CATHODIC PROTECTION SYSTEM FOR FLEET MOORINGS 



Technical Report R-702 



YF 51.543.006.01.007 



by 



R. W. Drisko 



ABSTRACT 



A cathodic protection system was developed for protecting from 

 corrosion both the underwater portion of a mooring buoy and its ground 

 tackle. The final design of this system protected both buoy and chain for 

 3-1/2 years, and sufficient zinc appeared to remain for at least another 

 6-1/2 years of protection. The system performed well on both a sandy and 

 a muddy bottom. The zinc anodes used on the ground tackle were specially 

 cast on steel chain links to become an integral part of the chain system. The 

 tight riser-chain secured to the peg-top buoy had the required electrical 

 continuity to permit the necessary flow of current for protection, but it 

 was necessary to use a steel cable woven through the links of each ground 

 leg to achieve electrical continuity there. A cost analysis indicates that use 

 of such a cathodic protection system can result in a considerable reduction 

 in costs associated with maintenance of Fleet moorings. 



