Maintenance and Repair at the Operational/Management Level
This domain tests planned maintenance, classification and survey requirements, condition monitoring, and the judgement needed to decide when a defect becomes a repair.
Planning
A planned maintenance system schedules jobs by running hours or calendar interval. Critical items are those whose failure affects safety, class or the environment. Work orders should record the job, spares used, man-hours and any defect found, so the history is auditable.
Class and surveys
Classification societies require annual surveys, an intermediate survey around the second or third anniversary, and class renewal (special survey) every five years. Bottom surveys are two in five years with an interval not exceeding 36 months. Dry docking allows examination of shell plating, sea valves, rudder and shaft.
Condition monitoring
Vibration analysis, lubricating oil analysis (wear metals, water, TBN), thermography, and performance trending of exhaust temperatures, turbocharger speed and compression pressure.
Worked example
A main bearing clearance measures 0.34 mm against a maker's limit of 0.20-0.30 mm. The correct action is not simply to re-tighten: record it, compare with the previous reading and the crankshaft deflection, inform the chief engineer and the class surveyor, and plan renewal. The reasoning: excessive clearance drops oil-film pressure, causing hammering, overheating and possible bearing failure.
Traps
Making permanent structural repairs without class approval; recording a defect only in a notebook instead of the PMS; applying limits from a different engine model; skipping the running-in check after an overhaul.