Ships Hull Corrosion Diagnosis From Close Measurements of Electric Potential in the Water

We present here an original method to search the corroded zones of an underwater steel structure. Nowadays, after a defined navigation period, a vessel is placed in dry dock, to examine its hull state, find the damaged areas and then paint them. This step of identification, very long and relatively inefficient, could be replaced by a series of electrical measurements which would be processed to get clues about the state of the hull. Those results are obtained thanks to the study of the cathodic protection system equipped on the hull. This new method allows a great timesaving but also a precision never reached before.