Container ships carry nearly every manufactured and packaged product in global trade, from electronics and clothing to furniture, food, chemicals, and vehicles. Maritime transport moves over 80% of goods traded worldwide by volume, and container ships handle the bulk of finished and semi-finished products within that total. If you bought it in a store or ordered it online, there’s a good chance it crossed an ocean inside a steel shipping container.
Consumer Goods and Manufactured Products
The single largest category of containerized cargo is everyday consumer goods. Clothing, shoes, toys, appliances, electronics, furniture, and packaged food all travel in standard dry containers, typically loaded onto pallets, stacked in boxes, or packed in barrels. A standard 20-foot container holds up to about 21,850 kg of cargo (roughly 48,000 pounds) with 33 cubic meters of internal space. A 40-foot container nearly doubles that volume to about 67 cubic meters, with a maximum payload around 26,680 kg. The 40-foot high-cube variant adds extra height, bumping capacity to over 76 cubic meters.
These standard boxes are the workhorse of global shipping because they’re stackable, easy to transfer between ships, trucks, and trains, and don’t require temperature control. Everything from auto parts and building materials to paper products, textiles, and household chemicals moves this way.
Refrigerated and Temperature-Sensitive Cargo
Perishable goods travel in refrigerated containers, often called “reefers.” These are standard-sized containers with built-in cooling units that maintain temperatures anywhere from deep-freeze to just above ambient. Meat, seafood, dairy, fresh fruits, vegetables, pharmaceuticals, and certain chemicals all require this kind of climate control. Reefer containers plug into the ship’s electrical system and run continuously for the entire voyage, which can last weeks.
Liquids Shipped in Flexible Tanks
Non-hazardous liquids frequently travel inside flexitanks: large, bladder-like bags installed inside a standard dry container. A single flexitank can hold up to about 24,000 liters. Common liquid cargoes include wine, beer, fruit juice, edible oils, latex, and liquid food ingredients. The bladder has a valve for filling and draining, so the container itself stays clean and reusable. Certain cargoes like wine can ferment during transit, so the flexitank material has to be compatible with whatever’s inside.
For hazardous or more sensitive liquids, dedicated tank containers (a cylindrical tank inside a steel frame the same dimensions as a standard container) carry chemicals, fuels, and industrial solvents.
Vehicles and Heavy Machinery
Cars, trucks, motorcycles, and heavy equipment all ship inside containers. A 20-foot container typically fits one car, sometimes two small ones. A 40-foot container holds three to four sedans, or two to three SUVs and pickups. Racking systems, reinforced steel frames bolted inside the container, make it possible to stack cars on two levels, fitting up to four compact vehicles in a 40-foot box or six in a 45-foot high-cube. Skate-and-track systems let cars roll into position without starting the engine, reducing the risk of exhaust buildup and battery drain.
Oversized machinery that won’t fit through a container’s doors uses specialized container types. Open-top containers have removable roofs so cranes can lower heavy items like stone blocks, steel pipes, or construction equipment straight in from above. Flat-rack containers are essentially open platforms with end walls, designed for extremely heavy or wide cargo. Excavators, bulldozers, turbines, generators, yachts, and steel structures all ship on flat racks. A single 40-foot flat rack can handle loads of 34 tonnes or more, accommodating items nearly 3 meters wide that would never fit inside a standard enclosed box.
Chemicals and Hazardous Materials
Container ships routinely carry hazardous materials, though these are subject to strict international classification and handling rules. Dangerous goods are grouped into classes that cover a wide range of substances:
- Flammable liquids like industrial solvents and certain alcohols
- Flammable and non-flammable gases including compressed air and dissolved acetylene
- Corrosive substances such as concentrated acids
- Poisons and toxic materials requiring special labeling and isolation from other cargo
- Oxidizers and organic peroxides used in manufacturing and chemical processing
- Flammable solids and materials that are spontaneously combustible or dangerous when wet
- Explosives including certain types of ammunition
- Infectious substances classified as biological materials
- Radioactive materials for medical and industrial use
Each class has specific packaging, labeling, and stowage requirements. Hazardous containers are placed in designated positions on the ship, often on deck or away from crew quarters, and must be separated from incompatible cargo types.
What Container Ships Don’t Carry
Some commodities are too cheap per tonne and too uniform to justify packing into individual containers. Iron ore, coal, wheat, corn, soybeans, and other raw bulk commodities ship loose in the holds of specialized bulk carriers. Crude oil and liquefied natural gas travel on tankers. These materials move in such enormous quantities that containerizing them would be impractical and far more expensive.
The dividing line is straightforward: if cargo is homogeneous, unpackaged, and needed in massive volumes, it goes on a bulk carrier or tanker. If it’s manufactured, packaged, mixed, or needs to stay separate from other goods, it goes in a container. That’s why a single container ship can carry thousands of different products from hundreds of different shippers in one voyage, each sealed in its own steel box and tracked from origin to destination.