Preventing biofouling with the ECOsubsea solution
Tor Østervold, CEO and founder of ECOsubsea

Preventing biofouling with the ECOsubsea solution

Recently, Siem Offshore established a partnership agreement with ECOsubsea, a leading provider of environmentally friendly in-water hull cleaning services. The solution saves carbon emissions, and stops the spread of unwanted biological organisms in ports and coastal waters, such as e.g., sea vomit.

Cooperation is the key to success

The brother duo behind ECOsubsea, Tor and Klaus Østervold, has developed a solid solution for hull cleaning that removes and collect biofouling from vessel hulls. However, although they have created the needed technology, the key to success is rather good cooperation with the shipping companies and ports, T. Østervold says. He further points to Siem Offshore as an imporant contributor:

– Siem Offshore is a good example of a company that not only does something they are required to do, but they are at the forefront and take responsibility by looking for new solutions on how to help reduce the carbon footprint.

Siem Offshore also believes that a solid partnership is the key to success in achieving the goals we set for ourselves. Therefore, the Company is pleased to work with ECOsubsea on these important issues.

– The combination of scientific approach for measuring and rate the amount of marine growth, with the unique removal method itself, was the main reason for selecting ECOsubsea as our partner for this highly important sustainability measure. Further, using the Maress-system we can easily monitor the effects and results from the hull cleaning in terms of fuel savings, says Jon August Houge, ESG-director, Siem Offshore.

A major issue for the industry

The problem – biofouling – is a major issue for the industry and marine life. It attaches to the vessel hulls and creates friction, which again causes increased fuel consumptions, operating costs, and carbon emissions from the vessels. On the other side, it is also a serious threat to the marine eco-system, as the vessels transport ‘hitchhikers’ like alien invasive species from one part of the world to another.

- The spread of foreign organisms such as e.g., sea vomit, has addressed what overgrown vessel hull can bring to the coast and harbors. The requirements for cleaning vessel hulls will be as central to international shipping as the today’s requirements for cleaning ballast water, Østervold says.

Underwater robot as cleaningtool

For the inspections and cleaning, a remote-controlled underwater robot (ROV) is being used. The robot works like an underwater vacuum cleaner, or a lawnmower, using soft jets to clean off the biofouling. Attached to the hull, the machine strips off dirt and slowly cleans the surface. All the debris is then pumped back to the collection tank on the quay where it is being filtered and captured before it is sent to biogas production.  

According to Østervold, this cleaning method is more eco-friendly and less harmful for the ships than traditional ways of cleaning, like manual scrubbing.

– This method does not cause any pollution or risks to contaminate the coastal waters, and the solution leaves the hull coating in good performance, he says.

The ROV attached to the vessel hull while cleaning of the surface

He further explains that this way of cleaning is also more optimal for the antifouling, which protects the hull. Previously, it was common to use antifouling containing Tributyltin (TBT). This was highly effective against biofouling, but it was also an environmental toxin with endocrine disrupting properties and was therefore banned by the International Maritime Organization (IMO) in 2008.

– With today's antifouling, without TBT it becomes even more important to conduct regular hull-cleaning, he adds.

Regular inspections and cleaning

The partnership agreement of ECOsubsea and Siem Offshore implies regular vessel hull inspections and cleaning of Siem Offshore’s vessels.

– As part of the agreement, ECOsubsea regularly conducts hull inspections, which rates the biofouling severity from 1 to 10. Usually, we initiate cleaning when the rating is at 3 or 4, Houge explains.

The inspections and cleanings are conducted while the vessel is laying at quay

The most recent hull cleaning was done on the offshore supply vessel Siem Symphony, while laying at the quay in Bergen, Norway, where 40 kilos of biofouling was removed and collected.

– In addition to the pure fuel saving benefits, including the collection of marine growth in an environmental manner, we are very pleased with the support and service as provided from ECOsubsea. Hence, we are more than happy to recommend ECOsubsea to other ship owners, Houge concludes.


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