oltmanndSo, if there is a train in that block, does PTC try to enforce a movement authority to the end of that train or will it just let you run smack into it at 20 mph? That would kinda take the "positive" out of PTC.
This goes back to the basic definition of "restricted speed." Able to stop within half of ones sight distance. The maximum speed is not a factor in that - and it varies by railroad.
Larry Resident Microferroequinologist (at least at my house) Everyone goes home; Safety begins with you My Opinion. Standard Disclaimers Apply. No Expiration Date Come ride the rails with me! There's one thing about humility - the moment you think you've got it, you've lost it...
dpeltierAgain, I'm no expert, but I'm pretty sure that's not true. It is possible that PTC will raise a warning if a train crew tries to release an authority while they're still within its limits. But preventing a premature release of authority is actually quite different from what you said - namely, that PTC would prevent the dispatcher from issuing an authority to another train. That is not the role of PTC, but of the Computer-Aided Dispatcher (CAD) software on the dispatcher's workstation. These systems were pretty sophisticated well before PTC came along. PTC doesn't control the issuance of authorities, just keeps trains within their authorities.
The PTC test train I rode a few years ago was testing the release of authority behind the train in signalled territory. PTC would give the train an authority of 20 miles, lets say, and the system needed to roll up that authority behind the train block at a time so another could follow.
They were also testing "delayed in block" functonality, although I can't fathom why you need that in PTC territory unless you're concerned about a broken rail occuring during the delay or some such thing.
-Don (Random stuff, mostly about trains - what else? http://blerfblog.blogspot.com/)
oltmanndThey were also testing "delayed in block" functonality, although I can't fathom why you need that in PTC territory unless you're concerned about a broken rail occuring during the delay or some such thing.
"Delayed in block" is a regular part of Amtrak's radio vocabulary, account station stops.
"Amtrak 789 departing Podunk, delayed in block, in on a clear."
tree68 oltmannd They were also testing "delayed in block" functonality, although I can't fathom why you need that in PTC territory unless you're concerned about a broken rail occuring during the delay or some such thing. "Delayed in block" is a regular part of Amtrak's radio vocabulary, account station stops. "Amtrak 789 departing Podunk, delayed in block, in on a clear."
oltmannd They were also testing "delayed in block" functonality, although I can't fathom why you need that in PTC territory unless you're concerned about a broken rail occuring during the delay or some such thing.
The delayed in block rules are an outgrowth of the MARC vs. Capitol Limited collision that happened control point Georgetown Jct in Silver Spring, MD in 1996. The MARC train entered a station stop on an Approach Signal (prepared to STOP at next signal), however the crew departed the station stop as if they were operating on a Clear Signal (proceed at maximum authorized speed). MARC train being operated in push service came around a curved to find a STOP signal displayed and being unable to stop their train collided with the locomotives of the Capitol Limited that was moving through crossovers from #2 track to #1 track. Eight people on the MARC train died including the entire crew.
https://www.ntsb.gov/investigations/AccidentReports/Pages/RAR9702.aspx
Never too old to have a happy childhood!
oltmannd jeffhergert oltmannd tree68 oltmannd PTC can't enforce restricting because there's no way of knowing the end point of the authority. I would submit that PTC can't enforce restricted speed because it doesn't have eyes. The limits of restricted speed may be known. What is not always known is the conditions that require it. This would be why PTC would only enforce the maximum allowable speed under restricted speed. This could occur on main track. I wonder if PTC does enforce slow speed when restricting speed is indicated (such as being "talked by" a stop signal? Anybody know? PTC allows you pass an intermediate (non-absolute) signal at restricted speed. PTC gives a warning at 18 mph and initiates a brake application when speed goes over 21 mph, speeds as indicated on the PTC screen. (Speed on the locomotive's speedometer may differ by a few mph either way. My experience has been that usually the PTC indicated speed is 1 to 2 mph less than the locomotive indicated speed.) The same conditions apply when talked by an absolute signal. Jeff This is interesting. Thanks for taking the time to explain so clearly. So, if there is a train in that block, does PTC try to enforce a movement authority to the end of that train or will it just let you run smack into it at 20 mph? That would kinda take the "positive" out of PTC. I get the "talking by" an absolute. Signal could be broken - in which case PTC is, too. Or you could be tucking in a siding behind another train - which makes it look more like the first case.
jeffhergert oltmannd tree68 oltmannd PTC can't enforce restricting because there's no way of knowing the end point of the authority. I would submit that PTC can't enforce restricted speed because it doesn't have eyes. The limits of restricted speed may be known. What is not always known is the conditions that require it. This would be why PTC would only enforce the maximum allowable speed under restricted speed. This could occur on main track. I wonder if PTC does enforce slow speed when restricting speed is indicated (such as being "talked by" a stop signal? Anybody know? PTC allows you pass an intermediate (non-absolute) signal at restricted speed. PTC gives a warning at 18 mph and initiates a brake application when speed goes over 21 mph, speeds as indicated on the PTC screen. (Speed on the locomotive's speedometer may differ by a few mph either way. My experience has been that usually the PTC indicated speed is 1 to 2 mph less than the locomotive indicated speed.) The same conditions apply when talked by an absolute signal. Jeff
oltmannd tree68 oltmannd PTC can't enforce restricting because there's no way of knowing the end point of the authority. I would submit that PTC can't enforce restricted speed because it doesn't have eyes. The limits of restricted speed may be known. What is not always known is the conditions that require it. This would be why PTC would only enforce the maximum allowable speed under restricted speed. This could occur on main track. I wonder if PTC does enforce slow speed when restricting speed is indicated (such as being "talked by" a stop signal? Anybody know?
tree68 oltmannd PTC can't enforce restricting because there's no way of knowing the end point of the authority. I would submit that PTC can't enforce restricted speed because it doesn't have eyes. The limits of restricted speed may be known. What is not always known is the conditions that require it. This would be why PTC would only enforce the maximum allowable speed under restricted speed. This could occur on main track.
oltmannd PTC can't enforce restricting because there's no way of knowing the end point of the authority.
I would submit that PTC can't enforce restricted speed because it doesn't have eyes.
The limits of restricted speed may be known. What is not always known is the conditions that require it. This would be why PTC would only enforce the maximum allowable speed under restricted speed.
This could occur on main track.
I wonder if PTC does enforce slow speed when restricting speed is indicated (such as being "talked by" a stop signal? Anybody know?
PTC allows you pass an intermediate (non-absolute) signal at restricted speed. PTC gives a warning at 18 mph and initiates a brake application when speed goes over 21 mph, speeds as indicated on the PTC screen. (Speed on the locomotive's speedometer may differ by a few mph either way. My experience has been that usually the PTC indicated speed is 1 to 2 mph less than the locomotive indicated speed.) The same conditions apply when talked by an absolute signal.
Jeff
This is interesting. Thanks for taking the time to explain so clearly.
So, if there is a train in that block, does PTC try to enforce a movement authority to the end of that train or will it just let you run smack into it at 20 mph? That would kinda take the "positive" out of PTC.
I get the "talking by" an absolute. Signal could be broken - in which case PTC is, too. Or you could be tucking in a siding behind another train - which makes it look more like the first case.
PTC recognizes the block is occupied due to the signal system. (I don't work dark territory with PTC. I don't believe we have any dark-PTC territory in my area.) It, like the signal system does not know why there is an indicated occupancy. It could be an open switch (PTC will ask the position of facing point hand throws and stop you short if you don't verify the switch alignment.), a broken rail or a train. Other than the switch, a fixed location, it won't know where in the block the cause for the occupncy is. Yes, it will allow you to run into something at 20mph.
There is now a requirement for a stop test of every engineer at least once a year under a PTC-Restricted Speed scenario. I don't know if it's a FRA or company requirement. I've had one about 6 weeks ago.
The on-board PTC does not see other trains, whether on the same or adjacent track, going in either direction. The master, back office big brain may know where everything is, at least the head end of trains, but the on board brain doesn't
jeffhergertThere is now a requirement for a stop test of every engineer at least once a year under a PTC-Restricted Speed scenario. I don't know if it's a FRA or company requirement. I've had one about 6 weeks ago. The on-board PTC does not see other trains, whether on the same or adjacent track, going in either direction. The master, back office big brain may know where everything is, at least the head end of trains, but the on board brain doesn't Jeff
Before I retired, I heard Road Foremen of Engines discussing the need for 'Banner Testing' Engineers for Restricted Speed Compliance - I don't know if there was a requirement to test each Engineer each year or not.
Shortly after EHH took command the Road Foreman of Engines postions were abolished system wide. I have no idea who, if anyone, is performing the functions that the RFE's did.
BaltACD Shortly after EHH took command the Road Foreman of Engines postions were abolished system wide. I have no idea who, if anyone, is performing the functions that the RFE's did.
That is very bad news indeed, in my experience the RFE group is able to reign in or shoot down the idiotic whims and ideas that other managers (without on-the-ground railroad experience) come up with.
Removing that buffer will lead to the idiotic ideas being given free reign and that will cause accidents, if it has not already.
Greetings from Alberta
-an Articulate Malcontent
BaltACDShortly after EHH took command the Road Foreman of Engines postions were abolished system wide. I have no idea who, if anyone, is performing the functions that the RFE's did.
Trainmasters with engineer cards?
It's been fun. But it isn't much fun anymore. Signing off for now.
The opinions expressed here represent my own and not those of my employer, any other railroad, company, or person.t fun any
zugmann BaltACD Shortly after EHH took command the Road Foreman of Engines postions were abolished system wide. I have no idea who, if anyone, is performing the functions that the RFE's did. Trainmasters with engineer cards?
I am being told that 'Trainmasters' are doing downloads and 'Certification Rides' are being peformed on a simulator and signed off by 'Trainmasters' that have no idea what a train is or does.
Yikes! The blind qualifying the blind!
SD70Dude Yikes! The blind qualifying the blind!
Johnny
BaltACD zugmann BaltACD Shortly after EHH took command the Road Foreman of Engines postions were abolished system wide. I have no idea who, if anyone, is performing the functions that the RFE's did. Trainmasters with engineer cards? I am being told that 'Trainmasters' are doing downloads and 'Certification Rides' are being peformed on a simulator and signed off by 'Trainmasters' that have no idea what a train is or does.
I've heard of that happening here to for the intial cert ride for engineers. That was some time ago.
I've heard a couple of times when we had planned detours over other railroads, they qualified our people who were going to act as Pilots by giving them a ride over the territory in a high-rail pickup.
BaltACD jeffhergert There is now a requirement for a stop test of every engineer at least once a year under a PTC-Restricted Speed scenario. I don't know if it's a FRA or company requirement. I've had one about 6 weeks ago. The on-board PTC does not see other trains, whether on the same or adjacent track, going in either direction. The master, back office big brain may know where everything is, at least the head end of trains, but the on board brain doesn't Jeff Before I retired, I heard Road Foremen of Engines discussing the need for 'Banner Testing' Engineers for Restricted Speed Compliance - I don't know if there was a requirement to test each Engineer each year or not. Shortly after EHH took command the Road Foreman of Engines postions were abolished system wide. I have no idea who, if anyone, is performing the functions that the RFE's did.
jeffhergert There is now a requirement for a stop test of every engineer at least once a year under a PTC-Restricted Speed scenario. I don't know if it's a FRA or company requirement. I've had one about 6 weeks ago. The on-board PTC does not see other trains, whether on the same or adjacent track, going in either direction. The master, back office big brain may know where everything is, at least the head end of trains, but the on board brain doesn't Jeff
I think there is an FRA requirement for a certain number of stop tests, but a company can require more. A stop test can be done by any manager. Stopping for an absolute signal, even if it wasn't structured by the manager (having the dispatcher purposely hold the signal) can count.
Once we stopped at our crew change point, just short of a control point. A lower level manager got on board and checked off a number of tests (we passed all) we would be credited with. I noticed one for me was for stopping for the signal, and stopping where stop must be made. I didn't say anything, but the signal we stopped at was a Restricting. The signal didn't require a stop, the crew change did.
oltmannd dpeltier Again, I'm no expert, but I'm pretty sure that's not true. It is possible that PTC will raise a warning if a train crew tries to release an authority while they're still within its limits. But preventing a premature release of authority is actually quite different from what you said - namely, that PTC would prevent the dispatcher from issuing an authority to another train. That is not the role of PTC, but of the Computer-Aided Dispatcher (CAD) software on the dispatcher's workstation. These systems were pretty sophisticated well before PTC came along. PTC doesn't control the issuance of authorities, just keeps trains within their authorities. The PTC test train I rode a few years ago was testing the release of authority behind the train in signalled territory. PTC would give the train an authority of 20 miles, lets say, and the system needed to roll up that authority behind the train block at a time so another could follow. They were also testing "delayed in block" functonality, although I can't fathom why you need that in PTC territory unless you're concerned about a broken rail occuring during the delay or some such thing.
dpeltier Again, I'm no expert, but I'm pretty sure that's not true. It is possible that PTC will raise a warning if a train crew tries to release an authority while they're still within its limits. But preventing a premature release of authority is actually quite different from what you said - namely, that PTC would prevent the dispatcher from issuing an authority to another train. That is not the role of PTC, but of the Computer-Aided Dispatcher (CAD) software on the dispatcher's workstation. These systems were pretty sophisticated well before PTC came along. PTC doesn't control the issuance of authorities, just keeps trains within their authorities.
Not sure I understand your first paragraph fully, but I'm reasonably certain that in CTC territory the PTC computer doesn't keep an independent version of "authority limits" that's any different from the signal system, and that in dark territory it doesn't keep anything different from what the track warrant says. Because most authorities don't allow for unlimited backup moves, it does have to keep track of where the rear end is and it how far back it can move legally, but it doesn't "roll up" anything to the dispatcher.
Regarding your second paragraph, I believe that, even with every train using PTC, the delayed in block rule is still required to protect against certain kinds of problems. Consider a situation where you have an electric lock switch in CTC territory. Train A passes the block signal in advance of the switch points and then stops. Train B starts running time on the electric lock, and after it runs they open the switch. Meanwhile Train A starts moving again and accelerates quickly, so that when they get to the switch they can't stop and they crash into Train B. The DIB rule is supposed to prevent this from happening. (Of course, Train B's crew shouldn't have opened the switch without permission, and the dispatcher shouldn't have given permission if Train A was going to proceed across the switch... but these processes are not failsafe.)
Would PTC somehow prevent this from happening even without DIB? No. In signaled territory, PTC doesn't directly monitor each switch position; the signal system detects open switches and responds accordingly, then the PTC enforces the signals. Train A got a clear signal when they entered the block, and probably has a clear signal at the next block, so without DIB the PTC on Train A will allow maximum authorized speed. Train B never even came out on the main line, so there is nothing for its computer to enforce.
So you still need DIB.
Dan
Remember Delayed in the Block in GCOR is different in respect to ABS or CTC. In ABS, proceed at restricted speed until next signal is visible, displays a proceed indication and the track is seen to be clear to the signal. In CTC it's proceed prepared to stop at the next signal. (There ued to be a provision not to exceed 30 mph for freight trains, but it's been gone for quite a few years now.)
In my limited experience in such a scenario, once when there were facing point hand switches in CTC, the PTC screen showed restricted speed hash boxes only at the switches, not the entire block and asked for verifiction of the way the switches were lined before removing the hash boxes.
I haven't worked out one territory that is ABS/TWC/PTC. I don't know how DIB works up there.
BaltACDThe delayed in block rules are an outgrowth of the MARC vs. Capitol Limited collision that happened control point Georgetown Jct in Silver Spring, MD in 1996.
I think you will find that rule may go a lot further back, although perhaps not on all roads. Part of Rule 514 in a 1951 CPR Rule Book (Canadian UCOR) is:
"When a train or engine has passed a signal permitting it to proceed and is delayed in the block, it must proceed at restricted speed to the next signal."
I did not immediately find an exact upper limit for speed, but the 1962 version called for no more than 15mph (slow speed).
John
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