Subs in Schools: Engineering a Reliable Depth-Control System and Pressure-Hull

摘要

The "Subs in Schools" STEM project baseline remotely-controlled submarine kit suffers from several functional deficiencies; predominately its resistance to water ingress and effective depth-control. The aim of the project reported is determining whether the pressure-hull and depth-control system can be redesigned to significantly improve reliability, manufacturability and maintainability. Discussed is the intended approach for developing a new design and associated prototype. This includes construction and testing of the current design to identify limitations; conducting reliability analysis of the key components; presenting a proposed concept design for the improved version; and a summary of work completed to date. The tests on the existing model confirmed reports of leakage and limited depth-control functionality. Literature suggests that bulkhead penetrations are the primary weakness for water ingress; an argument supported by the experimental findings. The Failure Mode and Effect Analysis (FMEA) model in conjunction with the exponential random failure analysis model, is used to estimate the reliability of the pressure hull. A concept for a revised design is presented that will require proof of concept experiments and the subsequent manufacture of a testable prototype.