Sound Damping: Modutech used coating to insulate and reduce engine noise.
Modutech’s berthing tug passed the Navy’s inspection based on the 84 dB limit with the use of Mascoat’s Db acoustic damping coating and Marine insulation coating only.
Modutech Marine of Tacoma, Washington has built boats for the Navy, Coast Guard, National Park Service, Alaskan Fisherman and many others since 1970. One of their latest projects is a series of 9 berthing tugs for the US Navy. This innovative boat is powered by a Cummings QSM11 Turbo-diesel with 455 hp @2100rpm and uses the same state of the art controls used by in the big tugs.
Modutech’s berthing tug passed the Navy’s inspection based on the 84 dB limit with the use of Mascoat’s Db acoustic damping coating and Marine insulation coating only. Two layers of damping coating were applied on the bottom side of the aluminum pilothouse sole, interior sides, ceiling, air trunk and storage spaces. Two layers of thermal coating were applied throughout the interior, with the exception of the deck. A total of 15 gallons of DeltaT dB damping coating and 10 gallons of DeltaT Marine thermal coating was used on all surfaces of the pilothouse. Noise levels could be further reduced with use of flexible engine mounts and acoustic barrier material on the engine space overhead.
DeltaT dB is a flexible adhesive coating loaded with sound-suppression materials engineered to reduce sound energy’s conversion from structurally transmitted energy to airborne sound waves. DeltaT Marine is a thin ceramic-loaded coating with highly efficient thermal insulation properties for anti-condensation and energy conservation.
Noise control is a serious issue for the Navy. In FY 2005, the Veterans Administration (VA) paid $137M to more than 18,000 Department of Navy Veterans with hearing loss. Close to half of sailors who complete a career have some measurable hearing loss. The US Navy considers any sound above 84dB as noise hazardous or having the potential to cause hearing loss. Prolonged noise at levels greater than 84dB over an eight-hour period may result in temporary, and gradually permanent, hearing loss.
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