Noise on dredging ships and auxiliary vessels

Abstract

High noise aboard dredges and auxiliary vessels is for the most part attributable to diesel engines. Diesels are used in dredges for propulsion, dredging pump operation, and electrical generation. High diesel noise is as a rule confined to the diesel compartments. Other potentially high-noise sources are the ventilation system; and various mechanical equipment such as conventional and hydraulic pumps, motors, and compressors. Sources other than diesel and ventilation systems produce high noise only in their immediate vicinity. With personnel confined to dredges, hearing conservation criteria must account for 24-hour-per-day exposure as well as an 8-hour-per-day workspace exposure. Approaches for noise control depend on whether a ship is being retrofitted or newly designed. Costs are important. For new designs, isolation of diesels and personnel within separate compartments and judicious location of noise-producing equipment with respect to quarters are effective control methods. For existing dredges, personnel boothes are an effective solution. Ventilation noise is reduced with conventional building industry approaches of duct linings and silencers. Sealed passenger compartments and acoustically treated engine compartments are utilized on launches and auxiliary vessels.