Optical data was acquired from boreholes drilled at the peak of these slopes to look for signs of fracturing, faulting, collapse, or other signs of weakness.
A Robertson Geo Mini Winch was chosen due to its portability which allows engineers to carry it to the borehole, as access to the site was very limited. This winch was used to run the Robertson Geo High Resolution Optical Televiewer (Hi-OPTV). Although these boreholes were drilled immediately before investigation, data obtained was excellent due to the lack of water in the borehole which clouds optical images if disturbed by drilling.
This approach allowed the site to be investigated to depths of 20m with a rapid turnaround to minimise disturbance to the surrounding residential area without compromising data quality.