A railroad car (or, more briefly, car), also known as an item of rolling stock in British parlance, is a vehicle on a railroad or railway that is not a locomotive - one that provides another purpose than purely haulage, although some types of car are powered. Cars can be coupled together into a train, either hauled by a locomotive(s) or self-propelled.
Most cars carry a revenue load, although non-revenue cars exist for the railroad's own use, such as for maintenance-of-way purposes. Such uses can generally be divided into the carriage of passengers and of freight.
"Revenue" cars are basically of two types: passenger cars, or coaches, and freight cars or wagons.
Passenger cars, or coaches, vary in their internal fittings:
Seating is usually three, four, or five seats across the width of the car, with an aisle in between (resulting in 2+1, 2+2 or 3+2 seats) or at the side. Tables may be present between seats facing one another. Alternatively, seats facing the same direction may have access to a fold-down ledge on the back of the seat in front.
- If the aisle located between seats, seat rows may face the same direction, or be grouped, with twin rows facing each other. Sometimes, for example on a commuter train, seats may face the aisle.
- If the aisle is at the side, the car is usually divided in small compartments, each with two seat rows opposite to each other, with 6 or 8 seats.
Cars usually have either air-conditioning or windows that can be opened (sometimes, for safety, not so far that one can hang out). Toilet facilities are also usual, though the setup varies.
Other types of passenger car exist, especially for long journeys, such as the dining car, parlor car, disco car, and in rare cases theater car (picture). Observation cars were built for the rear of many famous trains to allow the passengers to view the scenery. These proved popular, leading to the development of dome cars multiple units of which could be placed mid-train, and featured a glass-enclosed upper level extending above the normal roof to provide passengers with a better view.
Sleeping cars outfitted with (generally) small bedrooms allow passengers to sleep through their night-time trips, while couchette cars provide more basic sleeping accommodation. Long-distance trains often require baggage cars for the passengers' luggage. Historically in European practice it was common for day coaches to be formed of compartments seating 6 or 8 passengers, with access from a side corridor -- corridor coaches fell into disfavor in the 1960s and 1970s partially because open coaches are considered more secure by women traveling alone.
Another distinction is between single- and double-decker cars. An example of a double-decker is the Amtrak superliner.
A 'trainset' (or 'set') is a semi-permanently arranged formation of cars, rather than one created 'ad hoc' out of whatever cars are available. These are only broken up and reshuffled 'on shed' (in the maintenance depot). Trains are then built of one or more of these 'sets' coupled together as needed for the capacity of that train.
Often, but not always, passenger cars in a train are linked together with enclosed, flexible gangway connections that can be walked through by passengers and crew members. Some designs incorporate semi-permanent connections between cars and may have a full-width connection, making in essence one longer, flexible 'car'. In North America, passenger equipment also employ tightlock couplings to keep a train reasonably intact in the event of a derailment or other accident.
Many multiple unit trains consist of cars which are semi-permanently coupled into sets; these sets may be joined together to form larger trains, but generally passengers can only move around between cars within a set. This 'closed' nature allows the separate sets to be easily split to go separate ways. Some multiple-unit trainsets are designed so that corridor connections can be easily opened between coupled sets; this generally requires driving cabs either set off to the side or (as in the Dutch Koploper) above the passenger compartment.
Freight cars or (UK: "wagons") exist in a wide variety of types, adapted to the ideal carriage of a whole host of different things. Originally there were very few types of car; the boxcar (UK: "van"), a closed box with side doors, was among the first.
Common types of freight cars include:
- Autoracks - (also called auto carriers) specialized multi-level cars designed for transportation of unladen automobiles
- Boxcars (or vans) - box shape with roof and side or end doors
- Refrigerator cars (or, colloquially, Reefers), a refrigerated subtype of boxcar
- Flatcars (or flat) for larger loads that don't load easily into a boxcar. Specialised types such as the depressed-center flatcar exist for truly outsize items or the Schnabel car for even larger and heavier loads. With the advent of containerised freight, special types of flatcar were built to carry standard shipping containers and semi-trailers. Some allow containers to be stacked two high (double stacked).
- Gondolas with an open top but enclosed sides and end, for bulk commodities and other goods that might slide off
- Hopper cars, a gondola (rail) with bottom dump doors for easy unloading of things like coal, ore, grain, cement and the like. Two varieties; open top, and closed top.
- Tank cars for the carriage of liquids
- Slate wagons - specialized freightcars used to transport slate
- Stock cars for the transport of livestock
- Well cars - specialized cars designed for carrying shipping containers. These have a very low bottom floor to allow double stacking, and articulated 3- and 5-car sets are common.
The vast majority of freight cars fit into the above categories.
- Cabooses (or guard's vans or brakevans) which attach to the rear of freight trains to order to watch the train and assist in shoving moves.
- Maintenance of way (MOW) cars, for the maintenance of track and equipment
- Handcars, which are powered by their passengers
Military armoured trains use several types of specialized cars:
- artillery - fielding mixture of guns and machine guns
- infantry - fielding machine guns, designed to carry infantry units
- machine gun - dedicated to machine guns
- anti-air - equipped with anti-air guns
- command - similar to infantry wagons, but designed to be a train command center
- anti-tank - equipped with anti-tank guns, usually in a tank turret
- Platform - unarmoured, with purposes ranging from transport of ammunition or vehicles, through track repair or derailing protection to railroad ploughs for railroad destruction.