SHIPS' BOTTOM PAINTS IN RELATION TO CATHODIC PROTECTION

Although cathodic protection of copper sheaths on wooden ships was proposed and practised over 100 years ago and the use of zinc protectors near bronze propellers on steel ships has been common for many years, it is only in about the last ten years that the present techniques of cathodic protection of ships’ hulls have been developed. Much study has been devoted to the design of the installations, including type and composition of anode materials, number, size, shape and position of anodes, and designers specialising in this field now have considerable practical and theoretical knowledge of such matters. Another factor which must be taken into consideration is the choice of coating for the bottoms of cathodically protected ships, particularly on areas close to the anodes; this is discussed in the present paper.