A freight train is a train which is used to carry cargo, in contrast to passengers. Freight trains consist of at least one engine and a chain of train cars which are coupled together. People use trains to carry freight all over the world, with costs for shipping by train being generally lower than those for air freight or truck freight. However, freight trains are less flexible for shipping than trucks, planes, and ships, since they must stick to the regions where tracks are available for use.
People have been using freight trains for cargo ever since the train was invented. Trains have a number of advantages when it comes to shipping cargo, including the capability of pulling a very heavy load with a surprisingly low use of energy. A single powerful locomotive can pull a very long train of freight cars, with some companies using multiple locomotives in what is known as a locomotive assist. Locomotive assists are used for extremely long freight trains to ensure that the train has enough power to get over steep hills.
There are a number of ways in which freight can be packaged on a freight train. Classically, freight trains carried goods in bulk in boxcars or wagons, and this technique is still used for some things. More commonly, freight trains are loaded with shipping containers. Containerization allows goods to be moved easily between ships, trains, and trucks without the need for repacking. Freight trains also have specialized cars like refrigerated cars for food, and specially-built racks for loading cars.
In some nations, railroads and trucking companies have come up with a creative cooperative shipping method in which trucks drive straight up onto the flat cars of a freight train. This technique, known as “trailer on flat car” or “piggybacking,” can be extremely useful. It allows truckers to take advantage of the high speeds and efficiency of train travel, while ensuring that goods can reach their end destinations, even if those end destinations are beyond the reach of a freight train.
The rise of trucking, shipping, and flying freight has led some railroads to alter their methods of doing business in order to attract customers. Many companies have supported containerization and piggybacking to make it easier for customers to combine shipping methods, and the use of frequently scheduled trains also encourages customers, by assuring them that their goods will be moved quickly. The energy efficiency of using a freight train also became a selling point in the early 21st century, when many companies wanted to engage in more environmentally-responsible business practices, and the costs of fuel began to rise radically, making energy efficiency appealingly cheap as well as environmentally sound.