A reefer container is a refrigerated intermodal shipping container, built with insulated walls and an integrated cooling/heating unit, used to transport temperature-sensitive cargo.
Key Operational Requirements
- Continuous power supply — reefers must be plugged into the ship’s electrical system throughout the voyage; loss of power for an extended period can spoil the entire cargo
- Temperature setting and monitoring — each reefer is set to the specific temperature its cargo requires, and monitored regularly to catch any malfunction before cargo damage occurs
- Ventilation settings — some cargo (certain fruits, for example) requires controlled ventilation alongside temperature control to manage ripening gases
Common Reefer Cargo
Fruit, meat, seafood, dairy, pharmaceuticals, and other perishables that require a controlled temperature chain from origin to destination.
Reefer Plug Monitoring Onboard
Checking reefer containers — verifying power connection, monitoring displayed temperatures, and responding promptly to any alarm — is a real, recurring watchkeeping and deck duty on container vessels carrying reefer cargo, given the commercial value at stake if temperature control fails.
Reefer vs Standard Container
Reefers require dedicated power sockets and are typically stowed in specific areas of the vessel with reefer plug infrastructure, unlike standard dry containers which can be stowed anywhere structurally suitable.
Exam Relevance
Reefer container handling and monitoring is a standard Cargo Work topic in deck officer competency exams, particularly relevant for container ship operations.