by theseaandalifesaver
I'm in Pittsburgh for the night into tomorrow. What's there to see without a car? Mostly looking for cool artifacts, abandoned stations, etc as opposed to just freight traffic.
Well, if you go south along the Mon, you can find some wild remnants (and some active bits!) of steel mills. In order from N to S, there are the Carrie furnaces in Rankin, the Edgar Thomson plant in Braddock, the ERW line in Mckeesport (which I think is now shut, but Mckeesport still has the CSX main), the irvin works and then Clairton Coke.
All of those locations have trains -- either CSX, NS or the Union Railroad. For constant action, I'd go to ET, 'cause it has not only URR switching the works, but the NS Pittsburgh line and the ex-B&O/PLE CSX line along the river (also, there are some epic bridges!)
That's what I've got!
Downtown P'burg has the NS Pittsburgh line, the Amtrak station and the other lines along the rivers.
Have fun!