Illinois Central Gulf GP-26 #2601, Chicago, IL, January 1982, photo by Chuck Zeiler
What time is it? There is a clue in this photo.
A full description of a GP-26 is at this link:
http://www.railroadforums.com/photos/showphoto.php/photo/47489
There is much to see in this photo, for instance, I assume that the station wagon parked on the embankment (below the yellow Railbox boxcar) belongs to the bridge tender, but the door on the shed on top of the bridge is open, so either he is careless, or the bridge is unattended. I think that might be Ashland Avenue passing below the tracks. The bridge carries the rails over an unnamed canal off the South Branch of the Chicago River. Looking at maps of this era, the unnamed canal appears to end at the north side of the Chicago Stockyards. There are plenty of signalheads at the entrance to the bridge, I count eight, so perhaps the building on top of the bridge was also a dispatch point in earlier days. This is a serious bottneck to the system, and correct me if I'm wrong, but the Santa Fe also had to drag their Super Chief's across this bridge.
The time is 12:12 PM, or so, if you believe the clock hands below the water tower in the upper left of the frame. I shot the photo, and I did not see the clock hands for 25 years. Was the clock functioning when I shot this photo, I don't know. Here's a link to a photo of another view of the bridge.
http://illinoiscentral.net/rosters/ic9639.html