that is both safe and efficient, with minimal disruption to this sensitive environment.

“It is extremely satisfying for the team to work on a project of this nature. The chalk cliffs are part of our heritage and synonymous with the region and specifically Brighton. To ensure everyone can safely appreciate the beauty of the cliffs, we need to understand the extent and the nature of the erosion and the particular challenges this will create, especially in terms of public safety, given the use of the popular Undercliff Walk.”

CAN, an RSK company, is working with RSK Geosciences on the project, with their colleagues responsible for the geotechnical inspection. CAN is carrying out the work for FM Conway as part of a project for Brighton and Hove City Council.