Abstract
Physical scale modelling was employed to examine the characteristics of five different two zone impressed current cathodic protection systems, with six, seven or eight anodes. A one-hundredth scale detailed metal model of a warship hull was employed to measure potential profiles, ICCP current outputs and the proportion going to the propellers, in at–anchor and simulated under way conditions with intact and damaged paint coatings. System configuration determined not only the protection profiles but also the current outputs. The five configurations differed markedly in their current outputs, with different increases in response to paint damage and simulated under way conditions. Also, the relative contribution from forward and stern zones varied not only according to hull state and operational conditions but also with the ICCP configuration. Results are discussed in relation to determining required system current capacities for real ship systems. It is evident that not only must sufficient capacity be installed to provide good protection under way with a damaged hull coating but also that the required capacity of each zone must be determined.
