INTRODUCTION 



Because Naval Facilities Engineering Command field activities have 

 difficulties and spend a great deal of time and money in maintaining steel 

 mooring buoys, the Naval Civil Engineering Laboratory (NCEL) was assigned 

 the task of investigating plastic mooring buoys as a means of reducing mainte- 

 nance costs. Because the steel framework of the buoy is filled with foam and 

 covered with glass-reinforced plastic skin, the only steel components of the 

 buoy exposed to hostile marine environment are the fittings used for securing 

 the buoy to ships and ground tackle. 



The fabrication of two plastic mooring buoys is described in NCEL 

 Technical Report R-365.^ One buoy has an exterior shell composed of ten 

 layers of fiberglass cloth impregnated with polyester resin; the other has an 

 exterior shell composed of a spray-up coating of chopped fiberglass strands 

 in polyester resin. The performance of these buoys while in service to the 

 Fleet in San Diego Bay for a period of 3 years is described in Technical 

 Report R-601 ^ Reference 2 also describes the fabrication of another plastic 

 mooring buoy of improved design. The exterior shell of this buoy consists of 

 alternate layers of fiberglass cloth and mat impregnated with polyester resin. 



This report provides additional data on the condition of the first two 

 buoys in San Diego Bay after 4 years and of the third buoy at Pearl Harbor 

 after 1 year of service to the Fleet. It also presents cost data for purchasing 

 and maintaining steel and plastic mooring buoys. 



CONDITION OF BUOYS 



San Diego Bay 



After about 4 years of service to the Fleet, the two plastic mooring 

 buoys in San Diego Bay were lifted from the water onto the deck of a floating 

 crane for their annual inspection required by BUDOCKS Instruction 1 153. 4B 

 of 9 April 1965. During the previous year these buoys had received moderate 

 to heavy usage. The marine fouling organisms were examined and then removed 

 with a high-pressure stream of seawater (Figure 1 ) so that the underlying sub- 

 strate could be examined. On both buoys there was moderate to heavy fouling 



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