A container is a container, right? Aren't they just all the same? Big metal rectangles that our stuff is shipped in?
Most of the containers we see on a regular basis do look the same and that's because they are. There are several different types of containers though, ranging from very generalized to very type-specific.
There are 2 main lengths of containers and 3 less common length, one(ish) single width, and several heights.
Containers come in 2 main sizes, 20 foot, and 40 foot. Because containers were invented in the United States and were brought to market in the US as well, the containers we're built to US measurement standards.
During the formation of the container market, there were several different sizes of containers. Some very small, others very large. Over the refinement period of the container industry, there was an agreement to standardize length and width so that any container could fit on any ship. Containers were standardized to 20 foot and 40 foot, with measured measured based on the 20 foot unit. The standard unit is of measurement is known as a Twenty Foot Equivalent Unit or TEU. A 20' container is considered a single TEU and a 40' is considered 2 TEU's. Container ships, terminals, truck chassis all count their capacities based on TEU's.
Less Common Lengths
The 3 less common sizes for containers are 24 foot, 45 foot, and 53 foot. These are containers that are mostly left from the days where containers were all different types of sizes.
The 24 foot container was mostly a Matson Navigation invention to add extra space in the container to fit a few extra pallets inside along with the California traffic code's regulations. Presently, 24 foot containers are being phased out of circulation, with some still in transit with Alaska Marine Lines from Seattle, WA to Alaska and Hawaii.
The 45 foot container was created in a similar fashion as the 24', a way for shippers to fit a few more pallets into the container without going into a second and wasting space sending something mostly empty.
The 53' container is largely a United Stated and Canada based truck and rail container. These containers fit a significant amount more inside but do not work well for international trade. Most ships are not configured to carry 53 foot containers as there is a large unsupported overhang from where the 40 foot supports are to the end (both 45' and 53' containers are essentially a regular 40' container with an even addition welded to each end so they can be stacked properly with 40' containers). In older countries, like many in Europe, the roads that existing roads are typically not suitable to a long truck traveling on them safely.
All(ish) containers are standard width so they can fit onboard ships, trucks, and trains without different equipment required.
A vast majority of containers are 8 foot, or 96 inches, or 2.438 meters wide.
Some containers are 6 inches wider than standard at 102 inches or 8.5 foot. These are typically only used for rail and over the road trucking. They can fit pallets inside them slightly better than their 8 foot counterparts. 53 foot containers are 102 inches wide.
There are two main heights of containers that circulate the globe, standards and high-cubes. The standard height for a container is 8.5 foot, and the height of a high-cube is 9.5 foot. All 45 foot containers are high-cubes.
Here is a handy table for container dimensions both external and internal
|20ft||40ft||40ft High Cube||45ft High Cube||53ft|
In combination with multiple container sizes there are multiple different types of containers.
Most containers are considered dry containers, meaning nothing special. These are the most standard type of container that is around. They are the general purpose container. These are good for boxes, cases, sacks, pallets, and more. Dry containers have corrugated sides.
These are essentially dry containers but have either passive or active ventilation. Some products that wold be best suited for this type of a containers are something like onions.
Temperature Controlled / Reefers
These containers are insulated in some way to help control temperatures. These are typically containers that are required to be plugged in to keep temperatures low and the contents cold, or from freezing. These are called reefers in the industry. They are best for refrigerated or frozen goods like groceries. In the winter they can be used to keep cargo from freezing. Reefers have smooth sides.
Tanks are fit into (typically 20 foot) container frames to hold liquids on ocean voyages. They can hold liquids and gasses.
Open Top Containers
These containers have a canvas or tarp top that make it easy to load bulk commodities like grain or animal feed. These also can be used for items that are too tall to fit in a standard container.
Flat Rack Container
Flat rack containers have no side or roof. They are great for lumber, dry wall, logs, or anything that doesn't really fit well in other containers. These containers also work great for items that are too wide or tall, out of gauge.