Reefer cargo: keeping the cold chain intact at sea

A reefer container is designed to maintain the temperature of cargo that is already at the right temperature. Most reefer claims can be traced to something that happened before the doors were closed.

Set-point and ventilation

Each commodity has its own carriage temperature. Frozen goods typically travel at −18 °C or colder; chilled produce anywhere from around −1 °C to +13 °C depending on the product. Fresh fruit and vegetables continue to breathe and may need fresh-air ventilation settings; frozen goods do not.

Pre-cooling

Cargo should be at the set-point before it is loaded. Loading warm cargo into a reefer strains the unit and can take days to correct, during which the product ages.

Loading

• Pre-trip inspection (PTI) of the container before release.

• Load quickly, ideally from a cold dock.

• Leave space for air circulation — do not load above the red line or block the T-floor.

• Close the doors and plug in as soon as possible.

During transit

Reefers need power at every stage: on the truck (a generator set), at the terminal and on board. The time the unit is unplugged at each handover is a risk point and should be kept short. Many reefers record temperature continuously, and remote monitoring is available on some equipment.

At destination

Plan clearance and delivery before arrival. Health certificates and import permits for food are checked at the border, and a reefer waiting for documents keeps running up terminal and power charges.