Platinum Metals Rev., 1957, 1, (1), 26
Cathodic Protection of Naval Vessels
In a paper on “Navy Experimental Work with Cathodic Protection” presented to the National Association of Corrosion Engineers (Corrosion, 1956,12,18–24), Irving D. Gessow describes the work done by the United States Navy Bureau of Ships on the cathodic protection of ships’ hulls. Impressed current systems using graphite rod anodes are satisfactory for the external protection of inactive ships, and may increase the docking interval from five to seven or eight years.
No clear evidence is yet available as to the economic advantage of the general use of cathodic protection for active ships, but work has been concentrated principally on destroyers and submarines, where the pitting of plates may have serious consequences. Both sacrificial and impressed current systems have been fitted; magnesium anode sacrificial systems are relatively heavy and require replacement in two years or less while impressed current systems with either graphite or platinum-clad anodes are lighter and more permanent but are higher in first cost. One destroyer and one submarine have been fitted with platinum-clad anodes. The submarine installation appears very successful; results from the destroyer installation were not available at the time the paper was prepared, but it is understood that an inspection of the destroyer after fourteen months of service showed that the anodes were clean and bright and apparently performing satisfactorily, while in general the hull was in excellent condition.