Question 9 UFIV02 - Assistant Engineer - UFIV

The Correct Answer is B. ### Explanation for Option B (Correct) **B) Engine lubricating oil supply header pressure.** The engine lubricating oil (lube oil) is the lifeblood of any internal combustion engine. Upon start-up, oil must be immediately pressurized and circulated to all critical moving parts, especially main and connecting rod bearings. If adequate oil pressure is not established within a few seconds (due to low oil level, a failed oil pump, or a major leak): 1. **Friction:** Metal-on-metal contact occurs instantly. 2. **Heat:** Rapid friction generates extremely high localized heat. 3. **Damage:** Bearing failure, scoring of cylinder liners, and piston seizing can occur almost immediately (within seconds to a couple of minutes of running), resulting in catastrophic and irreversible engine damage. Checking the lube oil pressure is the **FIRST** critical step to ensure the engine is internally protected and to prevent this immediate mechanical failure. *** ### Explanation of Incorrect Options **A) Fuel oil supply header pressure.** While necessary for the engine to run, low fuel pressure will cause the engine to run poorly, lose power, or stall. It does not cause immediate, catastrophic **mechanical damage** to the internal components (bearings, pistons) in the way that lack of lubrication does. **C) Winch gear oil pump discharge pressure.** This parameter relates to the lubrication of the winch mechanism (gearbox, clutches, shafts), which is driven by the engine. Damage resulting from low pressure here would affect the winch machinery, not the prime mover engine itself. The question specifically asks about avoiding immediate **engine** damage. **D) Cylinder jacket water pump discharge pressure.** Cooling is essential to prevent overheating, which can lead to eventual engine failure (warped heads, cracked blocks, or piston damage). However, catastrophic failure due to overheating takes significantly longer to manifest (minutes of operation) than catastrophic failure due to lack of lubrication (seconds of operation). Lube oil pressure is the more immediate preventative check against sudden mechanical seizing.