In the late summer of 2003 I had the opportunity to take front facing photos from SEPTA R5 trains in both directions between Center City and City Line Ave, aka Overbrook Station. 20 years later I figured I would take the opportunity to look back and comment on some of the changes made to the old PRR Main Line within the Philadelphia City Limits.
Perhaps the biggest change to Philly area Amtrak operations has been the disappearance of Amtrak's mail and express services that were increased in the late 90's to attempt to replace declining passenger revenue. Philly served as a terminal for Amtrak's road railer service that were sent out behind the Pennsylvanian and Three Rivers. Business was seemingly robust enough that a third frequency was even proposed, however in 2005 the Amtrak completely exited the business after analysis showed both direct and indirect costs (ie delays) could not be justified by the freight revenue. Here Amtrak RoadRailer trailer #410115 sits on track #2 at the JO section of ZOO interlocking.

ZOO handled a good deal of wye moves to reverse road railer cuts before
and after their journey over the old PRR Main Line. Here we see a gray
painted Amtrak GP10 work engine at the head of the roadrailer cut. After
the passage of the SEPTA local it will head up on the oldVALLEY flyover
before shoving into the old New York-Pittsburgh Subway on the left to
initiate the wye move.
Silverliners II and III were still relatively plentiful in 2003 with
former Reading #9008 and PRR #263 sitting at the Overbrook maintenance
facility. This replaced the old Paoli Shoppes in 1994.

Changing direction we return towards Philly on track #1 and encounter
the famed Valley flyover. Part of the junction with the ill-fated PRR
Schuylkill Valley Branch, the flyover also allowed PRR Main Track 4 to
jump over the Belmont freight yard allowing Main Line freights to access
the yard through center track #2 and #3 at Overbrook. When the
Overbrook Maintenance Facility was built in 1994 it was placed on the
old track #4 alignment and track #4 was moved where the old freight yard
tracks used to be. The Valley Flyover and its truss were then only used
by R6 Cynwyd trains until the late 2010's when a new at grade
connection was built to the re-aligned track #4 at PAXON interlocking.
Here we can see the VALLEY interlocking eastbound signal bridge with the
amber 56R signal for track #2 and the newer 4E mast position color mast
signal for PAXON on track #4.
Here we see the old track #1 platform for the
52nd St station,
which served as an important transportation hub for West Philadelphia.
Years of urban decline and a shift to both cars and cheaper city transit
had gutted ridership and after a fire destroyed the station building
and elevator system in 1980 the station was closed. Both platforms
remained with the old Main Train #4 platform just visible at the upper
left cantilevered off the Valley Flyover viaduct. This would be later
removed with the track #1 island platform, which also served the
Cynwyd/Schuylkill Valley, increasingly covered in ballast. It was about
this time that the old track #1 platform saw its last official use to
transfer inbound Cynwyd passengers to a passing R5 train after a switch
failure.

The Main Line enters ZOO interlocking at Girard Ave at what used to be
the site of JO tower. Today the track on the old Valley Flyover to the
left has been removed, however here you can see how that track was
aligned with a straight shot from the NY-Pittsburgh Subway such that the
PRR's premier passenger trains like the Broadway Limited would not be
delayed as it bypassed 30th St Station after a stop at North
Philadelphia.
Speaking of ZOO tower, it is just visible through the Zoo Subustation.
While the tower is still in operation as of 2024, the black 1930's
vintage 128kv transformers were replaced starting in 2005.
Up through about 2005, ZOO tower controlled this SEPTA exclusive portion
of the interlocking where the R7 Trenton and R5 Paoli/Thorndale mix
after departing 30th St station. This would soon be spun off as its own
interlocking with modern amber LED position light signals replacing the
vintage finial topped masts.
Seen here at Powerton Yard, SEPTA Silverliner III #235 was one of a
handful converted to captive R1 Airport Line service with 2+2 seating, a
wide isle and luggage racks. After some time the Airport III's were
released to general service, but retained their plush interiors. #235
would ultimately participate in the final run of Silverliner II/III
equipment between Cynwyd and Center City with Reading car #9010 in 2012 .
Here we see the double slip switch across track #2 just west of 30th St
station for trains entering from the Powerton Yard ready service tracks.
The bridge in the background is for the West Philadelphia Elevated
freight line, now used by CSX.
I'll wrap things up as the train approaches the 20th St portal in BROAD
interlocking. Today a new apartment building is going up in what used to
be a parking lot immediately to the left of the photo and the old
westbound pedestal signals have been replaced by new ones from L&W.
I hope you found this little trip back in time interesting!