Intermodal freight describes the transportation of goods in standardized containers. This type of transport makes use of multiple transportation methods such as rail, ship and truck. The use of standardized containers enables the freight to be safely and quickly transferred from one type of carrier onto the next. Because there is limited human interference, the risk of damage to the cargo is also very limited. Furthermore it is much easier and faster to transfer containers from one carrier to another than it would be with bulk cargo.
Due to the standardized size of the containers, the carriers for the containers can be adjusted to maximize the number of containers they can carry. Furthermore the equipment used to unload the containers of the first carriers and load them on to the next are designed to maximize the efficiency at which they can transport containers.
Different equipment is used to transfer the containers between different forms of carriers. This equipment can be found on locations where the transfer between carriers take place, such as a port or terminal.
The first type are the transtainers. A transtainer is a large overhead crane, which is either based on rails or has pneumatic tires. When the transtainer is based on rails it has a limited operation range as it can only operate above its rails. A transtainer will be employed for the loading and unloading of containers onto trucks or railway wagons or storing the containers on top of each other. When a transtainer is based on pneumatic tires it is able to perform similar actions, except its operation range will be increased.
The second type is the container crane. This type of crane is used at ports for the unloading of containers from a ship. A container crane is bound by the rails laid sideways to the docks. The cranes can move on these rails to reach a suitable location to start lifting the containers from the ship. Once the crane has lifted the container form a ship it will be either be directly loaded onto trucks or railway wagons or be stored on each other, for later delivery.
Another type of equipment for transporting containers are reach stackers. A reach stacker is a small vehicle with a long arm used to lift and transport containers. It is most commonly used on small ports and terminals, where large cranes are impractical. They can be used for either storing containers or for loading them on and of trucks and railway wagons.
There are three types of transportation which can be involved in intermodal freighting, however not all three types are mandatory.
The first type are ships. They are capable of transporting the most containers at once. They require the most time for unloading their containers and also require the largest and most specialized equipment for unloading the containers.
The second type of transportation are railways. Rails are the fastest type of land transportation. A single train can carry a large number of containers. Depending on the country the train is operating in, it will be possible to stack containers two high on each other. Allowing for even more containers to be transported by train.
The third type of transportation are trucks. A truck is limited in the amount of containers it can transport. A single truck can carry a forty-foot and a twenty-foot container. Trucking is becoming increasingly used for small distances only. As the costs and speed of this transportation type are becoming bigger concerns, rail transportation is becoming the favored choice of land transportation. trucking will be used mostly to cover the small distances from terminals to its final destination.