The US Office of Naval Research (ONR) has recently conducted tests with a unique ship hull grooming robot called the Robotic Hull Bio-inspired Underwater Grooming (HULL BUG) tool. This system is similar to a lawn mower or autonomous vacuum cleaner and incorporates the use of a biofilm detector that can differentiate between unclean and clean surfaces.
“One of the avoidable costs in fuel for the Navy is related to marine fouling such as barnacles that accumulate on ships,” says ONR Program Officer Steve McElvany. “They create increased drag as these ships move from port to port across the world’s oceans.”
Known as a “hard fouler” for ships worldwide, colonized barnacles and biofilms on the hull of a Navy ship translate into about $500 million annually to be spend on fuel costs and extra maintenance that are required to keep ships free of oysters, algae, barnacles and other marine life. In addition to the requirement of about 40% more fuel these microorganisms also reduce the speed of a ship by as much as 10%.
“The best way to stop barnacles from colonizing is don’t let them settle and colonize on the hull in the first place,” advises McElvany. With that in mind, ONR recently conducted tests with a developmental ship hull grooming robot, called the Robotic Hull Bio-inspired Underwater Grooming tool or Hull BUG. The tests showed that this little groomer, similar in concept to a autonomous robotic home vacuum cleaner or lawn mower has a lot of promise.
For the beginning the best way to keep ships free from marine fouling is to stop barnacles from colonizing the hull. The HULL BUG system detects the presence of microorganisms and cleans the hull before a colony is built. “Basically any boat over 45 feet, which is in the water all the time, can benefit from this kind of technology,” says Don Darling, President of SeaRobotics.