This excerpt taken from the CSX 10-K filed Feb 15, 2007.
Freight Car Fleet
CSXTs freight car fleet consists of five main types of cars. Gondolas support CSXTs coal and metals markets and provide transport for woodchips and other bulk commodities. Flat cars are used for shipping intermodal containers and trailers, while box cars transport commodities that must be protected from the weather, such as paper products, appliances and building materials. Insulated boxcars deliver food products, canned goods, and certain beverages.
Additionally, CSXT has open-top hoppers, which handle heavy dry bulk commodities such as coal, coke, stone, sand, ores and gravel that are resistant to weather conditions, and covered hoppers, which have a permanent roof. Lighter bulk commodities such as grain, fertilizer, flour, salt, sugar, clay and lime are shipped in large cars called jumbo covered hoppers. Heavier commodities like cement, ground limestone and glass sand are shipped in small cube-covered hoppers. Finally, other cars owned or leased on the network include, but are not limited to, center beam cars for transporting lumber and building products.
At December 2006, CSXTs owned and long-term leased freight car fleet consisted of the following:
At any point in time, over half of the railcars on the CSXT system are not owned or leased by CSXT. Examples of these are railcars owned by other railroads (which are interchanged to CSXT), shipper-furnished or private cars (which are generally used only in that shippers service) and multi-level railcars.
Multi-level railcars are used to transport finished motor vehicles, such as sport utility vehicles and light trucks in bi-level cars, while sedans and smaller automobiles are shipped in tri-level cars. Multi-level railcars are owned jointly by participating railroads, and the fleet is managed as a nationwide pool to serve the automobile industry. As noted, in certain markets, CSXT uses railcars supplied by railroad customers. For example, chemical shippers typically supply tank cars for the transportation of hazardous and non-hazardous materials.