They come in a plethora of sizes, but the most common are 20 and 40 feet long.
The modern container shipping industry owes much of its success to the standardization of containers.
Shipping containers come in several standardized sizes, but the two most common sizes are 20 feet and 40 feet in length. There are several reasons for this standardization:
Efficiency: Standardizing container sizes greatly improves the efficiency of loading and unloading cargo. Ports, trucks, trains, and container ships are designed to handle containers of specific sizes. This consistency streamlines the transportation process, reduces the need for custom handling equipment, and speeds up cargo transfer.
Intermodal Compatibility: Standard container sizes are compatible with various modes of transportation, including trucks, trains, and ships. This intermodal compatibility ensures that containers can seamlessly transition between different forms of transportation without needing to transfer their contents.
Stacking and Storing: Containers are often stacked and stored in container yards or on container ships. Standard sizes make it easier to stack and secure containers efficiently. Different sizes or non-standard containers would complicate the stacking process and lead to inefficiencies in storage and transportation.
Industry Adoption: The adoption of 20-foot and 40-foot containers as industry standards has led to economies of scale. Manufacturers produce these container sizes in large quantities, making them more cost-effective to produce and purchase.
Cargo Flexibility: While 20-foot and 40-foot containers are the most common sizes, they still offer flexibility in terms of cargo capacity. Businesses can choose the container size that best suits their cargo needs, ensuring that space is used efficiently while minimizing empty space and transportation costs.
International Agreement: The International Organization for Standardization (ISO) established standard container sizes in ISO 668. This international agreement helps ensure consistency and compatibility in global trade.
While 20-foot and 40-foot containers are the most common sizes, there are variations and specialty containers designed for specific cargo types. For example, there are high-cube containers that are taller than standard containers, refrigerated containers for temperature-sensitive cargo, and open-top containers for oversized cargo. These variations provide some flexibility to accommodate different cargo requirements while maintaining the benefits of standardization.