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Sunday, February 19, 2012

Signaling Flickr Photo Sets

Found a couple of interesting photo sets on Flickr.  The first are signal surveys of some N&W districts and the former C&O Buckingham Branch owned line from Gordon to Clifton Force.

The second is a signal and interlocking enthusiast's collection of Tower photos and I'll be damned if he doesn't have a photo of just about every currently and recently standing interlocking tower in the United Stated.  Really worth a look.

Friday, February 17, 2012

PHOTOS: THORN Interlocking

Before you think this is a duplicate post I should explain the previous post on THORN tower concerned the interlocking tower itself and the contents within. This post will focus on the THORN interlocking plant outside the tower. I had a lot of photos and some videos of the interlocking plant itself so I decided to split that off into a separate post. Also for those of you who care there are pictures of actual trains in this post instead of just interlocking equipment.

So once again I will be referring to this track diagram dating from 1992. Despite being almost 20 years old it is still an accurate reflection of the state of THORN interlocking. ... C/C-7.html

As I mentioned before in my previous post THORN interlocking proper was a 6-track full crossover located at MP 35.0 on the old PRR Main Line that originally consisted of 4 main line through tracks, 2 tracks of the Philadelphia and Trenton low grade freight line to the east and two tracks into Thorndale yard to the west. The last major change to the plant occurred when the P&T was reduced to a single track which changed the 53 switch from a crossover to a turnout. Since that time as the P&T and thorn yard were further abandoned the disused tracks were simply stubbed out to avoid costly changes to the interlocking plant.

In 2010 track #3 is a stub on both sides of the interlocking along with track 5 to the east. Track 6 to the west still has space to store MoW vehicles and #5 Running is also still in place. Track #2 to the east is out of service past the old P&T flyover, but the tracks are still in place.

To set the stage I will start us off with some video. Here is a rear facing view from an Eastbound Amtrak train traveling on track 1 through THORN interlocking. The video starts in the middle of thorn yard and continues through the interlocking, under the P&T flyover and then through the overhead power phase break that divided the Harrisburg power dispatch zone from the Philadelphia zone. Track #2 through between CALN and THORN through Thorn yard is active and is sometimes used as a pocket to hold SEPTA commuter trains or the odd local freight clear of the main. The train is traveling at about 90 mph and you can see the fairly new Thorndale station with its full length high level platform, the three track eastbound high signal gantry, the full 6-track crossover, MoW equipment stored on the #6 track stub, THORN tower itself, the silver painted air line for the 43 switch, the reverse direction position light "pot" signals, the P&T flyover and finally the Thorndale substation and phase break.

In the next video we have the opposite rear view from a westbound train traveling on Track #4. Here we see the removed #3 track, the abandoned P&T ramp to the flyover, the two track high signal gantry on #3 and #4 tracks, the mast mounted signal for the P&T, THORN tower and the air line, the reverse direction position light pot signals, the low level Thorndale platform, thorn yard ad finally what used to be CALN interlocking which is no longer in service on #4 track.

Tuesday, February 14, 2012

Active Tower Lost Then Found Then Lost For Good

I just discovered an active tower previously unknown to the signaling community that has the glorious distinction of being active despite having closed over 20 years ago...and then after adding it to the active list, had to take it right back off again as it was closed for good in 2010 and DEMOLISHED in 2011.  The tower in question is 'CA' tower in Terra Alta, WV on the famous CSX Mountain Sub, a all brick B&O design that is a sister to the famous SA tower at Sand Patch, PA (also demolished) and HX tower in Halethorpe, MD.  Apparently, when the tower was first closed sometime in the 1980's due to a track rationalization, the line was still not put up for a re-signaling.  As happened to a select few other towers, the maintainer chose to leave the interlocking machine in place, in this case a 56-lever GRS Model 2, and leave one lever wired up and active to run a single remaining B&O CPL automatic signal (previously a controlled signal in the interlocking plant).  After, after 20 years in zombie service CSX finally got around to re-signaling that portion of the line, but also decided that as long as they had their backhoes in place they might as well demolished the secure and structurally sound tower.  Way to preserve your heritage CSX, make sure that nobody might ever be in a position to preserve it.  Let's hope that someone in the know was able to make off with the interlocking machine in some form.

Anyway, I was alerted to the ups and downs of CA tower by a pair of photos posted on

Here we see the GRS pistol grip machine.

The single active lever equipped with a blocking device so nobody accidently causes a service disruption.

Monday, February 13, 2012

Vintage Japanese Signalling Film

Now here is a little gem that proves the rule that sometimes the best way to learn about domestic history is to go abroad.  This two part YouTube scan of a 1950's Japanese public information film on railway signaling starts off like you would expect, lots of lower quadrant semaphores and block instruments.  However you will soon notice a US&S Style-S electro-mechanical lever frame...and then the entire second half of the film is dedicated to the operation of an electro-pneumatic plant operated by a rather impressive US&S Model 14 machine.

Now the entire film is in Japanese with no subtitles, but it really doesn't matter.  The film is spot on showing action on the Model 14 and the corresponding action in the field.  They get it all right, signal levers display signals and switch levers display switches.  You can see in detail the exact way one goes about throwing a lever.  Also on display is the Japanese system of Say-Point-Do (and sometime point again).  Where the train director issues a command, the leverman repeated it, points at the lever to be operated, operates the lever, points at the change in indication then states the action is complete.  The Japanese put American operators to shame (and its not the first time).  Anyway, here are the videos and if you get bored the Model 14 machine stuff picks up immediately in the second part.