Corrosion Protection of Ship & Boat Hulls While In Harbor

Common harbor materials like steel sheet piles, and stray electrical currents from multiple harbor sources such as: public docks, nearby shipping & harbor cathodic protection systems, radio & wireless equipment, and power utility facilities cause millions of dollars of damage to the Naval and Coast Guard fleets each year. Damage is especially heavy to ships made of advanced materials like aluminum. Aluminum is very difficult to protect from stray electrical current corrosion. It is easily destroyed by standard cathodic protection methods, and does not respond well to hull anodes especially in non-salt water.

This paper describes how to locate exactly where the stray currents are coming from and identify the sources. It also provides a very unique way that the Coast Guard solved this problem on one of its all aluminum boats located in the Great Lakes.  New innovative stray current testing techniques are described, and new cathodic protection schemes using custom modified cathodic protection rectifiers, permanent voltage monitors, and diver located impressed current anodes are deployed. The readiness of the CG boat was not effected, and the corrosion protection results after over 2 years of installation are impressive.