2024A-OS13-1 Issues and Countermeasures for Underwater Radiated Noise (URN) from Ships

－IMO Guidelines and Global Trends－

Abstract

The present paper discusses the issues surrounding Underwater Radiated Noise (URN) from ships and the countermeasures being implemented globally. URN poses potential threats to marineecosystems, necessitating action for environmental protection. The study outlines URNcharacteristics, focusing on propeller cavitation noise as a dominant source at higher speeds. It reviews the International Maritime Organization’s (IMO) revised guidelines on URN reduction and globaltrends, including incentive programs in ports like Vancouver. The paper highlights Japan’s stance andproposals to IMO, emphasizing the need for balance between URN reduction and greenhouse gas (GHG) emission control. It advocates for region-specific regulations due to varying marine ecosystems and suggests utilizing the Brown-Shiraishi method for simple URN estimation during the design phase. The study concludes by stressing the importance of sustainable shipping development through continued international dialogue and research.