Containerization is a system of intermodal freight transport using intermodal containers (also called shipping containers and ISO containers) made of weathering steel. The containers have standardized dimensions.
They can be loaded and unloaded, stacked, transported efficiently over long distances, and transferred from one mode of transport to another — container ships, rail and trucks — without being opened. The handling system is mechanized so that all handling is done with cranes and forklift trucks. All containers are numbered and tracked using computerized systems.
The system was developed after World War II and it dramatically reduced transport costs, supported the post-war boom in international trade and was a major element in globalization.
Containerization did away with the manual sorting of most shipments and the need for warehousing.
Containerization also reduced congestion in ports, significantly shortened shipping time and reduced losses from damage and theft.
Today, intermodal containers are sold and rented to clients as storage units. These include car dealerships, construction companies, event companies and those in the mining and forestry industry.
Before containerization, goods were usually handled manually as break bulk cargo. This involved the loading and unloading of goods in barrels, sacks and wooden crates from land transport to ship and back again on arrival and it was slow and cumbersome.
When the vessel arrived, they would be moved to the side of the ship along with other cargo to be lowered or carried into the hold and packed by dock workers. The ship might call at several other ports before off-loading a given consignment of cargo.
Each port visit would delay the delivery of other cargo. Delivered cargo might then have been offloaded into another warehouse before being picked up and delivered to its destination. Multiple handling and delays made transport costly, time consuming and unreliable.