Preventing Stern Tube Corrosion through Shipboard Cathodic Protection

Abstract

Cathodic protection extends the life of ships and decreases the cost of maintaining a ship fleet. Ships built with less noble metals, like steel, will corrode alarmingly and require protection. This work aims explicitly to present an analysis of the cathodic protection of a stern tube, a complex area to protect, and whether impressed current cathodic protection can aid a U.S. Coast Guard Fast Response Cutter with localized corrosion. Furthermore, this work presents multiple methods for studying the effectiveness of cathodic protection, including COMSOL Multiphysics, polarization experiments, and sacrificial anode wastage estimation. Lastly, nonintrusive load monitoring, with its diagnostic capabilities, provides an opportunity to advance the complicated field of study of corrosion protection. A nonintrusive load monitor (NILM) samples the voltage and current at the utility point and then computes real and reactive power, harmonic content, and system operating frequency. This work expands upon previous successes with NILM, namely, its ability to collect high-bandwidth data to generate an automatic log of the shipboard load operation. The record of energy consumption provided by a NILM gives designers in the seagoing services a continuously evolving picture of present and future power requirements, can shift some or all responsibility away from watchstanders, and provide data for corrosion research.