U.S. energy companies using rail to carry crude must conduct tests to help ensure the oil cargoes won’t explode or eat holes through tank cars after rising train derailments spurred new emergency rules. The order issued yesterday by the U.S. Transportation Department inspired some protests, but mainly confusion as refiners and producers tried to understand what the new requirements will mean to their operations and how broadly they will apply to shipments across the country. “What do you want us to do? What do you want us to test for?” said George Stutzmann, director of supply, trading and business development for oil refiner Alon USA Energy Inc. (ALJ) “I’m not really sure what this means or what they expect from us,” he said on the sidelines of a conference in Glendale, California , held to discuss the markets for oil by rail. Oil explorers including Continental Resources (CLR) Inc. […]