In RR Lingo, the “Hump” is a hill in the middle of a large train yard that they shove cars over one-by-one so they roll down thru selective switches and speed retarders down into the ‘bowl’ of classification tracks below. This is the most effiicient way of sorting out cars in a large rail yard. In this photo, the Hump is seen next to the grove of trees in the middle. The hump has it’s own control tower off to the right that is in control of the whole operation.
So it’s “Hump Day”. I wonder where they will send us next? (Apologies to Camels everywhere)
http://www.railpictures.net/viewphoto.php?id=511890