Special cargo container shipping

Loading Methods for Refrigerated Cargo in Container Sea Transport

Container shipping of refrigerated cargo can be divided into two types: chilled cargo and frozen cargo. Chilled cargo refers to cargo kept at a temperature selected to prevent freezing, or at a temperature slightly above surface freezing, generally ranging from -1°C to +11°C, with the aim of maintaining cargo respiration and preventing condensation inside the container. Frozen cargo refers to cargo transported in a frozen state, with transport temperatures generally ranging from -20°C to -1°C.

For the temperature that should be maintained during the transport of refrigerated cargo, the cargo owner gives clear instructions at the time of consignment. The carrier must strictly comply with these instructions and properly keep the documents issued by the cargo owner relating to the required conditions for the shipment during transit, so as to avoid disputes between the cargo owner and the carrier over temperature issues after a conflict arises.

1. Pre-loading Inspection

Before loading refrigerated cargo, both the container and the cargo should be inspected:

• The container has a container certificate or document issued by the container owner.
• The container's starting, running, and stopping devices are in normal condition.
• The container ventilation openings are in the required state, and the drain pipes are unobstructed.
• The cargo has reached the specified loading temperature.
• When loading the cargo, the cold air passage must not be blocked, and space should be left at the top part.
• During loading, the refrigeration unit must be turned off.

Before loading, the dunnage and other lining materials used inside the refrigerated container should be pre-cooled; clean and hygienic lining materials should be selected so as not to contaminate the cargo. It is strictly forbidden to load cargo that has lost freshness or has gone bad and become smelly into the container, to avoid damaging other normal cargo.

II. Key Points for Loading and Transportation

• Pre-cooling of cargo: All refrigerated cargo must be pre-cooled to the transport temperature before loading; the container's refrigeration system must not be used to lower the temperature.
• Proper stacking: Leave ventilation gaps between cargo packages to ensure even circulation of cold air and avoid localized overheating.
• Temperature setting: Set the precise transport temperature based on cargo characteristics, e.g., frozen meat at -18°C, fresh fruits and vegetables at 2-4°C.
• Loading volume control: Loading volume must not exceed 80% of the reefer container's capacity to ensure smooth cold air circulation.
• Temperature recording: The reefer container is equipped with a temperature recorder that logs temperature data throughout the journey, which can serve as proof of cargo quality upon arrival.

Common refrigerated cargo falls into three categories by temperature requirement: frozen cargo (below -18°C), chilled cargo (0-8°C), and constant-temperature cargo (15-20°C). Shippers should choose an appropriate refrigerated transport solution based on cargo characteristics and promptly pick up the cargo to avoid spoilage.

Further reading: Baled cargo loading for general cargo; Liquid cargo loading covers liquid cargo; Quarantine cargo loading for fruits, vegetables, and grains.

Reefer Cargo Loading FAQ

Q: What inspections should be performed before loading refrigerated cargo into a container?

A: The container has a certificate of conformity; the start/stop device operates normally; ventilation openings are in compliance and drain pipes are clear; the cargo has reached the specified loading temperature; loading does not block cold air passages, leaving clearance at the top; the refrigeration unit is turned off during loading.

Q: What are the key points for loading refrigerated cargo into a container?

A: Pre-cool the cargo to the transport temperature before loading; leave ventilation gaps between packing boxes; the loading volume should not exceed 80% of the reefer container capacity to ensure cold air circulation; set the precise temperature according to the cargo characteristics (e.g., frozen meat at -18°C, fresh fruits and vegetables at 2–4°C); keep temperature records throughout the entire process as proof of quality.

Bofeng Logistics provides one-stop logistics services including domestic container sea freight, international shipping (FCL/LCL), Hong Kong and Macau special logistics routes, and trailer transportation, customs declaration, and warehousing. Contact: 130-7567-8958 (Manager Huang), call now for your exclusive quote!

Disclaimer: This article was compiled by the Bofeng Logistics team and verified as of August 2026. Cargo loading practices may change with the International Maritime Dangerous Goods Code (IMDG Code), carrier policies and industry standards; always refer to the carrier's current requirements for your container loading.