http://www.articleheaven.net en-us editorial@articlealley.com Hopper Cars: Hopper cars are open-topped cars with high sides and ends. Their bottom has hoppers or chutes that can be opened. The grain, flour, or cement would fall down into storage bins beneath the cars. This makes for quick unloading because the ... http://www.articleheaven.net/coal-to-oil-and-gas-873378.html 29th April 2009