Moving oil by train

Railroad tank cars are unloaded on a loop track at a refinery in Delaware City, Delaware. July 28, 2013. The refinery receives 110,000 barrels of crude oil a day, which is about 150 cars, or two trainloads. The shipments originate in the Bakken region of North Dakota, the center of a new American oil boom. With a shortage of new pipeline capacity, oil producers have been using rail as an alternative, and in some cases it's the preferred mode. (Curtis Tate/Tribune News Service via Getty Images)