Cargo Frost Formation: Investigation into Temperature Fluctuations and Drain Hole Issue

During the on-site inspection, we found evidence of frost on both the surface and inner packaging of certain cargo, indicating possible temperature fluctuations and/or moisture entry. After analyzing the temperature records, we determined that there were no instances of high temperatures during the transportation process prior to handing the container over to the Consignee.

However, after the container was handed over to the Consignee, from 0846hrs on July 21 to 2257hrs on July 22, 2023, for a total of 39 hours, there were persistent occurrence failure codes indicating a power failure. During this period, the maximum return air temperature reached 0.6 degrees Celsius. It is possible that these high temperatures contributed to the formation of frost on the cargo.

Upon conducting a thorough inspection of the container in question, we discovered that one of the drain holes, located at the front end left of the container, was not plugged. In the event that the non-return valve in the drain hole fails to function properly, it is possible for moist air to enter the container through the valve. This could result in the formation or worsening of frost on the cargo.