Question 13 1AE01 - First Assistant Engineer

The Correct Answer is C **Why Option C is Correct:** A large condenser tube leak means that the cooling medium (typically seawater) is entering the freshwater/distillate side of the condenser. Seawater has a high salt (salinity) content. The purpose of the salinity monitoring equipment is to continuously measure the purity of the produced distillate. If a significant leak occurs, the high-salinity seawater will contaminate the otherwise pure distillate, causing the measured conductivity (salinity) to rise rapidly above the set point. This sudden increase in salinity will trigger the alarm circuit (annunciator) of the monitoring equipment, immediately alerting the operator to the contamination and the need to dump the contaminated water. **Why the Other Options are Incorrect:** * **A) A decrease in the level of the main engine expansion tank as indicated by a low-level alarm.** This tank is part of the main engine's closed jacket water cooling system. While jacket water is often used as the heat source for the distiller, a leak in the condenser (which handles seawater and distillate) would not directly or immediately affect the closed-loop jacket water expansion tank level. A jacket water system leak would typically be noticed as a low level in the jacket water system itself, but a condenser tube leak involves the seawater side, not the jacket water side. * **B) A slow continuous rise in the lube oil cooler outlet temperature indicated at device "4".** The lube oil cooler is an entirely separate piece of equipment from the distiller's condenser. While both might use seawater as a coolant, a leak in the distiller's condenser tubes has no direct effect on the temperature performance of the main engine lube oil cooler. The lube oil cooler performance is more related to seawater supply pressure, flow, or fouling. * **D) An increase in distiller output resulting from the combination of jacket water and the distillate produced.** The condenser tube leak introduces **seawater** into the distillate stream, not jacket water. Furthermore, a large leak typically leads to a loss of vacuum and operational instability, often causing a **decrease** in usable distillate output (because the contaminated water must be dumped) rather than a clean increase in usable flow.