Page 25: of Maritime Reporter Magazine (September 2021)

SHIP DESIGN MITIGATING RADIATED NOISE we expect underwater radiated noise

Lessons Learned targets to be included in a growing num-

In 2021 the ECHO Program contract- ed West Paci? c Marine to work with BC ber of new vessel builds. Understanding

Ferries to prepare a case study report to and managing the risk is necessary to encourage innovation.

capture the ? ndings and learnings sum- marized in this article. While the New

FIGURE 3: Propeller cavitation

Major Vessel Replacement Program pro- simulation modelling.

curement process has been delayed due to COVID-19 impacts, the case study report illustrated that the initial phases of work undertaken by BC Ferries have led to some key learnings for other vessel operators considering the implementa- tion of underwater radiated noise targets: • Obtain baseline measurements of your ? eet to determine where your start- ing point is before setting underwater noise reduction goals; • Make design decisions in consid- eration of the larger system. Underwa- ter radiated noise is a function of many complex interactions within a vessel, and as such, it is important to design the propeller and propulsion systems in concert with the hull design to ensure that functional requirements are ac- counted for; • Engage an underwater radiated noise expert to assess design impacts and conduct trade-off analysis. Ensure the expertise is available when work- ing closely with the selected shipyard throughout the detailed design and build process; • Anticipate con? icting requirements as a part of the design optimization pro- cess. For BC Ferries, for example, meet- ing underwater radiated noise reduction requirements while achieving improved energy ef? ciency is a balancing act that requires careful consideration.

Underwater radiated noise is still a nascent ? eld in the commercial shipping sector, but one that is gaining attention and focus. A collaborative work envi- ronment between the operator, owner, shipyard, naval architect and ship classi- ? cation society is vital. As we continue to improve our understanding of quiet vessel design’s possibilities and limits, www.marinelink.com 25

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