ATC

[dale]

When are the railroads going to install ATC on the engines.

 

[CCC1007]

What do you mean?

Air traffic control?

Automatic trained chimps?

 

[Dale]

This has never been funny to me its Automatic train control dummy.

 

[amtkstn]

ATC is outdated. Now Amtrak uses PTC.

 

[Eric S]

Guest Dale, perhaps rather than insulting people you could elaborate on what you mean - are you referring to PTC (Positive Train Control) or something else?

 

[Dale]

I am sorry but after such a bad crash I don't like jokes. How good is PTD if accidents happen.

 

[CCC1007]

Accidents will happen with any human made system because of the inherent limitations of human minds

We can't think of everything!

 

[Dale]

Perhaps your right but if the engineer has to touch a lever every 30 seconds perahaps the carnage will stop.

 

[CCC1007]

That is already in place

It is called the "alerter"

 

[MattW]

When are the railroads going to install ATC on the engines.

When they can get the money to do so.

 

[tomfuller]

Congress voted today to cut funding for PTC.

 

[George K]

No, Tom. A committee of Congress voted to cut Amtrak spending. It hasn't gone to a vote yet.

 

[Eric S]

I am sorry but after such a bad crash I don't like jokes. How good is PTD if accidents happen.

PTC (I assume that's what you mean here) is not yet in place on this stretch of track.

 

[Alexandria Nick]

Perhaps your right but if the engineer has to touch a lever every 30 seconds perahaps the carnage will stop.

This is the kind of stuff that makes me wish the internet hadn't ever been invented.

That's needless hyperbole. What "carnage" are you referring to? One recent accident that killed fewer people than some car accidents? What's happening in Syria is carnage. This was an unfortunate accident.

 

[Dale]

All I know is when ATC was used accidents were avoided almost entirely. With techonolgy today they may have found a way to disable it but I don't think so. Yes it cost money and its a little inconvenant but well worth it if it saved even 1 life.I hope all of you who have seen ATC or any other back up for safety sake used will consider it as necessary especially on passenger trains.I wish we would have been one of the first countrys with high speed rail but we started too late I guess. Thanks for responding to a very important subject .

 

[user 1215]

PTC is NOT the absolute savior of rail safety! There has been technology in place for half a century to automatically stop a runaway train. The fact that there wasn't PTC doesn't mean that there were NO safety provisions installed. The question is what was installed, was it working, and could it have been overridden?

It's extraordinarily important, though, that if the powers that be say that PTC is important, that it gets fully implemented on the most critical portion of human life transport corridors before anywhere else.

 

[jis]

I have been staying clear of these discussions so far because the wheat to chaff ratio was so overwhelmingly on the chaff side. but let me try to see if we can bring some semblance of groundedness to the discussion.

The primary signaling system in place at that location is the old PRR Coded Track Circuit based Cab Signaling system enhanced with a second carrier frequency and an additional pulse code (270) to allow for additional signal aspects for speeds above 45mph. I believe the speed aspects that were added are 60mph, 80mph, 100mph and 150mph. So all in all the only speed limits that can be signal enforced are 20, 30, 45, 60, 80, 100, 125, and 150.

This section of track has most of the ACSES related hardware installed but ACSES is not in service in that area possibly because the radio link part of ACSES is not in place there yet.

The speed limit on the curve is 50mph, which is not enforceable at that exact value using signal speed indication as you see from the list above.

At present I don't know what signal indication is given at Shore for an eastbound train. It is probably a Clear, which leaves it to the Engineer to obey speed limits as documented in the employee timetable.

If ACSES (Advanced Civil Speed Enforcement System) were in service there would be a passive transponder in the track at Shore which would have the speed limit for the curve (its Civil Speed Limit) of 50mph and the start and stop mile reading for the limit, which the train would read as it passes over the transponder and self-enforce it even if the Engineer ignores it.

The present FRA decree is that ACSES must be in service in all segments where trains are allowed to operate at speeds over 125mph. Amtrak at present meets and exceeds that, in that it has ACSES in service on trackage beyond those mentioned in the decree. Starting 2016 it will be mandatory on all main line trackage, and Amtrak is well on its way to meet the deadline. At present all Amtrak equipment is equipped with ACSES and are not allowed to depart from an origin station with ACSES inoperative.

These are the facts (as best I know) of what protection systems are in place at that location.

Terms like ATC and PTC are pretty meaningless, except apparently for people who get impressed by confusing sounding acronyms. ATC is a especially fraught acronym, because it is applied to many different systems with varying capabilities. PTC as defined by FRA at least has a precise definition of required capabilities, but even there the actual implementation may vary quite a bit within parameters allowed by the regulation. You need to understand what the exact capabilities are to determine what could or could not have happened.

At present I don't have enough concrete information to go beyond this in terms of speculating what may or may not have happened, and am happy to wait for NTSB to complete its work.

In a post at another time in less emotionally charged environment, I will discuss what alternative means could be deployed within what is available to make it a little safer. However, everything costs money, so choices have to be made on prioritizing where the safety money is best spent for the maximum bang for the buck. So jsut because something can be done does not mean it is the thing to do in the bigger picture all the time.

 

[Ryan]

Thank you Jishnu, for bringing some much needed knowledge to the discussion.

 

[user 1215]

Excellent. I would like to add some chaff with another question. The famous "overspeed" switch. I've asked the question before about how P42's can operate on the SWC if the max speed for the rest of the fleet is 79. That question was answered with a box that allows up to 90 MPH. But then my question becomes, if (in SWC territory) the max speed is 90 MPH, the P42 will obviously stop the machine if that number is exceeded for more than a moment or two. In theory, then, are there parts of that route that are limited to, say, 25 MPH in a yard where the loco won't care if the train hits 90 MPH because that is the limit set?

I've heard over and over in this forum how it's nearly impossible for an engineer to overspeed a train - that it will put the train into emergency when the train goes too fast. The regulatory PTC isn't fully implemented yet, and my understanding is that is supposed to keep trains from colliding or fouling a red zone. Will PTC (or any variation of it) prevent overspeed around a curve, or how about even speeding through a temporary slow order?

Many of these have been in place without PTC, though with the various entities involved the standardization is probably non-existent. Even without PTC, there should have been some sort of safety mechanism to prevent the train from overspeeding through that curve. Or, do really have to have that much faith in our driver?

 

[jis]

Excellent. I would like to add some chaff with another question. The famous "overspeed" switch. I've asked the question before about how P42's can operate on the SWC if the max speed for the rest of the fleet is 79. That question was answered with a box that allows up to 90 MPH. But then my question becomes, if (in SWC territory) the max speed is 90 MPH, the P42 will obviously stop the machine if that number is exceeded for more than a moment or two. In theory, then, are there parts of that route that are limited to, say, 25 MPH in a yard where the loco won't care if the train hits 90 MPH because that is the limit set?

Correct. That is what will happen.

I've heard over and over in this forum how it's nearly impossible for an engineer to overspeed a train - that it will put the train into emergency when the train goes too fast. The regulatory PTC isn't fully implemented yet, and my understanding is that is supposed to keep trains from colliding or fouling a red zone. Will PTC (or any variation of it) prevent overspeed around a curve, or how about even speeding through a temporary slow order?

The specific PTC in question on the NEC is the combination of the coded track circuit based signal enforcement together with the ACSES based civil speed enforcement. In that setup, yes, speeds on curves, which are civil speed restrictions, will be enforced.

Many of these have been in place without PTC, though with the various entities involved the standardization is probably non-existent. Even without PTC, there should have been some sort of safety mechanism to prevent the train from overspeeding through that curve. Or, do really have to have that much faith in our driver?

We have had that much faith in our Engineers (both for signal enforcement and civil speed enforcement) since the inception of railroads, and it has been remarkably safe operation even in spite of these occasional glitches. The automation systems are basically being put in place to reduce the chances of such accidents, which is already very low, to even lower level and possibly eliminate them altogether.

 

[John Bobinyec]

Apparently, getting radio spectrum for wayside radios and getting those radios installed will cause delays to the implementation of PTC.

What role does radio play in the system? Why can't the information be sent through the track?

Here in NC, CSX controls its interlockings in places by sending the control signals through the track itself. Those signals have to come from and go back to Jacksonville. So if that kind of system works, why does PTC need radios?

jb

 

[Thirdrail7]

At present I don't know what signal indication is given at Shore for an eastbound train. It is probably a Clear, which leaves it to the Engineer to obey speed limits as documented in the employee timetable.

This is just a casual comment that has nothing to do with any sort of incident. I'm am responding to a general question in a general manner. No specifics are addressed or implied.

There is no cab signal drop heading east. They typically put them in where there is a dramatic change in track speed approaching a restriction. In this case, the change in track speed is only 30 mph for trains other than an Acela and 20 mph for an Acela set.

To put it in perspective, that is the equivalent to the Portal Bridge speed restriction in the middle of the High Line or the High Line speed change transitioning from 90mph to 75 mph to the 60 mph tunnels.

 

[jis]

That is what I thought was the case. Thanks Thirdrail. My interest is also purely in learning how things are set up and not with any specific reference to any specific incident, as might be obvious from the rest of this thread.

 

[TheTuck]

Just to provide additional information not necessarily related to any incident... the Santa Fe had a system known at Automatic Train Stop (ATS) which is still in use today on their former lines. ATS equipped passenger trains in ATS territory are allowed speeds as high as 90 mph (over the standard 79). This system simply provides an audible and visual warning to engineers when conditions change (passing a restrictive signal or approaching a permanent speed drop). It's up to the engineer to act accordingly as the ATS is simply a reminder to "do something", it will only apply the brakes if the reminder alarm is not acknowledged by the engineer. Cab signals go a step further as they are associated with the condition of the track ahead. This extra layer of safety allows equipped trains as much as 110 mph. I believe ACSES or any version of PTC is currently required for speeds above 110 mph.

 

[jis]

Actually Continuous Cab Signals are adequate for upto 125mph. ACSES overlay to enforce civil speed limits has so far been required only above 125mph. But with the PTC mandate it is required at all speeds to claim PTC compliance. Remember ACSES by itself is just half the story for PTC. The other half is the underlying continuous coded track circuit based cab signaling system. They have to work together to provide full PTC functionality and high speed capability.

I have heard that ETMS (the freight railroad adopted PTC system) will be restricted to 110mph, but that was sometime back and things may have changed since then.

California HSR as well as Texas HSR (if it comes to pass) will almost certainly use a different system, some form of ERTMS 2 (or some Japanese equivalent) in all likelihood.