United States Naval experience with antifooling paints

Performance of several anti fouling tributyl tin (TBT) paints on a variety of Naval ship types is presented. The current Naval assessment of TBT paints is presented in terms of economic, environmental, and health and safety issues. a1 ternate ablative paints tested have given mixed results , but acceptable economic and environmental results. directions are discussed. The Future antifouling paint needs and UNITED STATES' NAVAL EXPERIENCE WITH ADVANCED ANTIFOULING PAINTS Extended drydocking intervals and foul-free service of up to 7 years became a reality for the marine industry with the introduction of ablative organotin antifouling paints. These coatings resulted in reduced propulsion fuel costs up to 16 percent, completely eliminated the expense of underwater scrubbing, and halted the ensuing damage suffered by the paint from the mechanical process which further increased the savings. is an outstanding achievement because, at 20 knots, a fouled ship may require 19 percent more horsepower to maintain its speed. The ablative organotin copolymer paints replaced the old conventional cuprous oxide paints, which are good for only 18 to 24 months, and are no longer able to meet the increasing demands of the commercial marine industry and combat naval forces. Ablative copolymer-type organotin paints were first introduced in Europe in 1974 on commercial ships. By 1978, the news of its superior performance had become well-publicized in the United States, and led to the application, in February 1979, on a U. S . Coast Guard cutter. This ship performed foul-free for the next 7 years. At the interim dockings in 1980, 1983, the ship was water washed to remove the slime mechanically damaged areas were touched up, and the ship was returned to the water. The coating continued to perform well until 1986. This from June 1981 to September 1987. In both cases, the ships did not require any underwater brushing in the 6 years that the organotin was on the hull. Other examples of outstanding long service, where organotin is still performing, are a submarine painted in 1982, and an aircraft carrier painted in 1984. combatants and auxiliary ships up to the end of 1985, just before the ban went into effect, and these ships are continuing to perform well. A complete list of the ships painted with organotin and their length of service is contained in Table 1. Organotin paints were applied on assorted