A sea container, also known as a maritime container, is a water and windproof cargo unit in which goods can be transported by sea and/or land. A sea container is available in many different designs and sizes. In this article we tell you more about the history, use, types and dimensions of the container and how you can recognize a container.


The sea container as a transport unit was invented in the 20s by Malcom McLean. Initially, the containers were used to simply transfer goods from trains to ships. In the end, it took another XNUMX years before the container was really used as a loading unit for the transport of goods by sea.

In the 60s, the transport time between Europe and the United States was several months due to increasing world trade, congestion in the ports and labor unrest. For various reasons, there was also some resistance among the classic shipping companies, but in 1966 container shipping company Sea-Land started the first trans-Atlantic container service. With this service it turned out that it was possible to transport the sea container from Europe to the United States and vice versa in a week. It made international trade possible on an unprecedented scale. And the flexible system of liner shipping and tramp shipping with general cargo ships that had served so well for 30 years disappeared.

In 1966 the first container was unloaded in the port of Rotterdam. The container was unloaded from the SS fairland, the first ship of container shipping company Sea-Land Service in a scheduled service between New York and Rotterdam. The first 226 35-foot containers were unloaded using the ship's own cranes. But ohBecause the unloading of a container required the necessary facilities, in 1966 a number of Rotterdam shippers set up the Europe Container Terminals (ECT). 

In the years that followed, the port of Rotterdam continued to develop, partly due to the transport, storage and transshipment of sea containers. Sea containers and terminals have now become indispensable in the port of Rotterdam.

Types of containers

A sea container has many different versions. The choice of which sea container to use depends on the type of goods to be transported. The possibilities are great, sometimes it is obvious what the best option is and sometimes there are several options. The most common container types that we transport are as follows: 

⊗ Standard container

A standard container is the most commonly used shipping container used for the transportation of all kinds of goods. The goods being transported have no special requirements during transportation. Standard containers are also referred to as general purpose containers or dry van (DV) containers.

⊗ Open top container

With an open top container, the sea container does not have a closed roof. These containers are extremely suitable for goods with unusual heights. Because the container does not have a closed roof, it is also useful for loading bulk goods that can be poured into the container via the top. The top of the container can be closed with a tarpaulin. When loading an open-top container, the maximum height of a truck must be taken into account, more info

⊗ Flat rack container

A flat rack container only has bulkheads and a bottom. This container therefore has no roof and long side. The advantage of this is that the container can be loaded and unloaded from both the side and the top. A flat rack is also very suitable for heavy and oversized loads. The bulkheads can also often be folded in, but when an empty flat rack is transported, they must always be secured with lashing straps during transport. When loading a flat rack container, account must be takenelderly with the maximum height and width of a truck, more info

⊗ Refrigerated container (reef)

A reefer container is equipped with a cooling unit, which makes it possible to cool the goods if it is connected. Temperature-sensitive goods can therefore be transported in a conditioned manner. This includes foodstuffs, medicines and other perishable goods. Due to the controlled atmosphere there is no loss of quality. The cooling unit must be connected during transport or storage, otherwise it will not work. During transport, a so-called generator set can be used to supply the reefer container with power en route.

⊗ Tank containers 

A tank container is made for the transport of liquids, gases and powders in bulk. A tank container has a vessel surrounded by a steel frame that has the dimensions of a container. This makes it easy to transport the container via intermodal transport. 


The standard container invented in the thirties is still the standard size today. The standard size of a container is indicated in TEU, this abbreviation stands for Twenty Foot Eequivalent Unit. A TEU is approximately 6,10 meters (20 feet) long, 2,44 meters (8 feet) wide and 2,59 meters (8,5 feet) high. The length of a sea container is indicated in feet (ft.), for example a TEU (20 foot) container is indicated with 20ft.

The most common international sizes in sea containers are 20ft and 40ft (2 TEU) containers. But there are also less common sizes such as 10ft (0,5 TEU), 30ft (1,5 TEU) or 45ft (2,5 TEU) containers. 

20ft 40ft 40ft High Cube 45ft


5,9 meter

12 meter

12 meter

13,56 meter


2,35 meter

2,35 meter

2,35 meter

2,35 meter


2,39 meter

2,39 meter

2,70 meter

2,70 meter

Weight with empty container (tare) KG 2.230 KG 3.720 KG 3.900 KG 4.700
Maximum loading weight KG 28.250 KG 26.760 KG 26.760 KG 25.780

  The dimensions mentioned are representative, although the dimensions may vary per manufacturer, production date and owner of the container.

 The maximum weight to be loaded is what the container could handle. It is true that for each destination, from where the container is going, there are also restrictions regarding the weight of the container. This limit is always leading and therefore always ask what the maximum weight to be loaded is for the port of destination/departure and the route it will follow afterwards. more info

Identification, verification and inspection

Since its invention, the sea container has been strongly developed in a sturdy design, which has to be done with all the kilometers they cover. Before a sea container can be transported, it must have a valid inspection, which is called a CSC inspection. This CSC inspection is standard for new sea containers and is valid for the first five years, after which it must be inspected every time. The extended period of the inspection can be a maximum of 24 months.

If the container has a valid safety approval, it has a CSC plate (Cinvention for Safe Ccontainers). This contains a lot of information about the container such as identification and technical data, it states the identification number, country where the container is registered, the owner of the container, the tare weight, maximum net and maximum gross weight. This information can be found on the doors of the container. 

Each container has its own unique identification number, which consists of 3 parts. The first 4 characters consists of letters, also called prefix, which refer to the owner of the container. These prefix codes are issued and managed by the organization BIC (Bureau International des Containers), so that no duplicate prefix codes arise. The prefix is ​​followed by a 6 digit serial number and this is followed by a check digit. 

Use of the container

Where the container was initially used to simply transfer goods from trains to ships, the mechanization now has the advantage that the entire container can be easily transferred from one means of transport to another. This means that the sea container can be used for multimodal transport. The container can easily be transported by various means of transport by sea, road and rail.

Due to the standard sizes, the container also has the advantage that it is easily stackable. When stacking containers, stackers are used, which are stevedoring tools. These are used to connect stacked containers to prevent mutual shifting. Another tool is the twist lock, which is used to secure a container on a ship, chassis or train. Almost every sea container has an attachment point on the corners of the container to secure a stacker or a twistlock. The difference between a stacker is that it can prevent it from shifting and a twistlock secures the container.

Frequently asked questions

What is the weight of a sea container?

The empty weight is determined by the construction and is different for every container. The weight of an empty sea container is often referred to as 'tare' (empty weight).  On the CSC plate you will find a lot of information about the container, such as identification and technical data. The tare weight, maximum net and maximum gross weight are also stated here.

What is the maximum weight that can be loaded in a container?

The maximum weight is different for every container. On the CSC plate you will find a lot of information about the container, such as identification and technical data. The tare weight, maximum net and maximum gross weight are also stated here.