MEPC 84 Approves Guidance on Underwater Radiated Noise Reduction and Energy Efficiency
The Marine Environment Protection Committee (MEPC) 84 has approved a technical guidance circular aimed at co-optimizing propulsion equipment for energy efficiency and reducing underwater radiated noise during the design and retrofit stages of ships. This guidance seeks to clarify the trade-offs between noise mitigation and conventional propeller design, promoting the co-benefits of quiet ship technologies alongside energy performance improvements. Case studies presented at a prior workshop demonstrated that retrofits, such as propeller upgrades, appendage modifications, and air lubrication systems, can achieve noise reductions of 2-10 dB while also enhancing energy efficiency. The guidance emphasizes the need for precise definition of ship operating profiles and speed ranges, moving beyond generic approaches to tailor strategies to specific operational conditions. 
