Practical suggestions for the design, construction and maintenance of vessels with high acoustical performances

This paper describes the broad outlines of the problems related to vessels with high acoustical perforrnances during all the phases of their life, from the very early design up to maintenance. The terms of the problem of sound attenuation on a vessel are discussed, with reference to the main sources present on board and the paths connecting them to the receiving positions. Practical procedures as well as theoretical investigations to predict acoustical performances are briefly reported, with indications about their effectiveness, reliabiliry and applicability. Some anti-noise suggestions are presented to reduce the noise levels of the sources and to increase the transmission losses along the various paths. General criteria to be put into practice during the operational life of the vessel are suggested in order to maintain the original low-noise characteristics.