Freight Container

A freight container is a shipping equipment with strength suitable to withstand shipment, storage, and handling and used to transport cargo.

According to ISO 668:1995(E), a shipping container means an article of transport equipment which is:

a) of a permanent character and accordingly strong enough to be suitable for repeated use;
b) specially designed to facilitate the carriage of goods, by one or more mode of transport, without intermediate reloading;
c) fitted with devices permitting its ready handling, particularly its transfer from one mode of transport to another;d) so designed as to be easy to fill and empty;
e) stackable; and,
f) having an internal volume of 1 cubic meter or more.

Under above definition, swap bodies are excluded. Although without internal volume, however, and therefore not satisfying criterion (f) above, flats used in maritime transport should be considered a special type of container and therefore are included here.

In practice, the term “iso freight containers” is also usually used, and that word means freight vans complying with all relevant ISO container standards in existence at the time of its manufacture. The term "container", unless clearly explain otherwise, means iso freight container and is used throughout this website.

The container standardization process went along with history of container. During that time, the "Father of Containerization" - Malcolm McLean, conceived the innovative idea of using such "boxes" in his Sealand Inc, and overcame many challenges to make the receptacle so popular in the shipping world.

Container sizes

The 20ft and 40ft box are the most popular ISO containers in the shipping world today. Longer vans become more and more popular in service in North America, while shorter ones (e.g. 10’) are now used much less than before.

Most of shipping practitioners are interested in shipping container dimensions in general. Others in academia may want to search for exact specification. Thus, I also write an article about ISO container sizes for the later group.

Container types

Containers in general can be classified into two main groups: standard and non-standard.

The former are those complying with international standards (ISO) and can be used in international shipping. The later have length and width dimensions similar to those of ISO boxes but have different heights and weights and, therefore, may not be intermodal worldwide.

According to ISO 6346 (1996), freight containers consist of following main categories:

  1. General purpose container 
  2. Bulk container 
  3. Named cargo container 
  4. Thermal container 
  5. Open-top container 
  6. Platform container 
  7. Tank container 

>>See more about about container types

Container markings

On the surface of containers, there are many numerical and alphabetical symbols, codes, signs indicating necessary introduction, instruction, and requirements. ISO 6346:1995 is currently regulating those markings of three main groups.

  1. Identification system 
  2. Size and type codes 
  3. Operational markings 

Besides, other markings on freight boxes include

  • CSC Approval Plate 
  • Approval for Transport under Customs Seal 
  • Approval of International Union of Railways - UIC (IC code
  • Logo of classification societies (e.g. Bureau Veritas, Lloyd's Register) 
  • Test plate (by classification societies) 
  • Owners’ name, logo, slogan 
  • Container manufacturers (CIMC, VTC…) 
  • Material type plate (corten steel)

You may want to watch video about container markings offered by

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