Containerization Explained

Containerization (or containerisation) is a system of intermodal freight transport cargo transport using standard ISO containers (known as shipping containers, ITUs (Intermodal Transport Units or isotainers) that can be loaded and sealed intact onto container ships, railroad cars, planes, and trucks.


The introduction of containers resulted in vast improvements in port handling efficiency, thus lowering costs and helping lower freight charges and, in turn, boosting trade flows. Almost every manufactured product humans consume spends some time in a container.


Although having its origins in the late 1780s or earlier, the global standardisation of containers and container handling equipment was one of the important innovations in 20th century logistics.

By the 1830s, railroads on several continents were carrying containers that could be transferred to trucks or ships, but these containers were invariably small by today's standards. Originally used for shipping coal on and off barges, 'loose boxes' were used to containerize coal from the late 1780s, on places like the Bridgewater Canal. By the 1840s, iron boxes were in use as well as wooden ones. The early 1900s saw the adoption of closed container boxes designed for movement between road and rail.

In the United Kingdom, several railway companies were using similar containers by the beginning of the 20th century and in the 1920s the Railway Clearing House standardised the RCH container. Five or ten foot long, wooden and non-stackable, these early standard containers were a great success but the standard remained UK-specific.

From 1926 to 1947, in the US, the Chicago North Shore and Milwaukee Railway carried motor carrier vehicles and shippers' vehicles loaded on flatcars between Milwaukee, Wisconsin and Chicago, Illinois. Beginning in 1929, Seatrain Lines carried railroad boxcars on its sea vessels to transport goods between New York and Cuba. In the mid-1930s, the Chicago Great Western Railway and then the New Haven Railroad began "piggy-back" service (transporting highway freight trailers on flatcars) limited to their own railroads. By 1953, the CB&Q, the Chicago and Eastern Illinois and the Southern Pacific railroads had joined the innovation. Most cars were surplus flatcars equipped with new decks. By 1955, an additional 25 railroads had begun some form of piggy-back trailer service.

Toward the end of World War II, the United States Army began using specialized containers to speed up the loading and unloading of transport ships. The army used the term "transporters" to identify the containers, for shipping household goods of officers in the field. A "Transporter" was a reusable container, long, wide, and high, made of rigid steel with a carrying capacity of 9,000 pounds. During the Korean War the transporter was evaluated for handling sensitive military equipment, and proving effective, was approved for broader use. Theft of material and damage to wooden crates, in addition to handling time, by stevedores at the Port of Pusan, proved to the army that steel containers were needed. In 1952 the army began using the term CONEX, short for "Container Express". The first major shipment of CONEX's (containing engineering supplies and spare parts) were shipped by rail from the Columbus General Depot in Georgia to the Port of San Francisco, then by ship to Yokohama, Japan, and then to Korea, in late 1952. Shipment times were cut almost in half. By the time of the Vietnam War the majority of supplies and materials were shipped with the CONEX. After the U.S. Department of Defense standardized an 8'x8' cross section container in multiples of 10' lengths for military use it was rapidly adopted for shipping purposes.[1] [2]

These standards were adopted in the United Kingdom for containers and rapidly displaced the older wooden containers in the 1950s.

Even the railways of the USSR had their own small containers. [3]

Purpose-built ships

See main article: Container ship. The first vessels purpose-built to carry containers began operation in Denmark in 1951. Ships began carrying containers between Seattle and Alaska in 1951. The world's first truly intermodal container system used the purpose-built container ship the Clifford J. Rodgers, built in Montreal in 1955 and owned by the White Pass and Yukon Route. Its first trip carried 600 containers between North Vancouver, British Columbia and Skagway, Alaska, on November 26, 1955; in Skagway, the containers were unloaded to purpose-built railroad cars for transport north to the Yukon, in the first intermodal service using trucks, ships and railroad cars. Southbound containers were loaded by shippers in the Yukon, moved by rail, ship and truck, to their consignees, without opening. This first intermodal system operated from November 1955 for many years.

The U.S. container shipping industry dates to 1956, when trucking entrepreneur Malcom McLean put 58 containers aboard a refitted tanker ship, the Ideal-X, and sailed them from Newark to Houston. What was new in the USA about McLean's innovation was the idea of using large containers that were never opened in transit between shipper and consignee and that were transferable on an intermodal basis, among trucks, ships and railroad cars. McLean had initially favored the construction of "trailerships" - taking trailers from large trucks and stowing them in a ship’s cargo hold. This method of stowage, referred to as roll-on/roll-off, was not adopted because of the large waste in potential cargo space onboard the vessel, known as broken stowage. Instead, he modified his original concept into loading just the containers, not the chassis, onto the ships, hence the designation container ship or "box" ship.[4] [5] See also pantechnicon van and trolley and lift van.

Towards standards

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 in the U.S. alone. Among the biggest operators, the Matson Navigation Company had a fleet of 24feet containers while Sea-Land Service, Inc used 35feet containers. The standard sizes and fitting and reinforcement norms that exist now evolved out of a series of compromises among international shipping companies, European railroads, U.S. railroads, and U.S. trucking companies. Four important ISO recommendations standardised containerisation globally[6]

In the United States, the Interstate Commerce Commission was created in 1887 to keep railroads from using monopolist pricing and rate discrimination on customers, especially rural Western farmers, but fell victim to regulatory capture, and by the 1960s, before any shipper could carry different items in the same vehicle, or change rates, the shipper had to have ICC approval, which impeded containerization and other advances in shipping. The United States' present fully integrated systems became possible only after the ICC's regulatory oversight was cut back (and later abolished in 1995), trucking and rail were deregulated in the 1970s and maritime rates were deregulated in 1984. [7]


Containerization has revolutionized cargo shipping. Today, approximately 90% of non-bulk cargo worldwide moves by containers stacked on transport ships ; 26% of all containers originate from China. As of 2005, some 18 million total containers make over 200 million trips per year. There are ships that can carry over, for example the Emma Mærsk, 396 m long, launched August 2006. It has even been predicted that, at some point, container ships will be constrained in size only by the depth of the Straits of Malacca—one of the world's busiest shipping lanes—linking the Indian Ocean to the Pacific Ocean. This so-called Malaccamax size constrains a ship to dimensions of 470 m in length and 60 m wide (1542 feet by 197 feet).[5]

However, few initially foresaw the extent of the influence containerization would bring to the shipping industry. In the 1950s, Harvard University economist Benjamin Chinitz predicted that containerization would benefit New York by allowing it to ship industrial goods produced there more cheaply to the Southern United States than other areas, but did not anticipate that containerization might make it cheaper to import such goods from abroad. Most economic studies of containerization merely assumed that shipping companies would begin to replace older forms of transportation with containerization, but did not predict that the process of containerization itself would have some influence on producers and the extent of trading.[5]

The widespread use of ISO (International Organization for Standardization) standard containers has driven modifications in other freight-moving standards, gradually forcing removable truck bodies or swap bodies into the standard sizes and shapes (though without the strength needed to be stacked), and changing completely the worldwide use of freight pallets that fit into ISO containers or into commercial vehicles.

Improved cargo security is also an important benefit of containerization. The cargo is not visible to the casual viewer and thus is less likely to be stolen and the doors of the containers are generally sealed so that tampering is more evident. This has reduced the "falling off the truck" syndrome that long plagued the shipping industry.

Use of the same basic sizes of containers across the globe has lessened the problems caused by incompatible rail gauge sizes in different countries. The majority of the rail networks in the world operate on a gauge track known as standard gauge but many countries (such as Russia, India, Finland, and Spain) use broader gauges while many other countries in Africa and South America use narrower gauges on their networks. The use of container trains in all these countries makes trans-shipment between different gauge trains easier.

ISO standard

Dimensions and payloads

There are five common standard lengths, 20-ft (6.1 m), 40-ft (12.2 m), 45-ft (13.7 m), 48-ft (14.6 m), and 53-ft (16.2 m). United States domestic standard containers are generally 48feet and 53-ft (rail and truck). Container capacity is often expressed in twenty-foot equivalent units (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 (2.9 m) High cube and the 4-ft 3-in (1.3 m) half height 20feet containers are also called one TEU. Similarly, the 45-ft (13.7 m) containers are also commonly designated as two TEU, although they are 45 and not 40feet long. Two TEU are equivalent to one forty-foot equivalent unit (FEU).

The use of Imperial measurements to describe container size (TEU, FEU) reflects the fact that US Department of Defense played a major part in the development of containers. The overwhelming need to have a standard size for containers, in order that they fit all ships, cranes, and trucks, and the length of time that the current container sizes have been in use, makes changing to an even metric size impractical.

The maximum gross mass for a 20feet dry cargo container is 30,480 kg, and for a 40-ft (including the 2.87 m (9 ft 6 in) high cube container), it is 34,000 kg. Allowing for the tare mass of the container, the maximum payload mass is therefore reduced to approximately 28,380 kg for 20feet, and 30,100 kg for 40feet containers.[8]

Since November 2007 48-ft and 53feet containers are used also for international ocean shipments. At the moment (April 2008) the only ocean company who offer such containers is APL[9] . However, APL containers have slightly different sizes and weights than standard 48feet and 53feet containers (that are used in the US by rail and truck services).

Standard containers

The 40feet container is the most popular container worldwide. Longer container types have become more common, especially in North America. Shorter containers (e.g. 10feet containers) are rare.

The following table shows the weights and dimensions of the three most common types of containers worldwide. The weights and dimensions quoted below are averages, different manufacture series of the same type of container may vary slightly in actual size and weight.

20′ container40′ container45′ high-cube container
length20′ 0″6.096 m40′ 0″12.192 m45′ 0″13.716 m
width8′ 0″2.438 m8′ 0″2.438 m8′ 0″2.438 m
height8′ 6″2.591 m8′ 6″2.591 m9′ 6″2.896 m
length18′ 10 ″5.758 m39′ 5 ″12.032 m44′ 4″13.556 m
width7′ 8 ″2.352 m7′ 8 ″2.352 m7′ 8 ″2.352 m
height7′ 9 ″2.385 m7′ 9 ″2.385 m8′ 9 ″2.698 m
door aperturewidth7′ 8 ⅛″2.343 m7′ 8 ⅛″2.343 m7′ 8 ⅛″2.343 m
height7′ 5 ¾″2.280 m7′ 5 ¾″2.280 m8′ 5 ″2.585 m
volume1,169 ft³33.1 m³2,385 ft³67.5 m³3,040 ft³86.1 m³
gross mass
66,139 lb30,400 kg66,139 lb30,400 kg66,139 lb30,400 kg
empty weight4,850 lb2,200 kg8,380 lb3,800 kg10,580 lb4,800 kg
net load61,289 lb28,200 kg57,759 lb26,600 kg55,559 lb25,600 kg

20-ft, "heavy tested" containers are available for heavy goods (e.g. heavy machinery). These containers allow a maximum weight of 67,200 lb (30,480 kg), an empty weight of 5,290 lb (2,400 kg), and a net load of 61,910 lb (28,080 kg).


The original choice of 8 foot high for ISO containers was made in part to suit a large proportion of railway tunnels, though some had to be deepened. With the arrival of even taller container, further enlargement is proving necessary. [10]


Various container types are available for different needs:[11]


See main article: ISO 6346. Each container is allocated a reporting mark (ownership code) four characters long ending in the letter U, followed by 6 numbers and a check digit.

Air freight containers

See main article: Unit Load Device.

While major airlines use containers that are custom designed for their aircraft and associated ground handling equipment the IATA has created a set of standard container sizes, the LD-designation sizes are shown below:

DesignationWidth (in)Height (in)Depth (in)Base (In)Max load (lb)Max load (kg)Shape
LD-261.564.047.061.52700~1225Type A
LD-379.064.060.461.53500~1588Type A
LD-6160.064.060.4125.07000~3175Type B
LD-7125.064.080.0n/a13300~6033Rect. or Contoured
LD-8125.064.060.496.05400~2449Type B
LD-9125.064.080.0n/a13300~6033Rect. or Contoured
LD-29186.064.088.0125.013300~6033Type B

LD-1, -2, -3, -4, and -8 are those most widely used, together with the rectangular M3 containers.


Increased efficiency

Although there have been few direct correlations made between containers and job losses, there are a number of texts associating job losses at least in part with containerization. A 1998 study of post-containerization employment at United States ports found that container cargo could be moved nearly twenty times faster than pre-container break bulk.[12] The new system of shipping also allowed for freight consolidating jobs to move from the waterfront to points far inland, which also decreased the number of waterfront jobs.

Additional fuel costs

Containerisation increases the fuel costs of transport and reduces the capacity of the transport as the container itself must be shipped around not just the goods. For certain bulk products this makes containerisation unattractive. For most goods the increased fuel costs and decreased transport efficiencies are currently more than offset by the handling savings. On railway the capacity of the container is far from its maximum weight capacity, and the weight of a railcar must be transported with not so much goods. In some areas (mostly USA and Canada) containers are double stacked, but this is in other countries in the world usually not possible.


Containers have been used to smuggle contraband. The vast majority of containers are never subjected to scrutiny due to the large number of containers in use. In recent years there have been increased concerns that containers might be used to transport terrorists or terrorist materials into a country undetected. The U.S. government has advanced the Container Security Initiative (CSI), intended to ensure that high-risk cargo is examined or scanned, preferably at the port of departure.

Empty containers

Containers are intended to be used constantly, being loaded with new cargo for new destination soon after having emptied of previous cargo. This is not always possible, and in some cases the cost of transporting an empty container to a place where it can be used is considered to be higher than the worth of the used container. This can result in large areas in ports and warehouses being occupied by empty containers left abandoned. However, empty containers may also be recycled in the form of shipping container architecture, or the steel content salvaged.

Loss at sea

Containers occasionally fall from the ships that carry them, usually during storms; it is estimated that over 10,000 containers are lost at sea each year.[13] For instance, on November 30, 2006, a container washed ashore on the Outer Banks of North Carolina, along with thousands of bags of its cargo of Doritos Chips. Containers lost at sea do not necessarily sink, but seldom float very high out of the water, making them a shipping hazard that is difficult to detect. Freight from lost containers has provided oceanographers with unexpected opportunities to track global ocean currents, notably a cargo of Friendly Floatees.[14]

In 2007 the International Chamber of Shipping and the World Shipping Council began work on a code of practice for container storage, including crew training on parametric rolling, safer stacking and marking of containers and security for above-deck cargo in heavy swell.[15]

Double-stack containerization

Most flatcars cannot carry more than one standard 40feet container, but if the rail line has been built with sufficient vertical clearance, a double-stack car can accept a container and still leave enough clearance for another container on top. This usually precludes operation of double-stacked wagons on lines with overhead electric wiring. However, the Betuweroute, which was planned with overhead wiring from the start, has been built with tunnels that do accommodate double-stacked wagons so as to keep the option to economically rebuild the route for double stacking in the future. The overhead wiring would then have to be changed to allow double stacking.[16] Lower than standard size containers are run double stacked under overhead wire in China.[17]



Railways have flat wagons and gondola (rail) wagons that can hold 40' ISO containers.

Narrow gauge railways of gauge have smaller wagons that do not readily carry ISO containers, such as the 30' long and 7' wide wagons of the Kalka-Shimla Railway. Wider narrow gauge railways of e.g. gauge can take ISO containers.

Other uses for containers

Shipping container architecture is the use of containers as the basis for housing and other functional buildings for people, either as temporary housing or permanent, and either as a main building or as a cabin or workshop. Containers can also be used as sheds or storage areas in industry and commerce.

Containers are also beginning to be used to house computer data centers, although these are normally specialized containers. Sun Microsystems was one of the first to do this with their Sun Modular Datacenter; Hewlett-Packard introduced the HP Performance Optimized Datacenter (or POD).


Biggest ISO container companies

Top 10 container shipping companies in order of TEU capacity, first January 2006
CompanyTEU capacity[21] Market ShareNumber of ships
A.P. Moller-Maersk Group1,900,000+18.2%600+
Mediterranean Shipping Company S.A.865,89011.7%376
CMA CGM507,9545.6%256
Evergreen Marine Corporation477,9115.2%153
China Shipping Container Lines346,4933.8%111
American President Lines331,4373.6%99
NYK Line302,2133.3%105

Other container systems


Before the International Standard Container appeared, various countries had their own containers. These containers were generally small, and not able to be stacked one upon another. Clearly the idea of containerisation is not new, though the implementation of the ISO container was much better done.



BBC tracking project

See main article: The Box (BBC container). On 5 September 2008 the BBC embarked on a year-long project to study international trade and globalization by tracking a shipping container on its journey around the world.[23] [24]

See also


Further reading

In Fiction

Notes and References

  1. "History & Development of the Container"
  2. CONEX
  3. Photos of containers in Baku
  4. Cudahy, Brian J., - "The Containership Revolution: Malcom McLean’s 1956 Innovation Goes Global" TR News. - (c/o National Academy of Sciences). - Number 246. - September-October 2006. - (Adobe Acrobat *.PDF document)
  5. Book: Marc Levinson. The Box, How the Shipping Container Made the World Smaller and the World Economy Bigger. Princeton Univ. Press. 2006. ISBN 0-691-12324-1.
  6. Rushotn, A., Oxley, J., Croucher, P. (2004) The Handbook of Logistics and Distribution Management Kogan Page: London
  7. News: Postrel. Virginia. The Box that Changed the World. 2006-03-23. 2008-02-14.
  8. Web site: Shipping containers. Emase. 2007-02-10.
  9. APL: Equipment Specifications - Standard Containers
  11. Web site: Selecting a Container. CMA CGM Group. 2006. 2008-02-14. PDF.
  12. Herod. Andrew. Discourse on the Docks: Containerization and Inter-Union Work Disputes in US Ports, 1955-85. Transactions of the Institute of British Geographers. 23. 2. 177–191. The Royal Geographical Society. United Kingdom. 1998. 2008-02-14. 10.1111/j.0020-2754.1998.00177.x.
  13. Podsada, Janice. (2001-06-19) 'Lost Sea Cargo: Beach Bounty or Junk?', National Geographic News. Retrieved 2007-04-17
  14. "Rubber Duckies Map The World"
  15. News: Banana box slip a worry. Lloyd's List Daily Commercial News. Informa Australia. 2008-02-07. 2008-02-14.
  16. Web site: Betuweroute:Frequently Asked Questions. Ministry of Transport, Public Works and Water Management, Government of the Netherlands. 2007. 2008-02-14.
  17. News: Das. Manumi. Spotlight on double-stack container movement. The Hindu Business Line. The Hindu Group. 2007-10-15. 2008-02-14.
  18. Chronological History
  19. Kaminski, Edward S. (1999). - American Car & Foundry Company: A Centennial History, 1899-1999. - Wilton, California: Signature Press. - ISBN 0963379100
  20. "A new fleet shapes up. (High-Tech Railroading)"
  21. Web site: Liner market shares. January. 2006. BRS report for Alphaliner.
  22. Book: Gunn, John. Along Parallel Lines: A History of the Railways of New South Wales. Melbourne University Press. 1989. 387. 0522843875.
  23. Web site: The Box takes off on global journey. BBC News. 2008-09-08.
  24. Web site: BBC - The Box. 5 September 2008. BBC. 2008-09-05.