The Future of Autonomous Robotic Hull Grooming

摘要

Ship hull biofouling has significant impacts on fleet readiness, ship performance, cost, and the environment. Biofouling results in increased hydrodynamic drag which results in greater fuel use and greater emissions per distance traveled than a hydraulically-smooth hull. A study by Schultz, et al. found the typical fouling rating (FR) of a US Navy DDG-51 class vessel, FR-30, increases fuel consumption by 10.3% over a hydraulically-smooth DDG-51. Results showed that reducing this fouling rating to FR-20 would lead to savings of S340K per ship and more than double that when the hull was kept at a fouling rating of FR-10, saving the US Navy nearly $800K per hull annually. And while such studies on commercial vessels are almost nonexistent, similar economic impacts of fouling are certain. A recent report cited the EMMA MAERSK, a 397m container vessel, estimated spending approximately $20K per day in propulsive fuel lost to biofouling. The economic impact of fouling is also due to costly conventional cleaning and containment activities . A study in 2016 commissioned by the US Coast Guard, determined the cost to remove light biofouling from a ship's hull to be $0.33 per ft2 (approximately $3.55 per m2). Based on that estimate, complete biofouling removal from a DDG-51 would run more than $ 1 Ok, while the cost to remove bio- fouling from a Panamax class container ship would run more than $98K. These estimates are for traditional cleaning methods, which degrade the ablative coatings used for anti-fouling, leading to dry-docking for re-coating once every few years. Dry-docking a large ship may run as much as $1M-$2M.