Consulting Engineer, Corrosion Control and Protective CoatingsPettit Paint Company, College ParkBorough of Rockaway, GANJ
Pages: 16 Published: Jan 1984
Present-day operation of commercial and military ships requires smooth ship bottoms in order to minimize the ship's frictional resistance as it moves through the water. The hydrodynamic advantage of the smoother hull results in lower fuel consumption, which, at current fuel prices, significantly lowers operating costs.
Frequent drydockings to renew antifouling coatings are intended to maintain ship-bottom smoothness. However, they are expensive, interfere with the flexibility of ship operations, are not always completely successful, and do not permit full realization of the economic potential of smooth bottoms for long periods. Recognizing the need to overcome these limitations, the Norwegian Ship Research Institute, with the support of the maritime industry and in close cooperation with paint manufacturers, has developed a successful underwater reactivation technology for an antifouling paint. This technology is described and compared with conventional coatings and another advanced type of coating. Ship-bottom roughness requirements for optimal fuel economy are discussed in numerical terms. The cumulative roughness of underwater hull surfaces during periods between drydockings is compared for conventional and advanced reactivatable antifouling coatings. Finally, a typical program for a ship on a five-year drydocking cycle that is consistent with U.S. regulatory and certification requirements is illustrated.
antifouling paint, underwater reaction, corrosion protection
Paper ID: STP29529S