Common ISO Container Size and Type Codes
In 1995 an ISO agreement was reached concerning container
codes that would depict the length, height and type of container in a
short and easy to read sequence. This sequence is composed of four
letters or digits. The first element of the sequence is about the length of the container with
thee most common being 2 (20 foot container) and 4 (40 foot container).
The second element is about the height of the container with 2 (standard
height of 8 feet and 6 inches) and 5 (high cube container of 9 feet and
6 inches) prevalent. The third and fourth refer to the container type.
G1 relates to a general container that has passive vents at the upper
part of cargo space. R1 would be a mechanically refrigerated and heated
container. U1 would be an open top container with removable top members
in end frames. P1 is a platform container with two complete and fixed
ends. Finally, T1 is a tank container for non-dangerous liquids.
The most common container used for maritime shipping, a standard 40
footer, would have 42G1 as a sequence while the same container as an
high cube would have a sequence labeled as 45G1 (see above figure).
22U1 is a standard 20 foot open top container. 45R1 is the most common sequence
for a reefer (40 foot high cube). The container width code is usually
not used since the great majority of containers have a width of 8
feet, but there are pools of containers having a width of 8 feet and 2
inches that uses the E label. High cube 45 foot containers (LEG1)
are convenient for intermodal transportation in Europe as they have a
size that fits exactly 33 European pallets of 1.2 by 0.8 meters.