Engineering Knowledge and Watchkeeping
Core concepts
A candidate must be fluent in the main engine and auxiliary systems: fuel oil service and settling, lube oil, cooling (freshwater high/low temperature and seawater), compressed air starting, and steering gear. Know the sequence and interlocks for starting an engine, the purpose of each alarm and trip, and how a watchkeeper records parameters and responds to deviations. Understand how a diesel engine's power, scavenge air, exhaust temperature, and fuel index relate, and why an exhaust temperature spread across units signals a problem.
Traps to expect
Questions often test the difference between an alarm and an automatic trip, or ask what the watchkeeper does first. The correct first action is usually to verify the indication and inform the bridge/engineer, not to shut something down reflexively. Another trap is confusing settling and service tank functions, or the purpose of a slow-turning gear versus a turning gear. Watchkeeping questions reward the STCW habit of regular rounds, reading instruments, and logging-not heroics.
Worked example / rule of thumb
If one cylinder's exhaust temperature rises while the fuel index is steady, suspect that unit's fuel injector or valve, not the whole engine-compare all units before acting. Rule of thumb: a single-parameter deviation is investigated locally; multiple related deviations point to a system-level cause (air, cooling, fuel supply). Always log the reading, the time, and the action taken.
Watchkeeping discipline
Maintain the engineering log, monitor sump levels and temperatures on rounds, and never leave a running machine unattended without proper relief. Understand unmanned machinery space (UMS) alarms and the dead-man/engineer's alarm system.