Intermodal container

A "40-foot (12.19 m)" long shipping container. Each of the eight corners has a simple "twistlock" fitting for stacking, locking and craning

There are over seventeen million shipping containers in the world

Containers standing with their loading doors open

An intermodal container or freight container (commonly shipping container) is a reusable transport and storage unit for moving products and raw materials between locations or countries; the terms container or box may be used on their own within the context of shipping. Containers manufactured to ISO specifications may be referred to as ISO containers and the term high-cube container is used for units that are taller than normal. There are approximately seventeen million intermodal containers in the world and a large proportion of the world's long distance freight generated by international trade is transported inside shipping containers.

The containerization system developed from a design of an 8-foot (2.438 m) cube (2.44 m×2.44 m×2.44 m) units used by the United States' military and later standardised by extension to 10-foot (3.05 m), 20-foot (6.10 m), and 40-foot (12.19 m) lengths. Longer, higher and wider variants are now in general use around in various places.

Container variants are available for many different cargo types. Non-container methods of transport include bulk cargo, break bulk cargo and tankers/oil tankers used for liquids. For air freight the alternative and lighter IATA defined Unit Load Device is used.

Description

Stacking shipping containers each with a standard ISO 6346 reporting mark

A typical container has doors fitted at one end and is constructed of corrugated weathering steel^[1] and were originally 8 feet (2,438 mm) wide by 8 feet (2,438 mm) high and either a nominal 20 feet (6,096 mm) or a nominal 40 feet (12,192 mm) long and can be stacked up to seven units high.

Taller units have been introduced including 'Hi-cube' or 'high-cube' units at 9 feet 6 inches (2,896 mm)^[2] and 10 feet 6 inches (3,200 mm) high^{[citation needed]}.

The United States often uses longer units at 48 ft (14.63 m) and 53 ft (16.15 m). Some rare European containers are often about 2 inches wider at 2.5 m (8 ft 2.4 in) to accommodate Euro-pallets.^[3] Australian RACE (container) are also slightly wider to accommodate Australia Standard Pallets.

Lighter Swap body units use the same mounting fixings as Intermodal containers but have folding legs under their frame so that they can be moved between trucks without using a crane.

Each container is allocated standarized ISO 6346 reporting mark (ownership code) four characters long ending in the letter U, followed by six numbers and a check digit.

Container capacity is often expressed in twenty-foot equivalent unit (TEU, or sometimes teu). An equivalent unit is a measure of containerized cargo capacity equal to one standard 20 ft (length) × 8 ft (width) container. As this is an approximate measure, the height of the box is not considered, for instance the 9 ft 6 in (2.90 m) high cube and the 4-foot-3-inch (1.30 m) half height 20-foot (6.10 m) containers are also called one TEU. Similarly, the 45 ft (13.72 m) containers are also commonly designated as two TEU, although they are 45 and not 40 feet (12.19 m) long. Two TEU are equivalent to one forty-foot equivalent unit (FEU).

Containers have also been used to create buildings and house large computer data centers.

Types

A railroad car with a 20 ft tank container and a conventional 20 ft container

Variations on the standard container exist for use with different cargoes including Refrigerated container units for perishable goods, tanks in a frame for bulk liquids, open top units for top loading and collapsable versions. Containerised coal carriers, and 'bin-liners' (containers designed for the efficient road/rail transportation of rubbish from cities to recycling and dump sites) are used in Europe.

Container types:^[4]

• Collapsible ISO
• Flushfolding flat-rack containers for heavy and bulky semi-finished goods, out of gauge cargo
• Gas bottle
• Generator
• General purpose dry van for boxes, cartons, cases, sacks, bales, pallets, drums in standard, high or half height
• High cube palletwide containers for europallet compatibility
• Insulated shipping container
• Refrigerated containers for perishable goods
• Open top bulktainers for bulk minerals, heavy machinery
• Open side for loading oversize pallet
• Platform or bolster for barrels and drums, crates, cable drums, out of gauge cargo, machinery, and processed timber
• Rolling floor for difficult to handle cargo
• Swapbody
• Tank containers for bulk liquids and dangerous goods
• Ventilated containers for organic products requiring ventilation

Specifications

The following table shows the weights and dimensions of the most common types of containers. The weights and dimensions quoted below are averages. Containers of the same type of produced by different manufacturers may vary slightly in actual size and weight.

Handling and transport

Containers can be transported by container ship, semi-trailer truck and freight trains as part of a single journey without unpacking and they are transferred between modes by container cranes at container terminals. Units can be secured during handling and in transit using "twistlock" points located at each corner of the container. Every container has a unique BIC code painted on the outside for identification and tracking, and is capable of carrying up to 20–25 tonnes. Costs for transport are calculated in twenty-foot equivalent units (TEU).

Rail

When carried by rail, containers may be carried on flatcars or well cars. The latter are specially designed for container transport, and can accommodate double-stacked containers. However the loading gauge of a rail system may restrict the modes and types of container shipment. The smaller loading gauges often found in European railroads will only accommodate single-stacked containers. In some countries, such as the United Kingdom, there are sections of the rail network which high-cube containers cannot pass through, or can pass through only on well cars. On the other hand, Indian Railways runs double-stacked containers on flatcars under 25 kV overhead electrical wires. In order to do this, the wire must be at least 7.45 metres (24 ft 5 in) above the track, but IR is able to do so because of its large loading gauge and use of 1,676 mm (5 ft 6 in) broad gauge track. China Railways also runs double-stacked containers under overhead wires, but must use well cars to do so since China uses standard gauge and the wires are only 6.6 metres (21 ft 8 in) above the track.^[5]

History

GI loads a shipping container

The United States Department of Defense produced specifications for standard containers for military use of 8-foot (2.44 m) by 8-foot (2.44 m) square cross section in units of 10-foot (3.05 m) long in the 1950s.^{[citation needed]} The International Organization for Standardization (ISO) issued standards based upon the US Department of Defense standards between 1968 and 1970, ensuring interchangeability between different modes of transportation worldwide.^{[citation needed]} and they subsequently also became known as ISO containers for this reason.

A global system of intermodal freight transport has developed around these standard containers and new container sizes have been developed to suit different purposes. Since November 2007 48 ft (14.63 m) and 53 ft (16.15 m) containers are used also for international ocean shipments. As of April 2008 the only marine company who offer such containers is APL^[6]. However, APL containers have slightly different sizes and weights than standard 48 ft (14.63 m) and 53 ft (16.15 m) containers (that are used in the US by rail and truck services).

See also

• Intermediate bulk container
• Logistics Vehicle System
• MIL STD 129
• Sun Modular Datacenter
• RACE (container)

Wikimedia Commons has media related to: Shipping containers

References

Further reading

• "Freight Containers", 4th edition, ISO, 2006, ISBN 92-67-10426-8

External links

• International Convention for Safe Containers (Geneva, 2 December 1972)

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