At the 2nd IMO Workshop on the Relationship between Ship Energy Efficiency and Underwater Radiated Noise (URN), hosted by the International Maritime Organization (IMO) and the GEF-UNDP-IMO GloNoise Partnership, the LowNoiser project showcased how energy efficiency technologies can also reduce underwater noise — bridging two key aspects of sustainable shipping: decarbonisation and biodiversity protection.
Represented by Maritime CleanTech as project coordinator, and joined by partners including SINTEF Ocean, Bureau Veritas M&O, TSI, Lloyd’s Register, and Kongsberg Maritime, the LowNoiser team contributed to a growing recognition that energy efficiency and URN reduction are not separate challenges but two sides of the same sustainability coin.
From Awareness to Action
Just a few years ago, discussions on underwater radiated noise were limited to a small group of technical experts. Today, URN is increasingly recognised by the IMO community as a form of marine pollution requiring coordinated global action.
The workshop highlighted a turning point — from debating whether to act, to demonstrating full-scale solutions that achieve both fuel savings and measurable reductions in underwater noise.
LowNoiser plays a central role in this transition by providing scientific and practical evidence that energy-efficiency technologies — including air lubrication systems, vibration damping, and propeller optimisation — can deliver dual benefits: lower greenhouse gas emissions and reduced acoustic pollution.
Demonstrating the Synergy Between Efficiency and Quietness
Through a combination of onboard and offboard measurements, predictive modelling, and full-scale trials, LowNoiser partners are validating how energy-efficiency technologies perform under real operating conditions.
Key examples presented at the workshop included:
Integrated URN Monitoring and Prediction, TSI
Combines vibration, strain, and propulsion data with hydrophone measurements to distinguish between propeller- and machinery-induced noise, enabling control of operational parameters to reduce URN.
Vibration Damping, VIBROL
Uses advanced damping materials and modelling to minimise low-frequency vibrations that overlap with whale and dolphin communication bands.
Air Lubrication System, Alfa Laval
Applies air injection to reduce hull drag and propeller load, improving both energy performance and acoustic outcomes.
These demonstrations are supported by robust modelling frameworks led by SINTEF Ocean, VTT, and Bureau Veritas, ensuring that both energy-efficiency and URN effects are quantified and validated using real-world data.
Bridging Technology, Regulation, and Biodiversity
A key objective of the LowNoiser project is to bridge the gap between technological innovation and regulatory development. The project’s findings will inform international guidelines, including the IMO Revised Guidelines for the Reduction of Underwater Radiated Noise (MEPC.1/Circ.906/Rev.1), and contribute to the EU Marine Strategy Framework Directive, which identifies underwater noise as a key indicator of good environmental status.
By collaborating with shipowners such as Ibaizabal Tankers and Hurtigruten Expeditions, the project ensures that solutions are tested under operational conditions. Full-scale trials aboard MS Montespanza, MS Roald Amundsen, and MS Fridtjof Nansen will provide data for future frameworks such as the IMO’s forthcoming Energy and Sound Index (ESI).
A European Contribution to Global Progress
“The IMO workshop clearly showed how the conversation has matured — we’ve moved from awareness to implementation. LowNoiser is proud to demonstrate that practical solutions exist to reduce underwater radiated noise, whether through energy-efficiency technologies or targeted mitigation systems. Our mission is to bridge these approaches — connecting decarbonisation, noise abatement, and marine biodiversity — because ultimately they are all part of the same sustainability challenge,” said Emilie Dorgeville, Project Manager for LowNoiser at Maritime CleanTech.
Bringing together 16 partners from eight European countries, LowNoiser represents a coordinated European effort to develop validated, evidence-based solutions for a quieter and cleaner maritime industry.
Looking Ahead
The discussions at the IMO workshop reaffirmed that measurement capability, incentives, and collaboration are key enablers of progress on underwater noise reduction. As the maritime sector prepares for the introduction of the Energy and Sound Index (ESI) in 2027, LowNoiser provides a crucial foundation — combining data, technology, and methodologies to guide practical implementation.
By integrating both energy-efficiency solutions and dedicated URN mitigation technologies, LowNoiser offers a comprehensive framework for reducing ship-generated noise. Through its monitoring systems, predictive models, and full-scale demonstrations, the project is helping to shape the science-based regulations and practices that will define the next generation of sustainable maritime operations.
LowNoiser’s work underscores a simple truth: the future of sustainable shipping must be both cleaner and quieter.
