The East Cliff wall is being inspected by surveyors on ropes this week ahead of restoration work on the Grade II* listed Madeira Terrace starting this autumn.
Plans for the first 30 arches, including installing a new lift and staircase and repairing the Shelter Hall lift, were approved in November.
Preparatory work is now underway, and this week surveyors will be lowered down the wall on ropes to inspect its condition.
The East Cliff wall protects the chalk cliff behind it from weathering associated with wind, rain, frost and thaw. Engineering works to this section of wall go back as far as the early 19th century, when the cliff face was stabilised with a special limestone cement mortar to stop it eroding.
That work protected the east cliff area where, in the 1800s, the new buildings of Kemp Town were being laid out. Today the cliff wall’s role also includes protecting the A259 highway.
Over time the Green Wall of Japanese Spindle plants has colonised the cliff. The cliff wall behind it has been overcoated historically with different generations of concrete and lime mortars during the development and maintenance of the Terrace.
Engineers now need to inspect the thickness, condition and build-up of these historical coverings to make sure that proposals to restore the Terrace balance structural considerations, future maintenance and biodiversity.
This week a specialist rope access team will be deployed to complete localised trial holes in 6 different bays of the Terrace to investigate the existing coverings.
They will be carefully working around some of the colonised bays and the historic Green Wall. The information gathered will help to minimise maintenance of the wall when the Terrace re-opens, maintain protection of the East Cliff, and protect biodiversity.