Specialized Zinc Anodes 



The anodes in the new cathodic protection system had to be 

 specially manufactured. They were prepared by casting SA-3 zinc alloy 

 on a 2-1/2-inch-thick, 35-inch-long steel link. The zinc casting was 1.8 feet 

 long, was approximately 6.6 ft^ in total surface area, and had a trapezoidal 

 cross section. The entire anode weighed approximately 485 pounds (Figure 9). 



The design of the cathodic protection system is shown in Figure 10. 

 Two of the smaller zinc anodes (approximately 144 pounds) used in the 

 previous study on buoys were located in the sea chests on opposite sides of 

 the buoy cone. Three of the special anodes were inserted in each leg, and one 

 was inserted in the riser-chain approximately 3 feet above the ground ring. The 

 anodes were secured into the recoated ground tackle using standard detachable 

 links. With this method no place on the chain was farther than 45 feet from an 

 anode. 



Figure 9. Specially cast zinc anode on chain link. 



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