Commonwealth Signaling Diagrams

Found two interesting websites with some top notch non-North American signaling diagrams.  The first is called SA Track and Signal and features all manner of track and signaling diagrams covering a significant portion of the Australian rail network.  Australia is a government owned model with lines being leased or trackage rights assigned.  This site looks like it caters to crews that need to qualify on unfamiliar lines.  Everything is in full color PDF's that starts at the regional scale and allows one to click down to the individual track and signal diagrams.  Signals are represented in full detail along with signs and other operating information, however these are not interlocking charts and switch numbers along with other signaler oriented information is not provided.

The other site I found hosts UK diagrams from the Glasgow suburban area, but the website itself is not railway related.  That is because it is a public access freedom of information site that put up a number of track and signal diagrams that were requested under a public information request.  These are much like the Australian diagrams with full color representations of the signals, but there is no convenient tree of linked maps.  The low level diagrams are provided on a web page list and you have to sort through them yourself.  These diagrams do include track and turnout speeds. 

Diagrams such as those apparently exist for the entire UK for use as training aids, but are not often made public due to misguided terrorism concerns.  Keep on the lookout because they are widely distributed and do show up from time to time in Google.

Bad Signaling at Bad Aibling

The Bad Aibling rail accident was a head on rail collision that took place on February 9th, 2016 on a single track portion of railroad near Bad Aibling Germany.  As of this writing the investigation is pointing towards human error on the part of the signalman and, more specifically, the fact that the signalman was playing a game on his mobile phone around the time the events of the accident occurred.  Now. while phone distraction has played a role in previous rail accidents, in this case I believe the true culprit is the design of the German railway signaling system itself and any claims of distraction are simply an easy answer.

This tower operator is distracted, but not unsafe

First let's deal with the issue of distraction.  Unlike operating a vehicle, operating a tower or dispatch interface does not require constant attention.  Of course it is better to have someone paying attention, but it is not unsafe and moreover, distractions are already built into the job.  Operators frequently have to use the restroom, eat meals, talk on the phone to other railroad employees or even leave the tower to deliver train orders.  In a job filled with distractions, the whole point of the signaling system is to prevent distraction from leading to accident.  It is a fundamental principal of railway signaling for things to fail safe.

German Zs1 Signal

The mechanism that allowed two trains to end up in a cornfield meet is the Zs1 signal, shown above.  Known as an "Ersatzsignal" or Substitute signal it is placed below a "main signal" and lit upon command of the signaler when the main signal cannot be displayed normally.  Many in English speaking rail circles have described it as a Restricting or call-on signal, but that analogy is not entirely accurate. In practice it is more like a manual block clear of the type that can still be encountered on the LIRR.  Trains pass the Zs1 and proceed through all turnouts at no more than 25mph and before they can increase to normal speed .  Some sources state the 25mph limit applies to the next main signal, but a majority say normal speed and that would agree with the behavior of the second train involved with the accident.

Zs1 Displayed for a train movement

 The Zs1 signal is displayed when, for any reason, the main signal governing movement into a section of track, cannot be displayed.  This can be due to a bulb out condition, an axle counter miscount or any other problem with the signaling system.  As far as I can tell, the Zs1 guarantees route locking only.  In most rail systems around the world, when the signal system fails trains must proceed on sight prepared to stop short of an obstruction or other problem.  This is because even in the case where the cause of the failure is known, that doesn't mean a second problem might exist.  Because the situation of compound failures can lead to accidents, in most of the world a substitute signaling system must replace the automatic one to relieve trains of this burden of traveling at Restricted speed .  As one might expect, performing this task can be quite involved, requiring multiple signalers and communicating the fact to many trains and qualified employees. However in Germany all it takes is a button press to light up the Zs1.

Bad Aibling Stellwerke

In North America there is no signal that can be displayed into a CTC block where traffic is set in the opposite direction in the same way a Zs1 is used in Germany.  You can't even give a Restricting against the flow of traffic, necessitating a permission past stop procedure and even then the train will continue to be limited to Restricted speed.  The permission past stop procedure involves speaking to the locomotive engineer, usually over an open radio channel.  Yes. dispatchers in North America can screw this up, but the procedure takes time, requires two persons and requires the operator or dispatcher to pay attention.  In Germany the signaler presses a button and the train operator heads on his way.  When used for routine problems like bulb out or axle miscounts the process can become rote and the procedure can be shortened or skipped entirely.

The Zs7 Caution signal is the best analog to North American Restricting

Unfortunately I don't as of yet know what the Zs1 procedure involves, but I from what I have read it consists of ensuring that the block is actually free of obstructions.  A newer signal, Zs7 Caution, is used in places where the signaler is unable to positively determine block occupancy and does in fact require the train receiving it to proceed at Restricted speed, but the problem of actually setting a route against traffic remains.

313 absolute signal where the Zs1 was displayed before the collision. Annotated version.

While misuse of the Zs1 was the ultimate cause of the accident, there were a number of other systemic factors that contributed to it.  First, closed channel radios are employed  in theory to prevent "confusion" over who is speaking to whom, but the end result is that train operators are kept in the dark.  Furthermore, in the case of the Bad Aibling accident closed channel radios actually prevented the signalman from being able to stop the trains involved with a radio call because he forgot the correct emergency broadcast code to use.  You know, as opposed to pushing transmit to talk.


Second, the use of axle counters as a cheap alternative to track circuits, only serves to further ingrain the manual block thinking.  Detecting track occupancy without track integrity only perpetuates the inability of distant signals to stop trains.  Moreover, while axle counters are prone to failure (or miscount), just like track circuits, the signaler is able to reset the problem on his own with a button, instead of needing a maintainer to fix it.  While some can see that as a feature, it removes a valuable form of two person control.  Again, fixing signal problems via the interlocking panel becomes habitual and eventually an accident happens.

Panel blocking was a basic way the PRR made operators think twice before bypassing signal protections.

Most signaling systems have their single point of failure.  In North America there isn't anything preventing an operator or dispatcher from giving a bad Form D and running a train into another on a stretch of single direction ABS track.  However for the last 50 years we have been on a quest to eliminate ABS and replace it with something where such a mistake cannot be made because the technology prevents it.  Germany however, despite all its fancy train protection systems, flank protection and signal overlaps, is still burdened with 19th century thinking when it comes to block systems.  As a society Germans are really good at following procedures so therefore these sorts of accidents are rare, but allowing something like the Zs1 still tempts fate and every so often you get burned.

Note: This is my 261st post.  Yay for important milestones!

Bad News In the East

Boy, it's getting hard to remember the last time I had any good news.  This week NS and CSX are taking center state as despite a decline in profits from falling coal sales, neither is putting a hold on signal replacement as one might expect.  I don't know what sort of world I'm living in where railroads have forgotten the art of deferred maintenance :-(

I'll start off with the most devastating news.   It looks like the CSX Chicago Line re-signaling project in New York has finally reached the 4-track raceway in the Buffalo terminal area.  This is pretty much the finest example of NY Central small target searchlight signaling there is and also one of the last.

 Out in Indiana, the Monon Sub, previously notable for losing its historic semaphore signals, is now losing its searchlights.  I always wanted to try and photograph these from Amtrak's Cardinal, but the signals on the daylight portion of eastbound trips had already been resignaled and the remainder saw the train in the hours of darkness.

If you think this scene from Michigan is more irrational disposal of new signal hardware you would only be partly correct.  These are C&O style signals being replaced by Seaboard.  No more economy lower heads without a red lens and no more Y/Y Approach Slow.  Why use 2 signal heads and 5 lamps when you can use 3 heads and 7 lamps!

 The CSX Toledo Sub continues to get hit at an uneven pace.  This B&O CPL gantry is an especially regretable loss.

Last month I reported on NS Marion Branch PRR PL replacement.  Well now I have confirmation that it does not just apply to automatic signals.

NS seems to be under the impression that the former N&W routes through coal country still have a future.  I don't even think these lines would need PTC due to the lack of any cargo other than coal and empty hoppers.  Come on, give the Pokey the Raton Pass treatment.

Chicago Line resignaling is still moving through Ohio.  I'm really going to miss those two lamp G heads.

Well that's pretty much all I can stomach for now.  Hopefully next week I'll have something more inspiring.

Updates!

Alright, I have an fairly major update of my METRA BLUE ISLAND Tower page to announce.  I had an opportunity to visit Blue Island in December, 2015 and was able to add a good number of exterior tower photos as well as interlocking layout photos.  Please go and check it out.

I also recently lost my long time web hosting mirror.  You might remember the problems I was having a few years back with photo hosting.  I actually went and swapped some of my posts over to use the backup host.  I believe I was able to change them back, but the occasional photo might still link to the old, palter,org site so if you see any broken links pointing there, please let me know and I'll fix them post haste.

Caught on Camera - Episode 8: Chinese Cab

I noticed this photo taken inside the cab of a Chinese HXD1C electric locomotive and immediately a number of interesting tidbits caught my eye.  Let's take a moment to step through them.

First my eye is drawn to the center of the cab and if I know my cab signal displays, that's a cab signal display with 8 bulbs.  Now each cab signal aspect may use multiple bulbs, so I can't tell how many cab signal indications this unit can display, but I believe it would be more than four.  There is one purple lamp lit and I know that, like France and the NY Central, China does does purple as a Stop indication at least on dwarf (shunt) signals.  By looking out the window we can see that the train is moving along the track at a good clip, however by looking at the centenary structure and condition of the concrete we can infer that the line has seen some years.

So what does this all tell us?  Well, we have a new model locomotive running at speed down a moderately old rail line with the most Restrictive cab signal indication displayed.  While China isn't big on safety, I don't this we're seeing a stop signal violation, instead the line is not equipped with cab signals.

In summary, China is a lot like the United States.  It has deployed an aspect based cab signal system with many new locomotives being equipped with the hardware, but for whatever reason the system has not seen universal adoption, or even adoption on all major rail lines.

Spring Newsbreak

I collected a number of additional news items over the last few weeks.  First and foremost, it appears that we might have a new contender for the "What Took You So Long" award.  Many many Newses ago (in 2014) I reported that NS was re-signaling the VRE portion of the Southern Main Line.  I even rushed out to photo document the line. Well the new signals were cut over about two years later!

Elsewhere on the former Southern, searchlight style signals continue to be replaced in Kentucky.

Re-signaling on the former NKP lines continues in Ohio.

It might not be NS anymore, but new interlockings are going in place around Port Jervis as part of the Port Jervis Line re-signaling project.  This interlocking will replace the old 'PA' manual crossovers west of the station in what is now a surviving portion of double track ABS.

PTC antennas are up at the former PRR Main Line Fostoria signals, but not to fear because there won't be any replacement signals.  This is partly because of long term NS plans to convert the line to 562 operation, something I consider preferable to Darth Vader heads.

Unfortunately, the same cannot be said for the NS Marion Branch out in Indiana.  This former NYC line was actually re-signaled with Rule 261 and PRR Position Lights by Conrail in the 1980's.  In a crushing loss low cost Vader masts are already in place :-(

Amtrak continues its slow project to re-signal STATE interlocking in Harrisburg.  The slow speed terminal is being upgraded for normal speed movements.  One casualty is the sole remaining double slip switch, here seen partly removed from service. In an odd twist, a new double slip was installed at the Albany-Rensselaer station terminal complex where one had not existed previously.

Also, Amtrak has just installed new Colorized Position Lights both east and west of the interlocking.  To the east is a two track cantilever mast.  To the west is this many track DIY gantry with more high PL signals.  This gives new evidence that PRR pedestal type signals are unavailable for new purchase and also that these passenger upgrade projects aren't trying to save $ buying used.

Russell's Teapot

If I were to tell you that on the hundreds of miles of former C&O trackage between Cincinnati, OH and Norfolk, VA there is still an island of C&O signaling with 3-4 track signal bridges displaying all the quirky old C&O signals, would you believe me?

Well you should, but not for much longer because it appears that despite plunging coal revenue and threats to downgrade the Cardinal route to 25/30mph operation, CSX has nevertheless found some money to make sure not a single signal without a Darth Vader helmet survives. 

 

The existence of this  strange island of misfit signaling is due to CSX's efforts to close RU CABIN, which controlled the eastern end of the giant Russell Yard complex, around the year 2000.  At that point the decision had still not yet been made to completely phase out the C&O signal rules so the new Darth Vader signals installed at RU and RACELAND interlockings were both of the C&O style.  

 RU Cabin westbound gantry

As seen at FOSTORIA, I believe the placement of a red lamp in the middle of the lower head was to allow for R/Y/R Slow Approach or R/R/G Slow Clear without using a third head, but I've seen no direct evidence of this.

Raceland westbound Passenger Track Mast

Moreover, NC CABIN, one interlocking east of RU, was re-interlocked with the existing signals left in place, sort of like as was done on the B&O Philly Sub and on many other rail lines before the cost of labour to splice and test overtook the cost of new signals.

NC Cabin westbound C&O masts.

Anyway, I guess someone had to spend a capitol improvement budget or risk losing it and with nothing left to re-signal, this island of the C&O was the only available target.  No word on if RU CABIN and its C&O Darth Vaders are also being modified, but I wouldn't be surprised.  If you happen to live in the area both RU and NC are a must see.