Fault Finding at Sea: Debugging Ship Automation and Electrical Faults

On a merchant ship the faults do not wait for daylight or a shore engineer. A pressure reading that slowly drifts, an insulation monitor that drops to a few kilohms, a generator breaker that will not close while the pilot is boarding: the ETO and engineers have to find the cause quickly and safely, with the plant running. This is Part 3 of 3 of the DART marine automation series, and it is about what to look for and how to debug real situations.

You will learn a fault-finding loop you can use on any system, the safety rules and the tool settings that go with it, the common fault families with a symptom-to-first-checks table, and the formulas you need at the panel. Worked cases take you through a drifting transmitter, an earth fault on a 440 V board and a blocked bow thruster start, with checklists for Modbus links, PLC faults, blackouts and handover records. The Python simulation injects open, short, drift, noise and frozen faults into a 4-20 mA loop, and finds an earth fault on a 12-feeder insulated board breaker by breaker and by half-split.