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Saturday, September 29, 2018

Central Buffalo Line Re-Signaling Due Soon

If you wanted a photo of the unique compact PRR position lights at CP-NORRY or just some run of the mill pics of the "downtown" PL's at CP-SF in Sunbury, now is the time to jump into the car and start driving because the word is that the Darth Vaders will be cut in sometime within the next week or so. 

Next Stop Ebay!
 Although the new signals only went up within the last few months, it looks like NS had put the pedal to the metal to get the project finished instead of letting it drag on for some number of years.  I don't know if the cut-over will extend all the way to CP-WYE at Rockville or just around the Sunbury area, but this is likely your last chance to get photos of some very accessible PRR PL signals, including the famous roadside ones at North Miller.


I did my photo surveys of the entire line last year, but the more photos the better.  get your ass out there before it all goes away!


Sunday, September 23, 2018

For Good Signaling References Try Google Books

While doing some research I was reminded that a lot of really informative books and technical journals are fully indexed and available free on Google Books.  Typically, niche railroad signaling books are only to be found at train shows and have steep prices.  Google Books lack the tactile element, but have all the information as well as a better index.

For example, when searching for information on GRS's "Dynamic Indication" I found it discussed in this volume of  Railway Signaling and Communications.  Moreover, when researching Switch-Signal protections, I found information on that and a lot more in the book Railroad Signaling and railroad Operation.




Saturday, September 15, 2018

NS Harrisburg Terminal Re-Signaled

So it appears that my prediction from two weeks ago was exactly flip-flopped.  Despite the 5-track signal bridge for CP-HARRISBURG remaining on the ground as of Labour Day weekend, it was the Harrisburg Terminal and not the old Middle Division that saw the new signaling cut over on the weekend of September 9th and 10th.  The affected interlockings are CP-HARRISBURG, CP-ROCKVILLE, CP-WYE, CP-HIP and CP-MARY.  CP-BANKS and CP-CANNON will be cut over in the next few weeks.

Ha ha, fooled me.
Coincidentally I just completed processing a photo set I compiled last October that documents CP-HIP and CP-HARRIS.  So click the link and take yourself back in time to August 2018 ;-)


Here is an official listing of the changes at CP-HARRISBURG, CP-ROCKVILLE and CP-MARY.  in addition the MP 107 automatic signals were removed from service due to the Rule 562 operation. 


Friday, September 7, 2018

1960's British Branch Line Cab Ride Films

So while this is a rail signaling blog and not a railfan video blog, sometime I like to highlight sets of videos that really show off the signaling.  Recently YouTube suggested a number of grainy 8 or 16mm film film compilations taken out the front of old school British DMU's running on long since defunct branch lines.

The videos were posted by the appropriately British sounding Alen Snowdon and were narrated by his wife.  Due to the limitations of old school home film recording, the clips are all about 3-5 seconds long and show only a fraction of the route.  However this fraction contains a large proportion of the signalboxes and signaling apparatus that the train passes.  It's sort of like one of those low frame rate fast motion videos, only the frames are a few seconds of every passing semaphore signals.



Not all of the videos are cab rides or even rail related, but the ones that are, are a wonderfun time capsule showing the anachronistic state of the British rail network in the 1960's.  Thanks to two World Wars even the main lines were stuck in he Victorian era, with very little power signaling and steam hauled trains galore.  Just before the infamous Beeching Cuts, the branch line infrastructure is absolutely decrepit, sort of like how the Amtrak Harrisburg Line and Conrail in general looked in the 1970's and 80's. 



Also worth noting is the astonishing level of employees needing to keep these old branch lines in operation with both signalmen and station agents working every 1-3 miles along the line.  It is interesting that instead of cuts British Rail didn't simply try massive cost reductions like CTC or even ABS!



There's even a little main line action out of london, although one would never know it due to the state of disrepair. Also note the high quality railfan view despite a full width cab. Anyway, enjoy the videos, they aren't hours long and the archive isn't intimidating.


Friday, August 31, 2018

NS Pittsburgh Line Cut Over This Weekend?

The scuttlebutt is that NS will be cutting over the new signaling and attendant Rule 562 operation on the Pittsburgh Line between Harrisburg and...somewhere.  There are two 12 hour outages scheduled for September 9th and 10th, or so I have heard.  However when I visited in person over Labour Day the new signal bridges at CP-BANKS and CP-HARRIS were still sitting trackside there I had seen them over a year ago. 

File Photo
Because the BANKS to HARRIS segment started being worked on after the CP-CANNON to CP-ANTIS segment, I suspect that the Middle Division is what will be cut over with the Harrisburg island to follow and the Altoona to Pittsburgh portion coming after that.  No matter what is happening, get your photos in ASAP. Tune back because I have some feelers out and hope to have the exact information about what is being cut over in a few days.


Also in other news NS is also planning to do some Chicago Line re-signaling sometime in October.


Wednesday, August 22, 2018

Mark D Bej's The Broad Way Archive Gone

It seems that I'm not the only person running into a hosting jam lately.  For literally the last 20 years when I have needed information on one PRR era interlocking or tower I have dutifully gone to Google, typed in "Maps of the PRR" and been taken to broadway.pennsyrr.com, and been taken to a wonderful Web 1.0 gem that gave me my information with little fuss.  The PRR part of the site had the aforementioned archive of interlocking sheets while else where on the file tree was a general signaling site with a good yet somewhat incomplete listing of signal rule sets and explanations of operating principles.



Unfortunately Mark's The Broad Way site was hosted on Keystone Crossing, a long running PRR history website that also hosted my interior photos of STATE tower in Harrisburg that I took in 2003. As the decades past the site owner Jerry Britton was overtaken by mounting costs and shrinking ad/donation revenue and I never noticed that he had announced the site's closing. While a stub of Keystone Crossing is still up (for now) most of Mark's page has completely vanished from the internet. 


Fortunately, back in the day when broadband internet was yet to be a thing and websites were often highly unreliable, I was obsessive about saving everything to disc and I have long since backed up The Boad Way's interlocking charts as well as the html pages they were linked from.  These have now been uploaded to Google Photos.  Moreover, a lot of the site was archived here, including the HTML copy of the 1956 PRR rulebook.   

I am still trying to find out what happened to Mr. Mark D Bej and/or the full contents of his website.  For all I know he may have passed away,  but if he is still out there, and if I can get my own hosting back, I might be able to get his content back online. I am sorry I was unaware of KC's problems as I would have done everything I could to drum up donations and support.  Meanwhile, some of KC's content has migrated to a PRR group on groups.io.  Of course I am now going to have to go through my own posts to change all of the broken interlocking chart image links 😢

Monday, August 13, 2018

New NORAC Signal Rules!

Yes, and before people get all nit picky yes NORAC is indeed adopting both new rules and a couple new aspects that go along with old rules.  All of the new changes have in fact been used for many years by a number of member railroads as system special instructions and moreover they have also been seen in other railroad signaling systems.  This is a nice example of a signal rules committee looking at the state of the art and deciding not to keep its head buried in the ground.

The new rules were made effective in the 11th edition of the NORAC Rule book released on Feburary 1, 2018. I've been a bit busy since the start of the year so I just hadn't noticed until now XD


We begin with Rule 281a, Cab Speed, which has been modified to include SEPTA's *G*/*G* dwarf indication which it has been using for about the last 10 years.  Also included was a PRR pedestal indication probably because of some situation on Amtrak.


 The next change plugs a major hole in several eastern signal aspect systems in that there is often no Approach indication available on dwarf signals. Y/R is Slow Approach, Y is restricting and for years NORAC had to make up with displaying Y/*R* Medium Approach for straight routes.  However there was one obvious solution and after appearing on the Conrail SAA timetable as a special instruction for years, *Y*/R has been adopted as Approach.  CSX please take notice.



A bit more consequential is the long overdue adoption of Medium Approach Slow.  Unlike CSX which had reserved R/Y/G for M-A-S forcing R/Y/*G* for M-A-M, NORAC went with a nod to the PRR using R/Y/Y.  This aspect had long been used in by the MBTA in the Boston area and possibly also on the former Boston and Maine territory. More recently it had been incorporated into Caltrains new speed signaling system in 2003. Note, NORAC Rule 283b does not include the "when first becomes visible" admonition, which I would suspect is something they are trying to get away from.


Finally in a weird nod to the Seaboard Coast Line, NORAC has adopted Limited Approach  signal as Rule 286a.  However, unlike the CSX Rulebook which is a bit ambiguous about when a train must slow to Medium Speed, NORAC Rule 286a states that Limited Speed applies only through the switches and turnouts, then Medium Speed applies.  Like Rule 286 Medium Approach, trains must begin reduction to Limited Speed as soon as it becomes visible.  I suspect this might be used to claw back a few seconds where trains had previously been stuck at Medium Speed due to a far-yet-visible Medium Approach indication.

All in all these are sensible moved by NORAC.  The real question continues to be when CSX will finally adopt *Y* Advance Approach!!

Tuesday, August 7, 2018

Closed and Closing NYCTA 6th Ave Line Towers

Another two major losses in the world of North American power interlocking machines as the 1940 vintage towers 34TH ST and W 4TH ST, both on the NYC Subway 6th Avenue Line, will both be closed by the end of this week.  Actually, 34TH ST tower already closed back in May, while W 4TH ST tower will be closed over the two week period centered on the weekend past.  Both towers were equipped with GRS Model 5 pistol grip type machines and W 4TH is perhaps the most famous of them all for its "fishbowl" windows looking out onto the lower downtown platform for all the world to see.


While W 4TH ST and it's 54 lever frame controlled an impressive plant, linking the 8th and 6th Ave lines south  of Midtown, it unfortunately did not put on much of a show unless trains were being diverted.  The operators could sit back with the entire plant straight railed and signals fleeted, pausing only to harass those interested enough to even peer through the window.




34TH ST tower on the other hand had a 68 lever frame controlling perhaps the closest thing the NYCTA had to a complete railroad 4 track crossover, although it was embellished with a few unnecessary scissors crossovers.  This tower was located a bit down front the end of the uptown platform, but due to the 34th St Station platforms being offset, it could be viewed from the side.


As we speak W 4TH is being slowly cut over, one track at a time with the process scheduled to be completed on the weekend of August 12th, 2018.  Anyone in the NYC area should make a special trip to get some video and piss the unionized tower operators off one last time ;-)


Don't believe the hype.  These old school machines will have lasted decades longer than what replaces them They are reliable and hack-proof as long as they see proper maintenance.  Unfortunately that is something the NYCTA can't afford so they beg for capitol money for a flaky CTBC solution that costs billions and only increases capacity by 5-10%.  So long, and farewell old friends.

Tuesday, July 31, 2018

Liverpool Lime Street Signalbox Closed

One of the last two active Westinghouse Brake and Saxby Signal Company power frames on British Rail was taken out of service on July 13th and it was quite an impressive example, controlling the 13 track stub terminal in Liverpool, England since 1948.  This matters because the WB&S Co Style L power frame installed in Liverpool Lime Street is pretty much a US&S Model 14 just with the levers rotated 90 degrees to moved in the proper British fashion.  Also the all brick structure with a bay window follows the pattern of high quality North American towers as seen on the Pennsylvania Railroad or New York Central.



With 86 active levers and a plant that had pretty much remained untouched since the signalbox was constructed after The War, this is a huge loss for living signaling history, although a number of these frames survive in various preserved forms.



The machine was shut down track by track instead of a simultaneous cutover.  This resulted in the unfontunate side effect of the model board being completely painted over aside from the last two active tracks along the bottom :-( All of this can actually be scene along with general tidbits about the Signalbox's history and future use in this video produced by Network Rail.




Unlike many other British towers Lime St is a listed building and should be preserved along with the rest of the station. Also make sure you check out the The Westinghouse Brake & Signal Company Ltd. Miniature power lever frame website for more information on this cross pond cousin.

Wednesday, July 25, 2018

2018 RF&P / A-Line / H-Line / Southern Main Line Trip Report

It has been three years since I last surveyed the RF&P, A-Line and Southern Main Line and quite a bit has changed. This report will try and cover more of the signaling related changes and less of the various capacity improvements that have occurred in tandem. On the RF&P third track projects are causing intermittent layout changes north of Fredericksburg, but a number of legacy 2 track bridges are isolating the new segments. Not much of a signaling change as the whole area was re-done between 2012 and 2014. South of Fredericksburg a few remaining RF&P large target US&S N-3 intermediates still stand along with the classic bracket mast at Doswell. Towers at Fredericksburg, Millford, Doswell and Greendale were also still standing.

Still hanging in there!

Acca Yard in Richmond has seen major changes. Previously both ends of the yard had been completely interlocked. Now the throats had been converted to hand operation with simplier terminal interlockings constructed farther out. On the south end the old AY interlocking has been relocated with a access cutting through the wye to allow northbound movements off the Belt Line to access all the yead tracks. South of Richmond AF interlocking was getting a complete set of limited speed crossovers to replace a single trailing 15mph crossover. The Petersburg Station has also been provided with a new interlocking to reduce the need for trains to cross passengers across an active main track.

This RF&P vintage modern style N-3 gantry is a goner :-(

South of Petersburg the only remaining classic signals are at CHARLIE BAKER interlocking in Rocky Mount. A few new limited speed crossovers have also been installed with a few extra miles of double track to reduce time spent waiting in sidings for meets which is what eliminated the last few N-3 holdouts after 2015. The NS H-line has also seen a number of improvements with new interlockings and new passing sidings, but the line had already been assimilated by NS so there wasn't anything to be lost. The new Raleigh Station is open, but not all the tracks are in service and there is still work to be done before the new terminal interlockings are fully in service.

The last A-Line N-3s were replaced by new crossovers.

On the Southern main line a smattering of interlockings remain unresignaled, typically 1990's builds with the traffic light style heads. One example is FAWELL interlocking south of Lynchburg. Also, CR TOWER interlocking in Alexandria, VA has seen new Darth heads placed on the Southern vintage ladder poles. Although there are some exceptions, NS did not use the opportunity to add new CTC features such as a Restricting indication into single track territory. This has been done on some NS lines like the former NKP route, I believe, but not Southern. Also, many of the old Southern signal gantries have been left in place along the RoW where it was somehow inconvenient to have them scrapped. So there might be something worth taking a picture of if anyone makes a signal trek.

Apt that FAWELL interlocking would be resistant to change.


All in all this was a pretty dull trip, signaling wise. Exactly what we have to look forward to across North America for probably the rest of time :-(

Saturday, July 14, 2018

Caught on Camera: Clear to Next Interlocking

Also known as NOARC Rule 280a, this special cab signal related signal was invented by the Pennsylvania Railroad for their experimental trial of cab signals without fixed automatic signals (today known as Rule 562) on the Conemaugh Line between CP-CONPIT and CP-KISKI back in the late 1940's or early 1950's.  Without wayside intermediate signals, trains that experience a cab signal failure en route would not be able to proceed without absolute block protection ahead.  Normally this would involve train orders (or today a track warrant/Form D) however the reliability focused PRR decided to automate the potentially delay inducing procedure with a special signal that would illuminate when the track was clear to the next interlocking where the next wayside signal would be located.


 One option could have been to simply display a Rule 280 "Clear Block" signal, which was an upper head | with a single marker below and used in manual block territory.  However because of the lack of manual block distant signals and because of the non-lack of train detection, a new Rule 280a was created, "Clear to Next Interlocking" and it would consist of a flashing lunar white market offset to the side and labeled with a reflective 'C'.  Any diverging movements through the first interlocking would be covered by the fixed signal and trains would be instructed to approach the next interlocking prepared to stop.  Here we can see an example of a Rule 280a being displayed along side an Approach signal at Amtrak's REA interlocking.



As you can see, the 'C' lamp is displayed independently if absolute block conditions are met.  On unit lever and VDU interfaces the 'C' lamp is a separate switch associated with each signal.  While technically unnecessary at back-to-back interlockings, 'C' boards are more often deployed uniformly so crews do not loose track of which signals they can pass with failed cab signals. In this more elaborate demonstration of signal progressions at Amtrak's HUDSON interlocking we can see how the 'C' lamp is placed on the fame flashing circuit as other flashing signals such as Cab Speed and Approach Limited.



Finally, we actually have an example of a display 'C' signal in the wild.  This was at the re-signaled STELL interlocking for a southbound movement against the flow of traffic on the NS Enola Branch.  NS has decided to employ waysideless operation on much of it's cab signaled PRR territory, following in the footsteps of Conrail in the 1990's.  Previously the Enola Branch had been run under single direction Rule 251, but when the line was re-signaled, the Rule 562 operation saved a bit of money on intermediate signals.  First note the NS style backings on the 'C' boards, a practice not carried forward to subsequent projects. Second this is an interesting occurrence as a train with failed cabs could in theory be swapped out at Enola yard and finally note the slower flashing cadence compared with the Amtrak signals.



That's it for this episode of Caught on Camera. Nothing is scheduled for the next time cause I won't know it until I catch it ;-)

Sunday, July 8, 2018

2018 PRR Main Line Trip Report

So it's been a year since my last comprehensive PRR Main Line trip report and a lot has changed in that time. First and foremost, NS's slow and steady re-signaling campaign has made a massive jump westward with new signals now going up along the entire western slope all the way to Pittsburgh on the Pittsburgh Line and Rochester on the Fort Wayne Line. This is a recent development and some of the masts in the Pittsburgh area are still sitting on the ground, however this marks the beginning of the end of the last great position lit terminal on a Class 1 railroad.

Twilight of the PLs at CP-PITT
In a small silver lining it appears that NS is expanding it's cab signaling to cover the Pittsburgh Gap between CP-EAST PITT and CP-KISKI on the Pittsburgh and Conemaugh Lines and CP-ROCHESTER on the Fort Wayne Line. All the new signals are going up with Rule 280a 'C' boards. This would mark a rare modern occurrence of a freight railroad installing a new safety system on it's own accord as the PTC mandate did quite a bit to forestall additional cab signal. Of course this will definitely ruin some of the aesthetics of the 3-4 track freight raceway between Pittsburgh and Rochester, however only about 3-4 automatic signal locations will be impacted.


It also appears that the former ALTO tower territory, resignaled in 2012, will not be getting Rule 280a 'C' boards, continuing to operate under Rule 261 with a single automatic on #2 track adjacent CP-HOMER. Other areas with back-to-back interlockings, like the Pittsburgh terminal, go not appear to be getting the same treatment despite the presence of some shortline operators that would need to get their engines cab signal equipped. NS is potentially increasing the number of signal blocks as the RoW has sprouted numerous new relay huts in odd locations, but these could just be for grade crossings or other secondary functions.

This new signal bridge is here to stay.  The westbound one will be replaced.

On the pneumatic front the entire Middle Division has been changed to electric M23 point machines. Over the hill CP-MG and CP-SO have both lost their pneumatic plants while CP-AR, CP-UN and CP-MO still retain them. West of Johnstown CP-CONPIT, CP-RAGE, CP-TRAFF, CP-WING and CP-HOME are still pneumatic, but will likely be converted soon. Interestingly, CP-C shows no work whatsoever in either the point machines or signals.

Missed my chance to take photos of the pneumatics at CP-SO and CP-MG :-(

In Pittsburgh specifically, signals will no longer play a role in protecting trains approaching the 20mph curve west of the downtown station. Instead of an Approach Medium -> Approach Slow -> Slow Clear (removed) progression, non-diveging trains will get Clear straight through. However the closely spaced interlockings will result in the use of R/R/*Y* Slow Approach signals. Also because the old Pitt signaled siding was removed, the new westbound signal at CP-PITT will only slow straight route signals and Restricting.

In the future trains through Pittsburgh will proceed on straight Clear signals.
While I have been able to document a lot of the infrastructure on this line before the charges started, I can't get to it all, so once again I am urging anyone nearby to get as many photos as you can before the past is gone for good :-(

Saturday, June 30, 2018

UPDATE: ALTO Tower Page Hi-Res Photos

So I took the time to re-process the photos from my 2004 trip to ALTO tower that formed the core of my 2011 blog post about the tower and its interior. The old photos had been edited for a 2004 web standard of 100-200k file sizes.  Although only taken on a 3MP camera, that still meant I could use the full resolution available without blowing up the page load time.


In addition, I streamed two photo processing sessions where I talked about the history of ALTO and the story of my visit to the tower along with all sorts of interesting factoids and hijinks.





Yeah that's right, I've getting into live streaming! Who says one can't squeeze content from a stone 😏


Sunday, June 24, 2018

Atlanta Terminal South Tower Demolished

One of the few bits of railroad history left in downtown Atlanta was torn down last week when wrecking crews came for the former Southern Railway Terminal South tower, one of the last surviving parts of the great Terminal Station that closed in 1972, itself razed for a Federal Building in 1979.  


While the brick structure was not in danger of fire, a number of large cracks had opened up on the walls and it could be assumed that the tower was less than structurally sound.


Unlike the Northeast and industrial Midwest, the South and West never featured large numbers of tower, especially high quality non-combustable ones with power interlocking machines.  A Georgia Rail history website could only list three surviving towers in the state, a number now reduced to two.  The Terminal South tower had also anchored the railfanning scene in the city and it is unknown at this time what might be able to replace it what with the unrelated re-signaling efforts that have been going on.

Saturday, June 16, 2018

Railroad Signals and the Materials of Yesteryear

NOTE:  This article first appeared in the Summer 2017 issue of The Trackside Photographer.

In 1967 young people were told that plastics were the future and the future did not disappoint.  Today the world is made out of plastic, carbon fibre, corrosion resistant lightweight alloys, high strength concrete and LEDs.  This technology has generally converted our world from one where stuff is expensive and people are cheap, to exactly the opposite.  I could go on and on about the many economic ramifications of this, but in essence "things" went from being crafted and artisan, to being so invisible that they might as well not matter.  Back in the day the Pennsylvania Railroad was the largest private employer in North America with over 300,000 employees, roughly the same as WalMart.  This vast army of workers was needed to polish, paint, lubricate and generally maintain all of the expensive, labor intensive technology that allowed humans to move at speeds faster than brisk walk.  Replacing the materials of old was part and parcel to being able to replace the workers that cared for them, however as we charge into the middle of the 21st century some of these materials have soldiered on in the service of railroad signaling and, until their inevitable replacement, they provide a window into the pre-digital industrial age.

CSX Washington Sub - South Orange Interlocking
Steel and iron are the stereotypical railroad materials as demand for bridges, rails and locomotives practically created the modern steel industry.  Of course steel wasn't just used for girders and boilers. Back in the day this was the only metal one had available for structural components of any size and before the advent of plastic or other composites, metal was one of the only materials available with an adequate strength to weight ratio.  Stronger, weather proof and more durable than wood, iron and steel became the materials of choice ofr railroad signals and signal structures.  This US&S style N color light signal mast shown above is almost completely made of iron and steel, right down to the base.  Cast iron housing and brackets, sheet steel backing, steel pipe mast, strap iron ladder work, heck, even the signal wires are sheathed in iron.

CSX Philly Sub - MP 80 Auto Signal "Whitemarsh"
Cheap and easy to stamp, cut, forge or cast, steel was everywhere, but it's suffers from a major weakness against air and water.  The scourge of rust requires care and paint, and paint requires workers to apply and remove.  In the 21st century aluminum is cheap and plentiful.  Lightweight and rust free, any signal made of aluminum will look as good on the day it is installed as the day it is removed perhaps decades in the future without needing so much as a man hour of skilled labour.

CSX Cumberland Sub - Paterson Creek interlocking

Also used for bridges and track structure, wood was the plastic of its day.  Light and easy to shape, it also has tensile strength allowing it to span distances in a way that stone or concrete cannot.  Although it was excluded from most signal structures, wood was employed in pole lines to support the signaling and telegraph wires that carried little bits of voltage from one signal location to the next.  Unlike steel, stuff can be easily attached to wood with nails or screws and, somewhat surprisingly, wooden poles can also last decades after being impregnated with petrochemical tars.  However modern technology found other ways to eliminate the wooden pole lines by replacing the wires they carried with fiber optics or wireless signals.

D&H 'QS" Interlocking, Mechanicville, NY
Surprisingly, cotton was an important material in railroad signaling.  Before the advent of PVC sheath insulation, large signal cables were wrapped in cotton impregnated with tar to keep out the elements.  Cotton insulated cables went hand in hand with the pole line concept as attempting to bury such a cable would quickly lead to its failure.  Damage vulnerable to wind, snow, rain and trees, this was accepted a cost of doing business.

PRR 138kv Transmission Line near Martic Forge, PA
From the smallest telegraph wire to the thickest high voltage transmission cable, copper carried the electrons that powered the signals and sent the data.  Synonymous with the term "electrical conductor" to this day, copper was generally replaced by aluminum braids in power applications and of course its role in data transmission was tied to the pole line . Ultimately railroads did all they could to get out of the power transmission business, in some cases going as far to replace copper cable with solid state solar panels.

CP-MIDWAY - Port Road Branch
Large ceramic insulators met the same fate as the copper wire when the business of providing signal power was turned over to the local utilities.  Outsourcing is the name of the game in the 21st century.  It made no sense for railroads to act as power companies, employing linemen and stocking electrical hardware such as this.

CP-SLOPE, Altoona, PA.
PCB's are probably the best class of material for insulating transformers being non-flammable and possessing a high dielectric coefficient.  Unfortunately they also cause cancer and persist in the environment almost indefinitely.  All the more motivation for railroads to stop running their own power grids.

CSX Cumberland Sub - Magnolia, WV
 Glass was the insulator of choice for low voltage signal and telegraph wires running along side the power supply lines on the poles.  Edging out ceramic in the same use case, the sparking glass insulators made railroad poles a look a bit like Christmas trees.  Replaced at first by cheap rubber and plastic models and ultimately by wireless, glass insulators became a staple of country antique shoppes and the preferred target of rural target shooters.


More expensive than its pole line cousin, optical glass collected the light from the low wattage signal bulbs and and protected it 1-2 miles down the track for approaching trains to see.  Most color light signal lenses consisted of an inner colored glass filter assembly with an outer Fresnel lens that focused the beam.  Today these have been replaced by high intensity LED's that often do not need a focusing lens, making do with a cheap clear plastic cover.

CP-RADE, Radebaugh, PA
Compressed air was the power source of choice for many early power interlocking installations.  Not only were air operated switch machines simple and cheap, it was also easy to safety control the flow of air using low voltage electrical circuits passing through an electro-machanical interlocking machine.  Of course air was only cheap as long as the workers needed to keep the lines dry and leak free were also cheap.  Today pneumatic switch machines are fading fast in the presence of bullet proof, high voltage electric machines.

CP-TRAFF, Trafford, PA
Silver paint is typically applied to relay huts and cabinets to reflect the sun and keep internal temperatures low.  In this case the need for painting has been replaced by corrosion free shiny materials and compact air conditioners.

CP-HAWSTONE, Lewistown, PA
Lead acid batteries were once provided in large quantities for when the railroad supplied power suffered some sort of outage, as was frequently the case in the pole line era.  Because the batteries would vent hydrogen gas as they charged and discharged, they were stored in concrete "wells", outside the relay huts where there was no risk of explosion.  Today improvements in battery technology and power reliability have made such large bulky backup power arrangements unnecessary.

PRR OVERBROOK tower.
Relays are constructs of copper coils moving silver plated electrical contacts to make and break electrical circuits, all sealed up in a glass envelope.  Once the standard unit of electronic logic until the advent of the transistor, the function of relays was duplicated by solid state gizmos such as transistors.  Relay logic was standardized across vendors and can't be hacked, but changes are costly and time consuming to implement, making software based alternatives far more attractive.

CSX Cumberland Sub MP 130 Auto Signal "Drywall"
Up through the middle of the 20th century railroads were once at the vanguard of technical innovation, leading the way in telecommunications, computing and material science.  While today these technologies and materials of yesteryear can make railroads seem like an under-funded anachronism, a different view shows how well the engineering of the past has stood the test of time.  While the materials of today are in many ways superior, they lack much of the spirit of what came before.  A spirit created by human hands crafting, fitting and maintaining the materials of yesteryear from one century to the next.

Sunday, June 3, 2018

Caught on Camera: Bobbing SEPTA Main Line Signals

Several years ago I discussed the topic of relay logic and how it can create interesting signal displays as they change from one aspect to the next.  (Usually this involves a change from some form of Clear to some form of Restricted Proceed as that involves two or more discrete relay flips.)  Well last week I had taken a trip to the SEPTA North Broad station, just south of the busy 16TH ST JCT, to photograph the last remaining AEM-7 locomotives in operation.  At one point, towards the tail end of the peak period, the track 1 signal on the Milepost 2.9 automatic signal bridge began to cycle between Approach Medium, Approach and Stop and Proceed.  The northbound home signal at 16TH ST was displaying Medium Clear, so Approach Medium was indeed the correct indication, however the signal continued to move between the three at a fairly brisk clip indicating that the track circuit between there and the interlocking was moving between an occupied and an unoccupied state, a phenomena known as "bobbing".



As time went on the rate of the cycling increased and as soon as the AEM-7 led push-pull on the adjacent track 2 cleared tthe approach block to 16TH ST, that signal began to bob as well, although only between Approach and Stop and Proceed. In due time a northbound train approached the 29-1 signal and I can only imagine what the crew was thinking as they not only watched the wayside signal change ahead of them, but also endured a constant stream of cab signal flips. As one might have expected, the train passed the malfunctioning signal at Restricted speed and shortly thereafter the track 2 signal was also brought down to the Stop and Proceed position full time by an adjacent northbound train.



After the two trains passed whatever temporary fault condition that existed was resolved and the MP 2.9 automatic signals went back to normal operation.  There was a later service disruption at the junction, but it appeared to be related to some sort of stuck switch or disabled train. The funny thing was that this wasn't even my only recent encounter with bobbing signals as I also caught two northbound signals at Milepost 69.6 on the Amtrak's Southern NEC also bobbing.



Some bobbing track circuits can be fixed with a few simple adjustments.  Others can be quite stubborn and can linger for weeks.  Some parts of the southern NEC had bobbing circuit conditions that had been around for years, often where electric movements on one trackcould cause an adjacent track to temporarily show occupied.




Sunday, May 27, 2018

A Few Bits of News

I haven't had much to report on lately, but I did save up a few random news items, some good, some bad.  On the good side of things I finally discovered why the former DRG&W route has not seen its new signaling cut over between Helper, UT and Grand Junction, CO since it I first spotted it in 2012.  Well, Union Pacific has decided not to PTC equip the line due to low traffic volumes, so that's cool.


The former ATSF transcon in Illinois is seeing increasing amounts of re-signaling so if you live in the area get out soon to document the searchlights and signal bridges.

Edelstein, IL
While no stranger to re-signaling efforts, the last searchlight signals on the freight level of Blue Island Jct are now on tap for replacement.


I had also reported on the NS Harrisburg Line re-signaling between Philadelphia and Reading.  At first glance it appears that CP-TITUS, at the junction of the old southern Belt Line and the Main Line into downtown, was going to be spared, but as I have learned many times before, looks can be deceiving and the new double crossover between here and CP-BIRD will replace CP-TITUS in its function as a junction.  Ultimately that is all CP-TITUS is, a double crossover, just with a lot more complexity and it's otherwise isolated location, accessible only through the locked gate of a private power facility, made NS relocate the track split a mile to the east.



Sunday, May 20, 2018

LIRR Reduced Aspect Signals

Well it looks like the LIRR has decided to jump into the same pool as Metro-North and SEPTA by adopting a Go, No-Go signal system in conjunction with cab signals.  However, instead of following the practice of either MNRR or SEPTA, the LIRR has decided to do things their own way.

No Restricting
For a bit of context, the LIRR adopted a Rule 562 (no waysides except at interlockings) type system way back in the 1970's, a decade or more before MNRR went with it's no famous Go, No-Go signals.  The LIRR simply used full signals at interlockings, seeing no need to differentiate wayside ABS territory from non-wayside ABS territory. 

No Cab Speed
 In designing a reduced aspect system, the LIRR faces a few challenges that do not apply to either SEPTA or Metro North.  First, the LIRR is not a NORAC member, but runs on NORAC territory between HAROLD and Penn Station, so new signals should try to avoid confusion with NORAC.  Metro North does not run on foreign territory so it had more freedom in it's design.  Second, the LIRR already deployed a new color light system so a new, new system should also not conflict with that.  Thirdly, the LIRR employs a Manual Block system that must have some compatibility with the new indications.

No Absolute Block


The result is a series of 6 signal indications, instead of the more typical 3 (Stop, Cab Speed, Absolute Block or Restricting).  The LIRR not only uses both Restricting and Absolute Block, but also two additional ones Exclusive to the LIRR.  These are Slow Cab Speed and Restricting Cab Speed.  The difference is that the first relieves the engineer from having to stop within one half the range of vision etc.  "Restricted Proceed" even explicitly handles the not uncommon situation where something in the interlocking creates the need for a call on, but beyond that everything is ok.


LIRR is also leaning heavily on the lunar white lams in order to differentiate all of the new signals from their current crop of color light signals.  The only aspects not using lunar are Stop and Restricting, both of which already exist in classrooms. 

Something for everyone
The expectation is that these will be used on dwarf signals placed at rebuilt interlockings away from major terminals and other congestion zones.  If these can spreads to the entire system remains to be seen, but both the HAROLD and JAMAICA terminal interlockings are getting new standard color lights. The first interlockings to get the new signals will be those on the outer Ronkonkoma Branch where a double track project is under way.