Saturday, July 6, 2024

Pittsburgh Line Points of Interest

While NS's move to embrace cab signaling without fixed wayside signals (which I will refer to as Rule 562) on the former Conrail Pittsburgh Line was a big loss for the casual observation of railroad signaling in action, there remain a few points of interest between Harrisburg and Pittsburgh that I was able to identify during a journey on Amtrak's Pennsylvanian in 2023. If you find yourself railfanning in that corridor, you might want to check them out.


The first thing worth pointing out are the few remaining number plated intermediate signals that still exist along the line. There is one on the Main Line adjacent to CP-HOMER due to the retention of Rule 261 operation between CP-ANTIS and CP-ALTOONA. There are also a pair of autos on the Altoona Yard leads west of CP-ANTIS.


Another distant type automatic exists on the South Fork Secondary adjacent to the Main Line near CP-SO for trains approaching CP-W.


We've all seen the signed "signal indication points", but did you see the two different SIP's located right next to each other between CP-MO and CP-AR/UN near Gallitzin due to slight differences in the mileage chaining between the two alignments.


Also present are half size SIP huts like this one near CP-MARY in Marysville, PA that serves only a single track.


Of course when a SIP shares a relay hut with an interlocking why not sign them both like at CP-JW in Johnstown.


Finally we have the mystery of those places where full speed three headed interlocking signals are still present. When the Rule 562 operation went in, many back-to-back interlockings that supported signals like Medium Approach Medium (R/Y/G), saw their replacements only support Medium Clear (R/G) with the cab signal being held at Approach Medium. 
 

However a few locations on the Pittsburgh Line retain full speed three headed masts. The first are obviously where trains might immediately exit Rule 562 territory such as at CP-ATOONA, CP-ANTIS, CP-ROCKVILLE and CP-BLOOM, or are not in Rule 562 territory at all (CP-WORKS).


However around Pittsburgh we also see three headed signals at CP-PITT and the former CP-EAST PITT. These might exist for the benefit of certain area short lines that might be able to run unequipped locomotives, or to provide better advance routing information for shortline and Passenger movements that need to use specific tracks and/or get off the Pittsburgh Line.


Anyway, keep all these locations in mind if you are looking for something a little bit extra signaling wise to capture in your photos.

2 comments:

  1. Its my understanding that you still need three headed signals where a control point might have medium and slow speed crossovers, or the need to put up a slow approach for a short block between CPs (like the Pitts). The signaling around Altoona was done in 2014 as part of the Alto replacement. So when they did the PTC upgrades, they could just add the PTC to the existing already compatible equipment. Hence you have the only automatic between Harrisburg and Pittsburgh.

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    1. There are some other locations with back-to-back interlockings that lack the third head, but there is a SIP in between.

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