Maintenance and Repair of Shipboard Machinery and Systems
This domain tests planned maintenance, condition monitoring, defect control and the survey regime that keeps certificates valid. It expects you to know what is critical, how to measure it, and when a reading becomes a defect rather than a data point.
Principles
- Planned maintenance system: every item has a frequency, a responsible rank, a procedure and a record. Critical items such as steering gear, emergency generator, fire pumps and main engine safety devices cannot be deferred by junior ranks alone.
- Condition monitoring: lube oil analysis, vibration, thermography, crankweb deflection and performance trends. The trend outweighs a single reading.
- Isolation: permit to work, lock-out/tag-out, depressurise, drain, prove dead, and record restoration before returning to service.
Worked example
A crankweb deflection of 0.28 mm is recorded against a builder's maximum of 0.20 mm for that position. One reading is not enough: repeat at the same crank angle with the engine at the same temperature, then compare with the commissioning record and the trend. If confirmed, suspect uneven main bearing wear or a distorted bedplate. Report to the chief engineer, notify class before opening up, and avoid high load until assessed.
Traps
Accepting a gauge reading without checking calibration; reopening a class-surveyed item without notification; confusing running hours with condition; closing a defect without a named owner and deadline.