ISO Shipping Containers
In the ISO shipping container industry, people talk about ‘containerization‘ .
Containerization is a system of transporting freight using different types and sizes of steel containers.
Known as ‘ISO shipping containers‘, they are today manufactured according to internationally recognised standards.
This means that they can be easily loaded and unloaded, moved, stacked, transported and tracked with ease and efficiency. Standardisation has meant that freight delivery over long distances, even between continents, is now easier than ever.
Freight can be moved from rail to ships to air without being opened and this system means lower transport costs and greater possibilities for international trade. All major shipping companies such as Maersk, OOCL, MSC, CMA CGM and CSAV provide comprehensive international cargo tracking for customers.
In the early years of the shipping container industry, however, many different sizes were used.
Differences in design also meant that containers could not be easily stacked or transferred from one mode of transport to another.
In the late 1960s and finally in 1970, significant strides were made to define standard terminology, dimensions, corner fittings, markings and ratings.
The ISO 6346 standard establishes a visual identification system for every container that includes a unique serial number, the owner, a country code, a size, type and equipment category as well as any operational marks.
Each code comprises 4 capital letters (3 for the ‘owner code‘ and 1 as a ‘category identifier‘ assigned by the owner) and 7 digits (6 assigned by the owner and a single check digit). It is this unique 11 digit shipping container number which is required for container tracking.
There are 3 possible category identifiers:
- U – all freight containers
- J – detachable freight container-related equipment
- Z – trailers and chassis
The standard is managed by the International Container Bureau (BIC). Hence the ISO 6346 standard is also known as a BIC code.
ISO 6346 Shipping Container Codes
- general intermodal dry cargo containers
- tank containers
- reefer containers
- open top containers
- flat rack (platform) containers
- insulated containers
- high cube containers
ISO Shipping Container – Standard Dimensions
The ISO 6346 standard mark recognises five standard lengths of ISO shipping container dimensions.
- 20′ shipping containers (6.1m)
- 40′ shipping containers (12.2m)
- 45 shipping containers (13.7m)
- 48 foot shipping containers (14.6m)
- 53 foot shipping containers (16.2m)
20 foot and 40 foot reefer containers are widely used in the transport of temperature-sensitive produce.
ISO Container Capacity & TEUs
The capacity of any given sea container is expressed in units of 20 feet.
Known in terms of Twenty-foot Equivalent Units (or with the acronym TEU), one equivalent unit is equal to the capacity of a single 20 foot by 8 foot container.
The height of the container is not considered in TEU’s. Therefore, a 9ft 6in high cube container is also referred to as a single TEU container.
Maximum Gross Mass or “Rating”
The maximum permissible weight (when loaded) for a 20 foot container is 24,000kg. For 40 foot containers, this extends to 30,480kg. These numbers must include the tare weight of the container.
The payload mass for a 20 foot container is reduced to about 22,000kg and 27,000kg for 40 foot containers.
ISO Height Standards
Given that many containers are transported by rail, the International Standards’ Organization set the standard height to 8m so that containers could be easily accommodated in railways tunnels.
Recent moves in the industry have seen the increased popularity of the 9ft 6in high cube container and in some countries, various modifications have had to made to transport networks to accommodate.
Without ISO shipping container standards, the cost of moving freight and goods around the worldwide would be extremely expensive and time-consuming.
ISO Containers & The Container Home Industry
ISO standardized containers are the stalwart of the shipping container homes industry. You will find architecturally inspired combinations of (usually) 20, 40 and 45 foot storage containers used in some of the many worldwide container housing projects.
We have provided a complete section on container home examples.