Search This Blog

Tuesday, June 13, 2017

PRR Main Line Trip Report

Well I just got back from a trip surveying the old PRR Main Line between Huntington and Lewistown and I have a few updates to share regarding the extent of the re-signaling project and other related news.  First, to summarize, new NS Darth Vader signals and Rule 562 operation is going in on the PRR Main Line between CP-BANKS and CP-ANTIS.  Nothing about that has changed, although I did notice the following details.

First, at CP-HUNT, new signals are up, but the PTC antenna is not, so there is still a bit of work to do.  The pneumatic point machines are still in place with no sign of replacement, so that's good.  The adjacent HUNT tower is now signed as the home for the local Chamber of Commerce with no mention of the museum that should be located there, so that was a bit worrying.

In terms of modifications, the new eastbound cantilever at CP-HUNT has been placed several hundred feet east of the existing PRR PL masts where they are visible around the curve.  I suspect that thanks to cab signals and PTC, NS is less worried about signal sight lines than Conrail had been.

The MP 200 automatics, seen above in 2009, had a fresh coat of paint, just in time for them to be removed for the Rule 562 operation.

The westbound dwarf at CP-JACKS is getting replaced by a cantilever mounted, slow speed, high signal, but adjacent to the signal bridge was an old school signal power transformer mounted on a short pole, complete with PCB stickers and everything!

An interesting feature that I first saw at CP-HAWSTONE also turned up at CP-McVEY and CP-LONG.  This is the use of the old pneumatic air line to deliver gas to the direct burner point heaters.  It does not appear that this system is being retired.  Also, the old air-line at CP-JACKS was still in place, even though those air switches were removed over a decade ago.

I can also confirm that new signal equipment appears to be going in all the way up to CP-ANTIS so anyone who wants pics at CP-TUNNEL, CP-GRAY and the famous Fostoria signals, better go get your photos soon.

Finally, on a different PRR Main Line, the one between Philadelphia and Washington, Rule 562 'C' boards have appeard at interlockings between PRINCE and REGAN, inclusive.  It looks like Amtrak will be re-signaling the "commuter free" zone, possibly for higher Acela Express speeds.

Monday, June 5, 2017

Relay the Hut

Ever since the demise of towers, railroads have needed a dry, climate controlled place to house the relays and other sensitive electronics that run the remotely controlled interlockings.  Since their first appearance in the 1920's and 30's, they have evolved quite a bit over the ensuing century.  This post will attempt to show some general trends in relay hut (or bungalow) design.

The earliest solutions involved building mini-buildings out of brick, cinder blocks or poured concrete.  These buildings would have climate control in the form of small heating plants and often a work area for C&S employees.  The building above at CP-HOLTWOOD on the port road also housed an air plant for the pneumatic switches.

This more modest concrete design was a favorite of the PRR during its 1930's CTC projects.  Here at CP-SHOCKS, the walls are poured slabs.

Moving on to the 1950's it became apparent that building solid walled little buildings might be a little overkill.  While a prefabricated approach was sought, the state of the art still involved a poured concrete foundation even if the walls and roof were of lighter sheet metal.  This hut adjacent to COLA tower was actually a C&S workshop, however it is similar in construction to early CTC huts used by the Santa Fe and others.

Here is a smaller version of the hut at COLA used for the 1950's Buffalo Line CTC project.  The builder's plate pretty much says it all.

The 1950's also brought the pre-fabricated concrete structure made from pre-poured concrete panels.  These examples are from the Reading and Erie railroads respectively.

Concrete mini-huts were also popular on a number of western roads like the SP and ATSF.  Note the raised footings that represented a lower cost innovation over the solid poured foundation and also indicate that these were indeed pre-fab structures.

Tuesday, May 30, 2017

To G or not To G

A lot of people like to throw the term "G Head" around as a generic reference for signals that have a circular target surrounding a triangular arrangement of three signal lamps.  Also known as target signal, target color light, V light or tri-light, this style of signal doesn't really have a good name so people tend to gravitate to the professional sounding "G Head" moniker.  However, instead of being a generic term for that style of signal, it is actually a specific model of signal produced by the General Railway Signal corporation.  You can't even say that it was the dominant producer of said signal type as US&S had their own competing products that tended to be purchased by railroads US&S bias towards.  As time went on even more producers entered the market so using G Head without any regard for the manufacturer is not only imprecise, but also inconsiderate to the actual brands involved.  So below is a quick field guide to tri-light signals to help you tell the G Heads from the Generics.

First up is an actual GRS Style G color light signal.  Note the partly rounded lamp housing and the GRS brand spelled out in words.  These were made popular by the New York Central railroad, but were also heavily employed by the Rock Island, MoPac and others. 

US&S responded with a couple of models.  Their first attempt, the Style TR, used a compact, three section lamp housing covered by a single detachable backing plate.  These are becoming quite rare, although Amtrak installed a bunch new at Chicago Union Station in the 1990's.

US&S later updated this style to be more like the GRS G-Head with a single piece lamp house.  Christened the CR-2, it was a favorite of Conrail and other northeastern commuter railroads that were willing t pay more for a brand name.

Of course Safetran couldn't help but make a knockoff.  Dubbed the NR (I think), it did show some innovation by having a split door on the lamp house.  

Of course even at Safetran prices railroads can't be bothered with purchasing large cast iron signals so to accommodate them, Safetram offers a V target configuration for its ubiquitous scallop shell modular signal lamps.   This produces a large gap in the center of the signal target, which is the easiest way to identify this style of hardware from the front.

I mentioned that other suppliers jumped on board back in the 80's and 90's.  This triangular single housing model was made by an outfit in Louisville, KY and was purchased by Amtrak for its 90's color light needs.

A decade later, this boxy LED modular Safetran knockoff is popular on Amtrak related projects throughout New Englande. 

Of course there are a few others in the V arranged modular lamp category, but I think you get the point.  Hopefully you've learned something and will be able to correctly give every style of tri-light signal its due.

Tuesday, May 23, 2017

Signal Power Save Mode

I am sure that many of you are familiar with "Approach Lit" signals, where the signal lamps only light up when a train is in the block approaching it (or sometimes, in CTC territory, leaving it).  This feature, still employed today, was originally used when block signals were lit by consumable battery power and hung around to conserve bulb life as well as battery power in times that pole line power failed (which was often).  Well it turns out that there is in fact a third option between leaving signals on at full brightness all the time or only lighting them up when a train is approaching and, at least as far as I can tell, it was a Conrail thing.

I first noticed this at CP-103 on the now-Amtrak Hudson Line where one of the 4 approach lit signal heads maintained a low level glow, in this case of the red variety, with the rest remaining completely dark.  

Of course when a train approached they lit up with their full intensity.  Strangely, the southbound masts did not exhibit the same type of power save feature, with all lamps remaining dark.

I thought this was a one off until a few weeks later when I noticed the same effect on the eastbound signal at CP-BLANDON on the former Conrail Reading Line. 

While the Hudson Line was re-signaled in the 1970's or early 1980's, CP-BLANDON was re-signaled in the late 1990's, so this is clearly a feature that was being employed for a number of years.  However it is not all together clear why it is used to selectively.  If I had to guess, the one similarity I noticed between CP-103 and CP-BLANDON was that a power save mode signal was located just past a grade crossing.  The ghostly red light may serve as a visual reminder of the interlocking limits to hi-rail vehicles entering or exiting at said grade crossings.  High rail vehicles and other track cars might not shunt the track circuit and therefore would not light up regular approach lit signals.  A burning red marker light would go a long way to preventing careless Stop signal violations.

Anyway, if anyone knows the true reason for this feature please let me know in the comments.

Wednesday, May 17, 2017

Canadian Pacific Mystery N-Lamps

For those of you who remember the case of the CP Mystery Searchlights, it seems that Canadian Pacific has been at it again, this time with mystery single unit traffic light style signals similar to US&S N types.  I first spotted these in photos about 2 years ago, at first thinking that they were recycling old US&S N-type signals, but then noticing the much more generic appearance.  Well I finally managed to get up close and personal with a few that were being installed up at CPF-483 in Mohawk, NY and, well, I don't know much more than I already did.

 They share the fully oval shape of the US&S type N, but the flat, rear panel of the GRS style traffic light.  The signals were not clearly labeled or branded so I could not tell who was responsible for their construction.

The faux N-types were being installed in mixed company with more typical Safetran clamshell type modular color light, Darth Vader configured signals.  Although a welcome break from the monotony of the Safetran monopoly, they are horribly generic to the point of not even having a knock off brand name or symbol or whatever.  If anybody can shed some light on this mystery please leave something in the comments.

It makes me thing.  With former CP hatchet man Hunter Harrison now at CSX, I wonder if he'll bring some creative cuts to the signal budget.  Of course he might have been the one to shift CP from their home grown searchlights and plunge them into the arms of Darth :-(

Monday, May 8, 2017

Amtrak Signaling Updates

So I just got two pieces of Amtrak related signaling news.  The first is an update on my previous NY Capitol Area signaling report where I said that it did not appear that Amtrak was ready to re-signal the portion of the Hudson Line between CP-156 and CP-159 based on some long distance observations of CP-159.  Well it turns out the new signals were located out of my line of sight because both NYC/Conrail vintage interlockings were replaced in April.

Also removed would be the NY Central two track intermediate signal bridge between CP-156 and CP-159.  Fortunately I was able to fully document that location a number of years ago.

I also got word that a reconstruction effort has commenced at PAOLI interlocking on the former PRR Main Line to replace the two side-wall platforms with a single island platform.  As such the two through tracks have been cut and both the 14L and 18L signals removed along with their associated turnouts. This is a huge blow to the character of the station and also eliminated the notable "high dwarf" signal mounted on the road bridge gantry adjacent to the two westbound high signals.


Tuesday, April 25, 2017

Swindon Power Signalbox Restoration

Hopefully most of you are familiar with the excellent job the crew at HARRIS tower has done reactivating its US&S Model 14 interlocking machine with the help of a lot of PLC's and Train Dispatcher 3.  Well over in the UK a project is afoot  to do the same thing to the old NX panel from the Swindon Power Signal Box.  The "PSB's" were a generation of British area signaling control centers that replaced the most hard pressed mechanical tower in the 1960's and 70's.  They used a lot of relay logic to implement push button N-X operation and many eventually came to feature integrated train description.  A tour of Swindon PSB can be seen below.

Swindon, like many other PSB's, are being removed from service because many of the telecon grade relays that drive the user interface and other ancillary logic are becoming nearly impossible to maintain.  Here below is a video showing the "domino" style panel board being re-assembled after it arrived at its preservation site.

Here is a brief demo of the old panel UI hooked up to some modern electronics.  And yes that is indeed the Danny Scroggins who is so well known for his comprehensive documentation of vintage British signaling and signalboxes.

Of course there is an entire Youtube Channel devoted to the project, with videos like this one showing the progress of the custom PLC components.

In fact the panel has its own preservation society and as of now they are projecting an grand opening date of June, 2018, plenty of time to score that cheap transatlantic airfare.

Tuesday, April 18, 2017

The Many Signals of Penn Station

In the first decade of the 20th Central, a number of transit mega-projects were under way in the United States.  Two of the most well known are Grand Central Terminal and Pennsylvania Station in New York City.  In addition to being civil engineering marvels, they also employed the latest technology in railroad signaling, which included both power operated interlocking machines and, gasp, electric signals.

I've mentioned before  how surprisingly difficult it was to create the first 100% electric railroad signals.  This was because high intensity electric bulbs (necessary to be seen under daylight conditions) of the time would have an impractically short service life and also because electric power was in vary short supply in might of the country.  However the projects of Penn Station and CGT did not suffer from these two limitations because they were underground, where it was dark all the time and they had reliable supplied of electric power on a 24/7 basis.

Right: Old GCT signal.  Left: New GCT Signal

Fast forward 100 years, while Metro-North replaced all the original 1913 signals in Grand Central, across town at Penn Station, the thrifty stewardship of Amtrak had resulted in much of the 1911 not only seeing the 21st century, but doing so just above the heads of millions of dashing commuters.  Union Switch and Signal, naturally, supplied the signaling for the entire projectfrom the interlocking machines to the relays to the signals themselves.  The signals were a custom job that, as far as I can tell, weren't used anywhere else since the electric age kicked off a rapid period of innovation that saw both searchlights and position lights entering the market in just a few years.

The Penn Station Signals consisted of a tri-light patterned upper head with G+Y+R lamps and then a lower head with an additional two R+Y lamps in a vertical orientation. Since the station trackage was all run at what is today known as "Slow" speed (15mph), there was no need for any of the more complex aspects such as Medium Clear or Approach Medium.  Two lamps were illuminated at all times to provide R/R Stop, Y/R Approach, G/R Clear and R/Y Restricting.  In the tunnels approaching the station Y/G Approach Medium and Y/Y Approach Slow indication were employed.

The Penn Station signal was a single cast iron housing with lovely rounded corners.  Due to the close clearances the signal was designed to be suspended from above, this would result in some awkward "gooseneck" mast mountings as I will show later.

From behind we can see how the signal was divided into two lamphouses, each with its own cast iron cover plate.  Note the very very old style US&S logos and markings.  Remember, all these pictures were taken in 2017, 106 years after the signals were installed.

Here we see a trio of 1911's litterally hanging out next to the now closed 'C' interlocking tower at the east end of the LIRR tracks.  The colored glass lenses are still vivid even to this day, probably because they were made with all sorts of now banned compounds.

Now if you think it is time to move on to the modern signals, you would be wrong as there is a second pattern of 1911 signal scattered about the complex.  One such example is the famous 122W "gooseneck" signal at the west end of track 7 (remember, I said they can only be suspended from above).  If you look closely you'll also notice that the G and Y lamps on the upper head are spread farther apart than on the standard Penn Station signal.

Now these "googly eyed" signals could have been some experimental or pre-production batch, but if you want a more satisfying answer I might say that this pattern was intended for ABS use in the tunnels.  The spread upper bulbs designed to simulate the offset heads of automatic signals.

Moving into the modern period we catch this Amtrak experiment with Safetran Unilens signals hanging at the east end of track 14.  Because of the problems with the Unilens that I have previously discussed, JO signal 566E appears to be an isolated incident.  So what then is the modern replacement for the unique 1911 signals?  Well actually its a modernized version of the unique 1911 signals.

Amtrak had suspended a pair of Safetran modular dwarf units below what may or may not be a Safetran lamp housing for a target style tri-light signal. The result is a nearly perfect drop in replacement for the cast iron 1911's.

Here we have an even more compact arrangement that omits the space for the "not in conformity" number plate on an absolute signal.  Hey, you can't say it doesn't work.

Here we can see how new and old compare at JO interlocking with the modern 564W signal displaying Restricting right next to the vintage 566W displaying clear.  The modern lenses are clearly larger, but both get the job done well.  In general, the former outdoor portion of A interlocking has been modernized while one is more likely to find 1911 signals scattered around JO and C, however there are many exceptions to those "rules".  Of course I'm also omitting the smattering of PRR position light dwarf signals scattered around the yard areas, but you've seen those before.

Anyway, I hope you've enjoyed this little tour of Penn Station.  Most of these photos were brought to you by the magic of modern smart phone cameras that excel at taking photos in low light conditions and also won't attract swarms of police and security officials.  Next time you are in Penn Station I urge you to look up and if you see something interesting, document it.  After all, nothing lasts forever.

Wednesday, April 12, 2017


So I have a brief news update here.  While riding the 2016 Amtrak Autumn Express I noticed that NS had advanced their Reading Line re-signaling effort to CP-ALBURTIS from the west.  It seemed that they would go and cut in the first half of the signaling and then work from CP-ALBURTIS to CP-BURN for the next season.  Well it not appears that they are going to do the whole conversion in one extended go as new signals have now appeared at CP-BURN.  Guess I'll have to schedule another field trip :-(

I am currently processing the photos from this trip and you can find the Lehigh Line portion here:  It's a real mixed bag od NS, Conrail and even a few surviving LVRR signals.

05/20/2017 UPDATE: I returned to the Allentown area to find that the re-signaling project has caught up CP-ALLEN and CP-HAM on the Lehigh Line. CP-JU and CP-CANAL so far appear to be unaffected.

Wednesday, April 5, 2017

Now For Something Completely The Same (#1AESS Retirement)

I just got word that on or about right now, the last active AT&T/Western Electric #1AESS telephone switches (generally confined to the former SBC territory) are being taken out of service.  This matters because the railroads are currently speeding towards the completely sterile, 100% digital environment that the telecoms have apparently just achieved.  Unlike railroads, which still have a few instances of electro-mechanical interlocking machines and hundreds of relay plants in service, the teleco's banished the last electro-mechanical switch from their network back in 2002, with the majority of the work taking place between 1970 and the 1990.  Back in the day, there was an entire scene of people who would go from place to place, listening to all the strange ways that the phone system functioned.  Today this sort of task would be a fools errand because everything is the same across the entirety of North America. 

Until recently, the #1ESS and #1AESS were the only exceptions.  Sort of like the 3400 series L cars or the NYCTA R68's and their cam-controlled DC propulsion systems, they were analog machines build in a digital world.  While the higher order functions were computer controlled, the actual switching was carried out using reed relays.  It's basically the N-X CTC panel of telephone switches with a computer bolted on to handle some of the route selection functions.  Even then, the attached were old school enough to fall into the "cool" category. 

Like with classic railroad signaling surviving on out of the way branch lines, the #1A aand #1 switches held on due to the recent wholesale divestment in copper wire / landline telephone services.  Still, the economics eventually because just too lopsided in favor of replacement and AT&T canceled its support contract with Western Electric successor Lucent in 2015, with an expected retirement date of 2017.  

This is why it's so important to get out and capture the classic technology before its just collecting dust in the corner of a museum.  In a few decades just about everything will be software running on some bog standard processor mounted on a raspberry pi.

Wednesday, March 29, 2017

Ditmars Tower (NYCS) Demolished

Interlocking towers serving old school rapid transit systems have surprising staying power.  In most cases they are often in underground spaces where any sort of demolition would literally bring down the roof.  Moreover, transit systems are often sealed, reducing the risk of vandalism, have limited windows for work to be done, making the cost higher and operated in a budget poor environment.  However, nothing is absolute and I just learned that a 100 year old IRT interlocking tower on the New York City Subway was demolished this past weekend.

DITMARS tower was located at the Ditmars Blvd terminal of the Astoria El in Queens, right in the shadow of the Hellgate Bridge.  It was originally built as an IRT tower, before eventually being transferred to the BMT division of the TA in 1948.   Although the tower appears to be the victim of fire damage, it is actually being removed for a switch replacement project that requires the use of an on-site crane. 

The demolition process actually provided a bit of an interior view showing that wooden appearance of the tower was a facade that surrounded a very robust steel and concrete frame.  The upper floor would have housed a US&S EP machine, the IRT being a strictly US&S operation.  The lower level would have housed relays wired to the machine above and the appliances out in the field.  Note the good condition of the roof structure, which is all the more remarkable given both its age and the amount of neglect the tower must have seen through NYC's lean years.

DITMARs tower in 2003
DITMARS tower controlled a 3-track full crossover leading into a 2-track terminal station.  Note the large air reservoir to power both the local point machines and the pneumatic trip stops all up and down the line. The tower was closed in 1989 as part of a full line re-signaling project, although the line was equipped with new US&S hardware, if that is any consolation.

Fortunately, DITMARS has many siblings up and down the former IRT elevated lines in the Bronx and Queens.  Almost all of them are out of service, but still hang on as relay rooms or CnS hangouts.  One old IRT elevated tower, 111th St, on the IRT Flushing, is still active, albeit with a fairly new master control NX panel installed.