Shipping Containers

The International Organization for Standardization (ISO) defines containers as an article of transport equipment: (a) of a permanent character and, accordingly, strong enough for repeated use; (b) especially designed to facilitate the carriage of goods by one or more modes of transport with or without intermediate reloading; (c) fitted with devices permitting its ready handling, particularly its transfer from one mode of transport to another, and (d) so designed as to be easy to fill and empty; (e) having an internal volume of one cubic meter or more but excluding vehicles or conventional packaging.

There are various types of containers according to the type of freight, major mode of transport, materials, carrying capacity, shape, etc. A container with an internal volume of not more than 3 ㎡ is categorized as a small container. A container with an internal volume of more than 3 ㎡ is characterized as a large container. Advantages of container transport are mechanized loading and unloading, lower packaging costs, prevention of theft, etc. Containers that are designed for door-to-door transport and do not require rehandling after loading are categorized into different types such as a tank container to transport liquid freight, a dry container (including a refrigeration container) that requires temperature control, and an open-top container. Containers are also commonly referred to as “boxes.”


Dry containers are the most commonly used type of containers to transport general cargo, with the exception of liquids, that does not require temperature control. They represent the majority of all containers. At one end of the container in the front and rear direction, there are two doors and each opens to 270 degrees. Because dry containers contain dry cargo, the edges of the doors are sealed with neoprene (a type of synthetic rubber) to protect the cargo inside from rain and wind.


The ISO standard-sized containers are 8 feet 6 inches in height. Some containers are 9 feet 6 inches in height, or, 1 feet higher than the standard-sized containers. Such containers are called “high cube containers.” Referred to as jumbo containers, they are usually 20' in height. Their passage can be restricted in Korea due to its height.


Large containers in Korea are categorized into two types according to the way the refrigerator is installed to preserve the temperature of the cargo. These categories are the clip-on type and the built-in type. Reefer containers, loaded on container ships, are capable of controlling temperatures up to 26°C to 28°C through the operation of a refrigeration unit. Power is necessary to maintain the cooling during-carriage. There are two cooling methods: water cooling and air cooling. If the reefer is stored on the deck, air cooling is used to radiate heat into the air. If the reefer is stored under the deck, water cooling is used because there ventilation under the deck is inadequate and the heat is radiated into the cooling water. As described here, reefer containers require special devices and cannot be stored in other spaces than those specifically prescribed


Open top containers are suitable for the transportation of heavy cargo such as machinery, steel products, and plate glass. They are fitted with a tarpaulin cover to create an open top. A crane is used for loading and unloading through the top of the container. They are usually fitted with spreader bows so that their strength does not decrease due to the open top..


Flat rack containers, also known as platform containers, have the form of a dry container and are removed of the top and side panels. Their walls are attachable, and can comprise only the floor and four columns in the corners. Cargo can be loaded from the top or sides. Flat rack containers have a high utility because they are suitable for the transportation of relatively heavy cargo that can be agitated, such as machinery, steel materials, and timber. Forklift trucks can be used for loading and unloading.


Tank containers are designed for sea transportation of liquid cargo. A vessel is installed inside the frame of the same dimension as general containers so that the work procedure can be the same as that of commonly used dry containers. Some tank containers are fitted with heating devices. They are specifically designed for the transportation of cargo in a liquid state, such as alcohol, oil, and chemicals. Both hazardous and non-hazardous products can be transported in tank containers.


Open-sided containers have a full side access door for loading and unloading. Generally, a surcharge on the ocean freight charge is imposed in the case of the sea transport using open-sided containers.


Ventilated containers are used for cargo that requires ventilation. They look similar to commonly used containers, but are designed to have ventilation openings on the top and bottom panels. They are usually used for the transportation of agricultural produce, such as coffee beans.