It may be hard to believe, but in today's world of faster, stronger, smarter and cheaper, the good old train system remains the most energy efficient way to move goods from one place to another. But the locomotives that pull these trains aren't the clunky, dirty, primitive steam engine workhorses depicted in old western movies; no, these machines are a sophisticated integration of power production, thermal management and system control technologies. Some of the recent advancements include dual fuel (diesel and natural gas) operation, the capability to meet U.S.