Remodeling and Basic Control System Integration on Lifebuoy for Marine Accident Mitigation

Abstract

A remodeled lifebuoy prototype integrating a self-propulsion and remote-control system was developed to support marine accident mitigation. The design process combined iterative concept development, hydrodynamic comparison, system integration, fabrication, and prototype testing. Three geometrical models—a boogie board, a seabob, and the proposed lifebuoy—were evaluated using Maxsurf: Modeller and Maxsurf: Resistance under the same comparison condition. At the highest plotted speed of 20 knots, the proposed lifebuoy showed a total resistance of 0.3 kN, compared with 0.5 kN for the boogie board and 0.6 kN for the seabob, corresponding to reductions of 40% and 50%, respectively. The corresponding predicted power requirement was 2.868 kW for the lifebuoy, compared with 4.622 kW and 5.255 kW, giving reductions of approximately 38% and 45%, respectively. A physical prototype based on the selected design was fabricated and tested in an outdoor freshwater basin for propulsion, control, and buoyancy. The prototype test confirmed basic propulsion and control operation and evaluated buoyancy under a design payload of up to 70 kg; however, quantitative speed, response-time, endurance, remote-control range, and propulsion-efficiency measurements were not recorded in the present study. The results indicate that hydrodynamic form and wetted-surface area are important design variables, while further controlled experiments are required to validate the simulation quantitatively and assess operational performance.