What coating type should I use on my ship? Which is most environmentally and cost-effective for the waters we sail on? HullMASTER has the answers to the questions. The new tool, which has been developed within the Swedish Transport Administration's industry program Sustainable Shipping, which Lighthouse runs, is intended to function as decision support for shipowners and authorities.

In shipping, one is well aware of the importance of a clean hull. Algae growth alone can increase fuel consumption by at least 10 percent. Of course, this is neither economically nor environmentally sustainable. But how do you clean the hull in the most cost-effective and environmentally efficient way? Today, most shipowners paint with chemically active antifouling paints. They are often considered the most cost-effective, but the problem is that they leak toxic substances, especially copper. However, there are
biocide-free alternatives, such as silicone-based foul release paints which create a "smooth" surface that causes the growth to drop at high speeds. The disadvantage of these is, among other things, that they are more expensive to apply and require that the hull must be cleaned completely when repainting.

“That they did haven’t had a major breakthrough I think also has to do with tradition. It is easiest to do as you have always done, and when you bring in ships for maintenance, the focus is usually not on repainting the hull. You do not know what the hull looks like and decisions sometimes have to be made quickly because you are only up for a few days. It is in such cases that our tool can help”, says Lena Granhag, researcher at Chalmers.

She talks about HullMASTER, a tool she has developed together with colleagues from Chalmers, SSPA and the University of Gothenburg. The idea is that it will function as decision support for both shipowners and environmentally responsible authorities to achieve optimal choice of of coating and interval of maintenance work.

“With the help of the tool, you can calculate the effects of emissions and the actual environmental costs that different types of paints have. Of course, this is something that environmental authorities can use when they make decisions about rules, instruments and other things.”

By entering parameters such as the type of ship, size, fuel, speed and which route you operate the most, shipowners can, through the tool, get advice on what type of color is suitable for their ship and what the costs will be for that type of maintenance and cleaning as divers or underwater robots do.

“HullMASTER also contains a graph that shows how long it takes before a repaint with a foul release paint pays off financially. This varies but usually pays off already after a couple of years, says Dinis Soares Reis de Oliveira, also a researcher at Chalmers.

The tests performed so far show that Hullmaster's forecasts have an 86 percent reliability. The results have been validated using programmed data from several RoRo vessels that have served the Baltic Sea and the North Sea for a total of 40 years.

On May 27, Dinis Soares Reis de Oliveira will present HullMASTER at an IMO event and in August he will do the same at the Hull Performance & Insight Conference.

Clean hulls wins in the long run