Signals, interlockings, etc

[Anonymous]

I've always found signals and operations particularly interesting, so here's an open-ended thread for operations, signaling, interlocking, and all that wonderful rigamarole! Any former block or tower operators out there?

- Eric "COPY 19 EAST" Pedersen

[Anonymous]

I've always found signals and operations particularly interesting, so here's an open-ended thread for operations, signaling, interlocking, and all that wonderful rigamarole! Any former block or tower operators out there?

- Eric "COPY 19 EAST" Pedersen

[Saxman]

While I am not a dispatcher or operator, how the railroads evolved their systems of moving more than one train at a time over a segment of track is very interesting. A study in and of itself. A good read is "Rights of Trains."

[Saxman]

While I am not a dispatcher or operator, how the railroads evolved their systems of moving more than one train at a time over a segment of track is very interesting. A study in and of itself. A good read is "Rights of Trains."

[kenneo]

To start off with, how about a few "grenades"?

Who takes the siding at a meet and why? (There are several answers!)

What do all those lights mean on a signal mast?

Why do some signals "blink" and what does that mean?

Perhaps that could get us started????

Eric

[kenneo]

To start off with, how about a few "grenades"?

Who takes the siding at a meet and why? (There are several answers!)

What do all those lights mean on a signal mast?

Why do some signals "blink" and what does that mean?

Perhaps that could get us started????

Eric

[Anonymous]

Good ones there - as far as I know:

1) Well, it used to be during Timetable & Train Order operation that if there were two opposing trains, or a faster train coming up on an inferior train, the inferior train had to clear. Who was inferior? Well, back then, scheduled trains were conferred classes: first, second, and third. Then there were the "extras" - unscheduled trains, that had to keep out of the way of scheduled ones. If there were two trains of the same class opposed to one another, the one traveling in a certain direction (specified by the timetable) had to clear: for example, on a particular railroad, all eastbound trains might have to clear all westbound trains of the same class. Of course, nowadays there are no scheduled trains and it's all done on a case-by-case basis!

2) I wouldn't even know where to begin! I'll refer you to these extremely cool links that give you a pretty good idea:

http://www.lundsten.dk/us_signaling/index.html Carsten Lundsten's excellent site on N. American dispatching and signals

http://broadway.pennsyrr.com/Rail/Signal/ Mark D. Bej's sprawling site focusing almost entirely on signals, their application, and relevance to operation

http://home.comcast.net/~candcb1/ As far as signals go, this last link is just plain cool! The Historical Reference of Operating Rules and Practices gives you an interesting view of the regional trends (i.e., western roads versus northeastern roads), and how it has evolved over the years.

!

[Anonymous]

Good ones there - as far as I know:

1) Well, it used to be during Timetable & Train Order operation that if there were two opposing trains, or a faster train coming up on an inferior train, the inferior train had to clear. Who was inferior? Well, back then, scheduled trains were conferred classes: first, second, and third. Then there were the "extras" - unscheduled trains, that had to keep out of the way of scheduled ones. If there were two trains of the same class opposed to one another, the one traveling in a certain direction (specified by the timetable) had to clear: for example, on a particular railroad, all eastbound trains might have to clear all westbound trains of the same class. Of course, nowadays there are no scheduled trains and it's all done on a case-by-case basis!

2) I wouldn't even know where to begin! I'll refer you to these extremely cool links that give you a pretty good idea:

http://www.lundsten.dk/us_signaling/index.html Carsten Lundsten's excellent site on N. American dispatching and signals

http://broadway.pennsyrr.com/Rail/Signal/ Mark D. Bej's sprawling site focusing almost entirely on signals, their application, and relevance to operation

http://home.comcast.net/~candcb1/ As far as signals go, this last link is just plain cool! The Historical Reference of Operating Rules and Practices gives you an interesting view of the regional trends (i.e., western roads versus northeastern roads), and how it has evolved over the years.

!

[kenneo]

Well, Captnclack, you did well on #1. The short answer is "right, class, direction". Right is conferred by train-order (or Track Warrant) and ranks first. Class and direction are conferred by timetable and rank # 2 (class) and #3 (direction). The Superior Direction is conferred by rule and therefore applies to extra trains as well as scheduled movements. Also, by rule, extra movements, even though created by train order or Track Warrant, rank behind class and direction unless given right by specific order or Warrant.

As for an overtaking train, it can not pass the train ahead under any circumstance UNLESS if has a superior class or right conferred by train order.

As for #2, perhaps I should restate the question. On signal masts, there is always at least one signal head and oftentimes more than one all pointing the same direction. When there is more than one signal head, how does the engine crew determine which signals pertain to them and what are some of the instructions these signals might be giving?

What I am looking for here is "The one on top means ..." "The one on the left means ... ". "A flashing Red means ..." "Flashing Yellow over Solid Yellow means ..." and so on. For instance, if a train came to a signal mast with three heads, each head would mean what? If the signals showed red over red over flashing red, what would be the instruction?

[kenneo]

Well, Captnclack, you did well on #1. The short answer is "right, class, direction". Right is conferred by train-order (or Track Warrant) and ranks first. Class and direction are conferred by timetable and rank # 2 (class) and #3 (direction). The Superior Direction is conferred by rule and therefore applies to extra trains as well as scheduled movements. Also, by rule, extra movements, even though created by train order or Track Warrant, rank behind class and direction unless given right by specific order or Warrant.

As for an overtaking train, it can not pass the train ahead under any circumstance UNLESS if has a superior class or right conferred by train order.

As for #2, perhaps I should restate the question. On signal masts, there is always at least one signal head and oftentimes more than one all pointing the same direction. When there is more than one signal head, how does the engine crew determine which signals pertain to them and what are some of the instructions these signals might be giving?

What I am looking for here is "The one on top means ..." "The one on the left means ... ". "A flashing Red means ..." "Flashing Yellow over Solid Yellow means ..." and so on. For instance, if a train came to a signal mast with three heads, each head would mean what? If the signals showed red over red over flashing red, what would be the instruction?

[Anonymous]

This might be totally of topic but here goes. Soemone asked why do signals blink.. it changes the entire aspect of that signal for example:

a Yellow signal means "Clear to Stop" ie. Expect teh enxt signal to be REd.

A blinking Yellow means "Advance Approach" Proceed prepared to stop at SECOND signal. Trains Exceeding 45 mphs must reduce by 10 MPH before passing next signal (hence assumingand expecting the next signal will be a "straight-up" yellow. (No need to slow up by 10 MPH if the next signal displays Clear, Approach Diverging or Advance approach.

although i have never seen a blinking signal.. thats what it means ( UP here)

if this is even on topic!

Kev.

[Anonymous]

This might be totally of topic but here goes. Soemone asked why do signals blink.. it changes the entire aspect of that signal for example:

a Yellow signal means "Clear to Stop" ie. Expect teh enxt signal to be REd.

A blinking Yellow means "Advance Approach" Proceed prepared to stop at SECOND signal. Trains Exceeding 45 mphs must reduce by 10 MPH before passing next signal (hence assumingand expecting the next signal will be a "straight-up" yellow. (No need to slow up by 10 MPH if the next signal displays Clear, Approach Diverging or Advance approach.

although i have never seen a blinking signal.. thats what it means ( UP here)

if this is even on topic!

Kev.

[wabash1]

QUOTE: Originally posted by kenneo

Well, Captnclack, you did well on #1. The short answer is "right, class, direction". Right is conferred by train-order (or Track Warrant) and ranks first. Class and direction are conferred by timetable and rank # 2 (class) and #3 (direction). The Superior Direction is conferred by rule and therefore applies to extra trains as well as scheduled movements. Also, by rule, extra movements, even though created by train order or Track Warrant, rank behind class and direction unless given right by specific order or Warrant.

As for an overtaking train, it can not pass the train ahead under any circumstance UNLESS if has a superior class or right conferred by train order.

As for #2, perhaps I should restate the question. On signal masts, there is always at least one signal head and oftentimes more than one all pointing the same direction. When there is more than one signal head, how does the engine crew determine which signals pertain to them and what are some of the instructions these signals might be giving?

What I am looking for here is "The one on top means ..." "The one on the left means ... ". "A flashing Red means ..." "Flashing Yellow over Solid Yellow means ..." and so on. For instance, if a train came to a signal mast with three heads, each head would mean what? If the signals showed red over red over flashing red, what would be the instruction?

We guess at all them signals i just think they are pretty lights there to amuse us at 3am in the morning. guessing where we are going is the next task at hand.

On a more sensible note. the only time you will have mutiple lights is in mutiple track territory. And to tell which one is for you is simple. lets say you have 2 tracks on this line you are a north south line and we are going north. Like driving we are to the right the signal on the right is your signal . if we was on the south bound side going north it be the one one the left. ( this applies to over head type signals) now if it is single mast signal the closese one to your rail is the one for your movement..

as far as aspects go. kev gave a signal of approach restricted. and in canada that might be true but not here in the states. I am glad i work where i do we have the simplest signal system .

Green= clear grab a notch and keep going blowing for all those crossing that dont have proper signals couse someone misaligned them stole them and no flagman with a paddle. site limited due to sunglasses at night etc.

yellow= approach slow down to 30 mph prepared to stop at next signal.

red with number plate= restricting not exceeding 20 mph stopping in half the distance of what ever is there. ( unless it is a trainmaster holding a banner then turn off lights and get 3 notches)

red over red or if signal mast just red no number plate.= stop.
red over yellow = depending on where you are could be restricting or diverging approach.

red over green = diverging clear.

yellow over yellow= advance approach. be prepared to stop at 2nd signal.

red over red over yellow =restricting

red over red over flashing red= stop get directions couse i am lost its not on my railroad and i never seen one. i probley end up beeing drug tested if i did see one.


As far as who holds the main when they got rid of the cabooses the rule was who got there first held the main. But to be truthful I think the dispatcher flips a coin to see what happens or if it is one of his friends then he gets to hold the main.

Hope this answers the question

[wabash1]

QUOTE: Originally posted by kenneo

Well, Captnclack, you did well on #1. The short answer is "right, class, direction". Right is conferred by train-order (or Track Warrant) and ranks first. Class and direction are conferred by timetable and rank # 2 (class) and #3 (direction). The Superior Direction is conferred by rule and therefore applies to extra trains as well as scheduled movements. Also, by rule, extra movements, even though created by train order or Track Warrant, rank behind class and direction unless given right by specific order or Warrant.

As for an overtaking train, it can not pass the train ahead under any circumstance UNLESS if has a superior class or right conferred by train order.

As for #2, perhaps I should restate the question. On signal masts, there is always at least one signal head and oftentimes more than one all pointing the same direction. When there is more than one signal head, how does the engine crew determine which signals pertain to them and what are some of the instructions these signals might be giving?

What I am looking for here is "The one on top means ..." "The one on the left means ... ". "A flashing Red means ..." "Flashing Yellow over Solid Yellow means ..." and so on. For instance, if a train came to a signal mast with three heads, each head would mean what? If the signals showed red over red over flashing red, what would be the instruction?

We guess at all them signals i just think they are pretty lights there to amuse us at 3am in the morning. guessing where we are going is the next task at hand.

On a more sensible note. the only time you will have mutiple lights is in mutiple track territory. And to tell which one is for you is simple. lets say you have 2 tracks on this line you are a north south line and we are going north. Like driving we are to the right the signal on the right is your signal . if we was on the south bound side going north it be the one one the left. ( this applies to over head type signals) now if it is single mast signal the closese one to your rail is the one for your movement..

as far as aspects go. kev gave a signal of approach restricted. and in canada that might be true but not here in the states. I am glad i work where i do we have the simplest signal system .

Green= clear grab a notch and keep going blowing for all those crossing that dont have proper signals couse someone misaligned them stole them and no flagman with a paddle. site limited due to sunglasses at night etc.

yellow= approach slow down to 30 mph prepared to stop at next signal.

red with number plate= restricting not exceeding 20 mph stopping in half the distance of what ever is there. ( unless it is a trainmaster holding a banner then turn off lights and get 3 notches)

red over red or if signal mast just red no number plate.= stop.
red over yellow = depending on where you are could be restricting or diverging approach.

red over green = diverging clear.

yellow over yellow= advance approach. be prepared to stop at 2nd signal.

red over red over yellow =restricting

red over red over flashing red= stop get directions couse i am lost its not on my railroad and i never seen one. i probley end up beeing drug tested if i did see one.


As far as who holds the main when they got rid of the cabooses the rule was who got there first held the main. But to be truthful I think the dispatcher flips a coin to see what happens or if it is one of his friends then he gets to hold the main.

Hope this answers the question

[cabforward]

i rode a pass. train in the 60s.. sitting in the last car, i saw that we passed a signal.. i looked at the post and the signal facing the opposite direction of the train was flashing green.. ??

btw, this was on the tex&pac, a sub. of the mopac sys..

[cabforward]

i rode a pass. train in the 60s.. sitting in the last car, i saw that we passed a signal.. i looked at the post and the signal facing the opposite direction of the train was flashing green.. ??

btw, this was on the tex&pac, a sub. of the mopac sys..

[Anonymous]

The problem with aspects is that when explaining them you have to generalize - practice does vary throughout the country. In the eastern US, the focus is on speed-signaling: the engineer is told what =speed= to go. In much of the midwest (and all of the west), the focus is on route-signaling: the engineer is told if he will be taking the main or diverging route, but must refer to trackside signs or the special instructions for the exact speed through the turnout.

And to cabforward1:

I know that under NORAC rules, a flashing green (on the top or only head) means Cab Speed. I forget the exact definition but I believe it informs the engineer he's entering cab signaled territory, and instructs trains not equipped with cab signals to proceed on fixed signal indication. (Also under NORAC rules, a flashing green on the middle head of a three-head signal means Proceed at Limited Speed - an example of speed signaling - where Limited Speed is defined as 45 MPH, I believe.)

Of course, the T&P didn't operate under current NORAC rules so I could be very wrong! I remember I was in the same situation, actually - on an Amtrak train from Chicago to Boston, I saw flashing green as we passed an opposing signal. I think we were in NORAC territory, though... some insight here would be really interesting!

[Anonymous]

The problem with aspects is that when explaining them you have to generalize - practice does vary throughout the country. In the eastern US, the focus is on speed-signaling: the engineer is told what =speed= to go. In much of the midwest (and all of the west), the focus is on route-signaling: the engineer is told if he will be taking the main or diverging route, but must refer to trackside signs or the special instructions for the exact speed through the turnout.

And to cabforward1:

I know that under NORAC rules, a flashing green (on the top or only head) means Cab Speed. I forget the exact definition but I believe it informs the engineer he's entering cab signaled territory, and instructs trains not equipped with cab signals to proceed on fixed signal indication. (Also under NORAC rules, a flashing green on the middle head of a three-head signal means Proceed at Limited Speed - an example of speed signaling - where Limited Speed is defined as 45 MPH, I believe.)

Of course, the T&P didn't operate under current NORAC rules so I could be very wrong! I remember I was in the same situation, actually - on an Amtrak train from Chicago to Boston, I saw flashing green as we passed an opposing signal. I think we were in NORAC territory, though... some insight here would be really interesting!

[kenneo]

You guys are doing great, here!!! We have really got something going!

The simple answer to Q2 is Single Track Main Line with Two Diverging Routs. Starting at the top, Main, 1st Diverging Rout, Second Diverging Rout. The solid Red means STOP, DO NOT PROCEED ON THIS ROUTE. because this would be an Absolute Signal. The Flashing Red means STOP, PRCEED AT RESTRICTED SPEED.

All of you guys are correct, but speed signalling came to the west 20 years ago on the SP. In single track territory or multipletrack teritory signaled only for the current of traffic, the railroad instituted and signal system that combined both rout and speed signalling because they were wantint to operate long TOFC/COFC trains at as close to passanger speeds as they could.

Route singaling is set up to stop a train within one block, so blocks are train length plus a bit. Operating rules reflect that. For instance, signals 3/4 mile apart can support speeds no faster than 35 MPH and often less.

So here is what the SP did with its standard vanila CTC System and signaled TO/TWC territories. With CTC, you had a HOME signal (A Block; A=absolute. They have a letter A on the mast) with two heads on one mast. Next out was the advance or distant signal, also with two heads on one mast. From then on, it was single head on single mast ABS (Automatic Block System). Old method if you were going to go inside would be GREEN, then Yellow over either Yellow or Red, and then RED over either Yellow or Red. (that is correct, no Red over Green.) New way was Green, Flashing Green, Flashing Yellow, Yellow over Y or R and Red over Y or R. It should be evident here that a 100 car Pig (89 foot cars) doing 75 MPH over humps could slow down and stop in a very controlled manner. Each signal indication had a mandatory upper limit. The lower head on the Distant Signal was simply a repeater for the lower head on the Ablolute signal except if the block ahead were occupied, then it would be red.

[kenneo]

You guys are doing great, here!!! We have really got something going!

The simple answer to Q2 is Single Track Main Line with Two Diverging Routs. Starting at the top, Main, 1st Diverging Rout, Second Diverging Rout. The solid Red means STOP, DO NOT PROCEED ON THIS ROUTE. because this would be an Absolute Signal. The Flashing Red means STOP, PRCEED AT RESTRICTED SPEED.

All of you guys are correct, but speed signalling came to the west 20 years ago on the SP. In single track territory or multipletrack teritory signaled only for the current of traffic, the railroad instituted and signal system that combined both rout and speed signalling because they were wantint to operate long TOFC/COFC trains at as close to passanger speeds as they could.

Route singaling is set up to stop a train within one block, so blocks are train length plus a bit. Operating rules reflect that. For instance, signals 3/4 mile apart can support speeds no faster than 35 MPH and often less.

So here is what the SP did with its standard vanila CTC System and signaled TO/TWC territories. With CTC, you had a HOME signal (A Block; A=absolute. They have a letter A on the mast) with two heads on one mast. Next out was the advance or distant signal, also with two heads on one mast. From then on, it was single head on single mast ABS (Automatic Block System). Old method if you were going to go inside would be GREEN, then Yellow over either Yellow or Red, and then RED over either Yellow or Red. (that is correct, no Red over Green.) New way was Green, Flashing Green, Flashing Yellow, Yellow over Y or R and Red over Y or R. It should be evident here that a 100 car Pig (89 foot cars) doing 75 MPH over humps could slow down and stop in a very controlled manner. Each signal indication had a mandatory upper limit. The lower head on the Distant Signal was simply a repeater for the lower head on the Ablolute signal except if the block ahead were occupied, then it would be red.

[Anonymous]

Hey cabforward Flashing green means:

CP: you have the right of way

CN: you may turn any dirrection with your train (unless a sign clearly states NO LEFT TURNS)

BNSF: combination fo the 2!!

HAAHAHAHHA!

[Anonymous]

Hey cabforward Flashing green means:

CP: you have the right of way

CN: you may turn any dirrection with your train (unless a sign clearly states NO LEFT TURNS)

BNSF: combination fo the 2!!

HAAHAHAHHA!

[BR60103]

While the meaning varies from railroad to railway, a flashing light is a way to increase the number of colours in a signal from 3 (red, yellow, green) to six (solid+flashing). Extra heads on the same signal post add extra conditions.
Canadian Rule 414 (limited to slow) is red over flashing green over flashing yellow and means "Proceed, limited speed passing signal and through turnouts, approaching next signal at slow speed".
Rule 419 (medium to slow) is red over green over flashing yellow and means "Proceed, medium speed passing signal and through turnouts, approaching next signal at slow speed".
6 aspects on each of 3 heads gives 216 possible signal indications. I don't think all of them are used.

[BR60103]

While the meaning varies from railroad to railway, a flashing light is a way to increase the number of colours in a signal from 3 (red, yellow, green) to six (solid+flashing). Extra heads on the same signal post add extra conditions.
Canadian Rule 414 (limited to slow) is red over flashing green over flashing yellow and means "Proceed, limited speed passing signal and through turnouts, approaching next signal at slow speed".
Rule 419 (medium to slow) is red over green over flashing yellow and means "Proceed, medium speed passing signal and through turnouts, approaching next signal at slow speed".
6 aspects on each of 3 heads gives 216 possible signal indications. I don't think all of them are used.

[Anonymous]

All this sounds like alot to remember. Do the railroads give you cheater cards to refer to? Do they test you on this stuff? If so how often?

[Anonymous]

All this sounds like alot to remember. Do the railroads give you cheater cards to refer to? Do they test you on this stuff? If so how often?

[wabash1]

yes you are tested every year . and if you know your territory you dont need cheater cards.

[wabash1]

yes you are tested every year . and if you know your territory you dont need cheater cards.

[Anonymous]

Well, Microsoft has no problem issuing a cheater card with TrainSim, so I don't see why your average, everyday, run-of-the-mill Class 1 road couldn't spare a few extra pennies per crew... *ahem*

[Anonymous]

Well, Microsoft has no problem issuing a cheater card with TrainSim, so I don't see why your average, everyday, run-of-the-mill Class 1 road couldn't spare a few extra pennies per crew... *ahem*