Four concrete sinker blocks were specially fabricated to hold the 

 cathodic protection units for the ground legs. Each sinker block was pre- 

 pared in a wooden form with a slot cut out to house a unit. Three and 

 one-half 2-1/4-inch chain links were cast into the block as shown in Figure 5. 

 Threaded J-bolts used to secure the cathodic protection equipment in place 

 were also cast into the concrete. A cathodic protection unit similar to those 

 on the buoy was attached to each of the sinker blocks. Each control head 

 had two 100-foot ground cables of no. 2 neoprene-insulated, stranded copper 

 wire attached to them. 



The riser-chain and ground legs used on the mooring were sandblasted 

 to white metal. The riser-chain and three of the four ground legs were coated 

 with cold-applied coal tar coating Ml L-C-18480A; the fourth leg was allowed 

 to remain bare during the test to determine the differences resulting from the 

 cathodic protection of coated and uncoated ground legs. 



Figure 5. Chain linl<s in wooden form ready for casting of concrete 

 sinker block. 



