3.0 Understanding Failure Modes & Intervention

When all subsystems of a rebreather function properly, very little diver intervention is required. The system is essentially on autopilot. However, there is tremendous value in the diver understanding each subsystem with an acute level of detail, hence providing our Principles of Design in the early sections of this book.

Each subsystem does have potential physical and mechanical failure points regardless of manufacturer or component make-up, and while all highly unlikely to occur when attention to design and quality assurance are placed, they do fail from time to time. These failures have largely influenced why certain units are designed to incorporate certain feature sets. When any failure takes place, steps should be taken towards aborting the dive; however, the logic of our proposed platform system often allows for failure isolation and the system can continue to be utilized during the abort sequence if required. This is a critical feature on extended range dives when a direct ascent and/or surfacing may not be an option, and complete open-circuit bailout from the furthest point of depth or distance may be best avoided.

Rebreather failure modes are all likely cause for changes to the breathing atmosphere which must be detected and remedied to carry on. This section addresses failure modes from this perspective, being acute attention on atmospheric management, and how to engineer both the dive, and consider rebreather systems that mitigate foreseeable risks.