Signals of the Reading and Northern Lehigh Line

Pennsylvania's Wyoming Valley, today home to the Scranton–Wilkes-Barre metropolitan area, was the West Texas or Saudi Arabia of the 19th century due to its massive reserves of Anthracite coal. A premium product demanding premium prices, anthracite coal was the way that industrializing America kept warm in the water months after the landscape had been stripped bare of trees for firewood. This is how the Wyoming Valley could fund the operations of three major railroads (the Lehigh Valley, Central RR of NJ and Delaware Lackawanna and Western) and similarly explain why those railroads seemed to evaporate without a trace when the world moved on to oil and natural gas.

Perhaps nothing optimized the uniquely American phenomena of direct railroad competition like the LVRR and CNJ, whose main lines were both functionally and in some places literally parallel. In the 1960's the anthracite collapse was well under way and a decade before Conrail, the CNJ had decided to throw in the towel and allow the LVRR to consolidate its operations to Scranton. North of its large yard in Lehighton, PA, the LVRR was able to stitch together a hybrid route, using better aligned portions of the CNJ over the Pocono mountain summit between White Haven and Laurel Run. Later, Conrail would choose to use the CNJ main line between Lehighton and Allentown creating a Frankenstein's monster "Lehigh Line" between NYC, Scranton and NY's Southern Tier. As the region's industry continued to shift, Conrail shoveled off the Lehigh Line north of Lehighton to the upstart Reading and Northern in the 1990's.

All this history is necessary to understand why the signaling on the Lehigh Line portion of the Reading and Northern's main line between Reading and Pittston, looks the way it does. Recently made visible by the series of R&N Iron Horse Rambles and its regular weekend Lehigh Gorge excursion service, the current signaling on the upper Lehigh Line reflect its unique history. In the 2024/2025 time frame I was able to gather enough content to put together a signaling guide covering the old Lehigh Line between Mauch Chunk and Pittston.

We begin at R&N's COAL interlocking, which was built new by them to support the R&N's "Main Line" concept between Reading and Pittston, but also its Lehigh Gorge tourist operations. Using a salvaged lattice cantilever mast, COAL connects what was the old CNJ route to the former LVRR route at the south end of the Lehigh Gorge.

Into the 2000's, Conrail (later NS) owned and operated this portion of the Lehigh Line as a double track Rule 251 main line. Traffic was so light that the southbound track was used bi-directionally with northbound trains needing to get a Form D, while the southbound track had its signal system taken out of service and used for R&M excursions and freights. NS moved first to convert the southbound track to Rule 261 (CTC) operation, with the R&N converting the former northbound track to Rule 261 in the late 2010's. Each track has a single ABS signal location in this line segment, NS at LVRR milepost 126 and the R&N's at its own milepost 124.

A quick note on Mileposts. In the Conrail era the Lehigh Line would alternately use legacy mileposts from the CNJ, LVRR and LVRR Mountain Cutoff. The Reading and Northern switched this to its own mileposts that continues the Reading Company chaining from the old Reading Terminal.  Somehow this has managed to match up with the legacy CNJ mileposts within a few tenths, but LVRR mileposts are off by several miles. I will be using the R&N mileposts for most of this article.
 

CP-M&H JCT marked the transition between double track ABS and single track CTC through the Lehigh Gorge and, starting in the 1990's, the start of the Reading and Northern lease. CP-M&H JCT was re-signaled by Conrail around the time of the lease and has the typical Conrail hallmarks of a CorTen steel relay hut and color tri-light signals. What sets CP-M&H JCT apart is the use of "budget" L&W brand modular signals in the tri-lights. It's entirely possible that the lease arrangement had Conrail responsible for some portion of the signaling system (the interlockings still appear in CR's 1997 signal charts) resulting in signaling that looked Conrail, but with different hardware.

When the R&N lease came into force the arrangement still created a gap in the R&N's conceptual Main Line between Mauch Chunk and CP-M&H JCT where they had to run under Conrail rules and dispatching. When NS finally transferred the northbound track to the R&N in the mid-2000's, they were so thrilled to be in total control that they built a new interlocking back-to-back with CP-M&H JCT named INDEPENDENCE.

The mast is for CP-M&H JCT and the dwarf for INDEPENDENCE.

CP-M&H JCT wasn't an isolated re-signaling as it appears that all of the signaling in the Lehigh Gorge proper was replaced around the time of the lease. This was possibly due to the desire to replace any pole line based system due to the inaccessible nature of the right of way in the Lehigh  Gorge. The new Conrail style signaling again reflected the economic decline of the region with a shift to extra long 3-4 mile signal blocks versus the standard 1-2 mile length. ABS signal locations in the gorge are at R&N milepost 130, 133/134 and 138. The 133/134 location split the Jeddo tunnel for visibility reasons.

134S from behind

It appears that the pole line was retained to supply 440v power to the signal locations, however it is unclear if this supply is still in service.

The end of the 90's re-signaling is at the controlled holdout signal CP-WHITE-HAVEN, which is just a few miles shy of the alignment change from LVRR to CNJ. I do not currently know the status of the CNJ main north of Lehighton prior to 1965, but the re-signaling boundary is surely related to the relative utility of the CNJ signaling versus the LVRR signaling. One possibility could be a post-war investment in CTC by the CNJ to cut costs that exceeded the standard of whatever the LVRR was up to at the same time. 

A Superb Web Resource for Railroad Defect Detectors

 It's not often that one gets a new web resource that isn't annoyingly flawed (yeah you Open Railway Map) or compromised by enshitification (like Gas Buddy). I might be late to the party on this, but Defectdetector.net has somehow managed to document every railroad defect detector in North America and then provide the information via a clean Google Maps type interface. Not only do we have both large and small railroads included, each pinned location has the full set of details about the detector including make, model and, if available, a recording of the output. 

Of course nothing is perfect so if I had to provide feedback I would recommend ways to map defunct detectors and historic recordings. I would also enable filtering based on detector details like type (HBD, DED, etc) and also collect data on the information contained in the radio readouts like axle count or temperature. 

One specific usability issue is the SP/DRGW practice of equipping every automatic signal location with a physical impact stick style DED that is attached to the signal system, as opposed to a radio readout. This results in many Union Pacific routes having every ABS signal location pinned as a DED. While this can be helpful in some sense, it also clutters/slows the interactive map interface.  

While this site represents an amazing resource, I worry it will not last as Google maps integration isn't free. Airraidsirens.net, which I assure you is a thing, makes use of a Google Maps layer that fully lives in the Google ecosystem.

View From the Head End

Recently a Youtube channel appeared called View From The Head End, that was posting complete head end cab videos from Amtrak trains. These were not the more typical "reversed" videos taken from a rear facing window, but legit head end videos that documented both signals and signaling. More significantly the videos were up to date, likely all recorded within the last couple of years. My first thought was that someone had recently retired because since the early 2000's Amtrak (and I assume most railroads) have been somewhat anal about employees moonlighting as content creators. Well, I guess they hadn't retired because if you haven't noticed the link is broken and the entire channel is gone.

While the practice of workers recording head end videos to feed Youtube channels seems to be quite common in Europe (where I should add its practically impossible to fire railway workers), there are surprisingly few full-line inside-the-cab videos from North America. Up through the early 2000's there was a cottage industry head end videos being sold at "Train Shows" on either VHS or DVD. Some of these were professionally produced by outfits like Pantex, while others were made by AV savvy employees with access to a Hi-8 camera and a capture card. Unfortunately the rise of The Internet brought this wildcat era of video to an end as the speed of information made it easier for previously underground works to become known by regulators, the media and lawyers.

In the early years of Youtube, spotty internet connections and the more ephemeral nature of online data encouraged folks to save off important video content like head end videos. This practiced has decreased as the internet became more reliable overall, however when you find something that seems too good to last, you might want to leap into action and save off a local copy. In a sliver of good news I was able to watch some of the videos before they vanished and resolve some outstanding signal questions I had.

Meanwhile if you'd like something similar to watch I can provide two pairs of videos from the late 2000's covering an Acela trip from Boston to NYP (head end) and the Former Conrail Chicago Line between Buffalo and Albany (rear facing). Intended for Train Show (tm) sale both had been scrubbed of ambient cab sounds and the Chicago Line also being video reversed (which I was able to undo). Although mostly silent, the Chicago Line video in particular captures the NYC/Conrail signaling immediately before its complete replacement ~2010.

Caltrain EMU Cab Video Signal Survey

After the loss of the Caltrain gallery car railfan window I wasn't holding out much hope for having anything worthwhile to do on the Caltrain system as European spec rolling stock typically come with bulkhead style cab doors. However videos have been appearing showing that front facing views are present. This have the added benefit of providing a southbound signaling survey as previously such photos and videos were only possible facing northbound. 

I have already covered changes between San Jose and Tamien and can now confirm that the remaining Southern Pacific style signals in the terminal area have been replaced. The good news is that the few SP target type signals on the north end near the tunnels are still in place although unfortunately the triple unilens stacks at CP-COMMON were replaced by a standard LED modular type in a three virtual head configuration. Another note is how bad the sight lines for some of the wayside mast signals have become. This makes clear the advantage for position lights and cab signals in electrified territory. Although the freight spec PTC system Caltrain uses is kinda like a cab signal, moving to a Rule 562 coded track circuit arrangement might save them a lot of trouble. 

You can watch the video for yourself, but despite the hype the weekend and daytime local service is still highly underwhelming with little in the way of interesting signaling or routing. Although faster than diesel, the speeds are still slow compared to a limited stop run and unfortunately these have been largely curtailed with the fastest peak period trains still 3 or 4 minutes slower than the famed 4 or 5 stop Baby Bullets of the 2004-2024 time period.

Inside the US&S A-5 Switch-Point Machine

This blog devotes a lot of coverage to the plight of the pneumatic switch-point machine and its long decline since its heyday between 1930 and 1955, but apart from the ka-chug--woosh sound, what makes them distinctive? Well its actually their simplicity compared to their electric counterparts and its that simplicity that made them so competitive with electric point machines despite the overhead of making and distributing compressed air. 

Above we see a Union Switch and Signal model A-5 pneumatic point machine. (An earlier A-1 model also existed and you can tell them in photos because the housing looks like a miniature Quonset hut.) At one end we see the double acting air piston, at the other we see a connection for the control circuits and a blind tube without an air piston, and in the middle we have a fairly plain looking box.

Next lets quickly go over a standard power operated switch layout using some casual terminology. Moving away from the camera we have a stretcher bar that provides rigidity. Next is the throw mechanism that transmits force from the point machine to the points via a rod. This uses a slack coupling so the point mechanism can begin to move and break the static friction. Finally we have the detection rods that accurately detect if the points are hard against the stock rail and communicate that state to the signaling system.

Exposed US&S A-5 pneumatic point machine.

The mechanism can be set up for operation from either side.

Here we see a naked A-5 without its cover on showing off the simplicity of the action. The air piston connects to an action bar which runs through a crank mechanism that transmits force to the point rodding and also its positional state to the circuit controller.

The crank (left) and circuit controller (right).

The coupling between the air piston and the action bar.

The air piston, these came in 3 inch and 5 inch diameter models.

The throw rod couples to the crank assembly. In the photo below this connection is the bolt hole on the stubby arm below the pivot pin. The detection rods sit under the circuit controller have the golden coated nuts on them.

The circuit controller pulls double duty, detecting both the position of the points for the signaling system and also the position of the action bar / air piston, which is sent to the style CP air value unit to cut the flow of air and dump the pressure in the piston. We can see the hind end of the action bar that is given room to push outward under the covering.

The upper two rods provide the actual point detection while I believe the lower rod that extends through the mechanism provides a physical locking function in conjunction with the action bar. When this technology was new that rod would serve the role of the familiar facing point lock.

The goal of the mechanism is to lock the switch point securely against the stock rail even when air pressure in the cylinder has been exhausted, but allow smooth movement of the action bar and points when air is admitted to move the piston. A similar concept is present in firearms where the bolt is locked against moving rearward by the force of gases in the chamber, but is able to be easily unlocked via motion in a different axis.

While I have personally captured video of an A-5 point machine performing a throw cycle, it only showed the points moving along with the admittedly cool sound. However I recently came across a different video from a UK rail museum that has their own flavor of a US&S A-series set up for live demonstrations. Still popular on the London Underground, these instances are commonly used without the protective cover which allows visitors to actually see how the mechanism functions. This flavor of Westinghouse point machine is intended to be set between the rails and has the throw rods moving through the mechanism. The extra circuit controller on the back provides feedback to the pneumatic value.

 

MARION (AC) Tower's Missing CTC Machine

A couple years ago the folks at the Railroad Media Archive Youtube Channel posted a video covering the last months of Conrail's MARION (formerly AC) tower in Marion, OH.  Originally built by the Erie Railroad in 1902 and located at the parallel crossing of the CSX Toledo Sub and NS Sandusky Branch with the Conrail Indianapolis Line, the video shows off the tower's GRS/Taylor Model 2 interlocking machine with its proto-pistol grip type levers. At the time, MARION's operator only had control of the local interlocking, which seemed reasonable considering that they had to deal with train movements on separate railroads. However a new video from Railroad Media Archive shows a whole other side to operations at MARION. Sometime after the closure of the Eire main line around 1978, MARION gained CTC control of the Indianapolis Line between Belelfonte and Galleon (CP-BURT) with a 80's "Traffic Master"-style CTC panel and interface situated behind the operator's desk controlled by a compact interface of action keys and a numeric keypad.

In the posted video full attention is given to this CTC panel, with MARION's legendary lever frame barely making an appearance. We watch freight trains slowly cross MATION's territory while the operator discusses his duties and lines routes while text annotations appear in the video's side bars. It is mentioned that the tower would be losing its CTC territory by the end of the year (1989). 

The video captures that fleeting period between classic towers and train order offices, and modern point and click computer dispatch interfaces. By the time MARION was fully closed in 1995, all traces of its 1980's CTC territory had been removed. 

New Pittsburgh Line Interlockings

Norfolk Southern's ability to extort the state of Pennsylvania to add additional passenger frequencies on the old Pennsylvania Railroad Main Line is resulting in a slew capacity expansion projects in the form of "new" interlockings and additional tracks. I use the quotes as some of the interlockings are actually restorations of those that existed within living memory, but were removed for the sake of efficiency. 

Restoration of the old SG and NY interlockings.

The first phase of this work is underway at the set of the old SG interlocking west of Johnstown. The new crossovers will allow Amtrak trains to use both sides of the single island platform that serves tracks 2 and 3. Currently if track #2 is unavailable, trains must use main track #3 which follows the slower route of the old Sang Hollow Extension for 15 miles between CP-CONPIT and CP-C since SG interlocking was removed by Conrail around 1980. 

Returning 3 tracks to the Rockville Bridge

Additional changes include the restoration of CP-WEST PITT, removed by NS around 2007, a new crossover on the West Slope near the old NY interlocking between CP-SO and CP-MO, a new third main track between CP-ALTOON and CP-ANTIS, a new interlocking on the Altoona raceway between CP-ANTIS and CP-GRAY and another third main track between CP-BANKS and CP-HARRIS, which would restore a third track to the Rockville Bridge which was lost around 2000. Summary details of the project can be found here with a 2021 report providing more details of the track and interlocking changes. Note the report is not gospel as photos of the new CP-SG show parallel crossovers instead of a universal crossover.

Although no longer equipped with Conrail/PRR era signals, the NS Pittsburgh Line is still Rule 562 cab signaled with "C" lamps, so more interlockings means adding signals where automatics were previously removed.