Railroads, Freight

Freight trains are those trains that transport freight rather than passengers; they consist of a series of freight cars pulled by a locomotive or series of locomotives. Freight or cargo consists of goods transported for commercial purposes, and today they are primarily shipped in standardized containers that have been optimized for intermodal transport—meaning they are easily transferred from one mode of transport to another, such as from a cargo plane to a train, without need of repackaging.

When it is practical, rail transport is a cheaper and more energy-efficient means of freight transport than trucking, and the gains increase with distance. For shorter distances, the railways' lack of flexibility is a disadvantage. Intermodal transport is more and more common, with freight railroads forming an important component of the overall freight transport story. In addition to carrying ordinary cargo, freight trains are critical to the transport of steel, wood, and coal. Because these industries predate or grew up alongside the advent of the railways, their production facilities and the destinations of their goods are located along railway routes.

The use of standardized containers is called containerization. The containers, called shipping, freight, or intermodal containers in formal literature, and often just “boxes” in the industry, are reusable and come in standard sizes. Most are of a height and width appropriate for transport by truck or train and come in lengths of 20, 40, 45, or 53 feet. Inside the container, freight is kept steady with lashes, synthetic webbing, and steel straps, and airbags are inflated to fill empty space to prevent freight from shifting during loading, unloading, and transport. Containers stack up and next to each other and lock in place, ensuring safe cargo so long as the freight inside has been properly packed.

Containerization is the bedrock of the modern shipping industry, allowing for maximum packing efficiency of freight transport vehicles (with no unused space left over because of containers of incompatible sizes) while significantly reducing the amount of time it takes to load a freight car. Most major cities and ports have a container terminal, often near an airport or seaport, where freight is received and transferred to the vehicles that will bring it to its final destination.

[Page 1133]One of the common types of train cars used for freight is the flat car, an open car consisting of a flat deck with some kind of mechanism on the sides for securing loads, which can range from simple tie-down points to sliding assemblies used to hold machinery in place. Flatcars are used for freight too large or unwieldy for enclosed cars, and in addition to the typical flatcar design, come in a variety of specialized freight designs, from “sky box” flatcars for transporting aircraft parts, bulkhead and centerbeam flatcars that have open tops but sturdy walls to keep cargo inside, even flatcars used to transport circus equipment.

Containerization has popularized the use of well cars, which are railroad cars designed to hold containers. Their name comes from the depression close to the rails that allows the container to be carried lower than on a standard flatcar. This allows loaders to stack two containers one on top of the other, with a center of gravity low enough that the load is still stable. Well cars are a distinctly American freight car, since European rails tend to have less manageable overhead clearances, often due to electrification. Another flatcar design that accommodates containers is the spine car, which uses lateral arms to support them.

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