AN ANALYSIS OF MAINTENANCE PERIODICITY EFFECTS ON THE AVAILABILITY OF COAST GUARD’S MEDIUM ENDURANCE CUTTER BOAT LAUNCH SYSTEMS

Abstract

This thesis explores the periodicity of planned depot maintenance and its effects on failure rates for U.S. Coast Guard shipboard davit systems. Davits are used on Coast Guard cutters to launch small boats, which are needed to accomplish a range of missions. The operational availability of these davit systems is important in keeping Coast Guard cutters fully mission capable. This study collected davit failure and maintenance data from nearly eight years of archived records for two cutter classes, which served as a sample of Welin Lambie davit systems that are widely used in the fleet. Concepts of reliability, availability, and maintainability were applied to calculate failure rates, mean time between maintenance, and mean time between failures. From this information, statistical hypothesis testing was used to determine what factors influence the system failure rate. It also addresses whether the historical data on these systems can be used to develop experimental models and whether those models can be used to influence decisions on maintenance periodicity.