The covered hopper is an enclosed car with a sloped interior floor that funnels bulk dry commodities to bottom discharge gates. Hatches along the roof allow top-loading of grain, plastics, or cement. Two broad classes exist: small-cube cars of roughly 3,000 to 4,000 cubic feet for dense commodities like cement and fertilizer, and large-cube cars of 4,500 to 6,000 cubic feet for light-density grain and plastics. The bottom outlet gates are pneumatically or gravity-discharged at destination.
Approximately 2,900-4,000 cu ft; typically 3-bay design for dense commodities like cement, potash, and fertilizer.
Approximately 4,500-5,800 cu ft; typically 3-bay or 4-bay for grain, plastic pellets, and other light-density bulk commodities.
Air-slide floor with pneumatic unloading for fine powders such as flour, starch, and cement that would otherwise bridge.
Covered hoppers dominate North American grain and fertilizer logistics, moving unit train volumes between elevators, mills, and export terminals. They also serve chemical plants shipping plastic resin and manufacturers requiring bulk cement delivery.