Ultrasonic Antifouling Could Cut Operating Costs
Ultrasonic technology is well accepted as part of modern class certification and ship management, with applications from non-destructive testing to thickness guaging to fire extinguisher inspections. But it has the potential to save money in another way, says Capt. Sven Fromm, managing director of Isle of Man-based Clever Marine.
Clever Marine delivers repair services, inspections and full-scale technical ship management solutions for its clients, leveraging long-standing relationships with OEM suppliers to keep down costs. After many years of experience with ultrasonic inspection methods, the firm also developed an interest in the use of high frequency sound for purposes of antifouling – traditionally a problem addressed with biocidal coatings, or through mechanical or chemical cleaning.
Clever is now a global vendor for a line of ultrasonic antifouling (UTAF) systems manufactured by Harsonic. The devices prevent barnacles and other marine life from growing on submerged surfaces by removing biofilm and killing larvae, algae and unicellular organisms, with no chemical residues. Ultrasonic antifouling has been employed in shoreside applications for years, from preventing clogging in pipelines and industrial coolers to keeping down lime scale buildup in process piping. In marine use, a permanently installed ultrasonic device can greatly reduce the growth of fouling, according to Fromm.
"When we came across UTAF for the first time we were sceptical if such technology could deliver the promised result, but by seeing the results of tests and experiencing the improvement after the installation of UTAF, we were fully convinced," Fromm says.
The system is most commonly used to prevent the fouling of boxcoolers, sea chests and sea filters – systems that are especially vulnerable to the growth of biofilms and marine organisms – but it can be used on the entirety of a vessel's hull.
When UTAF is used in hull or sea chest applications, soft antifouling coatings are no longer required in the installation area, allowing the ship manager to substitute a hard wearing, long lasting paint. Unlike cathodic systems, UTAF requires no exchange of spares, and it can be installed without drydocking.
Harsonic's system is proven, and the technology has been in use since the 1950s Other ultrasonic systems have been installed on thousands of vessels around the world – notably in yachts, where prolonged periods of inactivity (leading to high risk of fouling) and high standards for performance give ultrasonic protection an edge.