GAC EnvironHull, part of the global shipping, logistics and marine services provider GAC Group, developed an underwater hull cleaning system called HullWiper that features a
brush-and-diver-free remotely operated vehicle.
Marine fouling affects a vessel operator’s bottom line. Even the slightest fouling adds water resistance, slowing a ship down and increasing fuel consumption by as much as 20%, according to GAC EnvironHull. HullWiper is an unmanned hull-cleaning unit that uses adjustable pressure seawater jets rather than brushes or abrasives, resulting in minimal damage to the antifouling surface. A HullWiper clean costs $3.50 per square meter compared to a brush cleaning using a diver, which is $1.20 per square meter plus approximately $6 per square meter for antifouling damage repair, the company says.
In addition to the cost savings, HullWiper collects marine fouling removed from hulls, rather than polluting port water and risking the spread of harmful species. Captured fouling and residues are pumped into a filter unit and then deposited into dedicated drums on the support vessel. These drums are then emptied into a dedicated skip on the jetty, which is collected by a locally approved environmental waste disposal company. A clean hull also improves vessel’s speed and reduces carbon emissions.
Since HullWiper does not rely on divers, cleaning can be performed around the clock. The compact unit can clean up to 2,000 square meters of hull per hour, completing the vertical sides of a VLCC, approximately 8,000 square meters, in seven hours — half the time the same job would take using conventional cleaning methods with divers, the company reports. GAC EnvironHull’s online calculator factors in vessel size, speed, voyage, fuel type, temperature and anti-fouling coating used for a range of vessels including bulk carriers, container ships, LNG/LPG vessels and tankers. The HullWiper’s minimal impact on the vessel’s antifouling coating had been tested and confirmed by marine paint manufacturers including International Paint, Sigma Coatings, The Jotun Group, and Chugoku Marine Paints. The effectiveness of the Hullwiper’s ROV filter system in purifying the waste water collected has been verified by AMT Environmental, an environmental analysis and consulting professional. In addition, HullWiper’s features have been tested and certified by environmental authorities and agencies that include the UK Environmental Agency, the Climate and Pollution Agency in Norway, Gothenburg Authorities in Sweden, the government of Dubai Port Environmental Health and Safety, the Sultanate of Oman Environmental Ministry, and the Port of Valencia in Spain.