Cathodic Protection of Mooring Buoys and Chain. Part IV. Additional Field Studies with Cables Providing Continuity.

摘要

An investigation was continued into the cathodic protection of a fleet mooring (both buoy and chain) with sacrificial anodes. The zinc anodes used on the ground tackle were specially cast on steel chain links so that they became an integral part of the ground tackle. The tight riser chain secured to the peg-top buoy had the required electrical continuity between adjacent chain links to permit the flow of current, but it was necessary to use a steel cable periodically joined to each of the four ground legs to impart complete continuity to them. On two of the legs the joining was accomplished by silver-soldering and on two by the use of pipe clamps. The system provided full protection from corrosion to the underwater portion of the buoy and to the entire ground tackle. This was determined both by visual inspection and by periodically taking an electrical potential profile. It is estimated from the performance to date that the anodes can provide full protection for five years. (Author)