Glossary > #ISO 668

ISO 668 Standard

ISO 668 is a key international standard established by the International Organization for Standardization (ISO) that pertains to transport containers. Specifically, it classifies Series 1 containers based on their external dimensions, provides related ratings, and specifies minimum internal dimensions and door opening sizes, where appropriate. This standard is crucial for maintaining uniformity and compatibility in intermodal freight transport, ensuring that containers can be efficiently used in various transport modes such as ships, trucks, and trains.

Historical Context and Development

The path to the standardization of transport containers began significantly in the mid-20th century. Before the introduction of standardized containers, the transport industry relied on “break-bulk” shipping, where goods were loaded and unloaded individually. This method was labor-intensive and time-consuming, often leading to prolonged port stays and increased risk of damage or loss during transit.

The concept of intermodal transport containers was popularized by Malcom P. McLean in the 1950s. McLean, a trucking entrepreneur, revolutionized the transport industry by inventing a container that could be easily moved between trucks, ships, and trains without unloading its contents. This innovation required the development of standards to ensure interoperability and efficiency, leading to the introduction of ISO 668 in 1968.

What is ISO 668?

ISO 668 is an international standard that provides a classification system for Series 1 containers based on their external dimensions. It defines key parameters that ensure containers can be used interchangeably across different modes of transportation. The standard is maintained by the ISO Technical Committee ISO/TC 104, Subcommittee SC 1, which focuses on containers for general use.

Key Components of ISO 668

  1. Classification and Dimensions: ISO 668 classifies containers primarily by their length, specified in feet. The standard covers containers ranging from 20 feet to 45 feet in length, with specific designations for each size category. It ensures that containers are built to precise external dimensions, allowing for efficient stacking and handling.
  2. Related Ratings: The standard specifies the maximum gross weight (MGW) of containers, ensuring that they can safely carry heavy loads. The ratings have evolved over time to accommodate the growing weight of containers and the expansion of container ships, with the current maximum gross weight set at 36,000 kg for most container sizes.
  3. Minimum Internal Dimensions and Door Opening: For certain types of containers, ISO 668 provides specifications for minimum internal dimensions and door opening sizes. This ensures that containers can accommodate a wide range of cargo types and facilitate easy loading and unloading.
  4. Load Transfer Areas and Stacking Strength: The standard includes requirements for load transfer areas in the basic structures of containers, which are crucial for ensuring stability during stacking. It also addresses stacking strength, specifying the maximum weight that containers must withstand when stacked.

Importance of ISO 668

ISO 668 plays a key role in the global transport industry by providing a consistent framework for the design and use of containers. This standardization facilitates the smooth transfer of containers between different transport modes, reduces handling times and costs. Additionally, it enhances safety by ensuring the structural integrity of containers, capable of withstanding the demanding conditions of international shipping.

Benefits of ISO 668

  • Interoperability: Containers built according to the specifications of ISO 668 can be used interchangeably across different transport networks worldwide, supporting efficiency and reducing logistical complexities.
  • Safety and Reliability: By adhering to standardized dimensions and ratings, containers are less likely to fail during transport, thereby protecting the cargo and personnel.
  • Cost Effectiveness: Standardization reduces the need for custom solutions, lowering manufacturing and maintenance costs for operators and container manufacturers.

ISO 668 and Related Standards

While ISO 668 provides a comprehensive framework for the external dimensions and ratings of containers, it is complemented by other standards, such as ISO 1496, which details testing and specifications for various types of containers. Together, these standards ensure that containers meet strict performance and safety criteria.

Additions and Revisions

ISO 668 has undergone several revisions since its inception to address the evolving needs of the industry and technological advancements. The current version, ISO 668:2020, includes additions that reflect changes in the design and use of containers. It remains a dynamic standard that is subject to regular updates to incorporate new insights and requirements.

ISO 668 is a cornerstone of the modern transport industry, supporting the efficient movement of goods worldwide. By establishing a unified framework for classification, dimensions, and ratings of containers, it enables smooth intermodal transport, increases productivity, and enhances safety. As global trade continues to grow, ISO 668 will remain an essential tool for ensuring the smooth operation and interoperability of transport systems.