Can you tell us a little more about it? Where is it located, what are the surroundings, what are the engravings located on the lid? Otherwise, it doesn't look railroad related. Of course, I'm not a railroader, but a railfan.
Next stop, Willoughby ~el Jefe ("Jeff Smith Rules") :: RAILROAD.NET Site Administrator/Co-Owner
What Railroad, and can you be more specific as to location ( such as CSX near Buffalo, NY, etc.). I am thinking it might be a PTC Transponder, but the photograph is too focused in to see the location relative to the track.