Over a year ago I posted still pictures of a backhoe climbing on top of a hopper car. (M of W Procedures, April 16, 2008) I have now come across a video of these backhoes in action. It is a marketing video from Herzog, the company that supplies these specially equipped machines which they call "Cartoppers."
http://www.youtube.com/watch?v=Q4toJA5EXcM&feature=related