Question 23 1AE01 - First Assistant Engineer

The Correct Answer is A **Explanation for Option A (Correct):** Option A accurately describes the configuration and operational use of high and low sea suctions on deep-draft ships. 1. **Low Sea Suction (Near the Bottom):** This suction is positioned deep in the water, close to the ship's keel or bottom. When the ship is underway (especially at higher speeds), water flow is clean, consistent, and pressurized (due to the boundary layer effects of the moving hull), making this the preferred suction point for reliable, debris-free cooling water supply. 2. **High Sea Suction (Near the Turn of the Bilge):** This suction is positioned higher up on the hull, typically near the turn of the bilge (the curve where the bottom meets the side). When a ship is stationary (in port) or operating in shallow/congested water, debris, silt, and mud stirred up from the bottom tend to be concentrated near the keel. Using the lower suction in these conditions risks fouling the cooling systems. The higher suction draws water from a less turbulent and potentially cleaner layer closer to the surface, making it the primary choice in port or shallow water. **Explanation of Incorrect Options:** * **Option B is Incorrect:** This option reverses the operational use of the two suctions. It incorrectly states that the high suction (near the bilge) is used primarily while underway, and the low suction (near the bottom) is used primarily in port/shallow water. As explained above, the low suction is preferred underway, and the high suction is preferred in port/shallow water to avoid debris. * **Option C is Incorrect:** This option incorrectly identifies the location and use of both suctions. It places the low suction near the turn of the bilge (which is the high suction's location) and claims it is used underway, and places the high suction near the bottom (which is the low suction's location) and claims it is used in port/shallow water. The labels, locations, and uses are confused. * **Option D is Incorrect:** This option correctly places the low suction near the bilge (location of the high suction) and claims it is used in port/shallow water (correct use for the high suction), and places the high suction near the bottom (location of the low suction) and claims it is used underway (correct use for the low suction). The operational use is correct but the labels ("high" and "low") are wrongly assigned to the physical locations.