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Keeping your boat's bottom shipshape

U.S. Navy develops an underwater grooming robot that does away with hull-dwelling barnacles and slime.

Mark Rutherford
The military establishment's ever increasing reliance on technology and whiz-bang gadgetry impacts us as consumers, investors, taxpayers and ultimately as the defended. Our mission here is to bring some of these products and concepts to your attention based on carefully selected criteria such as importance to national security, originality, collateral damage to the treasury and adaptability to yard maintenance-but not necessarily in that order. E-mail him at markr@milapp.com. Disclosure.
Mark Rutherford

ONR

The U.S. Navy may have developed a solution to hull-dwelling barnacles and slime--a "foul" problem that has plagued sailors and their ships since Noah launched the ark.

The Office of Naval Research (ONR) has developed what looks like a combination pressure washer/minisub called the Hull Bio-inspired Underwater Grooming, or Hull BUG. It's designed to prevent or suppress the growth and build-up of nuisance marine growths such as barnacles--also known as biofouling (PDF).

This could be a major breakthrough. High-performance warships and submarines rely on a clean hull for speedy acceleration and hydroacoustic stealth--things that crustaceans easily impede.

Enter the Hull BUG. It's an autonomous, tether-free vehicle similar to an advanced pool cleaner. It uses four wheels and a negative pressure Vortex Regenerative Fluid Movement assembly to attach itself to the hull, where it deploys a variety of "grooming" tools, including rotary brushes and specialized water jets to groom and maintain ship hull surfaces.

It carries a suite of onboard sensors to provide obstacle avoidance, path planning, and navigation capabilities that include detection of fouled and groomed surfaces, according to ONR. Add weapons, and you also have a "force protection" vehicle.

Biofouling can reduce a vessel speeds by 10 percent and add 40 percent in increased fuel consumption in order to compensate for the added drag. In fact, biofouling on ships translates into roughly $500 million in extra fuel and maintenance costs annually, according to the Naval Surface Warfare Center's Carderock Division.