The advantage of this system delivers significantly reduced overall man hours to reliably inspect the sub surface structure in minute detail, as the most time consuming and potentially dangerous activity (diving operations) was reduced to a minimum, by utilising this cutting edge sonar technology therefore enabling ‘spot’ dives at the point of defects.
Diving Engineers – Any defects which the sonar array highlighted could then be analysed and a program of diver inspection on these specific points put into action.
A specialist team of Civil Engineer qualified divers were deployed in the inspection of the points of interest on the dam sub surface structure. This allowed us to produce a report with data collected from a physical ‘eyes on’ and tactile perspective using additional live diver helmet mounted camera feeds and video technology to record the dives and support the diver’s data collection. Penetrating coloured dye was deployed to demonstrate the rate of flow into any apertures discovered.
The deployment of this two tier approach to inspecting such a large sub surface structure significantly reduced the overall cost of the project whilst additionally making a huge reduction in the time taken to amass the technical data. This essential ‘real time’ knowledge of the existing condition is vital for future planning and maintenance decisions to be made with total engineering confidence.
There were practical considerations to be overcome – The underwater inspection of the Nalubaale Dam was not without specific technical and dynamic problems to be addressed. The greatest of which was working with divers in an area known as ‘Differential Pressure’ (DP)