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Track Signals

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Track Signals
Posted by power58 on Thursday, December 11, 2014 11:02 AM

A 2 Track BNSF has 2 signal lights on each track East bound and another set behind for West bound traffic. Last night a coal train was parked half way between the signals (Track 2) with the lead Loco east bound. If I looked back from the loco (West Bound) the Track 2 signals were Red/Red and the Track 1 signals were Red/Yellow. Coming the other way looking East bound the signals were Red/Red Track 2 and Red/Green track 1. In Somonauk There are crossovers for both tracks, the signals at the East bound entrance are Red/Red track 2 and Red/Red track 1 and on the exit of the crossovers looking West bound the same signal set up is used there are no green or yellow light in these signals, they seem to be on or off. Just wondering how to read the signals. Thanks.   

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Posted by Mookie on Thursday, December 11, 2014 3:04 PM

Amateur guess:  constant red, no other colors - may be approach signals. Just what it sounds like.  Red/green - go for now, but next signal may be a stop.  Someone will pick this up and give you chapter and verse on it, but for now - I think this is pretty close. 

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Posted by mudchicken on Thursday, December 11, 2014 3:15 PM

He's nor saying if its TCS or ABS or what signals have number plates - Needs to break out his GCOR rulebook and timetable.

(Sounds like he is on BNSF's ex-CB&Q Mendota Sub which is mostly CTC/TCS somewhere around Sandwich/Somonauk.)

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Posted by MikeF90 on Thursday, December 11, 2014 3:19 PM

I'm not a rail so I'll defer to the more expert. The reference for BNSF I have says:

Red over Yellow = Diverging Approach, reduce speed to 30 mph

Red over Green = Diverging Clear

Red over Red = Stop and proceed at restricted speed

power58
In Somonauk There are crossovers for both tracks, the signals at the East bound entrance are Red/Red track 2 and Red/Red track 1 and on the exit of the crossovers looking West bound the same signal set up is used there are no green or yellow light in these signals, they seem to be on or off.

Hmm, perhaps these are hold signals?

BTW Somonauk, IL is on the BNSF Mendota sub, 2MT CTC territory. Don't know of any others. Question To the OP, is this the one? https://goo.gl/maps/PMKji

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Posted by cv_acr on Thursday, December 11, 2014 3:24 PM

Probably looking at "Searchlight" signals which only have a single lens, which can be changed between different colours instead of separate lights for each colour. Absolutely one or more of those lights will be able to change to a different colour other than red.

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Posted by CShaveRR on Thursday, December 11, 2014 4:27 PM

I looked at the street view along Route 34.  The pictures are too blurry for me to decide whether these are searchlight signals or not.  But the appearance of some of these signals being "out" (say "dark" to a railroader) might be due to their extremely sharp directional focus.

From your original post, it sounds like the train is on both sides of one set of signals--of course those will be red-over-red, since the track is occupied on either side.  I could see only one set of signals in the shot of Somonauk, but there would have had to be others somewhere by the east end of the crossover pair.

These are "control point" signals (which I'm told is now the correct term for "home signals").  There, the aspects you're likely to see are:

Red/red:  stop (and stay).
Green/red:  clear down the straight route.
Red/green:  clear beyond the crossover, which you'll be using to go to the other track ("Diverging Clear").

The red/yellow signal you saw is just a variation on the red/green, showing that your train will be diverging through the crossover, and that the next signal you'll encounter will be red (stop and stay if it's a control point signal, and stop and proceed if it's not).  This was a "Diverging Approach" aspect.  Yellow-over-red would be an "approach" signal, telling you that the next signal will be stop or stop and proceed.

As others have suggested, so much depends on exactly which signals you're talking about.  If they have a number plate below the lights, they're intermediate signals, and the red becomes "stop and proceed" (or, in the case of most railroads nowadays, proceed at restricted speed without stopping).  

If you're still confused (or newly confused), you're not alone.  In spite of the fact that some railroaders are supposed to know all of this, it still can cause confusion, because the nuances might be different between railroads, up to the point where some signals can mean one thing on one railroad and a different thing on another.  And that has been known to cause some serious problems!

Carl

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Posted by power58 on Thursday, December 11, 2014 6:22 PM

The number plate for Track 1 looking west bound is 1575 and track 2  2575 Looking East bound Track 1 1574 and track 2  2574 . I made a mistake on the crossover signals they are 3 lamp and start at M.P. 59.48 in Somonauk. I have not heard of 2MT CTC.  

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Posted by power58 on Thursday, December 11, 2014 6:25 PM

Your map view looks correct for the crossovers at M.P. 59.48

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Posted by power58 on Thursday, December 11, 2014 6:29 PM

Yes the train was stopped between the signals. Thanks for your reply, it will make more sense next time I look over those signals.  Don 

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Posted by Mookie on Thursday, December 11, 2014 7:56 PM

Well, at least I knew what the poster meant by a signal. 

Our signals are a little different since they are still pretty close to the yard.  I can tell when a train is heading out to join the mainline pretty much what he is going to have to do.  They changed all those tracks around our depot, so they don't have to diverge that much any more.  Location, location, location. 

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Posted by K. P. Harrier on Thursday, December 11, 2014 11:15 PM

power58 (12-11):

 

Thanks to MikeF90’s post in this thread I was able to identify the area you mentioned.  The signals seem to be the traditional, modern color lights used contemporarily by BNSF.

 

Aerials of the area show nothing exotic signal- or track-wise.  So, I would venture to guess you saw absolute / control point signals other than red over red in a lined crossover mode.

 

If you were to see the area signals over several days, very likely you would see a high green, yellow, etc., and not just a red over. 

 

Best,

 

K.P.

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Posted by zinger7 on Thursday, December 11, 2014 11:24 PM

I semi-regularly drive US34 from Princeton, IL through Sandwich/Somonauk to Naperville, IL, and I can confirm that about a year ago or so, they switched the Searchlight signals for the new PTC signals.    :-(

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Posted by Deggesty on Friday, December 12, 2014 10:04 AM

Two maintrack (not double track) CTC is quite common now; it makes it much easier to run ane train around another one running in the same direction. And the track between Chicago and Aurora has been three main track with CTC for many years now.

"Double track" is usually taken to describe two tracks with each track signaled for traffic in just one direction--and if a train is operated in the reverse direction on such a track, its speed is limited, just as it is if there are no signals.

Carl, am I right that the UP also has three main track with CTC in the Chicago area?

I have stood at the rear of the eastbound California Zephyr as we traveled through Iowa and into Illinois, and enjoyed watching the movements as the dispatcher moved us from one track to another.

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Posted by Deggesty on Friday, December 12, 2014 10:10 AM

Number plates--those described show the track as the first digit (some roads put the track number at the end of the signal number, the next two digits (for less than 100 miles from the zero mp) give the last mp passed (when going out), and the last digit is the closest odd tenth mile (when going away from zero) for outbound signals, and the closest even tenth mile (when going towards zero) for inbound signals.

Incidentally, the CN, in Canada, has number plates on all signals, both interlocking and lineside. The convention in the U.S. is to number only lineside signals and not tonumber interlocking signals. So, in Canada, you have to know if a signal is interlocking.

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Posted by CShaveRR on Friday, December 12, 2014 10:30 AM

Johnny, you're mostly right about the UP.  It's three-main-track CTC most of the way from Kedzie (3 miles out from Chicago) to Elburn (45 miles out).  There are stretches that are still two-main-track CTC for now, but there are plans to put the third track in these in the near future.

Between Kedzie and Chicago, there are generally three or four tracks, but they aren't all CTC:  sometimes two are, and sometimes they're all directional, and close in they're under the control of the Lake Street tower operator.

I wish I could post the video I took of the entire Elburn-Chicago trip last fall (time-lapse...it took 24 seconds for the 45 miles!).  There were a few crossovers utilized then, trains met and passed, the whole nine yards (one yard=five miles, in this case).  


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Posted by power58 on Friday, December 12, 2014 11:23 AM

Thanks for all who have replied, learned a great deal from each post. Sorry I didnt become a Rail fan sooner Trains are a fascinating topic.  Don

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Posted by Deggesty on Friday, December 12, 2014 3:44 PM

Don, welcome to the forums. Do not hesitate to ask questions--and we (whether railroad employees or simply bystanders observing what goes on the railroad world) will be glad to answer your questions. When I became interested in railroading (63 years ago) I had to depend primarily on my reading, though I did learn some from the agent in my home town, and from trainmen in passenger service whom I had come to know.

And--when you are able to answer someone else' question, share what you know with the rest of us.

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Posted by jeffhergert on Friday, December 12, 2014 4:45 PM

Deggesty

Number plates--those described show the track as the first digit (some roads put the track number at the end of the signal number, the next two digits (for less than 100 miles from the zero mp) give the last mp passed (when going out), and the last digit is the closest odd tenth mile (when going away from zero) for outbound signals, and the closest even tenth mile (when going towards zero) for inbound signals.

I was under the impression. although the cases I know of it works out the same as inward or outward, that westward/southward signals ended in an odd number.  Eastward/northward signals ended in even numbers.  (Except for one wayside set just west of Clinton. IA where they attached the number plates backwards and have never changed them.) Just like the train numbering system used by most railroads back in TT&TO days.

UP signals (On railroads the UP acquired, the former railroad's numbering system may still exist.) just use the MP/tenths for the number.  The track number (for multiple track areas) have a separate number to designate the track.  Example 2092/1 and 2092/2 for the eastward signals at MP209.2.  The CNW was using separate numbers. Example eastward signals 1584 and 1586, one being on track 1, the other track 2 at the same location, about MP 158.5.  

Going back on an even older CNW numbering system, the old wayside signals in advance of the old Kate Shelley High Bridge when the line didn't have waysides except at, and in advance of, interlockings had numbers of 137 westbound and 140 eastbound.  (Signals were only installed for current of traffic movement.  At the time, only one train was allowed on the bridge at a time so it was protected by an automatic interlocking.)  The actual mile post locations were about MP 205 westbound and MP 210 eastbound, the best I can remember.  The numbering wasn't tied to mile post location. I think it encompassed the number of signals from a specific location.  I'm thinking the absolute or, from an earlier time, Home signals would've shown on a diagram as numbers 138 and 139.  Being absolutes, they didn't have number plates on them in the field.

Jeff 

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Posted by Deggesty on Friday, December 12, 2014 5:03 PM

Jeff, you would throw an oddball railroad in, wouldn't you?Smile

In general, the zero milepost is at the north or east end of the operation (of course, leaving New York City for Poughkeepsie and points north, zero is at the apparent south end--but you are moving west as you go).

I failed to mention the Wabash  as it comes out of St. Louis. As I recall, from my trip to Chicago on the Blue Bird, zero is in St. Louis, or thereabouts--and the tenth mile indicator on the signal number is even as you go towards Chicago, and odd, as you go towards St. Louis--I asked the flagman about that, but he had no real answer.

Numbering signals in succession--are they renumbered when the blocks are made longer?

 

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Posted by BaltACD on Friday, December 12, 2014 5:44 PM

Deggesty

Jeff, you would throw an oddball railroad in, wouldn't you?Smile

In general, the zero milepost is at the north or east end of the operation (of course, leaving New York City for Poughkeepsie and points north, zero is at the apparent south end--but you are moving west as you go).

I failed to mention the Wabash  as it comes out of St. Louis. As I recall, from my trip to Chicago on the Blue Bird, zero is in St. Louis, or thereabouts--and the tenth mile indicator on the signal number is even as you go towards Chicago, and odd, as you go towards St. Louis--I asked the flagman about that, but he had no real answer.

Numbering signals in succession--are they renumbered when the blocks are made longer?

 

On the P&LE, the station (now known as Station Square) at Pittsburgh was mile post 0.  East of Pittsburgh the milepost incremented upward as one move further East, the P&LE gave these a suffix of Y (for the Yougheheny River (sp) which it followed.

CSX has continued the existing mile posts on their Pittsburgh Sub with the MP East of Pittsburgh designated PLY and those West of Pittsburgh designated PLE. 

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Posted by rcdrye on Friday, December 12, 2014 9:45 PM
The last digit in some numbering system is more like a serial number - up to five in each direction between mile posts.
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Posted by cv_acr on Tuesday, December 16, 2014 3:29 PM

Deggesty

 

Incidentally, the CN, in Canada, has number plates on all signals, both interlocking and lineside. The convention in the U.S. is to number only lineside signals and not tonumber interlocking signals. So, in Canada, you have to know if a signal is interlocking.

 

In Canadian rules, the number plates have nothing to do with making the difference between a "stop" and "stop and proceed" signal. In many American rules, the presence or absence of a number plate isn't just convention, but makes a big difference in the meaning of the signal indication.

You don't just "have to know it's an interlocking signal"; the configuration of the heads will be different; for a home/interlocking signal displaying a "Stop" indication, there will be 2 or 3 heads all vertically aligned. Even for an isolated diamond otherwise in dark territory that can only display either a "Stop" or "Clear" indication, 2 heads will be used, the bottom one being permanently red.

For an intermediate signal displaying a "Stop and Proceed"* indication, there will either be just a single head, or 2 heads staggered to opposite sides of the mast if additional approach indications to an interlocking are required.

* Many are modified these days with a yellow metal plate with a large black "R" painted on it below the numberboard - which makes the red indication "Restricting" instead of "Stop and Proceed".

Here's the actual set of CROR signal indication rules on Transport Canada's website:

http://www.tc.gc.ca/eng/railsafety/rules-tco167-175.htm

Scroll down to rule 436, 437, 439, as these are the indications that actually change meaning based on the orientation of the signal heads.

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Posted by tree68 on Tuesday, December 16, 2014 4:41 PM

Deggesty
In general, the zero milepost is at the north or east end of the operation...

The Utica and Black River (later Rome, Watertown and Ogdensburg/NYC) is numbered north out of Utica.  The last milepost was U91 in Clayton, NY.

The Carthage,  Watertown and Sackets Harbor was numbered east from Sackets Harbor.  In fact, the mileposts on the old Carthage and Adirondack are still numbered west to east from Carthage to Newton Falls, with an "SH" (for Sackets Harbor).

Wasn't the SP numbered east from San Francisco?

Methinks it all depends on the anchor point of the railroad.

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Posted by CShaveRR on Tuesday, December 16, 2014 7:39 PM

The SP was mileposted everywhere from San Francisco!

Most railroads' mileposts were numbered upward from the north or east, because that was generally the way the railroads were built.  However, the line I grew up on was numbered from the south to the north, and even though the line has gone through many subsequent operators and is currently abandoned and with other parts spun off, the line's still numbered from south to north, starting from a number well shy of zero (because trackage was abandoned on the south end).

Just offhand, I suspect that the Grand Rapids & Indiana was numbered from Richmond, Indiana, north to Mackinaw City.

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Posted by BaltACD on Tuesday, December 16, 2014 10:57 PM

ACL & SAL numbered North to South on their primary lines with Richmond being MP 0.  The RF&P numbered from South to North with Richmond being MP 0.  Additional with the RF&P 2 main tracks - they are numbered 2 & 3.  Other territories on the SCL portion of CSX have their MP ordered South to North.   As territories have been acquired their existing MP designations have been continued with a CSX 3 character prefix which can be alphabetic or numeric.

On the CSX CADS model boards - West and North are on the Left side of the displays.  In at least one location where a N-S territory adjoins at E-W territory - Moving Northward (on what in Current of Traffic territory) would have been the Northbound track (top track on the display) would have you ending up on the Eastbound or bottom track on the E-W territory.  It can take some time for dispatchers to become accustomed to this quirk.

 

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Posted by Deggesty on Wednesday, December 17, 2014 10:49 AM

cv_acr
 
Deggesty

 

Incidentally, the CN, in Canada, has number plates on all signals, both interlocking and lineside. The convention in the U.S. is to number only lineside signals and not tonumber interlocking signals. So, in Canada, you have to know if a signal is interlocking.

 

 

 

In Canadian rules, the number plates have nothing to do with making the difference between a "stop" and "stop and proceed" signal. In many American rules, the presence or absence of a number plate isn't just convention, but makes a big difference in the meaning of the signal indication.

You don't just "have to know it's an interlocking signal"; the configuration of the heads will be different; for a home/interlocking signal displaying a "Stop" indication, there will be 2 or 3 heads all vertically aligned. Even for an isolated diamond otherwise in dark territory that can only display either a "Stop" or "Clear" indication, 2 heads will be used, the bottom one being permanently red.

For an intermediate signal displaying a "Stop and Proceed"* indication, there will either be just a single head, or 2 heads staggered to opposite sides of the mast if additional approach indications to an interlocking are required.

* Many are modified these days with a yellow metal plate with a large black "R" painted on it below the numberboard - which makes the red indication "Restricting" instead of "Stop and Proceed".

Here's the actual set of CROR signal indication rules on Transport Canada's website:

http://www.tc.gc.ca/eng/railsafety/rules-tco167-175.htm

Scroll down to rule 436, 437, 439, as these are the indications that actually change meaning based on the orientation of the signal heads.

 

Thanks, cv_acr, for clearing the matter up as to a distinction between interlocking and lineside signals. The next time I travel in Canada, I'll look for the distinction.

Balt, another practice on both the ACL and SCL--in general, branch mileposts read from Richmond. You can imagine how interesting this could be as the ACL's various lines in Florida wound about and crossed one another. And, the older employee TT's for both roads did not show the actual mileposts, but only the miles from the first station listed. This was quite annoying to me.

I'm sure you have noticed, that the main line coming south from Richmond has (or did have) negative mileposts in the TT--because of the relocation of the exit from Richmond, I believe. I have had no opportunity to observe signal numbers in that distance.

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Posted by BaltACD on Wednesday, December 17, 2014 11:04 AM

Deggesty
 

I'm sure you have noticed, that the main line coming south from Richmond has (or did have) negative mileposts in the TT--because of the relocation of the exit from Richmond, I believe. I have had no opportunity to observe signal numbers in that distance.

 

 

CSX computer and CADS systems do not permit negative milepost designations, they do allow zero as a legitimate value.

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Posted by mudchicken on Wednesday, December 17, 2014 11:23 AM

MischiefMilepost equations yes, short or long miles yes, negative mileposts no.

Mergers and line changes cause all sorts of havoc.

(Here in Denver, changes caused by the BN and BNSF mergers abound, there are several milepost zeros and plenty of befuddled operating and dispatching people, who in their zeal to simplify just made things worse. (We know who skipped math classConfused!!!)

DRGW/SP/UP created their own nightmare on the North Fork Branch in western Colorado where the actual location of mileposts is kinda a bizzare touchy-feely/ consult & read the tea leaves type of thingConfusedConfusedConfused

Like the SP, DRGW was always miles from Denver (original route) which created some odd equations after acquisition of D&SL and demise of the narrow gauge. DRGW Milepost zero now resides under the Pepsi Center (Former D&RG Market Street Yard)

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Posted by Deggesty on Wednesday, December 17, 2014 11:43 AM

BaltACD

ACL & SAL numbered North to South on their primary lines with Richmond being MP 0.  The RF&P numbered from South to North with Richmond being MP 0.  Additional with the RF&P 2 main tracks - they are numbered 2 & 3.  Other territories on the SCL portion of CSX have their MP ordered South to North.   As territories have been acquired their existing MP designations have been continued with a CSX 3 character prefix which can be alphabetic or numeric.

On the CSX CADS model boards - West and North are on the Left side of the displays.  In at least one location where a N-S territory adjoins at E-W territory - Moving Northward (on what in Current of Traffic territory) would have been the Northbound track (top track on the display) would have you ending up on the Eastbound or bottom track on the E-W territory.  It can take some time for dispatchers to become accustomed to this quirk.

 

 

Balt, don't forget the L&N, which had lines running all over the place, north from Louisville to Cincinnati and to Evansville, south from St. Louis through Evansville to Amqui (just above Nashville) and south from Louisville to New Orleans.

Many of the branches' mileposts were from the zero mp of the main (ACL influence?). For example, the two branches out of Flomaton carried Louisville mp's--so, going north from Flomaton to Myrtlewood, you were going out, and south to Chattahoochee you were going out.

I just checked my 1948 SAL TT's--they DO show the mp's from Richmond; it was ony the ACL which did not--and the ACL influence hovered over the AB&C, also in this respect.

When Champion Davis began supplying electricity from his grave (remember how he spokeof the Seaboard)the former ACL's mp's were prefixed with an A, and the former SAL's numbers were prefixed with an S. I wonder if any single person has memorized all the prefixes that CSX must use.

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Posted by cx500 on Wednesday, December 17, 2014 11:47 AM

While it is correct that signals are usually labelled with a mileage based designation there were, as always, exceptions.  A small interlocking plant where two railroads crossed, both dark territory, would sometimes in the past use a local alphanumeric name of 1 or 2 digits.  I suspect certain major terminal stations also devised different systems of naming each signal and turnout within their interlocking limits.

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