Quantitative reliability and availability analysis for design evaluation of generic pod propulsion systems

Application of pod propulsion on a variety of vessels such as cruise ships, ropax, and tanker vessels has increased significantly over the last two decades owing to the benefits offered by pods. Despite the clear benefits, operators are still reluctant to have this innovation on board because of unknown overall reliability. Many of the published research efforts in the area of pod propulsion have been concentrated on hydrodynamics and manoeuvring aspects with little in the area of quantitative pod reliability assessment. In this paper, the applicability and appropriateness of various quantitative fault tree solution techniques (exact and approximate) for the reliability assessment of a generic pod propulsion system are investigated. Also, the paper demonstrates that the proposed quantitative reliability assessment methodology can be used to make design changes by identifying critical components in system functionality and modifying the system with improvements, where needed.