Question 2 DDE01 - Designated Duty Engineer - Unlimited HP

The Correct Answer is B **Explanation for Option B (Correct):** Option B states: "When the oil level rises to the FULL mark on the side of the dipstick marked ENGINE STOPPED and OIL COLD." This is the standard procedure for topping up lubricating oil in a large diesel engine sump when the engine is stationary (stopped) and the oil is cold (or ambient temperature). The FULL mark indicates the maximum recommended safe operating level for the oil in the sump under these static conditions. Filling to this level ensures adequate lubrication capacity for operation without risking overfilling, which could lead to oil aeration, increased churning losses, and potential damage to seals. **Explanation of Incorrect Options:** * **A) When the oil level rises to the ADD mark on the side of the dipstick marked ENGINE STOPPED and OIL COLD:** The ADD mark (or LOW mark) indicates the minimum safe operating level, or the level at which oil *should be added*. If you stop adding oil once it reaches this minimum mark, you have not fully corrected the deficiency, and the engine will start with an insufficient reserve. * **C) When the oil level rises to a level well above the FULL mark on the side of the dipstick marked ENGINE STOPPED and OIL COLD:** Overfilling the engine sump (going "well above the FULL mark") is dangerous. Excessive oil volume can be picked up by the crankshaft and connecting rods, causing churning, foaming, overheating, and aeration of the oil, severely reducing its lubricating effectiveness and potentially causing bearing damage or blowing seals. * **D) B. When the oil level rises to the FULL mark on the side of the dipstick marked ENGINE STOPPED and OIL COLD. C. When the oil level rises to a level well above the FULL mark on the side of the dipstick marked ENGINE STOPPED and OIL COLD. D. When the oil level rises to the between the ADD and FULL marks on the side of the dipstick marked ENGINE STOPPED and OIL COLD:** This option formatting is confusing, but analyzing the last statement ("When the oil level rises to the between the ADD and FULL marks..."): While being between these marks is acceptable for operation, when performing a top-up (make-up), the goal is typically to restore the level to the designated full mark to ensure maximum reserve and optimal operating conditions. Stopping short between the marks is unnecessary if the intent is to fully prepare the engine for operation. (Note: Since the provided answer key confirms B is correct, we prioritize filling to the FULL mark).