Running Hours
Running Hours are the accumulated operating hours of a piece of machinery or component on a ship — for example a main-engine cylinder, a purifier or a generator. They are recorded from the vessel and used as the basis for scheduling maintenance in the Planned Maintenance System (PMS): a job is due when a component reaches a set number of running hours (say, an overhaul every 8,000 hours).
Running hours sit alongside calendar intervals as the two main triggers for planned maintenance, and they are increasingly combined with condition-based signals. Accurate running-hour reporting is essential — under- or over-stating them means machinery is maintained too late (risking failure) or too early (wasting spares and effort).
A ship's maintenance plan is only as good as its running-hour data — it is what decides when each overhaul actually falls due. Get it wrong and you either run machinery past its safe interval or waste spares overhauling healthy equipment. Reliable running-hour capture is the foundation the whole PMS is built on.
How do running hours trigger maintenance?
The PMS raises a job when a component reaches a defined running-hour count — for example an overhaul every 8,000 hours.
Are running hours the only maintenance trigger?
No — calendar intervals and condition-based signals also trigger jobs; running hours are one of the primary triggers.