Freight train

The earliest recorded use of rail transport for freight was in Babylon, circa 2200 BCE. This use took the form of wagons pulled on wagonways by horses or even humans.

Freight trains are almost universally powered by locomotives. Historically, steam locomotives were predominant, but beginning in the 1920s diesel and electric locomotives displaced steam due to their greater reliability, cleaner emissions, and lower costs.

Freight trains carry cargo in freight cars, also known as goods wagons, which are unpowered and designed to carry various types of goods.

Different types of freight cars may be used by a train, such as:

• Boxcar
• Tank Car
• Hopper Car
  • Covered Hopper Car
• Centerbeam Car
• Flatcar
• Intermodal Well Car
• Gondola Car
• Autorack Car

As of April 2020, there were 1.6 million rail cars in North America.

Freight trains often operate between classification yards, which are hubs where incoming freight trains are received, and then broken up, with the cars then being assembled into new trains for other destinations. In contrast to this type of operation, which is known as wagonload (or carload) freight, there are also unit trains, which exclusively carry one type of cargo. They normally operate directly between origin and destination points, such as a coal mine and a power plant, without any changes to the makeup of the freight cars in between. This allows cargo to reach its destination faster, and increases utilization of freight cars, lowering operating costs.

Unlike passenger trains, freight trains often do not follow fixed schedules, but are run as needed. When sharing tracks with passenger trains, freight trains are scheduled to use lines during specific times to minimize their impact on passenger train operations, especially during the morning and evening rush hours.