Page 42: of Maritime Reporter Magazine (September 2020)

SHIP NOISE

Quiet by Design

Environmental concerns drive ship noise mitigation efforts

Noise Control Engineering (NCE) recently completed an underwater noise study for

Washington State Ferries. Jesse Spence, President, NCE, discusses the growing mandate to mitigate noise from commercial vessels.

By Greg Trauthwein oise Control Engineering, our vessels on marine life, particularly ronment, the matter of noise mitigation

LLC (NCE) recently com- the critically endangered Southern Resi- with a focus on its impact to wildlife has pleted an underwater radiat- dent Killer Whale,” said Kevin Bartoy, been a long-running concern, growing

Ned noise study for Washing- Environmental Stewardship & Sustain- in stature in recent years as the overall ton State Ferries (WSF), a study which ability Program Manager, Washington health and well-being of the ocean and entailed measurement of nine vessels State Ferries. ocean issues have risen in the public representing all seven operating classes NCE used its Buoy Acoustic Measure- conscience. of WSF vessels, quantifying noise, po- ment System (BAMS) to perform vessel “Early in 2019 there was a meeting tential impacts to orcas and other marine noise measurements in general accor- held at the IMO of? ces in London, or- life, and methods of reducing noise. dance with ANSI S12.64 while allowing ganized by Transport Canada, to attempt “With the increasing awareness of un- the vessels to maintain their normal op- to quantify what we should do regarding derwater noise impacts on marine life, erating schedule. Simultaneously, vessel underwater noise limits and quanti? able both globally and locally in the North- operational and environmental data was approaches to noise mitigation. These west, WSF is interested in learning more collected allowing for assessments of meetings have all been in response to about how their operations may impact noise at varying propeller RPMs, oper- the rising recognition of our impacts to marine life,” said Jesse Spence, Presi- ating powers, and speeds. This informa- marine life, with respect to noise,” said dent, NCE. “They are also interested tion was compiled into a database which Spence. “Looking forward, I believe in learning what aspects of their vessel was used to calculate ‘source levels’ there will be greater acceptance of es- designs cause underwater noise, and if and identify impacts to marine life us- tablished noise criteria as independent they can reduce their impacts through ing NMFS guidelines. The measurement operators design vessels that meet these procedural changes as well potential im- data was also used to identify causes of criteria and modify existing vessels to provements to the design and engineer- noise ranging from propeller cavitation reduce underwater noise. This issue has ing of their vessels.” to speci? c machinery items. been discussed for nearly (or possibly “This work provides the information more than) 20 years, and the momentum that WSF needs to take the next steps Cutting Ship Noise is building.” towards operational and engineered While emissions from ship exhaust mitigation measures to reduce the im- has been the main target of regulators Drivers and Solutions pact of underwater radiated noise from to reduce shipping’s impact on the envi- According to Spence, there are ef- 42 Maritime Reporter & Engineering News • September 2020

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