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Sunday, July 27, 2014

Bad News with What Could Have Been

Almost all the new I post is of the 'bad" variety, but at the end of today's list I have two examples of the sorts of news we could be having if railroads weren't so slap happy about the scallop shell style Darth Vader signals.

First up it appears that NS has been going after the old Lehigh Line, which is fortunately leased to the Reading and Northern above CP-M&H Junction where NS re-signaling crews can't get to it.  I saw a photo of a train passing under a new southbound cantilever mast at CP-LEHIGHTON, which replaced older Conrail style small target searchlights.

CP-LEHIGHTON was notable for not only a surviving CNJ searchlight on the northbound main track, but also a ghost signal protecting the long removed LVRR main line that ran along the west side of the Lehigh River.  Additional photos can be found here.

NS is also re-signaling CP-253 on the Chicago Line at Port Clinton, OH.  The westbound masts were already given the Darth treatment years ago, but the new job will significantly reduce the length of the interlocking limits by 1000 feet or so.   What I don't get is why the slow speed siding signal is getting upgraded to something with a "straight" route head.  Planned triple-track project?

After dropping new signals all up and down the former Southern main line almost a year ago, NS is taking its time to actually cut them in.

The 32nd St (?) junction complex in Birmingham is probably getting ready to go into its second year as well. 

So would could we be seeing instead of this?  Well not so long ago in Canada new searchlights were still being installed and on right handed masts as well.

Considering LED searchlights are quite popular in the UK, that is one European technology I wouldn't mind importing.

Closer to home the aforementioned Reading and Norther is also installing brand new searchlights and although they are not being used in wider CTC projects, as you can see here the new masts are equipped for that eventuality.

Tuesday, July 22, 2014

Caught on Camera - Episode 3 Short Signal Distances

Today on CoC I wanted to follow up to my recent piece on NORAC signaling by showing a few interesting photos of the effects of short signal blocks and specifically those running under CSX's Seaboard style color light signaling. 

First up is this NS Penn Central Heritage unit running on the former NY Central Main Line in Amsterdam, NY at CP-188.  CP-188 was recently caught up in CSX's re-signaling fervor with the NORAC compliant former NYC signals getting the Darth Vader treatment with Seaboard style signal rules.  Here we see a Y/Y Advance Approach indication on the opposite track instead of the NORAC style *Y*.  This is a bit ironic as the NYC was a user of Y/Y for Advance Approach and Conrail had to change it all over to *Y*.  Incidentally  as the Seaboard signal rules lacks a flashing yellow aspect there was nothing preventing CSX from just adding it to the Advance Approach rule.  The short signal block is for the pair of "handed" interlockings the NYC liked to use in place of crossovers.

Sometimes Advance Approach just won't cut it.  Here we see F TOWER at Fostoria, OH which consists of three main lines meeting in a large triangle of diamonds.  The signal to the right has been pulled up to display a Seaboard R/R/Y Slow Approach for the stop signal plainly in view.  Under NORAC that yellow would have to flash.  Also note the strange central placement of the Red lamp on the middle heads.

Still at Fostoria, but on the C&O main line we can see that that railroad didn't care so much about stopping distances, especially since the C&O rulebook completely lacks Advance Approach (it uses Approach Medium instead).  Here we can see a Clear to an Approach all the way down to the Stop.

Finally we see an N&W 2-6-6-4 steam locomotive on a fan trip in 1991 about to take a an N&W CPL style Diverging Approach signal.  Yeah it doesn't have to do with short signal blocks, but its pretty cool.  Under the PRR this would be Slow Approach, but with route signaling there is no need to differentiate between speeds.

Saturday, July 19, 2014

Better Know a Signaling System - NORAC

Ah NORAC, the "there's more than one way to do it" signaling system was created out of the smoking mass of bankrupt railroads that were partly nationalized in 1970's in the form of Conrail, Amtrak and various state transportation agencies.  Primarily associated with Conrail, which was faced with merging the rulebooks of 10 or so former Class 1 railroads, NORAC effectively took the average of each of its predecessor's signaling systems and declared it a standard resulting in a signal aspect chart that some find to be rather confusing and bloated.

The truth is that NORAC is fairly straight forward with most of the "bloat" stemming from the incorporation of three flavors of PRR Position Light into every signal rule.  For today's discussing I will be ignoring the B&O CPL signal indications, which are basically used in Washington DC's Union Station complex and all the PRR PL rules as well seeing as they will get their own BKaSS post at some point in the future.

Simplified NORAC ruleset minus all the Amtrak specific aspects.
Strip out the PRR PLs and it is no more complex than any other.

The truth is that NORAC did an admirable job combining the signal rules from so many different railroads.  Both NS and CSX, when faced with the same problem, simply decided to adopt multiple signal rule sets with each railroad ending up with three, N&W, Southern and Conrail for NS and Seaboard, C&O and Conrail for CSX.  1999 Conrail breakup between NS and CSX devastated the "popularity" of NORAC as neither CSX and NS chose to enter into the compact, preferring their own rulebooks instead.  This leaves Amtrak, NJT, SEPTA, MBCR and the Guilford Rail System as the largest remaining "official" users, although technically everything I say will apply to any former Conrail signaling.

NYC route, Penn Central gantry, NS heads, NORAC signal aspects.
NORAC isn't just a speed signaling system, it is the speed signaling system which sets the bar from which all other speed signaling (or semi-speed signaling) systems can be measured against.  This isn't surprising considering it is the mashup of several existing speed signaling systems used by some of North America's largest railroads.  We've covered a lot of this before with the D&H rules, but unlike those NORAC is designed for more than a single track main line with passing sidings and includes a total of four primary speeds, Slow (15 mph), Medium (30mph), Limited (40/45mph) and Normal (Line speed). 

Medium Clear at SEPTA KALB Interlocking
While not less notable thanks to railroad consolidation, NORAC was an early adopter of Limited speed, taking what had been mostly limited to giants like the PRR and NYC and making it an option over its entire territory.  The speed upgrade was accomplished on high signals by flashing the Medium Speed green lamp.  Dwarf signals are a bit more interesting as NORAC decided to give the *G* option on single light dwarf signals over to Limited Clear as opposed to Medium Clear as seen on the C&O.  One might think that Medium Clear would be the morel likely upgrade path for a previously slow speed dwarf signal, but I guess Conrail had a bit of ambition or wanted to harmonize things with the *G*/R Limited Clear indication on a two lamp dwarf.

Speaking of Medium Clear, Conrail was faced with many instances of the legacy practice of having slow speed signals at the exits to sidings or non-signaled track.  These could take the form of a single searchlight or three lamp dwarf signal.  In some cases, where two lights were desired, the Red lamp in a G-Y-R stack could also be illuminated or a fixed red marker added below a searchlight.  As G/R Medium Clear is already less desirable thanks to bulb out issues, one way to provide Medium Clear is to keep the G/R Slow Clear and then use R/G for Medium Clear, which is what the Seaboard system went with.  As I mentioned before the C&O simply chose to flash its single green for Medium Clear, but  NORAC on the other hand picked a third option which was to flash the red marker light for G/*R*.  This is a unique solution to the Medium Clear indications on dwarf signals.

G/*R* is also a NORAC original seeing as the New York Central didn't even have a dwarf indication for Medium Clear. 

Medium Approach is another interesting signal aspect under NORAC.  Most of the NORAC color light tradition specified R/Y/R Medium Approach due to the use of R/Y for Restricting.  However requiring three heads on almost all interlocking signals was getting in the way of Conrail's cost cutting fervor so a more efficient needed to be found, especially as signaling systems were modernized.  

Each additional signal head costs upwards of $30,000!
The solution actually came from the PRR which in 1956 adopted a "R/*Y*" solution for the Medium Approach problem, which became an issue because the PRR only had use of two signal heads per mast and was running into issues having trains diverge over "straight" Approach. 

This was translated to color light and is another unique NORAC signal aspect.  Not content to stop there the Medium Approach not only followed in the Medium Clear pattern with Y/*R*, but, due to the lack of a straight Approach dwarf indication, took on that role as well.

NORAC was also unique in applying a special caveat to Medium Approach in that trains must begin reduction to Medium Speed as soon as the Medium Approach signal become visible instead of after passing it.  I am not sure why this is the case because visibility is a highly variable thing and such a rule would not be failsafe if it were actually safety critical.  I suspect there was some accident back in the day and someone thought it would be a good idea. Other speed signaled railroads not only ignore this idea, but spit it in it's space by offering a Limited Approach rule as well.  CSX makes use of its R/*Y* Limited Approach as a way to prepare lines to switch from NORAC to Seaboard rules seeing as how Medium Approach can be substituted for Limited Approach without loss of safety.

NORAC adopted the previously discussed practice of using both R/Y and R/R/Y for Restricting.  This was the root cause for having an issue fitting in Medium Approach in the first place.  While NORAC allows for the use of lunar Restricting I have never seen such a aspect employed by Conrail or any of the other NORAC member railroads, but again CSX found this useful when preparing lines to switch from NORAC to Seaboard rules.

Use of R/Y for Restricting can cause issues where engineers may also be used to traveling over territory with R/Y as Medium Approach and was cited as a contributing factor for an Amtrak rear end collision in Chicago.

Restricting into the yard.
With R/R/Y on high signals and Y on dwarfs reserved for Restricting this then begs the question what to do about Slow Approach.  Well once again flashing indications to the rescue.

NORAC broke from the NYC color light tradition in two additional places.  The first is the use of Y/Y for Approach Slow, even thought the Y/R/G option was retained.  Like R/*Y* Medium Approach, Y/Y Approach Slow could have been taken from the PRR tradition with its use of / over /.  No shenanigans on the dwarf signals for this one and unlike Seaboard or NYC, don't have a dwarf option for Approach Slow.

 If you are wondering what would then fill the role of Y/Y Advance Approach, you clearly didn't read my piece on signaling dialects.  Like many other signaling systems NORAC made the practical choice to adopt *Y* Advance Approach.  The primary advantage is that it allows existing single head signals to be modified in software in case block lengths are shortened.

The last major deviation from its predecessor roads is the use of R/Y/G for Medium Approach Medium as opposed to the older Medium Approach Slow.  Basically Conrail decided that the use case of Medium speed entrance to a siding with a dwarf signal exit was less important than back to back interlockings.  Moreover with so much single tracking Conrail was not really bound to the old school method of implementing single block passing sidings.  Lines with that system of operation were probably losing their signals entirely.

Still, M-A-M was never a popular indication on Conrail as signaling hardware and logic could be saved by the practice of diverging over Approach Medium/Slow/Limited to face a Medium/Slow/Limited Clear at the next interlocking.  In NS has been making far greater use of M-A-M in its recent orgy of re-signaling than Conrail ever did.  In fact the only place I regularly encounter this indication is on the River Line light rail system which is shared by the new Conrail SAA.

Well that is pretty much everything that makes the NORAC system unique and interesting.  As you can see NORAC is perhaps the most 'flashy' signal aspect system outside of Canada.  While most other systems may have one or two flashing indications NORAC has them all over the place, with their use in dwarfs pushing them past the likes of Seaboard. Now I didn't go into all the cab signal related signal rules, but those can be covered in their own post.

Sunday, July 13, 2014

PHOTOS: Port Road Trips - COLA to CRESS

For the last 4 installments of Port Road Trips we have been slowly making our way through COLA tower's CTC territory that stretched from STELL and JEB to CRESS and now be tackling the last last segment located south of COLA interlocking proper and running to the junction between the Port Road and the Atglen and Susquehanna Branch.  This section of the line originally consisted of three interlockings, MANOR, PORT and CRESS, and one automatic signal between MANOR and PORT.  Today only the automatic at A&S Milepost 35 and CP-CRESS remain.  For the first section we will once again refer to the COLA interlocking chart.

MANOR was located about 7000 feet railroad east of COLA's eastern hole signal and served as the east end of the Manor siding track as well as a trailing point crossover.  MANOR consisted of two switches, #25 onto the siding and the #23 crossover, and 5 signals controlled by two levers, the #26 for signals on track #2 and the siding and the #24 for signals on track #1.  The siding was restricted speed so the 26R was only equipped with a lower head \, the 24L making do with a Stop and Proceed marker. MANOR was removed sometime before 1986 and today there is almost no indication it was there except for the right of way narrowing slightly.

Between MANOR and PORT was the Milepost 35 automatics.  Like the automatics between COLA and STELL these were also prefixed with an 'L' before the 2010 resignaling project.  The original pair of PRR PL masts were numbered L351 in the westbound direction and L352 in the eastbound direction. 

With a restricted speed siding at MANOR diverging movements would get an Approach indication on the L351.  Both of these masts were relocated in the Conrail era, as evidenced by the steel caisson for one, as a result of the elimination of PORT. After the removal of MANOR the default indication on L351 remained Approach for a Stop signal at COLA.

In the opposite direction on track #1 the L352 mast was originally the distant to PORT interlocking where trains actually had a choice of routes and therefore a lower head | was provided for Approach Medium indications.

After PORT was removed the signal became the distant to CP-CRESS, where two tracks collapsed into one after the A&S flyover.  Track 1 drew the short straw and was signaled for a diverging move.  Without the "straight' route at PORT the best indication that L352 can display is Approach Medium with the default being Approach.

 After the 2010 resignaling these were replaced by a pair of bi-directional Darth Vaders.  Track #1 has the somewhat uncommon distinction of having a full lower head in the westbound direction to support the slow speed movements at COLA.  The L prefix has been removed from the number plate.  Note the old signal brackets on the catenary masts which are from the original L351/L352 placement.  I guess what's old is new again.

 As we move to PORT and CRESS we also move to a new interlocking chart.  PORT is the junction of the A&S "Low Grade" line and the Port Road.  As previously discussed the A&S was built in 1906 to provide an alternate route around the stiff grades on the Main Line between Atglen and Lancaster, including the high point of the Main Line at Gap, PA.   

PORT is one of the tradmark PRR Flying Junctions and compared to a flat junction PORT lacks the crossovers and/or diamonds such as were encountered at STELL.  PORT contained only two switches, #13 and #17, and two trios of signals, the #14 for eastbound trains and #18 for westbound.  Turnouts were both medium speed and driven with pneumatic point machines.  With the A&S removed PORT was straight railed for the Port Road, but unlike MANOR traces of the old interlocking still remain. Here we can see the old PORT relay hut and the bracket for the 14L signal.

Reverse view showing how the westbound tracks joined up a bit beyond the eastbound junction.  If you look closely you can see a large Conrail PORT station sign on the front of the relay hut which stayed in place some 20 years after the interlocking was removed.