It is a method of distribution of goods using containers. The use of containers has not only facilitated but has also revolutionized the carriage of goods among the developed countries. The exporters in developing countries are also making greater use of containers for the transportation of the goods. The enactment of Multi Modal Transportation of Goods Act, 1993 has enabled exporters from India to use containers for transportation of export cargo. Train or road to the seaports carries the containers, where they are loaded on the ships for onward transportation to their destination.
Containers: The container, as the meaning implies, is the equipment used to store and carry goods. In shipping, the term was used to refer to any type of box used to carry cargo.
The International Organization for Standardization (ISO) defined a freight container as an article of transport equipment,
- Of a permanent character and accordingly strong enough to be suitable for repeated use
- Specially designed to facilitate the carriage of goods by one or more modes of transport, without intermediate reloading
- Fitted with devices permitting its ready handling, particularly its transfer from one mode of transport to another
- So designed as to be easy to fill and empty
- Having an internal volume of 1m.cube (35.3cu.ft) or more
- Further, the general-purpose freight container is defined as “A freight container is rectangular in shape, weatherproof, used for transporting and storing a number of unit loads, packages or bulk material; it confines and protects the contents from loss or damage, it can be separated from the means of transport, handled as a unit load and transshipped without re-handling the contents
Advantages of Container
- Use of containers offers many advantages to the exporters. These are as follows:
- The risk of damage (due to pilferage and mishandling) to the goods during transport is reduced substantially.
- The cargo arrives in better condition and this creates a better impression about the exporter in the mind of the importer. This perception of delivery of goods in good condition enables an exporter to gain an edge over other competitors.
- There are no damages due to mishandling of the cargo at terminal ports in the case of transshipment.
Classification of containers
By raw material
A container can be classified in terms of its building or cladding materials i.e. it is defined by what it is made of. The maximum numbers of containers are made of steel, aluminum or GRP (glass fiber reinforced plywood). Almost 65 per cent of the entire container fleet presently consists of steel containers.
By size
The ISO has worked a great deal on standardization of container dimensions and published recommendations. Containers are defined in multiples of l0ft. i.e., 10ft or 20 ft, or 30ft, or 40ft. Presently 20ft, 40ft containers are used predominantly, and around 65-70 per cent of world fleet consists of 20 ft containers. Twenty-foot containers are referred as Twenty Foot Equivalent Unit or TEU and 40 footers as FEU (Forty foot Equivalent Unit). If all the containers are expressed -in terms of TEU, it becomes easier for the container terminal operators and, ship owner to estimate the space required in a container terminal or inside the vessel.
Most of the containers have width of 8 ft. However, in height containers vary from 8ft to 8Y2 ft. Presently about 75 per cent of world box fleet has a height of 8Y2 ft. and about 20 per cent have a height of 8 ft. However, there is an increasing tendency to use containers of 9Y2 ft (High cube)
The inside volume of a standard 20ft x 8 ft. X 8Y2 ft. container is around 33m3
Container Dimensions and Capacity
Containers intended for intercontinental use have external nominal dimensions of
Length 9.8125 feet (2.991m) as 10 feet;
19.875 feet (6.058m) as 20 feet; 29.9375 feet (9.125m) as 30 feet; and 40 feet (12.192m)
Width 8 feet (2.438m)
Height 8.5 feet (2.591m) and
9.5 feet (2.896m)
All above dimensions have permissible tolerances.
The 20 feet (20′) and 40 feet (40′) containers are very popular in ocean freight. The 8.5 feet (8.5′) high container—8 feet 6 inches (8′ 6″) high container—is often referred to as standard container.
The demand for the high cube container is increasing. The popular high cube container has a normal height of 9.5 feet (9.5′ or 9′ 6″).
There are half height containers (4.25′ or 4′ 3″ high) designed for heavy loads such as steel rods and ingots, which absorb the weight limit in half the normal space.
The most widely used type of container is the general purpose (dry cargo) container having a nominal length and height of 20′ x 8.5′, 40′ x 8.5′, and 40′ x 9.5′. Referring to the Dimension of General Purpose
Containers below, the dimensions shown in the table are not fixed, that is, the external and internal dimensions may vary among containers of the same length and height.
The container capacity is the total cube a container can accommodate. The term cube often refers to the cubic measurement of cargo. The capacity (i.e., the internal volume) is determined by multiplying the internal dimensions, that is, the product of internal length, width and height. The capacity may vary among containers of the same length and height.
Classification of Containers
Containers can also be classified by their uses. Containers maybe broadly classified into three types by cargo to be stowed therein.
The General Cargo Container
The General Cargo Container is the most representative type for general cargo (packed cargo) that does not require temperature control. This type occupies an overwhelming share of the total number of containers. The type is called Dry Cargo Container in ordinary parlance. It is generally of the closed van type with a door at one end.
These containers are closed and are suitable for the carriage of all types of general cargo both solid and liquid. Access for loading and unloading is through full width doors. The dimensions of general-purpose containers as follows
| Overall Dimensions | Inside Dimensions | Cubic Capacity |
| 1 20x8x8.5 ft. (6.1×2.4×2.6 mt.) 2 40x8x8.5 ft. (12.2×2.4×2.6 mt.) | 5.98×2.345×2.400 mt. 12.015×2.345×2.400 mt. | 32.7 m3 66.3 m3 |
Based on the length of the container, the container is generally known as a 20 ft container or 40 ft. container in practice.
The Thermal Container
The Thermal Container is designed for cargo requiring refrigerated or insulated storage. It is covered with material of low heat transfer such as polystyrene foam.
Thermal containers are classified into three types:
- Refrigerated (or Reefer) Container (for cooled foodstuffs, meat, fish vegetables etc): It has insulated walls, doors, roof, and floor, which limit the range of temperature loss or gain. It is used for perishable goods like meat, fruits and vegetables.
- Insulated containers: It is used for fruit, vegetables etc. Here dry ice is used as the cooling medium. It does not use any device for cooling and/or heating.
- Ventilated container allows for the passage of air by means of apertures on sides or ends. This type is used for cargo such as fruit or vegetable, which requires respiration. They are required for carriage of special cargo like tea, coffee, etc. which may lose moisture, that is; they may “sweat” if carried in closed box type containers.
Controlled and Modified Atmosphere systems
In the Controlled Atmosphere, there is computerized controller. The refrigeration unit maintains the set temperature and the controller maintains the ideal atmosphere by sensing the product’s consumption of oxygen and production of carbon dioxide. By integrating this information the controller continuously adjusts air exchange valves and activates the required scrubbing systems to maintain the atmosphere of the pre-set level.
In the Modified Atmosphere system, the desired atmosphere is created in the container when it is stuffed. The container is then sealed to prevent changes in the original atmosphere due to ventilation. The modified atmosphere system is limited to shorter voyages and fewer commodities than the controlled atmosphere system.
Special Containers
The category of container comprises of the balance types under the broad head of Special Containers. Prominent types in this head are: Bulk containers, Tank containers, open top Containers, Side Open containers, Flats, Car containers, Pen containers (to carry livestock).
- Bulk Containers: These containers are designed for the carriage of dry powders and gram substances in bulk.
- Ventilated Containers: These containers have full length ventilation galleries.
- Half-height version of the open top container is designed for the carriage of heavy dense cargoes such as steel, pipes and tubes etc.
- Tank Containers: These containers are generally constructed for the carriage of a specific product or range of products in mind.
- Open Sided Containers: These containers are designed to accommodate specific commodities such as plywood, perishable commodities and livestock.
Dry cargo containers
Dry cargo containers are by far the maximum in use. They are of different types. A standard dry cargo container is a of box type with a door at one end. Sometimes containers are provided with side doors, i.e., the entire side of the container can be opened for easier stuffing and unstuffing. These types of containers are useful when stuffing operations are carried out while the container is mounted on a wagon or trailer. There are various “dry specials” like open top containers, flat racks, bulk containers, garment container, ventilated containers, etc.
The open top container
The open top container is one having no roof and usually provided with a polythene lined tarpaulin to cover the container. The advantage of this container is that heavy machineries, structural etc. can be easily hoisted by a crane and put inside the container through its open roof.
- Flat container: Flat rack or flat container is a container having its base only. Usually a cargo of odd size and weight is put on to this container and is lashed to it.
- Bulk container: Bulk container is a container fitted with manholes to facilitate loading of bulk cargo through gravity.
- Garment container: Garment containers are fitted with hangers to help loading a large number of garments in hangers into the containers.
- Liquid containers: Liquid containers are usually made of stainless steel and have manholes for loading and unloading liquid cargo.
- Gas containers: Gas containers are special containers with fixtures and fittings for filling and emptying liquid gas. They also have special features like thick walls of special metal for safety during transit.
Other Container
- Insulated Containers: Such containers protect the cargo against head loss or gain and are used in conjunction with a blown-air-refrigeration system to protect perishable or other cargo which needs to be carried under temperature control.
- Fruit Containers: These are insulated containers with internal dimensions slightly longer.
- Refrigerated Containers: These containers are fitted with their own refrigeration units which require an electrical supply for their operation.
- Hanger Containers: These containers are used for dry cargo and are equipped with removable beams in the upper part. They are used for the shipment of garments on hangers.
- Bin Containers: These containers have no doors and are ideal for heavy dense cargoes such as steel, pipes etc.