I love Fairmont Park. It's actually right alongside I-76. The road through it is MLK Drive. I usually use the Montgomery Drive exit off I-76. It is important to note that MLK is closed on the weekends for bicyclists.
Here is one of the locations: 40.004246,-75.192726
This one is on the other side of the river, off Kelly drive. 40.00598,-75.190646
Zoo is hard to railfan. It's sort of a perfect storm of bad. Limited angels, lots of fences, and a
rough part of Philly.
You can get semi-decent views here: 39.971891,-75.19806 and along Mantua Ave: 39.967303,-75.193156 with the later being on the rougher side of Philly. (A prime example of "wrong side of the tracks.")
If you have a few extra minutes in Philly, I strong recommend South Street.
http://www.railpictures.net/viewphoto.p ... 76&nseq=26" onclick="window.open(this.href);return false; It's a long bridge over the tracks, I-76, the river, and the CSX line.
Now, if you have also some time, I will tell you about my secret location:
http://www.railpictures.net/viewphoto.p ... 43&nseq=25" onclick="window.open(this.href);return false;
The GPS is around 39.976471,-75.192713 You have to climb the outcropping, but it is doable with no special skills or equipment.