When the dewpoint temperature of the outside air is lower than that of the air inside the cargo hold, this can result in surface condensation.
The only way to minimize or prevent moisture condensation inside the cargo hold is through proper ventilation.
As such, Gard highlights that carrying out ventilation is one thing, maintaining accurate ventilation records is another.
Both are equally important. Ventilation helps prevent damage and the records assist in defending a cargo claim.
To defend against a claim in the event of moisture damage, the shipowner will have to provide evidence for each hold that proper ventilation was carried out by the crew.
Depending on which ventilation rule is followed (dew point rule or 3 degrees rule), crew members should record the following at least once a watch:
- temperature of cargo during loading;
- dew point for outside air, along with dry and wet bulb temperatures;
- dew point for air each cargo hold, along with dry and wet bulb temperatures;
- whether ventilation needed (Y/N);
- seawater temperature;
- time for starting and suspending ventilation in each hold, including reasons for suspension; and
- bilge soundings.