Intermodal units – or shipping containers, as they are more commonly known – have been specifically designed so that they are uniform. This means that they can be used to carry cargo across the world, being transferred easily between different modes of transport such as cargo ships, trains and trucks.
It is important, therefore, that these units are regulated to ensure that they can be easily manoeuvred, effective as a means for transporting cargo, and cost-effective.
Storage Box Sizes
Although there are also some unconventional sizes available, the majority of units that are used for carrying goods around the world are either 20ft or 40ft in length. This makes them easier to stack and store, as well as transfer them between different modes of transport.
All modular units have a standard width of 8ft and a height of 8ft 6in, except for the high cube options that have a height of 9ft 6in, making them easy to stack. The general dimensions for the normal intermodal models mean that:
The 20ft standard unit has a volume of 1160ft³
The 20ft high cube unit has a volume of 1310ft³
The 40ft standard unit has a volume of 2360ft³
The 40ft high cube unit has a volume of 2660ft³
Most of the modules that are used for transporting cargo are made from corrugated weathering steel and have a floor made from plywood. They will normally have a standardised door at one end, but there can be small differences between the different container manufacturers. This is fine, as long as they are within the standard regulations.
In order to ensure that intermodals can be easily and safely stacked, transported on a range of different modes of transport, and can protect their contents properly, they need to pass a series of standard tests. These tests can include:
- Their ability to be stacked
- Their ability to be lifted
- The strength of each wall
- The strength of the roof and floor
- Its rigidity
- Whether it is weatherproof
Without passing this test, an intermodal container wouldn’t be able to withstand some of the potential hazards that might be thrown at it, such as extreme weather conditions and the weight of other units being stacked on top of it.
Each storage box is given an ISO number or code. This method of classification is recognised internationally, and can provide information about the size and type. This is especially useful as when they are stacked on top of each other, you cannot see the length of them.
The ISO codes consist of four characters and are located on the top right-hand corner of the shipping container. The first number tells you the unit’s length (‘2’ = 20ft, for example). The second number signifies height and width, and the third and fourth numbers show the type of container that it is.
Intermodal Unit Regulations
The main regulations that are applied to these units are linked to their size. They need to be a regular size so that they can easily and safely be stacked and secured, especially when they are at sea. This way, operational costs can be kept low and there is less chance of damage.
It is important that intermodal containers are regulated and meet the specifications that are laid out. Without this, it would defeat the object of having them, affecting security and the cost-effectiveness of the world’s preferred method of transporting cargo.