Page 43: of Maritime Reporter Magazine (September 2020)

SHIP NOISE “Environmental’ limits are available which are aimed at reducing underwater noise emissions without imposing onerous design limitations and the need to put damping on every panel, stiffener & dinner plate.”

Jesse Spence, President, NCE forts to put more regulations in place, ery noise will also play an important particularly for newbuilds, as a focus role, particularly propulsion engines, on shipborne noise continues to grow. gensets, gearboxes, and other large “The marine vessel operator commu- equipment.” nity is generally aware of the issue, and When asked de? ne ‘top tips’ to miti- some are concerned that if the commu- gate underwater noise, Spence admit- nity does not take action to reduce noise ted “Really, I have one. Put a limit in emissions on their own, then tough lim- your vessel speci? cation and require the its will be set for them. vessel to be designed to meet it. There

One of my main takeaways from the currently are a variety of underwater 2019 IMO/Transport Canada meeting noise classi? cations from ABS, Lloyds, is the technology is available to reduce DNV GL, and others. Environmental’ noise on commercial vessels. However, limits are available which are aimed at the desire and need to have reduced reducing underwater noise emissions noise must be stated clearly in the ves- without imposing onerous design limi- sel speci? cation or it will not get imple- tations and the need to put damping mented.” on every panel, stiffener, dinner plate,

With the wide variety of private, com- etc. The more these limits are used the mercial and government vessels plying more we will learn about what it takes the world’s waterways, there is no single to meet them (with the associated con- ‘silver bullet’ solution used to mitigate ? dence that they can be met), and what noise from boats and ships. “Every ves- this all means to marine life. The limits sel is different, and there is no ‘one size will likely change over time, as we learn ? ts all’ solution for underwater noise,” more and re? ne our understanding of said Spence. quiet ship design and impacts to marine “However, propeller cavitation is a life. But without the ? rst step of stating prominent feature of underwater noise “I want lower noise,” no progress will for most commercial vessels. Machin- be made.” www.marinelink.com 43

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