Marine Log - January 2009 - (Page 15)

HULLMAINTENANCE WHAT’S ON YOUR HULL? Ship operators can choose from a host of TBT-free anti-foulings Jotun’s SeaMate anti-fouling is well suited for ships that sail at speeds between 12 to 26 knots H ull coating technology has come a long way since William Beale filed the first patent for an antifouling in 1625. Today’s hull coatings picture is a bit more complicated for ship operators since the ban on TBT-containing anti-fouling systems. For decades, tributyltin and other organotin-containing anti-fouling systems were extremely effective in keeping hulls free of barnacles, mussels and other marine organisms, reducing a ship’s drag and improving its fuel consumption. TBT, however, was found to have long term effects on the marine environment. Seven years after the International Convention on the Control of Harmful AntiFouling Systems on Ships Convention was agreed upon to ban organotin compunds in anti-fouling systems, it entered into force on Sept. 17, 2008. As of November 30, 2008, some 34 contracting states representing 62.69% of the world’s shipping tonnage had ratified the Anti-Fouling Systems (AFS) Convention. What the convention means is that ships cannot apply or re-apply organotin compounds that act as biocides in their anti-fouling systems. If the hulls of these ships already contain such compounds, they have to have a coating that forms a barrier to prevent the compounds from leaching into the sea water. WHAT’S OUT THERE? For ship operators, there are a host of www.marinelog.com alternatives to TBT-containing antifoulings, which yield varying degrees of cost and effectiveness depending upon operating conditions. Making the right choice for your hull is critical. For example, even a slight increase in hull roughness—as little as 100 microns, which is the diameter of a human hair—can lead to a 1% increase in fuel consumption. The main alternatives include: ablative systems, hybrid ablative/hydrolyzing systems, hydrolyzing systems and foul release systems. Here’s a look at three anti-foulings that were released late last year. NEW FOUL RELEASE SYSTEM FOOLS ORGANISMS This past November, Hempel A/S unveiled its third generation foul release system called Hempasil X3. The key to fouling release systems is their slipperiness, which prevents marine growth from attaching itself to the hull. The Hempasil X3 system uses hydrogel silicone to prevent fouling on a ship’s hull. Hempel says the concept is simple: the super water-absorbent hydrogel forms a polymeric network over the hull. Organisms perceive the hull as a liquid and not a solid surface—and as a result, don’t try to attach themselves to the surface. The hydrogel layer is effectively backed up by silicone, known for its self-cleaning properties. Depending on the type of ship, Hempel says Hempasil X3 could cut a vessel’s fuel bill by 4 to 8% in the first year, significantly lowering its CO2 emissions. The coatings manufacturer is marketing Hempasil X3 as a package that includes the paint system, the fuel saving guarantee and the Sea Trend fuel monitoring system, which is supplied by Denmark’s Force Technology. Sea Trend provides a means of measuring the fuel saving benefits of the fouling system. “This is the first time that a paint supplier has offered a complete fouling release package that gives the ship operator a fuel performance monitoring tool and guarantees a fast return on investment based on fuel savings,” says Torben Rasmussen, Group Product Manager at Hempel. Hempasil X3 can be specified for 90month service intervals, and unlike other fouling release products it works at speeds as low as 8 knots and is still effective at 50% activity levels. This means longer intervals between dry docking, and at the same time makes fouling release coatings relevant for a greater range of ships. NEW ECO-FRIENDLY ABLATIVE COATING At the WorkBoat Show in New Orleans this past December, SherwinWilliams Protective and Marine Coatings Division, Cleveland, Ohio, unveiled its SeaGuard Heavy Metal Free Antifoulant, a solvent-based ablative coating that uses a metal-free organic biocide agent to JANUARY 2009 MARINE LOG 15 http://www.marinelog.com

Table of Contents Feed for the Digital Edition of Marine Log - January 2009

Marine Log - January 2009 Contents Editorial Second Thoughts Update Inside Washington What's On Your Hull? That Sinking Feeling Newsmakers Tech News Contracts Wake Up Call From Mumbai Events Security Guide Vietnam Stretches its Portfolio ML Buyer's Guide ML Marketplace Marine Salvage

Marine Log - January 2009

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