Hull Structure Monitoring on a Fleet of High-Speed Patrol Boats - Data to Decisions

Accurate prediction of hydrodynamic loading on high-speed patrol vessels is critical for structural integrity and fatigue life assessment yet remains a complex challenge. To mitigate this, the U.S. Coast Guard employs Hull Structure Monitoring Systems (HSMS) on its Sentinel Class Fast Response Cutters (FRC). Data from over 60 vessels, in service since 2010, informs design improvements and sustainment strategies. This full-scale monitoring, coupled with analytical modeling and trial data, supports the development of a structural Digital Twin. Analysis focuses on fatigue life factors, with the goal of optimizing fleet maintenance and reducing Total Ownership Costs. The views expressed herein are those of the authors and are not to be construed as official or reflecting the views of the Commandant or of the United States Coast Guard. Distribution Statement A. Approved for public release: distribution is unlimited. INTRODUCTION The Sentinel Class Fast Response Cutter (FRC) is a 154-foot patrol boat and the most modern asset of its type operated by the US Coast Guard. The USCG patrol boats primarily focus on Alien Migration Interdiction Operations (AMIO), anti-drug smuggling, fisheries law enforcement, Search and Rescue (SAR), and national defense. All can deploy independently to conduct these missions. The Sentinel Class delivers a unique blend of speed, endurance, and mission adaptability to maintain high operational tempo across a wide range of mission sets. FRC's have a range of 2,500 nautical miles and a five-day endurance, enabling them to sustain operations in forward deployed environments, project presence in key areas of responsibility and serve as a force multiplier alongside larger cutters and joint partners. One of the main goals of the FRC's design was to improve performance in higher sea states compared to legacy Coast Guard patrol boats. Improved seakeeping would allow for more effective mission capability by increasing crew habitability and offering improved ability to safely launch and recover its cutter boat. The deployment of the cutter boat is essential to nearly all missions on the FRC, allowing crews to board, inspect, interdict, and seize surface asset targets of interest (TOI).