Containerisation can be defined as a system of intermodal [The term intermodal means that the container can be loaded on different means (or modes) of transport – for example, ships, aircraft, trains, trucks, etc. – with the minium of effort and without have to unpack and repack the container.] freight and cargo transport using standard ISO containers (known as Shipping Containers or Isotainers) that can be loaded and sealed intact onto container ships, railroad cars, planes and trucks. The idea of using standard containers that could be easily and quickly packed and loaded onto like ‘lego blocks’ onto ships, aircraft, trucks and trains, resulted in a huge reduction in port handling costs, contribute significantly to lower freight charges, increased cargo security and, in turn, boosted trade flows. (Source: Wikipedia [])

The use of containers began in the early 1950’s with purpose-built container ships being launched in Denmark in 1951. During the first twenty years of growth containerization meant using completely different, and incompatible, container sizes and corner fittings from one country to another. There were dozens of incompatible container systems used throughout the world. The standard sizes and fitting and reinforcement norms that exist now evolved out of a series of compromises between international shipping companies, European railroads, U.S. railroads, and U.S. trucking companies. The bulk of the discussions occurred in the late 1960s and the first draft of the resulting ISO standards were prepared for publication in 1970.

Over the past fifty years, the use of containers have revolutionised freight handling and helped to grow international trade. Almost every manufactured product consumed today spends some time in a container. Today, approximately 90% of non-bulk cargo worldwide moves by containers stacked on transport ships. As of 2005, some 18 million total containers make over 200 million trips per year.

The advantages of containers are:

  • Increased efficiency
  • Greater security
  • Economical shipping costs

Container dimensions

Even though the International Standards Organisation (ISO) has approved certain external dimensions of general-purpose containers, many additional dimensions exist. Essentially there are five main lengths of containers; they are: 20 ft, 40 ft, 45 ft, 48 ft and 53 ft (note that container sizes are often still given in feet and inches and refer to the outside dimensions of the container). Besides for these lengths, there are two common heights, namely 8 ft 6 in and 9 ft 6 in (the last-mentioned is referred to as a high-cube container). Most of these containers are 8 ft wide, although the 48 ft and 53 ft containers can be 8 ft 6 in in width. The 48 ft and 53 ft containers are not used in shipping and are generally confined to truck and rail use in the US. The 20 ft, 40 ft and 45 ft containers are common in trade throughout the world, with the first two being the most common. The dimensions of these last-mentioned containers are provided in the table below:

Type of container Length (internal) Width (internal) Height (internal) Carrying capacity
6m/20ft GP container 5,90 m (19′ 3″) ( 2,34 m (7′ 7″) 2,38 m (7′ 8″) 21 640 kg (47 716 lbs) maximum weight
12m/40Ft GP Container 12,01 m (39′ 3″) 2,33 m (7′ 7″) 2,38 m (7′ 8″) 26 500 kg (58 433 lbs) maximum weight
12m/40Ft GP High-Cube Container 12,01 m (39′ 3″) 2,33 m (7′ 7″) 2,69 m (8′ 8″) 26 330 kg (58 058 lbs) maximum weight
14M/45Ft GP Container 13,58 m (44′ 6″) 2,35 m (7′ 7″) 2,69 m (8′ 8″) 28 390 kg (62 589 lbs) maximum weight

Note: Variations can be found between series and makes.

You can buy the ISO freight container standards by clicking here

Twenty-foot equivalent units

This is a term you need to understand and that you will come across often in your exporting ventures. Container capacity is measured in twenty-foot equivalent units (TEU, or sometimes teu). A twenty-foot equivalent unit is a measure of containerised cargo capacity equal to one standard 20 ft (length) × 8 ft (width) × 8 ft 6 in (height) container. In metric units this is 6.10 m (length) × 2.44 m (width) × 2.59 m (height), or approximately 39 m³.

Most containers today are of the 40-ft (12.2 m) variety and are known as 40-foot containers. This is equivalent to 2 TEU. 45-foot (13.7 m) containers are also designated 2 TEU. Two TEUs are equivalent to one forty-foot equivalent unit (FEU). High cube containers have a height of 9 ft 6 in (2.9 m), while half-height containers, used for heavy loads, have a height of 4 ft 3 in (1.3 m). When converting containers to TEUs, the height of the containers typically is not considered.

The maximum gross mass for a 20-ft dry cargo container is 24,000 kg, and for a 40-ft, (inc. the 2.87 m (9 ft 5 in) high cube container), it is 30,480 kg. Allowing for the tare mass of the container, the maximum payload mass is there reduced to approximately 21,600 kg for 20-ft, and 26,500 kg for 40-ft containers.

Other types of containers

Various container types are available for different needs:

  • 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
  • Temperature controlled from -25°c to +25°c reefer
  • Open top bulktainers for bulk minerals, heavy machinery
  • Open side for loading oversize pallet
  • Flushfolding flat-rack containers for heavy and bulky semi-finished goods, out of gauge cargo
  • Platform or bolster for barrels and drums, crates, cable drums, out of gauge cargo, machinery, and processed timber
  • Ventilated containers for organic products requiring ventilation
  • Tank containers for bulk liquids and dangerous goods
  • Rolling floor for difficult to handle cargo
  • Gas bottle
  • Generator
  • Collapsible ISO
  • Swapbody

Container and seal numbers

All containers have a four letter and a seven number identification, which is unique to that container. When receiving a container for packing the exporter should always record this number for documentation purposes.
Example of a container number: MEAU 993982/5.

The container seal is provided by the shipping lines and serves as a lock for securing the container. Each seal has a unique number and the shipper should also record this number on all documentation pertinent to the shipment. Upon arrival of the container at the final destination, should the seal number not correspond with the documentation, the importer should immediately notify the shipping line and the marine insurance company.

Hazardous goods

The Department of Transport has a downloadable pdf list of approved training bodies for dangerous goods.

Hazardous Cargo Symbols
Wikipedia provides a detailed description of what is involved with hazordous or dangerous cargo and the symbols that are used to identify such cargo.

Training in Hazardous or Dangerous
A number of the training providers we list on ExportHelp’s training providers page as well as on the TradeTraining website, provide training in this important aspect of logistics.