Since we have been discussing freight forwarding in the last few weeks, what better way to continue than by talking about containers. In addition, we update the information to offer the latest news and trends.

Containers are the cargo containers par excellence. They can be used on land, although the most frequent use is for sea and river transport.

Manufacturing and ISO container materials

They are generally made of steel, although we can also find aluminum and plywood containers with fiberglass. The floor is usually made of wood or bamboo.

Although the containers have a built-in interior anti-moisture coating, for sea journeys it is necessary to use special anti-corrosion and anti-moisture protection, such as shrinkable plastic, heat-sealable bags and desiccant salts, since, as we mentioned in previous posts, the effect of saline compounds can severely damage the merchandise.

In addition, fasteners are usually incorporated inside such as airbags and webbing.


All containers are equipped with twistslocks to facilitate their attachment by cranes for loading and unloading.

The specifications for the manufacture of the containers have also been subject to the application of a regulatory standard for standardization, namely the International Standardization Organization (ISO).


ISO container types

We can not only classify containers according to the material they are made of, but also, of course, by their external characteristics and dimensions.

Let’s start with the types of containers we can find:

Dry Van:

This is the standard container, the most widely used worldwide. It is hermetically sealed and has no refrigeration or ventilation.



Unlike the Dry Van, it is not hermetically sealed. It is usually used for road rather than sea transport and is generally used to transport waste.

High Cube:

These are the standard containers but with a much larger size. They are characterized by their great height (almost 3 meters).



These are refrigerated containers for the transport of goods requiring cold or heat. They incorporate a thermostat to select a constant temperature during the journey. Due to their utility, they must be constantly connected (truck, ship, terminals…). They operate with three-phase current.


Open Top:

As the name suggests, they are open at the top, without a roof. This type of container is used for goods whose height exceeds that of a High Cube. It must be taken into account that, when the cargo exceeds the standardized height of the container, supplements will be charged for the rest of the goods that could not be transported due to this circumstance.


Flat Rack:

Like the Open Top, they are used for loads with dimensions exceeding the standard dimensions. This type of containers usually lack sides and, in some cases, even the front and rear walls, leaving only the base. As in the previous ones, they are linked to supplements depending on the space occupied by the cargo on board the ship.


Collapsible Flat Rack:

Same as the Flat Rack, but with the added feature that its sides are foldable on the base.



Open Side:

These are only open on one side, keeping the roof, the base and the rest of the walls. A supplement is also applied to them, as they are longer loads.


Tank or tank container:

They are used to transport liquids in bulk. A series of steel beams contain a tank in which the goods are stored. They can be stacked and travel in any type of transport.

– Flexi-Tank:

The difference with the normal tank container is that inside it there is a flexible tank made of polyethylene, called Flexibag.



The possibility of incorporating a new container size to accommodate European pallets or Europallets is being studied, the main problem is that the vessels are prepared to accommodate the current containers.


ISO container dimensions

As mentioned above, these cargo containers are standardized. Their width is fixed at 2.44 meters, the height varies between 2.60 meters and 2.90 meters and the length can range from 2.44 meters to 16.15 meters.

Generally, the unit of measurement used in containers is the foot and the most used and standardized ones are 20 and 40 feet long (around 6 and 12 meters, respectively).


Below, we show you the dimensions of the containers by type and in the standardized measures of 20 and 40 feet:



NOTE: The maximum load may vary depending on the type of transport.


For example, not all countries allow the same maximum weight for trucks and not all ships support the same load, depending on the type of transport used and the regulations of each country.

These are the containers to be used in a maritime transport according to the space and conditioning needs of the cargo to be transported.

In the following post we will analyze in detail the marking of these containers, as well as their format and calculation.