Covered hopper

A covered hopper is a railroad freight car designed for carrying dry bulk loads, varying from grain to products such as sand and clay. The cover protects the loads from the weather - dry cement would be very hard to unload if mixed with water in transit, while grain would be liable to rot if exposed to rain. However, they are unsuitable for perishables such as fruit or meat - these are transported in refrigerator cars, where they can be kept at low temperatures, as well. Similar to an open hopper car, covered hoppers tend to contain two to four separated bays. Each of these can be loaded and emptied individually, with access at the top to load the materials and visible chutes at the bottom for unloading.