coated steel. Through a proper selection of brushes, a skilled diver can 



remove fouling from exposed paint, metal, concrete, and plastic surfaces 



2 

 without damage to the surface. Cleaning rates of 80 to 200 m /hr have been 



121 122 

 attained by a diver using a single hand-held rotary brush. ' To 



operate brushes at depths required for the OTEC plant, the hydraulic hoses 



for powering the rotary scrubber may have to be lengthened, a modification 



that may pose interference problems for divers. Efforts might be made to 



provide the OTEC platform with a hydraulic manifold with quick connection 



at various depths. In this manner, convenient hose lengths can be used 



over a wide range of cleaning depths. 



Diver-Controlled Multibrush Vehicles . There are two diver-controlled 



multibrush vehicles that clean underwater surfaces and remove fouling at 



121 122 

 rates 10 to 20 times faster than single hand-operated rotary brushes. ' 



These multibrush vehicles are presently the most widely used devices to 



remove hull fouling. 



TM 

 Submerged Cleaning and Maintenance Platform . SCAMP is a 1. 8-m-diameter , 



three-brush vehicle. It is held against a vertical surface by an 



independent suction impeller positioned in the center, allowing the angled 



bristles to skim the hull surface by a shearing action. It is propelled 



by two motorized rubber wheels, and a third movable wheel provides steering 



control. The vehicle cleans approximately a 1.7-m swath during each pass. 



It usually is steered by divers when in use on contoured surfaces, although 



it can be operated from a workbot by remote control for vertical flat 



surfaces. The device. Figure 9,, and single hand-held diver-operated rotary 



brushes for the less accessible areas jointly provide the most effective 



means of fouling removal. A 440-V line from a diesel generator furnishes 



electric power to motors positioned on the vehicle. The motors operate 



hydraulic pumps to rotate the brushes, rubber wheels, and suction impeller. 



There has been some concern in regard to the safety of the 440-V cable 



extending into the water. According to Exxon, SCAMP will automatically 



cxxon Corporation. 



57 



