Combating Corrosion and Monitoring Microgrids on Coast Guard Patrol Boats

Abstract

Marine corrosion presents a persistent threat to the reliable operation of U.S. Coast Guard Fast Response Cutters (FRCs). This thesis investigates hybrid cathodic protection strategies combining impressed current cathodic protection (ICCP) systems and sacrificial zinc anodes to combat corrosion on such vessels. Observing over 550 cumulative months of ICCP system data across 46 FRCs, this thesis identifies operational trends, failure modes, and unique regional behaviors. To validate observed patterns and explore failure scenarios, the study implements finite element modeling using COMSOL Multiphysics. These simulations replicate normal operation, reference electrode failure, propeller passivation, localized zinc loss, and hull coating failure for both a generic 35m hull and the FRC hull. These models emphasize how system behavior responds to material variations, temperature, and system health, offering a diagnostic framework for optimizing ICCP configurations. Field and laboratory experiments further ground the computational findings. These include shipboard hull potential surveys and analysis of zinc anode wastage across multiple cutters. Controlled experiments on nickel aluminum bronze (NAB) passivation using miniaturized ICCP test systems are explored for further study. Initial results show variation in zinc consumption and corrosion behavior depending on ICCP setpoints, with higher protection levels (-1050 mV) often correlating with reduced zinc depletion. The thesis also explores energy diagnostics onboard FRCs via non-intrusive load monitoring (NILM). A case study on the USCGC WILLIAM CHADWICK describes monitoring auxiliary machinery loads through NILM signatures and suggests expansion to critical panels and DC systems. By integrating fleet data, physical experimentation, and simulation, this thesis advances future efforts in patrol boat corrosion monitoring, ICCP optimization, and resilient microgrid management.