The increase in shipping activity globally has resulted in an increased awareness of impacts on the marine environment. Effects of noise pollution, especially on marine life, have become highly prominent. Marine life is extremely sensitive to noise pollution. Due to their extreme reliance on underwater sounds for basic life functions like searching for food and mate and an absence of any mechanism to safeguard them against it, underwater noise pollution disrupts marine life (Singla, 2020). In short, marine animals depend on sound to live, making and listening to it in various ways to perform various life functions (US Bureau of Ocean Energy Management, 2014).
Noise travels much more in water, covering greater distances than it would do on land while travelling through air. Underwater sound has both pressure and particle motion components and hearing can be defined as the relative contribution of each of these sound components to auditory detection (Popper AN, 2011). Sounds radiated from ships are among the underwater noise sources. Among shipborne Underwater Radiated Noise (URN) sources are the following:
● Propeller’s rotational turn and the blades hitting to water flow lines
● Propeller’s cavitation
● Ship hull structure’s interaction water (fluid-structure interaction)
● Mechanical noises from onboard machinery
All of these noise sources are radiated to underwater from ships, especially when the ship speed is at higher rates, i.e. above 15 knots.
GDS Engineering R&D provides testing, analysis, and reporting services for URN emitted from ships and ocean platforms.
Our Expert Team
We have established a group of engineers and academicians, called “GDS Team”, to provide services on the URN Identification for companies in need of Underwater Radiated Noise identification for their platforms or ships through
- research,
- testing,
- analysis and computer simulations, and
- developing and submitting an internationally acceptable report.
Our staff consists of academicians from Istanbul Technical University (ITU) Marine Equipment Test Center (METC), sectoral experts experienced in noise measurement, and our personnel with experience. GDS Engineering R&D is established in the university research park with the permission of ITU Rectorate by laws. Consisting of both academic and sectoral subject matter experts, the GDS Team performs analysis and submit a report with extensive study onthe effect of the noise on marine mammals.
Our Expertise and Thoughts on he URN Measurement and Reporting
Our study reflects that there has been an increase in academic and scientific studies, in the last decade, with regards to shipborne noises and their effect on marine life. Our research indicates that the International Maritime Organization (IMO) Marine Environment Protection Committee has also held a subject meeting in 2019 and published a report (IMO MEPC 74/INF.28, 2019). The IMO report indicates that there is no requirement or a strong guidance document yet published with regard to Underwater Radiated Noise (URN).
Studies show that there are no standard thresholds established and currently required as design criteria for commercial ships.
Our study focuses on the following main areas:
- Overview of previous studies on the subject.
- Evaluation of Shipborne Machinery Design and Noise Radiation using computer simulations.
- Evaluation of design and considerations made countermeasures taken for the vibrations and noise including URN, using the state-of-the-art noise reduction and isolation techniques.
For more reading:
Read our post on Underwater Radiated Noise (URN) of your platform: https://www.globaldynamicsystems.com/posts/terrestial-and-underwater-radiated-noise-evaluation-for-a-powership/
Another post is on Terrestial and Underwater Radiated Noise from Powerships: Testing and Evaluation: https://www.globaldynamicsystems.com/posts/terrestial-and-underwater-radiated-noise-from-powerships-testing-and-evaluation/