Cargo Insight
Maritime & Sea Cargo
Types of Sea Cargo: General, Refrigerated, Oversized and Dangerous Goods
A practical guide to the main categories of sea cargo, how different goods are transported, the equipment used and the considerations that can affect maritime freight.
What are the main types of sea cargo?
Sea cargo covers a wide range of goods, from manufactured products and consumer goods to food, machinery, vehicles and specialised equipment.
Different cargo has different transportation requirements. Some goods can travel in a standard dry container, while others require temperature control, additional space, specialised equipment or specific safety procedures.
Understanding the characteristics of cargo is therefore an important part of understanding the wider sea cargo network.
Sea cargo is not one-size-fits-all.
Cargo classification helps determine how goods should be packed, loaded, secured, transported and handled at ports.
General Cargo
Ordinary manufactured goods and products that can generally be transported using conventional cargo equipment.
Refrigerated Cargo
Temperature-sensitive goods transported using refrigerated containers and controlled conditions.
Oversized Cargo
Large or unusually shaped goods that may not fit inside standard containers.
Dangerous Goods
Materials subject to specific safety, packaging, declaration and transportation requirements.
Bulk Cargo
Large quantities of unpackaged commodities transported as dry or liquid bulk.
Vehicles & Machinery
Cars, trucks, heavy machinery and other equipment requiring specialised loading or securing arrangements.
What is general cargo?
General cargo refers broadly to goods that do not require specialised transportation conditions and can generally be handled using standard cargo equipment.
A large proportion of containerised international trade consists of general cargo, including manufactured goods, furniture, machinery parts, packaged products and consumer merchandise.
Examples of general cargo
- Furniture
- Clothing
- Household products
- Machinery components
- Building materials
- Electronics
- Packaged consumer goods
- Industrial products
“The standard container made ordinary cargo easier to move around the world.”
Containerisation allows many different types of goods to travel through the same global network of ports, terminals, vessels and inland transport systems.
What is refrigerated or temperature-controlled cargo?
Some products need controlled temperatures throughout transportation. These shipments can require refrigerated containers, commonly called reefers.
Reefer Containers
Refrigerated containers are equipped with systems that maintain specified temperature conditions during the voyage and associated handling stages.
Temperature-Sensitive Goods
Depending on the product, refrigerated transportation can be used for food, pharmaceuticals and other temperature-sensitive cargo.
What needs to be considered when shipping refrigerated cargo?
Temperature-controlled freight requires more planning than ordinary dry cargo because maintaining the required conditions is part of the transportation process.
Required Temperature
The appropriate temperature depends on the characteristics and requirements of the goods.
Pre-Cooling
Some products and containers require appropriate temperature preparation before loading.
Power Supply
Reefers need an appropriate power supply while stored at terminals and during transportation.
Monitoring
Temperature conditions may need to be monitored throughout the transportation journey.
Product Requirements
Different products have different temperature and handling requirements.
Destination Handling
Refrigerated cargo must continue to receive appropriate handling after arrival.
What is oversized or out-of-gauge cargo?
Oversized cargo consists of goods whose dimensions or weight exceed the practical limits of standard container equipment.
These shipments can require specialised containers, lifting equipment, additional planning and carefully coordinated transportation.
Examples can include
- Heavy industrial machinery
- Construction equipment
- Large generators
- Industrial components
- Large vehicles
- Mining equipment
- Engineering structures
Containers and equipment for unusual cargo.
Cargo that cannot fit inside a standard dry container may require specialised equipment designed for particular loading and transportation conditions.
Flat Rack Containers
Flat racks can be used for certain heavy or oversized cargo where standard container walls would restrict loading.
Open Top Containers
Open top equipment can provide greater flexibility for cargo that is difficult to load through a conventional container door.
“When the cargo does not fit the container, the logistics plan has to fit the cargo.”
Oversized freight requires the transportation route, equipment, lifting capacity and port infrastructure to be considered before the shipment begins.
What are dangerous goods in sea freight?
Dangerous goods are substances or articles that can present risks to people, property, vessels or the environment during transportation and therefore require specific controls.
Flammable Materials
Materials capable of catching fire can be subject to specific packaging, marking and declaration requirements.
Gases
Compressed, liquefied or other regulated gases require appropriate classification and handling.
Corrosive Substances
Corrosive materials can pose significant risks and are subject to transportation controls.
Oxidising Materials
Certain substances can intensify combustion and require specialised transportation procedures.
Toxic Substances
Toxic materials require appropriate classification, packaging, labelling and documentation.
Marine Pollutants
Certain substances can pose environmental risks to the marine environment and require appropriate controls.
How are dangerous goods regulated at sea?
The International Maritime Dangerous Goods Code, commonly known as the IMDG Code, provides an international framework for the safe transport of dangerous goods by sea.
Dangerous goods are classified according to their hazards, with requirements covering areas such as packaging, marking, labelling, documentation and stowage.
Important considerations
- Correct dangerous goods classification
- Appropriate packaging
- Required marks and labels
- Dangerous goods declaration
- Correct shipping information
- Proper segregation where required
- Approved handling procedures
What is bulk cargo?
Bulk cargo is generally transported in large quantities without individual packaging units such as cartons or pallets.
Dry bulk can include commodities such as grain, coal, mineral products and other raw materials.
Liquid bulk includes products transported in tankers, including petroleum products and other liquids.
Bulk shipping operates differently from containerised cargo because the cargo itself forms the primary load rather than individual containers.
How are vehicles and heavy machinery transported by sea?
Vehicles and machinery can be transported using different methods depending on their size, weight and characteristics.
Ro-Ro Shipping
Roll-on/roll-off vessels are designed to allow wheeled cargo such as vehicles and machinery to be driven onto and off the vessel.
Project Cargo
Large industrial equipment and machinery may be handled as project cargo using specialised lifting, securing and transportation arrangements.
What determines how sea cargo is handled?
Cargo characteristics influence the equipment, storage, loading and transportation procedures required at each stage of the journey.
Weight
Heavy cargo may require specialised lifting equipment and structural planning.
Dimensions
Cargo dimensions can determine whether standard containers are suitable.
Temperature
Temperature-sensitive goods require controlled transportation conditions.
Hazard
Dangerous goods require classification and safety procedures appropriate to their hazards.
Packaging
Packaging protects cargo and can influence how it is loaded and secured.
Destination
Port infrastructure and destination handling capabilities can influence transportation options.
Different cargo types across the Australia–PNG shipping network.
The maritime connection between Australia and Papua New Guinea supports a variety of commercial cargo and supply-chain requirements.
Cargo may include general merchandise, machinery, food, industrial equipment, vehicles and other products depending on the trade and destination.
Cargo considerations
- Port capability
- Container availability
- Vessel equipment
- Temperature requirements
- Cargo dimensions
- Weight restrictions
- Dangerous goods requirements
- Customs and biosecurity requirements
“The type of cargo determines the transportation solution.”
Selecting appropriate equipment and handling procedures helps match the physical characteristics of the cargo with the requirements of the maritime transportation network.
Questions to ask before shipping sea cargo.
Understanding the cargo before booking transportation can help identify the equipment and handling requirements.
What is the cargo?
Clearly identify the goods and their characteristics.
How much does it weigh?
Weight can affect equipment selection and handling.
What are the dimensions?
Dimensions determine whether standard equipment is suitable.
Does it require temperature control?
Temperature-sensitive goods may require refrigerated equipment.
Is it dangerous goods?
Regulated cargo requires appropriate classification and transportation procedures.
How will it be loaded?
Loading and securing methods should match the cargo and transportation equipment.
Understanding the different types of sea cargo.
Sea cargo includes many different categories, and each type can require different equipment, documentation and handling procedures.
General cargo can often move in standard containers, while refrigerated goods require temperature-controlled equipment and oversized cargo may need specialised solutions.
Dangerous goods are subject to specific international safety requirements, while bulk cargo and vehicles operate through different transportation systems.
The characteristics of the cargo should therefore be considered before selecting the transportation method.
Continue exploring the wider subject through the main Sea Cargo guide .
Callum Whitmore
Callum Whitmore writes about sea cargo, maritime transportation, shipping routes and ports, with a particular focus on Australia, Papua New Guinea and the wider Pacific.