Help with ID'ing please

I was taking pictures in a RR graveyard the other day and ran into this guy. Can anyone tell me what I'm looking at?

Looks like a "fireless locomotive," also known as a fireless steam locomotive or a compressed air locomotive, depending on whether it uses steam or air. That particular one appears to be the steam type.

Wikipedia article: http://en.wikipedia.org/wiki/Fireless_locomotive

A lot of generating stations had them, for shoving coal cars around. If you arent going very far there is no need for a fire, or a fireman for that matter - instead of a boiler it has a thermos bottle, which can be filled with steam from the power plant boiler every so often.
nowadays many coal fired generating plants have diesel switchers.