Question 8 UFIV01 - Chief Engineer - UFIV

The Correct Answer is A **Explanation for Option A (Lubricating oil supply header pressure.)** Lubricating oil is the single most critical fluid for the survival of a running diesel engine. Upon start-up, the engine immediately begins moving at low RPM, generating friction and heat, particularly in the bearings (main and connecting rod) and on the cylinder walls. If the attached lubrication oil pump fails to establish sufficient pressure instantly (within a few seconds), metal-to-metal contact will occur in the bearings, leading to rapid overheating, seizure, and catastrophic damage (e.g., spun bearings, warped crankshafts) within minutes, or even seconds, depending on the load and RPM. Therefore, monitoring the lubricating oil pressure is the absolute first check required immediately after the engine fires to confirm the internal components are being protected. **Why other options are incorrect:** * **B) Cylinder jacket water pump discharge pressure:** This is important for cooling, but a brief delay (a few minutes) in establishing full cooling water circulation will not cause immediate catastrophic failure upon starting, provided the engine is running light and is not immediately put under load. Lack of lubrication causes damage much faster than lack of cooling. * **C) Sea water pump discharge pressure:** Similar to jacket water, this is important for the overall cooling circuit (intercooler and heat exchanger), but a short delay in cooling will not lead to immediate internal engine damage upon start-up like lack of oil pressure will. * **D) Fuel oil supply header pressure:** While necessary for the engine to continue running, insufficient fuel pressure would cause the engine to misfire or stop running, but it would not cause physical, structural damage to the engine's internal moving parts. The lubrication system is independent of the fuel system in terms of physical protection.