New coatings solutions include a robotic hull cleaning system that could cut industry CO2 emissions by 40M tonnes
Norwegian coatings supplier Jotun is offering a new hull cleaning system designed for challenging vessel operations that if widely adopted, could help to reduce shipping’s carbon emissions.
Jotun developed its Hull Skating Solutions (HSS) system in partnership with Kongsberg, Semcon, DNV GL, Telenor, Wallenius Wilhelmsen, Berge Bulk and Maersk and has been testing it on vessels and at selected ports.
The system consists of a remotely operated, machine-learning enabled robot called HullSkater that cleans vessels’ hulls, but Jotun business development director Geir Axel Oftedahl said the robotic cleaner was just one part of a larger system.
“It is a bigger solution, and it consists of the HullSkater, a high-performance coating SeaQuantum Skate, real-time fouling alerts, remote operation with trained skate operators and finally, a set of performance and service-level guarantees. All of this integrated into one, full solution. The integration here is important. Since we control all the parts, we can make sure all the parts work together in harmony.”
Mr Oftedahl said the move from Jotun’s traditional market segment into robotics was a major leap that required a good deal of assistance.
"The introduction of our hull performance solution back in 2011 really opened our minds to innovative solutions outside the paint can. We did not know anything about robotics, however, so when we came to realise robotics had the potential to revolutionise the market for hull performance, we did the sensible thing. We approached a global leader in subsea robotics in Kongsberg and asked their advice. We basically asked if we were crazy to head in this direction. Fortunately, the response was we would only be crazy if we moved forward without bringing Kongsberg on board as a partner," he said.
Kongsberg was only too happy to join as Kongsberg chief executive Geir Håøy noted, but shipowner Wallenius Wilhelmsen senior vice president Geir Fagerheim’s reaction was “a mixed bag”, he said. The shipowner quickly came around to the appeal of the project’s broader implications and used one of their vessels as a testing ground, he said.
“[I was]… surprised that a company mainly known for selling paint was coming to me with this advanced technical solution… I must admit there was a bit of scepticism… Could they really make this work, across the globe in the harshest environments and remotely operated? Because that is a huge challenge. We have had this in operation on our vessel Talisman for two years, working across the globe, and it has been a really interesting challenge and a good journey,” Mr Fagerheim said.
“From our side, we can see this as a potential game-changer in the way we manage biofouling… it is a self-sufficient solution, so there is no need for interference or action from the office to make this happen. It is a semi-autonomous solution to keep the hulls clean at all times and thereby also avoid the overconsumption [of fuel] from biofouling, which could be huge, while also helping us keep the emissions down. We see that it lays the groundwork for even more advanced paintings going forward that could be biocide-free but also lower the baseline consumption for vessels even further.”
“Wallenius Wilhelmsen has a zero-emissions ambition in its strategy, and this technology is a solution that could bring us toward that goal,” he said.
Kongsberg executive vice president of sensors and robotics Arne Rinnan described Kongsberg’s contribution to the system.
“One element is autonomy… we have a series of sensors which are crucial to get this operating reliably. We have battery technology and we also have connectivity solutions which we are applying in the HullSkater. It is a great challenge to navigate [the robot] on these huge hulls without getting lost, and we are doing that by combining the sensors with machine learning,” he said.
Classification society DNV GL, another partner, said the technology alone was tempting enough to draw them into the project but, as DNV GL senior vice president Per Marius Berrefjord said, larger concerns factored heavily in the decision to join.
“The project is so full of innovation and interesting technology we would have joined just because of that. If you look at the bigger picture, shipping needs to reduce its greenhouse gas emissions, and it needs to do it very fast – maybe two to three times faster than normal. And we are very serious in DNV GL about supporting any mission or action that can contribute to that,” he said.
According to Jotun, HSS provides condition monitoring services tailored for each vessel. The solution uses a proprietary algorithm and big data to accurately predict fouling development and cleaning schedules.
Jotun said HSS will help ship operators combat the early stages of fouling and significantly reduce fuel costs, CO₂ emissions and the spread of invasive species.
HullSkater removes individual bacteria and biofilm before macro-fouling takes hold. Jotun said this minimises the need for reactive cleaning which the company said can help cut costs and lower environmental risks.
HullSkater stays on the hull by the force of magnetic wheels. Each wheel is equipped with electric motors for propulsion and steering. The vehicle is equipped with cameras and sensors, supporting the operator with data for navigation and documenting fouling on the ship hull while a motorised brush keeps the hull free from fouling.
Jotun said inspecting and cleaning the hull will average between two and eight hours depending on its size.
Jotun is now in the final verification stage and recruiting select owners to be the first to use the solution.
In terms of its impact on CO2 emissions, Jotun chief executive Morton Fon said “We have done some calculations on that, and we believe this can be a substantial contribution to eliminating CO2 emissions. If we were to put this on all ships in challenging trades around the world, we believe we could save the world 40M tonnes of CO2 emissions. How much is that? That equals the normal CO2 emissions in one year from Norway. So that is a huge impact."
Scrubbers coatings boost
There have been moves within the container ship coating market to embrace less traditional coatings. Subsea Industries’ Ecospeed coating is not a traditional anti-fouling paint, but a durable, hard-coating system that can be cleaned as often as required to maintain the efficiency of the hull.
The company is seeing a growing need for its product to replace traditional coatings that have been corroded by the discharge produced by scrubbers.
Subsea Industries’ production and sales executive Manuel Hof tells Container Shipping & Trade “Many owners have to decide how to comply with regulations and some choose scrubbers. If scrubbers have an underwater discharge, this can come into contact with traditional coatings around the discharge outlet and overflow pipes and cause corrosion to the coatings. Our coating is based on a composite that is resistant against a variety of chemical products. We also supply another product Ecoshield to be used on rudders for big container ship owners. Ecoshield is designed to offer permanent protection for all running gear against cavitation damage.”
The company has carried out applications for several large container ship owners, with most of them using Ecoshield on the rudders of their entire fleet.
Ecospeed does not suffer any degradation during its lifecycle, so owners can save fuel and money. It is also impermeable to water because of the coating’s unique composition.
But while it does not need to be re-applied in drydock like other paints, it does need to be cleaned regularly. This is a more cost-effective and environmentally acceptable approach to hull protection and anti-fouling, though it does come with challenges. Mr Hof says “It can be tough to convince shipowners to use this coating because of the regular cleaning. They see it as a hassle at first, but it is a far better solution if talking about sustainability.”
Owners also need to understand the concept as it is a different approach to traditional coatings. Underwater cleaning is part of the concept, but it protects against the reduced hull efficiency shipowners face with traditional systems, Mr Hof says.
Nevertheless, attitudes are changing in the container ship market, and both Ecospeed and Ecoshield are being increasingly used on niche areas, says Mr Hof, including scrubbers, rudders and bow thruster tunnels.
He adds “We do both retrofits and newbuilds. Newbuilds are the most interesting to us, as why not start with the most durable system there is, rather than wait five years and re-apply. Ours is long lasting and far more durable. While others are heavily affected by cavitation phenomena, ours is not.”
He explains “The propeller has a turning speed and creates a pressure difference, creating bubbles that rush to the surface and implode on the rudder surface. This creates a shockwave and cavitation erosion on the rudder itself but can be avoided by using the right coatings system, like Ecoshield.”
Onboard applications advance
Elsewhere, equipment to apply onboard coatings has advanced. Graco is now using sprayers on board to maintain a painting job.
A spokesperson explains that the company traditionally provided paint application in shipyards with its mono or two components painters, the equipment used on board is “rather different than our King or Bulldog as it is oversized. We use them mainly for shipyard and ship repairs on drydocks for heavy jobs that need to be applied quickly with 100% solid epoxy paint.”
The company now supplies more appropriate equipment to be used on board to maintain a painting job: Merkur X48 or X72.
The spokesperson explains the benefits. “This equipment will do the same job, however the prices are lower and the unit is smaller than the King and Bulldog, meaning easier manipulation on board.”
He explains that while the pressure is the same, the difference is in the flow. The King gives 15 litres per minute of paint at the nozzle for the King 50:1 against 4.5 litres per minute for the X48 and 11 litres for the King 70:1 against three litres per minutes for the X72.
This means when “you apply paint with King or Bulldog you lose 70% of the paint into the air (10 litres for the 50:1 and 7 litres for the 70:1). With the Merkur you lose less; 2.5 litres per minute for X48 and 2 litres for the X72.
“In conclusion, you will save money purchasing the unit as you will use less paint.”