Parts of a Railroad Car
- Each type of railroad car has its own special purpose.Joseph Sohm-Visions of America/Photodisc/Getty Images
Railroad cars haul freight across the country, transport urban residents on their daily commutes and provide scenic or historic transportation for tourists. Whatever its purpose, each railroad train consists of a string of cars that are either self-powered, as in the case of an electric railway, or pulled and pushed by the force of a railroad engine. - A railroad car's chassis serves as a frame for the base of the entire car. It must not only be strong enough to carry the weight of the rest of the car -- as well as any cargo it will eventually hold while in use -- but also light enough to allow a single engine to carry many such cars at one time. A railroad car chassis also includes the hardware for mounting the wheels.
- A railroad car's wheels engage with the track and keep it firmly mounted during operation and while at rest. The wheels are positioned on the chassis at a specific distance from one another, known as the gauge. A car with a certain gauge can only run on tracks of the same gauge. Standardization is very important for allowing engines to pull different types of cars and for a railroad network to serve trains over a large geographic area. Railroad car wheels use hydraulic brakes and may also feature electromagnetic brakes for emergency stopping.
- A railroad car's couples is the mechanical latch that allows it to attach to other cars. Most cars feature couplers at either and, allowing them to be inserted between two other cars. Couplers vary from one train type to another, which means that only cars with the right type of coupler can come together to form a full train. Couplers usually take the form or a hook and may use a chain as a back-up coupler. They may also include electrical connections for wiring cars together.
- A railroad car's body gives the exterior shape and overall structure. The body usually includes viewing windows in the case of passenger cars or loading doors in the case of cargo cars. Passenger cars may also include a lower compartment for storing luggage and an upper compartment with windows as the seating area. In other railroad cars, the lower portion of the body houses the electrical components that power the car.
- Electric railroad cars include electric motors and controls for self-propulsion. These controls receive power from the track or an overhead power line and convert it into motion through a linear induction motor and a transmission connected to the wheels through a series of mechanical linkages. Train cars may also use a generator, battery or wiring to supply power for interior and exterior lighting, a communications system, a climate control system or automatic doors.
