# Help me understand railway signals



## brandon02852 (Oct 3, 2012)

I plan on applying for a job with Amtrak as an engineer in a couple years (after I get a bachelor's degree) and am beginning to teach myself the NORAC rules (10th edition). I am currently teaching myself about signaling and reinforcing what I am learning with scenarios in Train Simulator 2013 (the new train sim that came out last week).

However, there are things that are really confusing me. Refer to the NORAC Rules PDF file located at http://www.blet57.org/NORAC.pdf.

Page 78 is rule 279 "Cab Signal Aspects".

1. In the SDU Display column, what is meant by "A green band"? For instance, the SDU description for cab speed is "A green band 0 to 60 or 80 mph". I know that cab speed is 80mph. It is 60mph if the SDU display doesn't show the signal speed OR if the cab signals aren't working. I need some clarification on this.

2. For the restricting signal and stop signal, how do I know whether to go 20mph or completely stop? I am at a loss to understand.\

Page 79 is the conformity between cab signals and fixed signals.

1. What does any of this mean? If the fixed signal indicates cab speed, my cab signal will be either "clear", "cab speed", "approach limited", or "approach medium"? How can it be more than one? I don't understand any of it.

2. What does it mean to just "approach"? What speed so I approach? I understand that approach medium is approaching the next signal at half of normal speed, but what the heck does approach mean?

If you can think of anything else that can help me understand signaling, I would gladly appreciate it.

Thanks!


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## MetraUPWest (Oct 3, 2012)

Please don't take this the wrong way, but trying to learn everything now is sort of a waste of time. Signals are different for each railroad. What may mean one thing on the CSX may mean another on the NS and a 3rd thing on the NEC, and western lines don't even use NORAC, they use GCOR, and the signals can even vary in the same railroad because of mergers and whatnot! I would focus on getting your degree for now, anything Amtrak would want you to know they teach you after they hire you, and please also remember that train simulator is a game, anything you do on there is nothing like the real thing.

If you find the rules and signals interesting by all means keep trying to learn if it interests you, but don't feel like you need to learn it all now. In my experience, if you would go into an interview and act like you know the rules without having prior railroading experience that may in fact work against you, not for you. Good luck with everything!


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## Nathanael (Oct 3, 2012)

The only conceptually important thing I've learned from hearsay is that "restricted speed" isn't merely a speed limit and shouldn't be thought of as one -- it means "be prepared to stop within half the range of vision".

The other thing I've learned from comparing different international systems of signalling (I find the compare-and-contrast very entertaining) that there's a difference between "permissive stop" (stop and proceed) and "absolute stop" (stop and stay stopped!), which are present with various signals in different rulebooks under different conditions. However, this will *all change* as PTC is implemented, so it's barely even worth studying how that distinction is being used now.

You will find it more interesting at this point to learn about the *theory* of railway safety (maintaining safe stopping distance, principles of block occupancy, interlocking, etc) because as MetraUPWest says, the actual signal rules are wildly different from area to area to an extreme degree, and the railroads will actually teach you on the job (on-the-job education is so rare these days, isn't it?).

The principles, however, will hold true under all conditions and could possibly save your life ("wait a sec... I just heard the dispatcher authorize another train into that block and now he's authorizing me into that same block....")


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## brandon02852 (Oct 3, 2012)

Well these are the rules as they pertain to Amtrak on the NEC. I will be learning this stuff anyway if I do get hired, so I think it would be beneficial to have some prior knowledge.

I understand that train simulator is a game, but it has accurate representations of the signals on the NEC that I can use to practice my interpretations of them.

I don't feel like I have to learn all of it now, but the more I know going in the better off I think I will be.


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## Trogdor (Oct 3, 2012)

Approach means be prepared to stop at the next signal. The maximum speed is dependent on what rulebook you're using, and can be further limited by a railroad's own special instructions.

Restricting means to proceed at a speed at which you can stop within half the range of vision, short of any obstruction on the tracks (men, equipment, broken rail, banners/flags, derails, etc.), but not to exceed a certain speed (in many cases 20 mph, in some cases 15, in some cases less). Restricting does not just mean to go 20 mph.

Stop means stop short of that signal, and do not pass without receiving authorization from the dispatcher (or until you get a more favorable signal indication).

As to when a signal can mean restricting vs. stop, it basically requires being qualified on the territory to know the difference. But, intermediate signals that are red generally mean restricting, and interlocking home signals will mean stop.


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## Trogdor (Oct 3, 2012)

brandon02852 said:


> I don't feel like I have to learn all of it now, but the more I know going in the better off I think I will be.


Be careful with that approach (no pun intended).

On the one hand, knowing stuff going into it can be helpful in enabling you to learn faster. On the other hand, though, it can give you a false sense of knowing something you really don't know, which could make the interviewer/instructor a bit more critical of you (and have them think you're a bit cocky), or at worst, could cause you to be overconfident and actually miss important stuff because you think you already know it.


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## zephyr17 (Oct 3, 2012)

Trogdor said:


> Approach means be prepared to stop at the next signal. The maximum speed is dependent on what rulebook you're using, and can be further limited by a railroad's own special instructions.
> 
> Restricting means to proceed at a speed at which you can stop within half the range of vision, short of any obstruction on the tracks (men, equipment, broken rail, banners/flags, derails, etc.), but not to exceed a certain speed (in many cases 20 mph, in some cases 15, in some cases less). Restricting does not just mean to go 20 mph.
> 
> ...


Typically, intermediates (and non-CTC) have number plates, absolutes don't.


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## MetraUPWest (Oct 3, 2012)

brandon02852 said:


> Well these are the rules as they pertain to Amtrak on the NEC. I will be learning this stuff anyway if I do get hired, so I think it would be beneficial to have some prior knowledge.
> 
> I understand that train simulator is a game, but it has accurate representations of the signals on the NEC that I can use to practice my interpretations of them.
> 
> I don't feel like I have to learn all of it now, but the more I know going in the better off I think I will be.


My best advice to you was already mention before, but try to think of "restricted speed" as a speed where you are able to stop within half the range of vision. When they say 20, that's the max, but there are occasions where it may be only 1mph, maybe to be stopped completely. Say you're in a VERY thick fog and you literally can see nothing- half the range of no vision is no range, so in that case it's safest to not move at all! As for the absolute signals, most of the times the non-absolute red that you can go by without authority do have numberplates on them, but not always. A timetable of that area of the NEC would list where all the absolute signals are, so if you have a copy of that it would be very useful for you. Page 76 (Rule 277) explains the numberplate/no numberplate signal- "A number plate attached to a signal's mast or in an adjacent location signifies that the signal's most restrictive indication is more favorable than Stop." What this means is that anything with a number plate is NOT a stop signal, if it does NOT have a number plate and it's red, then you can not go past the signal without proper authority.

I haven't played Train Simulator 2013, so I can't say how accurate the signals are in that game, but the games I have seen are basically nothing like real life, just try to keep that in mind.

I will do my best to answer questions you might have, though I work for a western railroad, and our signalling system is a lot different of the speed type signals they use on the NEC, so my knowledge of them isn't as good.


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## MetraUPWest (Oct 3, 2012)

brandon02852 said:


> 2. For the restricting signal and stop signal, how do I know whether to go 20mph or completely stop? I am at a loss to understand.\


After reading this a bit more, I think I figured out where you're getting hung up.Page 79 the chart says restricting, stop and proceed, and stop will all give you a restricting signal in the cab. Cab signals are tied into the actual wayside (trackside) signals, and will only change once you pass the wayside signal. You can't get a "stop" signal in the cab because by the time the cab signal would change to "stop", you would've already gone by the actual stop signal. With cab signals you have to watch not only the cab signal but also the wayside signals as well.

For the "approach"= page 87 gives the definition of an approach signal- "Proceed prepared to stop at the next signal. Trains exceeding Medium Speed must begin reduction toMedium Speed as soon as the engine passes the Approach signal." 

 

Medium speed is defined on page 9 as being 30 mph, so when passing an approach signal, you slow down to 30 mph, and prepare to stop at the next signal.


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## Trogdor (Oct 3, 2012)

The November 2012 issue of Trains magazine has an article about signaling (among other topics). Probably nothing new there, but might be interesting anyway.


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## Shortline (Oct 4, 2012)

MetraUPWest said:


> Please don't take this the wrong way, but trying to learn everything now is sort of a waste of time. Signals are different for each railroad. What may mean one thing on the CSX may mean another on the NS and a 3rd thing on the NEC, and western lines don't even use NORAC, they use GCOR, and the signals can even vary in the same railroad because of mergers and whatnot! I would focus on getting your degree for now, anything Amtrak would want you to know they teach you after they hire you, and please also remember that train simulator is a game, anything you do on there is nothing like the real thing.
> 
> If you find the rules and signals interesting by all means keep trying to learn if it interests you, but don't feel like you need to learn it all now. In my experience, if you would go into an interview and act like you know the rules without having prior railroading experience that may in fact work against you, not for you. Good luck with everything!


Yep-that. Don't over think it. What you learn now will in all probability be modified, changed, or added to between now and then and will be dependent entirely on where you are hired for. All you need to know going into it, is "Green you go, Yellow you slow, Red you whoa".

Besides, does Amtrak really hire engineers with no RR experience as a conductor first? (Not mocking, just asking....didn't realize it I they did.....)


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## Just-Thinking-51 (Oct 4, 2012)

Shortline said:


> Besides, does Amtrak really hire engineers with no RR experience as a conductor first? (Not mocking, just asking....didn't realize it I they did.....)


Yes Amtrak will hire locomotive engineers with out any real experience. Modoc Railroad Academy, 6 month shake and bake students have in past got jobs with Amtrak. I do believe Amtrak send them back to there school, but not sure if it's the full course or just a short intro course.


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## Swadian Hardcore (Oct 5, 2012)

If you want to be a professional engineer, I an't believe that you're trying to learn from a Train Simulator. Railworks is fun to play but not to be taken as a training course!


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## caravanman (Oct 5, 2012)

Hi,

I believe that I saw a tv programme about trainee usa rail engineers, where they used a computerised train cab simulator to help the guys get a feel for the real thing, a freight line if I recall correctly.

Rather different from my days as a trainee here in the UK:

I joined British Rail in the mid 1970's as an "engine cleaner"... There was a strict line of promotion, starting as a cleaner, followed by becoming a "secondman" which was the diesel equivilant of the steam engine fireman. After a few weeks training in the classroom, concerning signals, safety,rules, etc we were soon out on the loco with our driver, doing whatever was required of us under the watchful eye of the driver. (A train driver here is the same as an engineer in usa.)

Great times, as we learnt the traditions, operations, and how to drive a train in a hands on way, learning a little more each day.

My local station here at Skegness in Lincolnshire still has semaphore signals in 2012, pulled by levers and wires from the signal box... so much for computers!

Best of luck!

Ed


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## Ryan (Oct 5, 2012)

Swadian Hardcore said:


> If you want to be a professional engineer, I an't believe that you're trying to learn from a Train Simulator. Railworks is fun to play but not to be taken as a training course!


I don't think anyone is suggesting that this is a *replacement* for a training course and this guy is just going to get hired on and jump into a cab without any further training.


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## jis (Oct 5, 2012)

caravanman said:


> Hi,
> 
> I believe that I saw a tv programme about trainee usa rail engineers, where they used a computerised train cab simulator to help the guys get a feel for the real thing, a freight line if I recall correctly.
> 
> ...


The route of the Southwest Chief through Raton Pass has upper quadrant semaphore signals between Raton and Lamy. Kind of neat to watch them. brings back childhood memories in India, though my usual stomping grounds back then (Eastern, Northern and South Eastern Railway) were all lower quadrant semaphores.

No semaphores on the NEC which is where the OP is located apparently.


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## jis (Oct 5, 2012)

Getting back to signals....

BTW, you also need to be aware that NORAC signal aspect rules apply differently depending on whether you are in Cab Signaled territory or not. This is all described in great detail in the NORAC rule book. Then ACSES adds a bunch of additional stuff, again covered in the rule book.

For example the rule for Approach is basically "be prepared to stop at the next signal". In non CSS territory, if you know the next signal is 5 miles away, you don't have to start slowing down immediately as you pass the Approach signal. however in CSS territory Approach speed (30mph on NEC) will be enforced as soon as you enter the block governed by the Approach signal. So you have to be prepared to act accordingly or worst case face a penalty brake application.

Cab Speed indication on track side signal is conformant with a whole bunch of cab signal aspects because that simply says do whatever the cab signal says. And the cab signal can say any of the things that are conformant with the lineside Cab Speed indication.

There is a general tendency these days to remove track side signals and simply use cab signals, since maintaining track side signals is a headache and takes resources. So MNRR has basically removed all block signals, and has dwarf signals for home signals. Amtrak has removed block signals between Newark and New York when they shortened the blocks to increase capacity. Only track side signals there are home signals. Block signals will also get removed between New Brunswick and Morrisville as the system is upgraded as part of the HSR work and variable length blocks are introduced.


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## xyzzy (Oct 5, 2012)

I don't know how Amtrak hires and trains, so you'll have to figure that out for yourself. But I have heard the following advice -- repeatedly -- from people who have been hired by freight railroads. Railroads tend to look on people who say "I already know..." with disfavor, unless the prior knowledge was obtained on the job at another railroad. Railroads prefer to indoctrinate new employees as to how to think and how to act the way that the railroad specifically wants them to think and act.

For many years, disclosing one's status as a railfan or even someone who thought a railroad job would be more than just a job was the second fastest way to be tossed out of a job interview with one railroad in particular that I'm familiar with (disclosing a criminal record was the other). What railroads look for, or at least what they used to look for, is level-headed, dependable, calm, careful, patient, rule-abiding people who are capable of learning what the railroad will teach them and who will do what they are told.


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## LookingGlassTie (Nov 28, 2018)

*bump*

As an Amtrak passenger and "newbie" railroad fan, I've started trying to learn about the different signals, and what they represent based on the particular railroad that is using them.    Which would help to explain why, on my past Amtrak trips, the train has passed many signals which appear to be red.   Of course, this is dependent on the type of signal, the particular aspect of it, and the signal block or territory that the train is being operated in.


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## Just-Thinking-51 (Nov 28, 2018)

The signal will turn red as soon as the locomotive crosses into the block.  So by the time signal lamp goes past your window it should be red.  If your approaching a signal on a curve, or watching from trackside you will see the change.  Or the view from a VIA dome car.


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## Seaboard92 (Nov 28, 2018)

Well it won't always turn red as the locomotive passes. Usually it's a short delay after the locomotive but I have seen an occasional one lag even more than that. I've seen some drop to red as far back as twenty cars before. But that's very rare. 

But to help you learn signals here is a handy website you can look at. NORAC governs multiple railroads in the northeast so you should see a decent variety in there. Of course each railroad has different aspects you can ask the Indianapolis crews how many rules and signals they have to test on. 

http://rail.pgengler.net/signals/fixed_norac.html


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## Just-Thinking-51 (Nov 29, 2018)

I was more concerned about the poster thinking that his train was travel past red signals at speed.  As Seaboard92 put it  the block can be quite long.  Ever track on a railroad has a history of different ownership.  Each past company had different ways of do things,  Types of signals, and how to interpret them.  Sure the big railroads are standardized the hardware, but upgrades are not cheap.


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## Thirdrail7 (Nov 29, 2018)

Thirdrail7 said:


> In case you don't have the updated version of the new signals that were added a few years ago, here you are:
> 
> Updated Signals
> 
> ...


Don't forget the signals listed above.

Yes, I will use this every chance I get.  It never gets old.


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## SP&S (Dec 1, 2018)

Thirdrail7 said:


> Don't forget the signals listed above.
> 
> Yes, I will use this every chance I get.  It never gets old.


Conductor: load shotgun and fire,    love it.


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## Acela150 (Dec 1, 2018)

Thirdrail7 said:


> Don't forget the signals listed above.
> 
> Yes, I will use this every chance I get.  It never gets old.


Ah yes! This is a classic!


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## LookingGlassTie (Jan 31, 2020)

Bump

Got a question about signal blocks:

As I've mentioned before in other threads, I took a trip from Newport News, VA to Baltimore, MD in June 2017. I took Northeast Regional 94 from NPN to BAL on June 15 and took Northeast Regional 83 from BAL back to NPN on June 16.

It was on June 16 that a trespasser (I believe) was struck by the 90 Palmetto around Lorton. Our train was held by CSX dispatch at ALX.

So the question is: Was our train in the same signal block as the Palmetto or were the two trains in different (perhaps even adjoining) blocks? Would that explain why our train was held at ALX as opposed to being allowed to proceed a little farther south?

(I should add that as a result of the delay, I didn't actually arrive back in Newport News until really early on June 17. )

Thanks!


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## Shortline (Jan 31, 2020)

Unless there is a a specific Dispatching rule that prohibits allowing a passenger train into an occupied block, the answer is, could be either one. When there is an incident, and trains are stacking up until it's cleared, it's not uncommon for the dispatcher to "talk a train by" an absolute stop signal. That train would then be following the preceding train at Restricted Speed, and simply pull up and stop behind it. Or, if the preceeding signal was an intermediate, the occupied block would just be entered by either a restricting signal, or a stop and proceed red signal, and again, simply enter the block, looking out for the train ahead.

Or the preceding train was in a separate adjacent block. Just not enough info to know. But it's certainly possible, either scenario could be correct.


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## jis (Jan 31, 2020)

They may also just have preferred to hold a passenger train at a station instead of in the middle of the sticks, where it would be hard to get to should a passenger emergency of some sort arise.


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## Thirdrail7 (Jan 31, 2020)

I just want to make sure I'm following this.




LookingGlassTie said:


> . I took Northeast Regional 94 from NPN to BAL on June 15 and took Northeast Regional 83 from BAL back to NPN on June 16.



On June 16th, you were heading south on train 83, towards NPN.




LookingGlassTie said:


> It was on June 16 that a trespasser (I believe) was struck by the 90 Palmetto around Lorton. Our train was held by CSX dispatch at ALX.



Northbound train 90 struck something around Lorton and your train was held in ALX.

Two things come to mind. One is they likely held you in a station for accessibility reasons. The other thing is you have a northbound train and a southbound train.

I would sincerely hope they would not have had two trains heading in opposite directions in the same block.


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## MARC Rider (Jan 31, 2020)

Thirdrail7 said:


> I would sincerely hope they would not have had two trains heading in opposite directions in the same block.



Well, it might be possible if the dispatcher was Uncle Fester.


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## Jovet (Feb 6, 2020)

Shortline said:


> Unless there is a a specific Dispatching rule that prohibits allowing a passenger train into an occupied block, the answer is, could be either one.


There is. Sorta. An _absolute block_ is a state where the dispatcher guarantees a train sole access to its signal block. These are common for passenger trains to reduce risk of human error and collision. But these have to be agreed upon, and often requested. But it's likely that trains were simply held to keep the scene clear.

I think the OP probably got his signaling questions answered. But, North American signals can be rather confusing without any grasp of their core logic. Best explanation that I urge everyone to read is this: http://web.archive.org/web/20160313144451/http://alkrug.vcn.com/rrfacts/signals/signals.htm


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## Jovet (Feb 6, 2020)

Actually, just in case, I'll answer these in my own way. Even though they were asked 8 years ago. 



brandon02852 said:


> 1. In the SDU Display column, what is meant by "A green band"?


It's specific to the type of speed display you'll find in one of their locomotives. 



brandon02852 said:


> 2. For the restricting signal and stop signal, how do I know whether to go 20mph or completely stop?


You proceed until you _have_ to stop. As others have already explained, Restricted Speed is not a fixed speed limit, but changes moment to moment based on track conditions. It puts all the onus on the driver (engineer) to safely control the train and stop before _any_ danger or inconvenience to the train.



brandon02852 said:


> 1. What does any of this mean? If the fixed signal indicates cab speed, my cab signal will be either "clear", "cab speed", "approach limited", or "approach medium"? How can it be more than one?


The _fixed signal_ is the permanently-installed signal encountered along the track the train passes. A fixed signal can be a sign or a yellow light or whatever else is depicted in the Rulebook.
If the fixed signal shows _Cab Speed_, then it means the train should be governed according to what its onboard signal or speed display shows. It also means if you encounter a _Cab Speed_ signal, and the cab signal display does not show any of those cab signal aspects, then something is wrong and you can't trust it.



brandon02852 said:


> 2. What does it mean to just "approach"? What speed so I approach? I understand that approach medium is approaching the next signal at half of normal speed, but what the heck does approach mean?


"Approach medium" does NOT mean go half of normal speed. Such signaling is of the _speed signaling_ paradigm. This means that signal aspects directing trains to change tracks will always require a specific speed limit, based on their signal aspect. There are three standardized speeds that such signals can indicate: Slow, Medium, and Limited. _Approach Medium_ means you must not exceed Medium speed by the time and while passing the next signal. The actual speeds will vary by railroad and region, but generally Slow is 15 MPH, Medium is 30 MPH, and Limited is 45 MPH. As a verb, "approach" means "to continue and arrive upon". You arrive upon the next signal, which this signal is warning you about. As a signal rule, _Approach_ (by itself) means the same as "Approach Stop". Some rulebooks specify a speed you must slow to upon accepting (passing) an _Approach_ signal (e.g. "reduce speed to not exceed Medium speed"); others do not. Similarly, an _Approach Medium_ rule usually will not state how fast you need to slow down to immediately, it only states you must not exceed Medium speed at the next signal. It is up to the engineer's knowledge of the territory and train to comply with this rule. Conversely, a _Medium Approach_ (means the same as "Medium Approach Stop") says how fast you can only go now (Medium speed) and how fast at the next signal (Stop).

Hope that helps someone.


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## Shortline (Feb 6, 2020)

Jovet said:


> There is. Sorta. An _absolute block_ is a state where the dispatcher guarantees a train sole access to its signal block. These are common for passenger trains to reduce risk of human error and collision. But these have to be agreed upon, and often requested. But it's likely that trains were simply held to keep the scene clear.
> 
> I think the OP probably got his signaling questions answered. But, North American signals can be rather confusing without any grasp of their core logic. Best explanation that I urge everyone to read is this: http://web.archive.org/web/20160313144451/http://alkrug.vcn.com/rrfacts/signals/signals.htm



Right-I get that. I understand signals quite well. But it’s not uncommon to put two trains or more, into an absolute block when traffic backs up for some reason. The first enters in signal indication and stops at the next absolute, and following trains can be talked by the absolute stop signal and essentially pull up behind the stopped train ahead. I was just not sure if there was a rule that prevented dispatchers from doing that with a passenger train. It’s not uncommon for a freight train.


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## Jovet (Feb 6, 2020)

Shortline said:


> Right-I get that. I understand signals quite well.


I apologize for the confusion. An absolute block has nothing to do with signals (absolute or otherwise), nor anything to do with _absolute block signaling_ (common in Commonwealth countries).


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## saxman (Feb 6, 2020)

This is the best video I've seen about signals and how to read them on CSX. He has about 6 of these videos about signals plus other railfan videos with excellent narration and drone footage.


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## Jovet (Feb 6, 2020)

saxman said:


> This is the best video I've seen about signals and how to read them on CSX. He has about 6 of these videos about signals plus other railfan videos with excellent narration and drone footage.


I agree Mr. Harmon does a stellar job of railfanning videos. The best on the internet I've ever seen! His signal videos featured here do show off many examples of the various aspects, but tend to gloss over whys and whens. The site I linked above explains the logic, so combinations of colors don't have to be just learned by rote. There are also a few incompletes/mistakes, which I tried to address in the comments.


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