Marine Engineering for Deck Officers
Practical engineering awareness
You must understand the main propulsion and auxiliary systems well enough to communicate with the engine room. Know the difference between a two-stroke and a four-stroke diesel engine, the function of the turbocharger, and why fuel viscosity and temperature matter. Understand the purpose of the steering gear, the emergency steering arrangement, and the meaning of the steering gear tests required before departure. Know the function of the ballast system, the oily water separator and the bilge system.
Traps in questions
A frequent trap is confusing a generator with the main engine; a blackout is an electrical failure, not necessarily propulsion failure. Another is assuming the emergency steering can be tested only in port; it must be tested before departure and periodically. Watch for questions on the difference between a controllable-pitch propeller and a fixed-pitch propeller, and on why a CPP can reverse thrust without changing engine direction. Also be alert to the hazards of fuel oil leaks and the need for drip trays.
Worked rule of thumb
Before departure, test the steering gear by moving the rudder through its full range from hard a-port to hard a-starboard, check the communication with the bridge, and confirm the emergency steering is ready. For fuel, remember that viscosity falls as temperature rises; pre-heating is needed for heavy fuel oil to reach the injection viscosity. If a blackout occurs, the watchkeeper must be ready to take immediate action, such as anchoring or steering by emergency means, and must inform the master at once.