Hull Bug Video Transcript
Speaker Key:
Darling: Don Darling, President, SeaRobotics
McElvany: Steve McElvany, Ph.D., program manager, ONR Environment Quality program
Holappa: Ken Holappa, Chief Engineer, SeaRobotics
Swain: Geoffrey Swain, professor, Oceanography and Ocean Engineering, Florida Institute of Technology
Narrator: High-performance U.S. Naval warships and submarines rely on critical design factors such as top speed, acceleration and hydroacoustic stealth to achieve their mission. The build-up of marine crustaceans, namely barnacles on ships’ hulls, adds weight and increases drag, reducing a vessel’s fuel efficiency, especially for Navy ships as they move throughout the world’s oceans. In fact, colonized barnacles and biofilms settled on the hull of a Navy ship translates into roughly $1 billion annually in extra fuel costs and maintenance efforts.
Narrator: As researchers around the world work to uncover new materials to combat marine biofouling, ONR is supporting the development of novel approaches that are proving to be effective at biofouling prevention. ONR-sponsored research includes the development of an underwater grooming device called the robotic hull bio-mimetic underwater grooming, or Hull BUG, designed to groom and maintain ship/yacht hull surfaces.
Darling: The Hull BUG is a hull bio-mimetic underwater grooming system.
McElvany: The concept really is kind of like the room vacuum cleaner: It’s designed to be an autonomous vehicle that attaches to the hull, runs around, and as it does that, does what we call grooming.
Holappa: In front here has a biofilm detector. This is a fluorometer. I can actually sense where the difference is between the cleaned surface and the uncleaned surface on the hull of the ship. So now, the vehicle can follow that line just like when you mow the grass. And on the underside, we have a VRAM. This is a patented negative pressure device. It generates a captured vortex and this captured vortex generates a negative pressure against the surface without anything being in contact with that surface. It’s much more efficient than say a propeller-type thruster.
Narrator: ONR's Hull BUG successfully completed its first grooming test in April.
Swain: It groomed very nicely. All the biofilms were removed. It didn’t remove the barnacle bases, but we didn’t expect that because grooming is meant to be proactive so barnacles are not meant to grow there. [It was] a very successful demonstration – very exciting.
Darling: And it makes the ship more efficient to operate. It allows new technology coatings to be utilized which are non-toxic [and] don’t use copper. And it also increases the period of time between dry-dock intervals.
Narrator: Another innovative Office of Naval Research program where revolutionary research is delivering relevant results.