Positive Train Control Myths and Facts

Come along with me for a ride ... on a commuter railroad with short headways. As an engineer on the commuter railroad your daily assignment is to operate (run) trains from one point to another making two to four trips per day. It is the same four trips at the same time, and while weather conditions change not much else does. Every day is the same consist or one very close to it. It is commuter rail. Some systems may have old vs new equipment and have more variance between number of engines and cars but your trip on this railroad isn't different day to day. Unless you're running from the extra board you're seeing the same patterns, day in or day out. It doesn't matter what that pattern is ... if it is seeing approach after approach because of short headways or always seeing clear. The pattern is there. Ask any experienced engineer ... they will tell you something like: "We run track two from CP X with every signal clear ... diverging clear at these three CPs. We normally get an approach at CP Y and occasionally get held at the next signal for opposing traffic. Once that train clears we get a diverging clear to continue and then due to traffic we see a lot of approach signals until we reach the terminal." If you don't want to refer to that as chasing the same pattern, fine. Life goes on. Call it what you want it is still the same pattern every day. That is what running trains on a tight schedule creates

Obviously traffic patterns exist and an Engineer on a regular run becomes familiar with them. I still don't understand how you are equating that to the Engineer running with his eyes closed guessing the signals because he's "learned" the pattern.

Where have you worked? Do you "run" trains in a 'cab, no wayside' environment? How about a system with grade timed signals?

I'm not questioning engineers' professionalism or skill. But I've been at this for over 20 years, and I think I know a few things about rail operations at this point in my career. Pre-action exists. You gave a wonderful example yourself when you said:

"One quality of a good Engineer is beating the code drops to the punch, knowing the location and sequence of the normal code changes. You have to very much be aware of what you are doing, and remember to put on brake. If you did not realize, you would be hitting that code."

Exactly. You don't know exactly where the code change is; you "feel" it, and you're on the brake before you hit the code. Couldn't have explained it better myself. PTC will have a similar effect approaching speed restrictions.

So what is it that you do again? If you are not an Engineer, your opinion based on your "over 20 years you been at this", does not mean shinola.
As an Engineer you know where the majority of code drops occur, and I am not pulling that info from my subconscious. You are entitled to believe whatever it is you want, just as I am entitled to tell you your wrong.

I'm not going to argue this point. It's already been proven, time and time again. The Long Island Rail Road (amongst others - I'm just using this one because they run the most trains) actually incorporates engineer pre-action in their network simulations because it HAPPENS ALL THE TIME. If they don't account for this conditioned behavior, the simulations turn out too optimistic (i.e. they don't correlate with reality; trains run "better" in simulation, consistently).
Your statement "You never approach a stop signal expecting it to change to a more favorable aspect..." is demonstrably false every single day on PATH, where engineers run up on Stop signals because they've become conditioned to the timing system. They're not sitting in their cabs with a stopwatch; they have become conditioned at each location to the "feel" of the timing. They "know" that the signal will upgrade just as they reach it. They have not memorized their physical characteristics or learned the book of rules so well that they know how to do this. It's conditioning.

What network simulations? Can you provide exmaples?
How do you know those PATH Engineers would not be able to stop their trains if the signal did not improve? Again, I am not a PATH Engineer nor have I run on a system with timer signals. I have been on PATH trains and Subways where the Engineer/Motormen was following the timer, and a few instances I was able to look out front and observe the signals. Every time I watched, the Engr/Mmen approached the signal with caution, knowing that it should change, I assumed due to the timer, but in such a way that the train could be stopped if need be.
Did you perform an interview of PATH Engineers? Have you ever run a train on a timer system RR? Then again, what do you do?
Sounds like the PATH Engineers has simply learned the signal system and KNOW (keyword) when the signal will improve.

RogerOverOutRR wrote:Obviously traffic patterns exist and an Engineer on a regular run becomes familiar with them. I still don't understand how you are equating that to the Engineer running with his eyes closed guessing the signals because he's "learned" the pattern.

I'm not. That is a lie that you have invented. The eyes are open and the guy is following the same chain of events that he follows every day. You are once again reading stuff into posts that was never written and never intended.

So what is it that you do again? Because if you are not an Engineer, your opinion based on your "over 20 years you been at this", does not mean shinola.
As an Engineer you know where the majority of code drops occur, and I am not pulling that info from my subconscious. You are entitled to believe whatever it is you want, just as I am entitled to tell you your wrong.

Are you saying that you are using intentional concentrated thought to remember the entire line you run? That every "feel" of the train is processed through a specific recall process? Nothing comes natural to an "experienced engineer"?

Sounds like the PATH Engineers has simply learned the signal system and KNOW (keyword) when the signal will improve.

Put it any way you want ... it is rote knowledge of the way their trip will go, not the result of higher intellectual thought.

Edited for language by UPRR

I'm not. That is a lie that you have invented. The eyes are open and the guy is following the same chain of events that he follows every day. You are once again reading stuff into posts that was never written and never intended.

I call things the way I see it. Perhaps you should make yourself more clear in the future. The armchair RR'ing on this board is entertaining.

Are you saying that you are using intentional concentrated thought to remember the entire line you run? That every "feel" of the train is processed through a specific recall process? Nothing comes natural to an "experienced engineer"?

I based my post on my experience. The majority of running a train safely requires a good amount of concentration. A great deal of information is recalled from ones knowledge of the physical characteristics/rules etc of that particular railroad, especially if one has not run a certain portion of railroad in awhile. If you are not a hogger, then perhaps this all looks "natural", or "mechanical" to you. I would not expect you to know, and I would certainly not come to your place of work and make assumptions about something I know nothing about. There is nothing "natural" to running a train. No one is born in the seat.

Put it any way you want ... it is rote knowledge of the way their trip will go, not the result of higher intellectual thought

Sorry, wrong again. There is nothing done without meaning, or mechanical while running a train. Yeah, some things may be routine night after night, such as signal patterns. But you cannot say running requires little thought.

RogerOverOutRR wrote:So what is it that you do again? If you are not an Engineer, your opinion based on your "over 20 years you been at this", does not mean shinola.
As an Engineer you know where the majority of code drops occur, and I am not pulling that info from my subconscious. You are entitled to believe whatever it is you want, just as I am entitled to tell you your wrong.

Aahh, the "you can't possibly know what I do because it's unimaginably complex" argument. You don't know where the code drops occur until you run over them several times at the very least. Without a visual cue like a signal mast, you have no way of knowing exactly where the master location is, so you set up targets for yourself where it *seems* the code change occurs, based on your experience in running over them. You adjust your trainhandling based on where it seems to you that the code drops (which itself is variable due to latency in the ATC receiver, etc.) and on your feel for the current consist you're operating. Oops, sorry, "running". You noted yourself that you're on the brake "before the code". That's pre-action, my friend.

RogerOverOutRR wrote:What network simulations? Can you provide exmaples?

Yes. The Jamaica Central Control simulations, the East Side Access simulations, and the GO 3.0 simulations, to name three. What do you want, screen shots?

RogerOverOutRR wrote:How do you know those PATH Engineers would not be able to stop their trains if the signal did not improve?

Because I've been on enough head ends to know what 15 to 20 mph feels like (in addition to knowing the physical characteristics of the system), and there's no way any engineer is stopping that train when the signal holds red right up to the last second. I've been on the head end of a PATH train, as a matter of fact, that ran a Stop signal and was tripped. I don't believe there was a train ahead, I think the engineer just misjudged the timer.

Don't believe me? Go out and ride PATH a few times. Or take a look at Jtgshu's last post - he's an engineer for NJ TRANSIT. Or just don't believe me. I couldn't possibly care less.

RogerOverOutRR wrote:Again, I am not a PATH Engineer nor have I run on a system with timer signals. I have been on PATH trains and Subways where the Engineer/Motormen was following the timer, and a few instances I was able to look out front and observe the signals. Every time I watched, the Engr/Mmen approached the signal with caution, knowing that it should change, I assumed due to the timer, but in such a way that the train could be stopped if need be.

I've seen a train run a Stop signal and get tripped. At least two other posters on this thread have noted how PATH engineers "run" the timed Reds. Once again, believe it or not - I really don't care.

RogerOverOutRR wrote:Did you perform an interview of PATH Engineers? Have you ever run a train on a timer system RR? Then again, what do you do?

Very high level transportation management, came up from the ranks. Been doing it since freshman year of college, and I'm turning into an old fogie now. I have supervised locomotive engineers and supervised the supervisors of locomotive engineers.

I don't need to interview PATH engineers; the timer settings are NOT in the PATH book of rules and as I've already noted, the PATH engineers are not sitting there with a stopwatch.

RogerOverOutRR wrote:Sounds like the PATH Engineers has simply learned the signal system and KNOW (keyword) when the signal will improve.

Explain to me how first they can KNOW (key word) what the timer setting is when it's not published in Transportation Department documents, and second how they would use that information had they had access to it to KNOW (key word) when the signal will time out?

They do it totally by feel. After they run the segment 10+ times in a day, they get conditioned to when the signal will clear. Again, each timing section's timer setting is different depending on the desired speed, block length, etc. The engineers do not have a list of the timer settings. They get used to the time-outs, and they run accordingly. And sometimes get tripped by the stop arm.

Edited by UPRR

Aahh, the "you can't possibly know what I do because it's unimaginably complex" argument.

You do not do what I do, nor did you go through what I did to get where I am. With that your words hold little weight regarding running a train. Your first paragraph holds merit though, regarding code drops. It's this whole notion that there is no thought process involved is what I am disagreeing with.

Very high level transportation management, came up from the ranks.

Ohhh, excuse me then. I was not aware I was talking with "Very high level" management. What were your previous crafts?

Explain to me how first they can KNOW (key word) what the timer setting is when it's not published in Transportation Department documents, and second how they would use that information had they had access to it to KNOW (key word) when the signal will time out?

They do it totally by feel. After they run the segment 10+ times in a day, they get conditioned to when the signal will clear. Again, each timing section's timer setting is different depending on the desired speed, block length, etc. The engineers do not have a list of the timer settings. They get used to the time-outs, and they run accordingly. And sometimes get tripped by the stop arm.

You are just repeating what I said. Knowing how the timers react after learning how the system works. Again, I am not familiar with timers, and find it hard to believe an Engineer would approach a stop signal without respect and caution, prepared to stop.
Agree or disagree with what I share here, I am not going to go back and forth with non-essentials who do not run trains.

The level of concentration that is required to run a train, especially a passenger/commuter train is not something that can be explained. and yes, a good engineer uses "intentional concentrated thought" to run his train. Im always thinking ahead as to what is coming up, what I am going to do, and also a lot of "what ifs" etc. Not thinking ahead can cause surprises, and personally I don't like surprises.

I can picture right now in my head, the 300 or so miles of territory that I can qualified on. I can run each line back like a video in my head, in both directions, making station stops, my braking points, where to spot the train (one car off, two cars off, loco leading, cab car leading, etc, etc) where the signals are, their USUAL progression, etc. I can see the grades, I know what the train SHOULD do in certain locations, I know when to throttle off, I know when to give power, the whole nine yards. I can picture that for each stop. There are a basic set of things that I do, but those things are adjusted based on the reaction of the train, and how its handing, and the weather conditions, and you can't go by the weather conditions for the general area, as one station could have snow, while the next one have rain.

Those basic elements can be inputed to a computer - I put the brakes on at the 465 signal bridge for Princeton Jct going west when I have MUs at 80mph, and at the Millstone River UG brdige (I think thats the name of it) when I have coaches and I can go 100mph. However, those are just baselines. The variables are infintie. Some of them including are how the train is handling, and the weather conditions, and how I must adjust. If im going 100mph in Multilevels, and the loco is pushing, and its rain/sleeting/freezing rain out, and I use that same braking point, Im gonna be hard pressed to get the whole train on the platform at PJ. If the loco is leading, I can use a point close to there, but cab car? No way - the brakes will lock up and slidng at 100mph is not something that is fun....but in dry conditions, thats fine. Even humid days with a lot of dew can make for really bad rail conditions, and in some places and not others.

Its NOT natural, but its a tremendous skill that is developed over time, and can only be developed by running actual trains. Some enigneers might find it to be natural and make it look natural, but thats the skill of that person, so people can do certain things better than others. Also, the longer they have done it, the more an engineer will "poo-poo" it. "It is really that easy" - thats because they have forgotten what its like to be new and not have all their skills developed yet......

RogerOverOutRR wrote:I based my post on my experience. The majority of running a train safely requires a good amount of concentration. A great deal of information is recalled from ones knowledge of the physical characteristics/rules etc of that particular railroad, especially if one has not run a certain portion of railroad in awhile. If you are not a hogger, then perhaps this all looks "natural", or "mechanical" to you. I would not expect you to know, and I would certainly not come to your place of work and make assumptions about something I know nothing about. There is nothing "natural" to running a train. No one is born in the seat.

No one here has tried to claim that engineers are "mechanical", or that operating/running/hogging comes "naturally" to some people. It takes a great deal of training. No one denies that. You seem to be very sensitive about something that nobody has said.

You described pre-action to a "T". You don't actually know where the code drop is because it is not marked. You figure it out by running over the territory a few times, and you (consciously or unconsciously) set yourself a visual cue, a target by which you identify where it is you think the code drop is (even though you're probably wrong as to its physical location).

How does this relate to PTC? Civil speed enforcement under PTC will result in the same "pre-action" phenomenon, and based on how conservative a braking regime is finally chosen, will likely result in some loss of capacity.

RogerOverOutRR wrote:Quick, your ignorance is showing. You do not do what I do, your words hold little weight. Your first paragraph holds merit though, regarding code drops. It's this whole notion that there is no thought process involved is what I am disagreeing with.

...which is a straw man that you set up. I never said that there is no thought process. I have a great deal of respect for engineers, having worked with them just about my entire career, but lets face it - you're not a space shuttle pilot. What you do requires a lot of training and a lot of experience to do well. We agree on that. What you seem to have a hard time getting through your biases is the fact that some things you do, you do by feel. Whether or not you think you know where a master location/code drop is doesn't matter. I'm here to tell you that you don't, and if I asked you to get out and walk the track and mark an "X" where you thought the location is, you'd be wrong 90+ percent of the time.

RogerOverOutRR wrote:Ohhh, excuse me then. I was not aware I was talking with "Very high level" management. What were your previous crafts?

You asked, Roger. I've been a ticket agent and conductor on the craft side. And many, many, many moons ago. I've been qualified NORAC and GCOR (still am qualified GCOR, actually), and I've supervised your craft through most of my management career. Anything else you need to know?

RogerOverOutRR wrote:You are just repeating what I said. Knowing how the timers react after learning how the system works. Again, I am not familiar with timers, and find it hard to believe an Engineer would approach a stop signal without respect and caution, prepared to stop.

You might find it hard to believe, but it's true. I'm not going to repeat myself.

RogerOverOutRR wrote:Agree or disagree with what I share here, I am not going to go back and forth with non-essentials who do not run trains.

And again with the "you can't possibly understand the complex job I do" argument. Well, look - agreed. You are completely non-essential to my job, which involves knowing what you do and a lot more. I rather think that with some training I could do your job. I don't know that you could do mine, but perhaps I've misjudged you.

...which is a straw man that you set up. I never said that there is no thought process. I have a great deal of respect for engineers, having worked with them just about my entire career, but lets face it - you're not a space shuttle pilot. What you do requires a lot of training and a lot of experience to do well. We agree on that. What you seem to have a hard time getting through your biases is the fact that some things you do, you do by feel. Whether or not you think you know where a master location/code drop is doesn't matter. I'm here to tell you that you don't, and if I asked you to get out and walk the track and mark an "X" where you thought the location is, you'd be wrong 90+ percent of the time.

If you did not, then I apologize. No, I agree, the actual moving of the train comes down to seat of your pants, just not the knowledge part. BTW, I like to think of ourselves as Airline Pilots.

You asked, Roger. I've been a ticket agent and conductor on the craft side. And many, many, many moons ago. I've been qualified NORAC and GCOR (still am qualified GCOR, actually), and I've supervised your craft through most of my management career. Anything else you need to know?

I have never heard of any management other than Road Foreman able to supervise Locomotive Engineers.

And again with the "you can't possibly understand the complex job I do" argument. Well, look - agreed. You are completely non-essential to my job, which involves knowing what you do and a lot more. I rather think that with some training I could do your job. I don't know that you could do mine, but perhaps I've misjudged you.

Yes, again with it. Thanks for proving my point. You are not the only one, the land is full of people who think they can do what we do. It's okay though, the train will still move without your wisdom. I guess you would not know until you gave it a shot. So let me get this straight, PATH has Road Foremen supervising Locomotive Engineers who were never Engineers themselves?

Kicking this one where it belongs, passenger trains and commuter lines. Dont send it back down here.

Cleaned it up a bit, play nice guys.

RogerOverOutRR wrote:If you did not, then I apologize. No, I agree, the actual moving of the train comes down to seat of your pants, just not the knowledge part. BTW, I like to think of ourselves as Airline Pilots.

OK, I'm going to try to keep this nice, because I think my ugly self-righteous side reared its ugly head. I will say it again - you need to have a lot of training and knowledge to be an engineer. That includes knowledge of the physical characteristics. However, in cab-no-wayside territory where there are code drops, you can't possibly know where the code drop actually is. So, in order to run your train the way that you yourself said that you run, you would need to basically decide by feel (which comes from the experience of running over the territory many times) where you need to be on the brake in order to not run into the drop.

How does this relate to PTC? PTC will create, where it enforces civil speed restrictions, a similar "pre-action" situation. Engineers will begin braking before the "alarm" point, which is before the "enforcement" point, which is before the "optimal" point, as calculated by the safe braking model that has been assumed in the design of the system.

RogerOverOutRR wrote:I have never heard of any management other than Road Foreman able to supervise Locomotive Engineers.

Well, you've probably only worked in a few places at most. I've worked in a variety, both as an employee and as an operations consultant where engineers are supervised by non-engineers. Of course, for training purposes, recertification purposes, and for *some* efficiency testing purposes, you need an engineer. And in those cases, supervisors who are also engineers are used.

RogerOverOutRR wrote:Yes, again with it. Thanks for proving my point. You are not the only one, the land is full of people who think they can do what we do. It's okay though, the train will still move without your wisdom. I guess you would not know until you gave it a shot. So let me get this straight, PATH has Road Foremen supervising Locomotive Engineers who were never Engineers themselves?

I have not worked at PATH as a supervisor. I have, however, done extensive work for them as an operations consultant. Just so we're clear, none of the things that I've said here have been intended to be offensive to you or any other engineer. But, to be just as clear, the things that I've said have also been well established, including the pre-action phenomenon. They are as real to those of us who work in managing and designing rail transportation as your brake handle is to you.

In designing PTC systems for passenger rail applications, pre-action is one of many myriad things that have to be considered - there are other human factors considerations, debates about the lowest possible rail/wheel adhesion, debate about enforcement of bumper blocks, debate about were to apply for MTEAs (main track exclusion authorities), and debates about interoperability.

The one thing that is clear through all of it is that PTC, like most safety systems, is not primarily designed to enhance capacity. The best we can hope for is minimal effect. At worst, PTC will severely affect capacity and throughput. In high density operations, that will have a profound effect on the railroad's ability to deliver its current level of service.

Jtgshu wrote:Those basic elements can be inputed to a computer - I put the brakes on at the 465 signal bridge for Princeton Jct going west when I have MUs at 80mph, and at the Millstone River UG brdige (I think thats the name of it) when I have coaches and I can go 100mph. However, those are just baselines. The variables are infintie. Some of them including are how the train is handling, and the weather conditions, and how I must adjust. If im going 100mph in Multilevels, and the loco is pushing, and its rain/sleeting/freezing rain out, and I use that same braking point, Im gonna be hard pressed to get the whole train on the platform at PJ. If the loco is leading, I can use a point close to there, but cab car? No way - the brakes will lock up and slidng at 100mph is not something that is fun....but in dry conditions, thats fine. Even humid days with a lot of dew can make for really bad rail conditions, and in some places and not others.

Its NOT natural, but its a tremendous skill that is developed over time, and can only be developed by running actual trains. Some enigneers might find it to be natural and make it look natural, but thats the skill of that person, so people can do certain things better than others. Also, the longer they have done it, the more an engineer will "poo-poo" it. "It is really that easy" - thats because they have forgotten what its like to be new and not have all their skills developed yet......

Excellent post. This is why it's a challenge to design a system that is virtually transparent to the engineer, that just hangs back and waits to step in, in case of a mistake, rule violation, etc. The irony is that the safety encoded in the system (by the safety margins implicit in the chosen design's safe brake rate) may "dumb" the operation down if we don't get this right as an industry.

So, is the goal (and base requirement) of PTC that the train cannot ever break a rule? The brakes will automatically apply if an engineer/operator fails to apply them (perhaps even throwing the train into emergency)? All speeds will be absolutely enforced (line speeds, permanent restrictions and temporary restrictions)?

What does the system need to know? CP and intermediate signals are obvious. I'm assuming the absolute position of every mainline switch needs to be tied in. The status of every crossing gate? (No, I'm not suggesting vehicle on track detectors, just an alert if there is a malfunction detected. Then again, are vehicle on track detectors required?)

I understand that cab signals are not a requirement of the system ... I assume that in non-cab signaled systems engineers will know where the restrictions are primarily based on signals. Will there also be the ability to add in restrictions at any point on the line for work zones/etc.? Is this a requirement of PTC or just a feature many will implement?

"PTC required by 2015" needs definition. If "SafeAuto" designed a PTC system, what would they need to do?

jb9152 wrote:

RogerOverOutRR wrote:If you did not, then I apologize. No, I agree, the actual moving of the train comes down to seat of your pants, just not the knowledge part. BTW, I like to think of ourselves as Airline Pilots.

OK, I'm going to try to keep this nice, because I think my ugly self-righteous side reared its ugly head. I will say it again - you need to have a lot of training and knowledge to be an engineer. That includes knowledge of the physical characteristics. However, in cab-no-wayside territory where there are code drops, you can't possibly know where the code drop actually is. So, in order to run your train the way that you yourself said that you run, you would need to basically decide by feel (which comes from the experience of running over the territory many times) where you need to be on the brake in order to not run into the drop.

How does this relate to PTC? PTC will create, where it enforces civil speed restrictions, a similar "pre-action" situation. Engineers will begin braking before the "alarm" point, which is before the "enforcement" point, which is before the "optimal" point, as calculated by the safe braking model that has been assumed in the design of the system.

JB, one of the reasons for the "pre-actions" especially in 562 territory is the need to get suppression, its rough on the equipment and passengers having to suddenly jam on almost 50psi of brake cylinder to get suppression to make the cabs happy, and especially on Amtraks in NJ where they constantly flip inbetween various allowed speeds. If PTC would allow graduated braking, but not the "distant to target" like NJT's SES had where the speed was calculated by the distance to target, i bet the "pre-actions" would go down. Something that would have like a timer where you have say 8 or 9 seconds to get suppression and be down to a certain speed, (all calculated by the computer, with how far away you are, how fast you are going, etc) with a countdown clock I think would be a best case scenario. And when the clock would count down and get to 0, you would then say have 4 or 5 seconds to get suppression if still going to fast or not have enough brake on.

But then that brings us back to the computers and how are they going to calculate and adjust for the conditions, without being WAY to rediculously conservative.