Getting to the bottom of hull coatings
DELFT – Antifouling discourages marine life from settling on hulls _ from your 24ft Pride-and-Joy to giant cargo vessels. But which works best? The Dutch research organization TNO has developed a methodology that sheds light on the performance of coatings. To help coating makers improve their products. And to let ship and boat owners make an educated choice.
Marine organisms _ from tiny spores to algae to barnacles _ are pesky freeloaders creating a below-the-waterline zoo that can be 1cm-thick. That raises your fuel costs, wears out your motor faster and creates more pollution. “Tests show even some slimy growth can easily increase (a hull’s) resistance by 5 to 10%,” says TNO senior scientist Job Klijnstra.
TNO has developed a new testing model that measures hull resistance. It does that in different conditions, both long and short term because the life span of antifouling depends on such factors as the miles a ship does and the season and region of operation. TNO’s “Friction Disk” technology measures underwater resistance of surfaces both treated with antifouling and untreated, and in short and long-term sea water conditions.
The TNO test facility is based on an older, US navy design. “Our equipment is more modern, especially in the way we gather and process data,” says Klijnstra. “We also developed new test protocols. It is a unique facility that can be deployed for any interested coating producer or shipping owner…Our independent position enables us to independently assess the performance of shipping coatings in terms of resistance reduction and fuel consumption.”