Unmanned vessels are considered the next step forward in certain shipping operations. At the present stage, reliable communication protocols, collision avoidance sensors, and remote-control technology allow ship operators to perform automatic missions.
But there is still a gap on defining the most reliable propulsion system for conceptual unmanned vessels as well as there are no clear solutions to the challenges in maintenance and repair of un-manned engine rooms. Since the propulsion systems are one of the essential machinery systems on-board a ship, this is the equipment that must be as reliable as possible to ensure equal or even better safety levels that today’s conventional operation.
The present thesis project aims to propose a methodology to analyze and effectively suggest reliability improvements of different marine propulsion systems configurations, considering maintenance tasks, re-design feasibility factors and cost implications of the process. The challenge was addressed on a generalist approach and focused on building a replicable method.
After an extensive data reliability data collection, A method was successfully developed to perform and optimize system metrics with regards reliability, availability and costs. It tested a set of propulsion system alternatives onboard a conceptual unmanned vessel. A benefit of this methodology is that it can be used to execute sensitivity analysis on the propulsion systems in order to investigate the effect of different design variants or maintenance guidelines.
The method was tested using a case study, with associated cost information. Proving that it is possible to run the iterative process as many times as necessary to propose a cost-effective propulsion solution. The major limitation of the methodology is the quality of the operational data. In the near future sensors in the engine rooms, onboard unmanned ships will deliver reliable data to integrate to this type of models. So far, the data collected for testing this methodology came from manned vessels.The methodology has the capacity to test the cost of adding redundancy. It also has the capability to test the cost of changing suppliers or redesigning a component in the system. Then the method approach includes a life cycle cost analysis estimation.