Tank cars are specialized railroad cars designed to transport liquids and gases. They are typically cylindrical in shape and made of strong materials to withstand high pressure. These cars can carry a variety of substances, including chemicals, petroleum products, and food-grade liquids. The design of tank cars includes safety features such as pressure relief valves and protective shields. They are an essential part of the freight transportation system, helping to move large quantities of materials efficiently across long distances. Proper maintenance and regulation ensure the safe transport of hazardous materials in these cars.