Question 47 OSE01 - Chief Engineer - OSV

The Correct Answer is C. ### Why Option C is Correct: **C) Engine lubricating oil supply header pressure** Engine lubricating oil (lube oil) is crucial for reducing friction, cooling critical moving parts (such as bearings, pistons, and camshafts), and cleaning the internal surfaces of the engine. Upon starting any internal combustion engine—whether it's powering a ship's main propulsion, a generator, or a deck winch—it is absolutely essential to establish the proper lube oil pressure within the first few seconds. * **Risk of Immediate Damage:** If the lube oil pump fails to prime or deliver adequate pressure immediately after the engine starts, metal-to-metal contact will occur rapidly in bearings and cylinders. This lack of a hydrodynamic oil wedge will cause catastrophic overheating, excessive friction, and rapid wear, leading to **immediate and severe engine damage (e.g., seized bearings, scored cylinders)** within seconds or minutes. * **Priority Check:** Monitoring the lube oil pressure gauge is the number one priority check after an engine fires up, often required to be confirmed within 5 to 10 seconds of starting. ### Why the Other Options are Incorrect: **A) Cylinder jacket water pump discharge pressure** While cooling water circulation is vital, especially for modern, high-power density engines, the failure of cooling water flow will lead to overheating and damage over a period of **minutes**, not seconds. The damage caused by a lack of lubrication pressure (C) is far more instantaneous and severe than the damage caused by a temporary lack of cooling (A) right at start-up. Lube oil pressure must be confirmed first. **B) Fuel oil supply header pressure** Fuel oil pressure is necessary for the engine to run, but if the engine has successfully started (which is implied by checking parameters "upon start-up"), the fuel oil pressure is already sufficient. A low or failing fuel pressure would cause the engine to stall or run poorly, but it would not cause the immediate mechanical damage associated with a lack of lubrication. **D) Deck winch gear oil pump discharge pressure** This parameter relates to the lubrication of the winch machinery (the gears, brakes, and drum) driven by the engine, not the engine itself. While important for the operation of the winch, a lack of lubrication to the winch gears will not cause the immediate destruction of the **engine** driving the winch. The integrity of the prime mover (the engine) must be verified first.