Question 60 GLI02 - Mate of Unlimited Tonnage

The Correct Answer is C **Why option C ("Dew point of the cargo hold") is correct:** Sweat damage (also known as "cargo sweat" or "ship sweat") occurs when moisture condenses onto cargo or the structure of the hold. Condensation happens when the surface temperature of the cargo or structure falls below the dew point temperature of the surrounding air within the cargo hold. Therefore, the **dew point of the air inside the cargo hold** is the critical threshold that determines whether condensation will form. If the dew point inside the hold is high, condensation is much more likely to occur when the vessel sails into colder regions, causing the hull/structure to cool down. Preventing sweat damage fundamentally requires managing the relationship between the cargo/structure temperature and the dew point of the *local* environment (the hold air). **Why the other options are incorrect:** * **A) Temperature of the cargo:** While the cargo temperature is highly relevant (it determines the surface temperature that might be cooled below the dew point), it is only one half of the condensation equation. High cargo temperature combined with low hold dew point will not cause damage. The cargo temperature must be compared against the hold dew point to predict condensation. * **B) Outside air temperature:** The outside air temperature is an *indirect* factor. It affects the temperature of the ship's structure (hull and overhead), which in turn cools the air and surfaces inside the hold. However, the outside temperature itself does not directly dictate the point at which condensation will form; the internal hold dew point does. * **D) Dew point of the outside atmosphere:** The dew point of the outside atmosphere is crucial when deciding whether to ventilate the cargo hold (e.g., if the outside dew point is lower than the inside dew point, ventilation can help dry the hold). However, the absolute threshold for condensation is determined by the dew point of the air *currently trapped* inside the hold, not the air outside the ship.