Question 58 GLI03 - Master-LT 500-1600 GRT

The Correct Answer is D ### Why Option D is Correct Sweat damage (also known as ship sweat or cargo sweat) is the condensation of moisture onto cold surfaces within the cargo hold. Condensation occurs when the temperature of a surface drops below the dew point temperature of the surrounding air. * **Option D states:** "The dew point of the hold is higher than the temperature of the ship's skin." * The air inside the hold contains moisture, and the dew point represents the temperature at which that moisture will condense. * The ship's skin (hull plating, deck head) is a primary cold surface, especially if the vessel is moving into colder climatic zones. * If the cold surface temperature (ship's skin) is below the temperature at which the air begins to release its moisture (dew point of the hold), then condensation will form directly onto the inner structure of the ship. This condensation, often running down the sides or dripping from the overhead, is "ship sweat," which can cause significant damage to the cased machinery. ### Why Other Options Are Incorrect **A) The air temperature of the hold is higher than the temperature of the outside air** This condition describes heat transfer, but it does not guarantee condensation. If the outside air is cold, the hull temperature will be cold, but sweat damage only occurs if the hull temperature falls below the *dew point* of the hold air, regardless of whether the general air temperature is higher or lower than the outside temperature. **B) The dew point of the outside air is lower than the temperature of the cargo** This condition relates to potential cargo sweat (condensation forming directly on the cargo itself), but it is primarily concerned with the relationship between the cargo and the outside air being introduced. Since the question specifies a *non-ventilated* hold, the relationship between the *outside* air dew point and the cargo temperature is largely irrelevant to the conditions *inside* the sealed hold, especially concerning **ship sweat** (condensation on the ship's structure). **C) The outside air temperature is colder than the temperature of the cargo** This is the condition that most frequently leads to **ship sweat**. As the ship moves from a warm region (where the air and cargo are warm and moist) into a colder region, the outside cold air cools the ship's skin below the cargo/air temperature. However, stating only that the outside air is colder is insufficient. The critical factor for condensation is the relationship between the *surface temperature* and the *dew point*, not just the relationship between the outside air and the cargo temperature. The statement in D is the definitive definition of when condensation (sweat damage) occurs.