Vessel Maintenance and Management - Keeping Hulls Clean
Oct 30, 2024
Image courtesy Jotun
A step-change to the industry’s approach to hull efficiency and environmental protection is underway.
That was the general view of experts taking part in the PortPIC conference this year, who also highlighted that innovation in terms of what typically would be viewed as hull management has changed quite rapidly and benefits are feeding through with untapped potential for further improvements if collaboration, engagement of port authorities and common regulations and standards can be achieved.
Decarbonization has become the dominant discussion subject across the industry and at the regulation setting arenas of the IMO and the EU. Overall, the shipping fraternity sees the need for new measures even if different aspects frequently disagree as to which measures are worth adopting and which may be expensive dead ends.
Future fuels, for example, promise much but currently are expensive and not available in sufficient quantities – if at all – to replace the fossil fuels that have served shipping for over a century. Mechanical efficiency measures on the other hand have already been employed so as to allow ships to meet the requirements of the EEDI and EEXI regulations.
Another measure is hull management, which is drawing the attention of all interested parties. Indeed, keeping the vessel free from biofouling through the use of proven antifouling coatings and hull cleaning can allow a ship to perform well under the CII regulations even if it is still not yet fully recognised in the EEDI and EEXI measures. Frictional resistance accounts for a large part of a ship’s fuel consumption and there is enormous potential for improving performance by reducing the annual 7-10% increase in required power or fuel consumption due to progressive fouling and hull roughness.
Moreover, improving vessel performance by effective hull management has become more important than ever in light of regulation such as the EU ETS and the possible financial mid-term measures for GHG reduction being formulated at the IMO.
Port Biofouling Challenges
Ironically, while owners and operators are seriously considering cleaning hulls and propellers more frequently, traditional methods of fouling removal are being banned by port authorities because of concerns related to invasive species and release of paint particles into the environment. An added problem of traditional methods is that rough cleaning practices often lead to premature depletion of the paints and subsequent loss of protection. However, these challenges can be overcome using new technologies and solutions now being developed as long as agreement can be reached on best practices and standards so the new ways can be rolled out as quickly as possible on a global scale.
“An essential step in further shedding light on the topic and finding best practises and standardisations is actively engaging with industry stakeholders,” said Morten Sten Johansen, Jotun’s Global Category Director, Hull Performance Category, “and that is why we co-founded PortPIC, to engage with them and get their own perspectives on the challenges and to see how we can work together to solve them.”
“It is important to have arenas like PortPIC and HullPIC along with the bigger commercial conferences like Nor-Shipping, Marintec, SMM Hamburg and Posidonia to mention just a few, which cut across competition, roles, mandates and where different views can enable us as an industry to make real progress. For Jotun, to contribute to this is a part of our Clean shipping commitment”, he added.
This year’s PortPIC was held recently in Pontignano, Italy. The conference, now in its 5th edition, brought together over 50 industry representatives to discuss the latest developments in the field of hull management, with experts from ship operators, coatings manufacturers, technology providers, robotic and diver in-water cleaning companies, regulators and academia.
Novel Hull Maintenance Solutions
PortPIC kicked off with a presentation by Volker Bertram (DNV) who shared information on recent innovations in hull fouling management options, looking at a variety of recent developments for biocide-free antifouling solutions, nano-coatings including graphene-based coatings, and coatings with passive air lubrication.
Bertram also highlighted the novel protection systems based on ultrasonic or ultraviolet radiation which have progressed significantly in recent years and spoke of the rapid growth in robotic cleaning technologies, many of which have now become mature market offerings.
“The progress towards more efficient and more sustainable hull management solutions in the last five years is impressive and encouraging. Indeed, where there is a problem, there is a solution. Challenges such as increasingly strict CII requirements for operational energy efficiency and wider application of biofouling management requirements, are answered by innovative solutions. Ingenuity and entrepreneurship thrive, and established big players are kept on their toes by start-ups challenging the status quo.”
He continued, “We are certainly moving in the right direction, but I also question whether the combination of emerging cleaning methods is aligned with the new coating technologies, and if the regulators and port operators have caught up with the step-change underway. The evolution of technology must be encouraged by the port operators but they, understandably, also want to be sure that the new cleaning technologies match with the coating technology on the ships and, moreover, meet their environmental requirements,” he said and added, “This barrier can be overcome through more cooperation and insight sharing.”
Expanding on ultrasonic technology, Ove Hagel (Hasytec) gave a presentation titled ‘Ultrasonic antifouling: an approach to mitigate biofouling on ship hulls and niche areas.’ Ultrasonic vibrations cause very high accelerations, which destroy cell structures of fouling. A strong point of ultrasonic protection is that it offers biocide-free protection for ships even at zero speed. Ultrasonic systems have been used successfully for some time on niche areas but application to the entire hull of a large vessel is a novel approach that Hasytec believes warrants investigation and so has developed an ‘intelligent’ dynamic biofilm protection.
Overcoming Obstacles
Various aspects of in-water cleaning (IWC) of hulls were also addressed, including a presentation by Anita Børve (Jotun). She highlighted Jotun’s long history in antifouling coatings and continuous focus on hull performance stating “the main goal is a clean hull and optimised hull performance, and both our coatings, our digital services, our advisory and expertise, as well as our innovations like the Jotun HullSkater is based on our almost 100 years of in-depth industry knowledge and performance testing. It’s a continuation of our Clean shipping commitment, and the work we do to help reduce emissions, preserve fuel and protect the oceans’ biodiversity.”
Børve acknowledged that the regulatory landscape concerning underwater hull cleaning is crowded and complex. “Several international and local entities are working in parallel but still technologies and regulations are under development with various maturity and timelines,” said Børve. She also highlighted that existing methods of testing and ensuring water quality during IWC are very comprehensive, labor and time consuming and do not match what is possible to achieve in practice during a normal port call.
Discussing a new method of testing water quality, she added, “Testing has also proven that proactive cleaning without capture can be done without imposing any excessive release of biocides as calculated by the MAM-PEC tool used by the competent authority in EU member states for assessing potential environmental risk from antifouling coatings.”
In a separate presentation, Anna Yunnie (PML Applications) presented ‘An alternative multifunctional strategy for testing in-water cleaning devices.’ She echoed Børve’s assessment of the complex and incomplete regulation or standardisation of the hull cleaning sector. She said current methods leave information gaps on the compatibility between different cleaning methods and coating types, and the physical impacts on coating integrity and antifouling performance following an in-water clean. If the shipping industry is to meet IMO guidelines on biofouling management, these information gaps require attention.
Yunnie went on to describe a how several systems have been tested on a small scale and said that although the tests have limitations when compared to BIMCO IWC trials, which they are not designed to replace, the methodology can help ensure that only the most useful and informative full-scale trials are conducted, saving the industry and regulators time and money.
A Shared Experience
PortPIC also covered broad ranging perspectives from regulators, shipping companies, NGO’s, robotic cleaning and inspection technology developers and class. For example, Sahan Abeysekara (Lloyd’s Register) shared information on LR’s ‘Clean hull notation: Industry advancements to achieve effective hull management’. The Clean Hull notation provides recognition of various hull management practices and quantifies it to a surveyable output. As its name suggests, the intention of the CH notation is to maintain the hull at near cleaned condition at all times. To obtain and maintain it requires a close relationship with hull management or vessel performance monitoring systems. The proactive identification of hull condition is by means of frequent biofouling inspections and fouling prediction modelling. “The ultimate goal of the CH notation is to serve as ‘compliance by design’ to the eyes of regulators and Port State Control” he said.
Voluntary notations such as Clean Hull may imply extra investment, but Abeysekara also pointed out that often there are tangible benefits such as reduced port charges offered by some ports and greater interest from charterers as well.
In her paper covering the Cleah Hull Initiative, Irene Ø. Tvedten (Bellona) shared the background and status of the CHI project. She also mentioned the challenges to proactive management as being inconsistencies in global policies, how regulators lack procedures for approval and how they often impose bans on in-water cleaning, leading shipowners to hesitate to conduct cleaning even if they can get access to services.
Best Practice
Tvedten also stressed the importance of collaboration and insight sharing and firmly believes the CHI can help raise awareness and drive the development of the ISO 6319 standard. This will provide several benefits, including an agreed “best practice” for in-water cleaning and help harmonize stakeholder requirements. Also, the standard, which will be published in January 2026 at the latest, will help ports and relevant authorities evaluate requests for in-water cleaning, as well as help shipowners ensure that cleaning services are performed in a specific way regardless of location.
Sharing her learnings from being a regulator in New Zealand writing and overseeing the world’s strictest biofouling regulations before joining robotic in-water cleaning company, EcoSubsea, Abigail Robinson gave a presentation titled “From Regulator to Regulated: A Perspective from Both Sides”. In it, she also called for more collaboration and the urgent need for ‘fit-for-purpose regulations’.
Robinson described fit-for-purpose regulations as those that set a high standard for environmental and human health protection, while also providing a clear process of application for innovators to be able to reach that standard. “Regulators need open and honest industry perspectives to be able to understand the operational complexity surrounding the in-water cleaning issue, as well as the wider impacts,” she said.
Another interesting paper titled ‘Copper release rates under static conditions along a salinity gradient’ was presented by Johansen (Jotun) and addressed the thorny subject of accurate risk assessments of biocide release rates under various conditions. Since regulators and port operators are likely to make decisions on approving products and services or not, based on risk to the environment, accurate data on release rates of substances of concern such as copper compounds are essential.
In the presentation a new field test method developed by Jotun researchers was described. Tests carried out on a variety of coatings in several European ports revealed that the standard input values for risk assessment based on ISO 10890 (mass balance method) can overestimate release rates. From the analyses presented it can be concluded that seawater flow has a greater impact on the release rate than salinity.
Questioning the Status Quo
After the presentations, a forum session was held featuring Ivana Melillo (GNV, a subsidiary of MSC Cruises), Jean-Loup Barrere (CMA CGM), Irene Tvedten (Bellona) and Simon Doran (Akzonobel) who covered questions from the moderators Bertram (DNV) and Johanson (Jotun) and the audience.
Questions were posed on a variety of subjects around what the industry stakeholders can do to pave the way for a cleaner, more efficient maritime industry and what the environmental regulations, standards and guidelines mean for shipowners and operators.
Responding to why port representatives were missing from the conference, Simon Doran said ports were missing an opportunity and should understand that there’s also a commercial opportunity for them to press home legislation. “They need to be guided in terms of how to get involved,” he said. Irene Tvedten believes ports may be lacking some incentive and questioning why they should be involved, but the growing focus on decarbonization and biosecurity could be a way to increase engagement. “We need to tap into these aspects, as well focus on the potential economic benefits.”
Ivana Melillo answering a query on whether owners’ attitudes to in-water cleaning and hull management were changing, said, “there is change underway in terms of going from traditional methods to robotic cleaning approach and also the different ways to monitor hull and propeller performance. We need to co-operate more, bring everyone together to find best practices”. She went on to say, “This is especially important as companies work to meet ESG requirements.”
Commenting on whether the sector was crowded and the difficulty in choosing technologies, Jean-Loup Barrere admitted that 10 years ago, his company did not consider biofouling to be a problem on its ships and only did what it thought necessary but that is changing with regular inspections and cleaning now the strategy. “As I see it there are many options, many questions and it is not easy to select the ‘right’ technology, but this conference brings together experts who share insights and advice on how best we can go forward to achieve effective hull management,” he said.
Looking Ahead
As the conference closed the panellists gave their key takeaways with Tvedten saying, “Despite the lack of port representatives at this event, PortPIC is still a very relevant conference because the importance of keeping updated is very high and the knowledge gained there can be shared with ports in other arenas.”
For Melillo the need for continued industry dialogue, knowledge sharing, and collaboration is important “but the perspectives and insights of ports is crucially important if we are to establish common best practices.” Barrero agreed with the previous two on the need to get ports more involved to exchange experiences, developments and new insights.
Doran said he finds PortPIC, alongside HullPIC, to be the most informative and educational forums. “Every day is a school day" in addition during these conferences it is refreshing that there are no competitors, just like-minded people working towards common goals of sustainability and protecting global biodiversity.”
Picking up on the collaboration theme, Johansen said, “There’s certainly a step-change underway in terms of innovative solutions and the industry’s approach to hull efficiency and environmental protection, but more collaboration is key to opening the untapped potential of effective hull management. “As part of our Clean shipping commitment, Jotun will continue to contribute to PortPIC and other important industry arenas so that shipping can become even more sustainable in the future.”
Technology
emissions
Fuel Efficiency
coatings
Hull Cleaning
hull monitoring
Green Ports