- A guide to containers for storage or shipping
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Sizes and types

Containers come in various shapes and sizes - this section outlines what sort of container you might want and standard dimensions.

Shipping containers are made in two main standard lengths – 40ft and 20ft. The width is almost always 8ft (external measurement) and the height is usually 8ft 6in, giving an internal height of 8ft. For the 20ft container, the metric measurements are 6.1 metres long, 2.4 m wide and 2.59m high, which gives a capacity of about 39 cubic metres.

For site storage these containers are often cut down into half sizes, being about 10ft long or even smaller units with lengths of 5ft or 6ft. These smaller containers are much easier to store and transport.

Exceptionally you can buy or lease a “high cube” container which is an extra 1ft high giving an internal height of 9ft. Most measurements are in imperial measures because the standards in the world shipping industry were set before metrification was established. References to TEU mean “20ft equivalent units”, so that a 40ft container is equivalent to 2 TEU etc. This term is often used to describe the capacity of a port or a container ship.

Structurally a container is based on a rigid frame with a strong wooden floor and four thick corner posts. This works well for lifting because cranes and port handling equipment use the corner castings at the top and bottom of these corner posts. These strong corner posts make it possible to stack containers up to nine boxes high even when filled. A typical 20ft container weighs 2.2 tonnes and can be loaded with 24 tonnes of cargo.

Various unusual containers are available, such as an “open-top” box, which can be used for craning-in heavy machinery that would be impossible to get into a standard container. There are also “flat-beds” which - while conforming to ISO standard sizes  - are used for wide loads that could not be carried otherwise.

"Side-loaders" are containers with doors at the sides for loading awkward shaped items and “Reefers” are refrigerated containers; these have much less steel in them and use more aluminium and fibreglass, but crucially they have a space at one end for a refrigeration unit. They are like giant fridges and are much more expensive to rent – you will need to establish carefully what the maintenance and fuelling arrangements are. As site storage boxes, Reefers are not usually satisfactory, being smaller and less secure than steel containers. There are also "Tanker" containers for carrying liquids.

High cube containers are easily recognisable from their warning flashes in black and yellow. These boxes give significantly more space without costing much more , and for storage at sports grounds they are especially helpful if you intend to store a tractor or goal posts.

The container locking bars are designed to hold the doors closed if the goods inside move around. Consequently for shipping purposes you need to keep them on, but for site storage they make the doors harder to open and close, so many people remove one of these bars from each of the two doors.

So there are lots of sizes and types of containers, but for most static storage purposes the best ones are standard steel 20ft and with easy-opening secure doors.