THE SIGNAL BOX
NORTH PHILADELPHIA (formerly GD) tower and its adjacent North Philadelphia station were built in 1914 as an important step to improve passenger flow around the busy city terminal. Trains to/from New York from/to points west (like Chicago) would have to make a costly stub end reversal in Broad Street station in Center City Philadelphia. The North Philadelphia station complex was built so that through trains could bypass the city center and just head west directly at ZOO interlocking via the Pittsburgh Subway. To avoid putting off passengers the station was quite grand with a roadside carriage reception house, large main building and waiting area and two extra long covered high-level island platforms. North Philadelphia station hosted such famous trains as the Broadway Limited and Train Blazer, neither of which stopped down town. In accordance with PRR sensibility, the North Philadelphia complex (only 2.9 miles east of ZOO) was built at an existing junction. The Chestnut Hill branch was built in 1883 to literally spite the Reading Railroad and its own Chestnut Hill commuter line (today Chestnut Hill has some of best train service in the region which annoys SEPTA to no end as the two lines are basically redundant) and the branch connected to the Connecting Railway at what became NORTH PHILADELPHIA interlocking. NORTH PHILADELPHIA is basically a flat junction with the 2 track Chestnut Hill Branch joining the 6 track Connecting Railway.
The junction is before the main line platforms, so the branch gets its own low-level platforms. NORTH PHILADELPHIA also interesting that it is a full crossover and spawns two short "station tracks" that serve the outside of each island platform. The PRR numbers its tracks from North to South so in this case you would have the 0 track for local freight, northbound station track, northbound platform, main line tracks 1-4, southbound platform, southbound station track and 5 track for local freight. The western sub-interlocking contains a full facing point crossover and the eastern sub-interlocking, after the platforms, has a full trailing point crossover. The facing crossover also crosses trains onto the Chestnut Hill Branch. NORTH PHILADELPHIA's signature is its massive 9 at the east of its western sub-interlocking track signal gantry (which oddly enough only carries 3 signal heads) which stands out in any ground level or aerial photo of the interlocking.
Photograph by Mike Brotzman, 2002
NORTH PHILADELPHIA tower is of interesting design. It is
reminiscent of the Victorian brick-based, wood-topped tower design popular from
1890 to 1900 but has a fully concrete base - reinforced concrete being a new
and popular material around 1910. NORTH PHILADELPHIA has a sister tower
FAIR which we will discuss separately. Built in 1913,
NORTH PHILADELPHIA had a 47 lever US&S F13 EP machine with 45 working
levers. All the switches were pneumatically operated. A two man operation,
NORTH PHILADELPHIA was one of the most demanding towers in the Philadelphia
Terminal Division due to the number of conflicting moves it had to handle (ZOO
had 4 flyovers to help it get by).
Photograph by Mike Brotzman, 2002
Alas, NORTH PHILADELPHIA has seen a considerable twilight in its long life. While still an active tower, the North Philadelphia area really went to pot in the 1960's and became one of Philadelphia's worst urban slums. The long distance trains no longer made stops here, and the platforms and station began to rot. Even though the station is still served by two commuter lines (the R8 and R7 for you SEPTA fans) hardly anybody uses the station. In the late 1990's a considerable effort was made to rehabilitate the area. The rotting station (no longer an actual station) was restored to its former grandeur, the old rotting concrete platforms were cropped short for their new commuter function and re-poured with new canopies. Even the old tower itself was painted with a pro-Philadelphia mural, making it the most colourful tower in the country. Still, the station will probably never regain its former importance. SEPTA is seeking to close Chestnut Hill Branch station stop as only a handful of people use it each month. Several changes have been made to the interlocking as well. The double slip crossover onto the CHB has been replaced with traditional turnouts and Amtrak is starting to replace the old A-5 pneumatic point machines with electric M-3's. The old 0 track is now the Conrail Delair Branch, a class 1 freight line that was totally separated from NORTH PHILADELPHIA interlocking in 1995 or so. One of the most radical changes has been the elimination of the old No2 track through the interlocking. Laid with concrete ties and welded rail for hi-speed operation, the No2 track was severed between the lever 47 crossover and the lever 2 crossover with both turnouts (along with the lever 19 and 29 switches) being eliminated as such. So now, the old No1 track runs straight through on the old northbound station track and the No2 track runs through on the old No1 track along the platform. Since the line speed in this area is only 50 mph, Amtrak so no need for a platform-separated high speed track and was able to eliminate six turnouts (which reportedly cost $25,000 a year to maintain). Because of alignment asymmetries, the same operation can not be applied to the southbound platform tracks. Right now both the southbound station track and the 5 track are both in a horrible state of rust and either might just be removed one of these days.
It is also interesting to note that at the point of the
diverging junction is right where the Reading RR main line passes under both
the PRR main, the point of the platforms and CHB with four plate-girder bridges
that form sort of a tunnel. The Reading's competing North Broad Street station
is only a block away from the PRR's station, showing just how much the two
companies were in competition. Furthermore, the home signals for the Reading's
16th Street interlocking are almost right under the PRR bridge. 16th Street
interlocking, where the 2 track Norristown Branch (and passenger main line to
Reading) splits from the four-track commuter trunk, is much the same sort of
configuration as up above at NORTH PHILADELPHIA. In this picture we can see the
PRR bridge and if you look closely you can see the top of the last cars of a
freight train traveling the Conrail/CSX Delair Branch (former PRR 0 track). And
check out those A-5 pneumatic switches, probably one of the last new
installation of pneumatics in the country.
Photograph by Mike Brotzman, 2002
Comments about this article should be addressed to Mike Brotzman