Explain about Type of Containers. Size and Features of Dry/Reefer/Open Top/Flat Rack/ISO Tank Container for Logistics

Today, I would like to talk about the types of containers used in international Logistics. There are various types of containers for ocean shipment.

We deliver the various type of cargoes, such as food, industrial goods, chemicals, and daily necessities to all over the world.

So, we have to choose the best container for each cargo transportation.

All about Containers by Animation Video

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Please watch it!

Type of Containers

First of all, let’s look at the types of containers.

Dry container / Reefer container / Open Top container / Flat Rack container / ISO Tank container.

Generally, there are 20’feet and 40’feet containers.

This “Feet” refers to “length”.
So 20′ feet is about 6 meters length and 40′ foot is about 12 meters length.

So let’s take a look at them.

Dry Container

The first is Dry container. Dry container has the function as a “Box” for transporting cargo. It is the most common container in the market and it is mainly used for general cargo.

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It is also used for dangerous cargo as well but it depends on the class.

From now, I will introduce various types of containers, but please understand this dry container is a standard container.

Reefer Container

Next, Reefer container. Reefer container is temperature-controlled container, like a moving refrigerator.

Depends on a manufacturer, most containers can adjust temperature in the range of -30°C to +30°C.

The temperature inside a container rises to 60 to 70°C just below the equator. However, with Reefer containers, the inside temperature can be kept constant.

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It is often used for food products and dangerous goods that require temperature control.

Open Top Container

Next is Open top container. Open top container is like Dry container without a ceiling.

Since there is no ceiling, it is used for tall cargoes. Open tops are also sometimes used to put heavy cargo into a container from the top.

It’s not easy for loading heavy cargo that a normal 3 or 5 ton forklift can’t lift. But it’s not that difficult to use an overhead crane or a wrecker at a factory to load from the top of a container.

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The cargo won’t get wet by rain Coz the ceiling is covered!

Flat Rack Container

Then Flat rack container. The flat rack is Dry container with no ceiling and no side walls. It is used for the cargo wider than the Dry container.

It is also used for not only oversized cargo, but also in-gauge items that can fit inside a container.

Even the in-gauge cargo but sometimes Flat Rack container will be used when the factory loading facility is not enough.

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Flat Rack is really easy for loading.

Limited space for Open Top and Flat Rack container

The ocean freight are generally higher for Open top and Flat Rack containers. That’s because there is limited space on a container vessel for those containers.

For example, when carrying oversized cargo on Flat rack, it uses extra container space on both sides as well as the top.

Ocean Freight is increased because it uses lots of places.

However, even though the Open Top and Flat Rack container are the special container, the space on a vessel is not limited for an in-gauge container, so the sea freight can be kept down.

ISO Tank Container

Finally, ISO tank container. ISO tank is used for liquid materials.

It may be cheaper to put wine, juice, chemicals, etc. directly into an ISO tank container than into a container with the drums.

Container Size

Next, let’s talk about the size of the container.

First is a 20’feet container. The size required for actual operations is internal container size.

Dry container size

20’feet Dry Container
Length: 6m
Width: 2.3m
Hight: 2.3m

40’feet Dry Container
Length: 12m
Width: 2.3m
Hight: 2.3m

40’HC container
Length: 12m
Width: 2.3m
Hight: 2.7m

20′ foot container is about 2.3m square and about 6m length. You do not need to memorize the exact size.

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It’s OK to remember roughly.

There are slightly differences in container sizes between shipping lines, so no need to memorize exactly. You won’t be tested, so it’s important to use it in the actual jobs.

Open Top Container Size

20’feet Open Top Container
Length: 6m
Width: 2.3m
Hight: –m

40’feet Open Top Container
Length: 12m
Width: 2.3m
Hight: –m

Flat Rack Container Size

20’feet Flat Rack Container
Length: 6m
Width: –m
Hight: –m

40’feet Flat Rack Container
Length: 12m
Width: –m
Hight: –m

Maximum Weight of Container

And maximum loading weight is also important as well. When transporting not bulky but heavy cargo such as steel, machinery, liquid, water, rice, etc., in sea shipment, the weight of the cargo is very important for safety control.

Therefore, the weight of the maximum cargo loading is about 25 tons for both 20’feet and 40’feet containers.

Please keep this in mind.

Just because it’s 40’feet doesn’t mean it can load twice as heavy as a 20’feet.

Container Grade

Lastly, let’s mention the grade of containers. The quality of containers will change depending on the type of the cargoes.

Used containers are cleaned and repaired at Container Depot, and they are classified into grades A, B and C.

For example, if it transports hygiene products such as food or medicine, the container grade must be A. Grade A container is in good condition with no major scratches, no peeling floors, and no smell.

And grade C container. If there is a hole in the ceiling of a container, it is not acceptable, but it is used on the assumption that it has damages to some extent.

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It is used for transporting the scrap material and steel.


If you are involved in trade, you have to use different containers depending on the contents of your cargo.And it is also important to understand the size of the container in order to load the cargo efficiently.

Today’s contents are very important.

Please review this video many times so that you can use it quickly in your actual work.