International classification society Bureau Veritas has developed a voluntary notation intended to assist shipbuilders and operators reduce underwater noise radiating from ships.
The comprehensive set of standards and measuring services is grouped as NR614 Underwater Radiated Noise (URN). It aims to control and limit the environmental impact on marine fauna of all self-propelled ships and provide a standard and a system to assess compliance with specific vessel requirements for underwater radiated noise.
It covers both shallow and deep water conditions, sets out a dedicated comprehensive measurement procedure, explains how to manage measurement uncertainties and sets specific underwater noise level requirements
Jean-Francois Segretain, technical director, Bureau Veritas Marine & Offshore Division, says, “Underwater noise radiating from ships is acoustic pollution, and there is no doubt that it will be the next big area to be tackled by regulators.This notation, backed by careful research with an extensive network of partners, means we can help designers, yards and operators to be ahead of regulation. And it makes commercial sense.
Reducing underwater noise directly contributes to reduced noise and vibration levels on board, which improves passenger and crew comfort. There is also a strong link between fuel efficiency and noise. Quieter ships burn less, and we can help make ships quieter and so more efficient.”
One of the main drivers of the notation is to aid European stakeholders in fulfilling the requirements of the Marine Strategy Framework Directive. This aims to improve the environmental state of European waters by proposing mitigation solutions to be put in place by 2016, with their efficiency proved by 2020.
The BV notation has been issued in parallel with the European research project AQUO, which is focused on underwater noise, and includes the work of 13 partners – shipyards, hydrodynamics research institutes and bio-acoustic experts – from eight countries, and an end user committee has been built to review the project, including BV’s notation.
Several new expedition cruise projects have underwater noise reduction in their specifications and other passenger ship operators are discussing BV’s URN notation and its services and technical assistance for implementing noise reduction solutions. Bureau Veritas has signed a collaboration agreement with TSI S.L. a Spanish company that specialises in Dynamic and Acoustical design of quiet ships as well as noise and vibration measurements.