Intermodal Containers

Intermodal containers are reusable steel boxes used for the storage or movement of products and materials. The term “intermodal” means the containers can be moved through different modes of transportation without unloading or reloading their contents. Intermodal freight transportation uses rail, ship and truck.

Intermodal containers are known by many different names. Containers, freight containers, hi-cube containers, ISO containers and shipping containers are common names for these steel boxes. They are also called boxes, conex boxes and sea cans. Whatever someone calls them, they provide safe and secure storage and movement of contents.

According to the World Shipping Council, there are 17 million inter modal containers in the world. They are manufactured in several standardized sizes to suit various types of cargo. Their capacity is usually expressed in twenty-foot equivalent units (TEUs), or twenty feet long by eight feet wide. Air freight uses lighter unit load devices (ULDs), which are pallets or containers used for luggage, mail and other aircraft freight.

Standardized shipping containers originated in the 1950s, when the United States military and commercial shipping operators developed them. The International Organization of Standards (ISO) published the first international standards for containers around 1970. According to the International Maritime Organization (IMO), every container traveling internationally must be identified with a Convention for Safe Containers (CSC) plate.

Typical intermodal containers have doors constructed of corrugated weathering steel. Traditionally eight feet wide and eight feet high, they are usually 20 feet or 40 feet long. They can be stacked several units high. The box corners have castings that work with twistlock fasteners to secure the containers during shipping. Many countries now use hi-cube or high-cube units that are taller than the average intermodal steel box. These taller units have a height that is greater than ten feet. The United States and Canada also use longer units that are 48 and 53 feet. Pallet wide containers are wider than standard boxes to accommodate EUR-pallets and EPAL-pallets, standard European pallets that are specified by the European Pallet Association (EPAL). They feature overhangs that allow for easy loading and unloading of side-by-side pallets. Australian pallets are also slightly wider than the standard sizes.

Different cargoes require different container types, such as refrigerated containers for perishable foods and tanks for bulk liquids. There are open-top and collapsible versions, gas bottle containers, flat rack containers for heavy or bulky items and swap body boxes for rail and road transport. Port Containers is an example of an American company that sells shipping containers. From a standard box or hi-cube version to a flat rack container, shipping container companies stock a variety of intermodal containers in standard and special sizes. Many of them have huge rental fleets as well.