New technology both measures and reduces underwater noise in real time

In several parts of the world, there are environmental protection zones where ships must reduce speed or take a longer route to avoid impacting marine life. However, this is not always enough. In a research project conducted under the Canadian government's Quiet Vessel Initiative, a new technology has been developed that offers entirely new possibilities.
Underwater noise is a growing environmental issue that is considered pollution by both the UN and the EU. Despite this, there are still no regulations or effective measures to reduce the noise. In the waters off Vancouver, Canada, there are environmental protection zones where ships must lower their speed or take a detour, mainly to protect the endangered orca population in the region.
How can this be made more efficient? Can emissions be reduced even further? Experts at the German propeller company Schottel were tasked with examining these questions. The first thing they discovered was that reduced speeds do not always lead to lower noise levels. Hull vibrations above the propeller have been found to have a direct correlation with underwater noise. To better understand these noise sources, Schottel developed an advanced monitoring system that combines hydrophone recordings, hull vibration measurements, and machine learning.
The research was conducted onboard double-ended passenger ferries operating in the Salish Sea between Canada and the USA. The correlation between hull vibrations, measured just above the propeller, and the noise emitted by the ships was analyzed. From this, an algorithm was developed that can predict underwater noise when the ferry is in motion. The algorithm considers factors such as propeller speed, pitch, and vessel speed to calculate the expected decibel level near the ship.
Schottel then developed a new propeller design that, with the help of the algorithm, is optimized to reduce noise. When tested in practice, it showed an average noise reduction of five decibels. The algorithm can therefore be used as early as the design phase to create propeller shapes that generate less noise.
The project also aimed to raise awareness of noise among ship operators by introducing a real-time reporting system. The idea is that the system will enable them to respond to high noise levels and take immediate action to reduce them during operation. Operators will also be able to conduct historical and comprehensive evaluations through a cloud-based internet system, which can, in turn, be used to provide noise emission information to authorities, organizations, or the public.
-
Nya regler och åtgärder – det här gäller för 2025
-
EU-rapport: Sjöfarten måste göra mer för att minska utsläppen
-
Elin Frändberg, ny koordinator på Lighthouse
-
Social hållbarhet till sjöss måste kunna mätas
-
Nu är det läge för den flytande containerhamnen
-
Informationsportal ska göra det enklare att utveckla och använda sjöfarten
-
Se webbinariet Säker storskalig vätgasbunkring
-
DNV: Tillgången avgör biobränslenas framtid inom sjöfarten
-
Traineeprogrammet tog Emil in i branschen
-
Beställningarna på fartyg som kan köra på alternativa bränslen ökar