zugmann Euclid If the crew can see a track hazard, the sensor will be able to see it. What if I'm shoving?
Euclid If the crew can see a track hazard, the sensor will be able to see it.
What if I'm shoving?
EuclidThat would require total optical sensing that could tell if anything was out of place and required stopping short of.
As Balt said, line of sight. And that is limited in curves, whether it is human sight or some form of optical sensor. While an optical sensor may be able to identify another large object ahead, such as a freight car, locomotive or bridge pier, it will have difficulty (especially on curving track) identifying that it is on the same track. Track problems such broken rails will not be detected by any optical sensor until too late.
Restricted speed, as others had said, is a necessary work-around when the PTC software or hardware fails. It is not only humans that are fallible!
EuclidHow fast would you be going? Maybe a shove move would not have PTC protection. I think the idea is concentrate on the higher speeds of restricted speed where people can get killed in collisions more easily. Or maybe the sensors are all mounted stationary, lineside, and just blanket the entire railroad with sensing coverage. Their functionality could probably be extended if they were covering the entire property 24 hours a day. It would not require a train to show up in order to sense a problem like a vehicle stuck on the track or a washout.
As long as you have it figured out.
The opinions expressed here represent my own and not those of my employer, any other railroad, company, or person.
zugmann Euclid How fast would you be going? Maybe a shove move would not have PTC protection. I think the idea is concentrate on the higher speeds of restricted speed where people can get killed in collisions more easily. Or maybe the sensors are all mounted stationary, lineside, and just blanket the entire railroad with sensing coverage. Their functionality could probably be extended if they were covering the entire property 24 hours a day. It would not require a train to show up in order to sense a problem like a vehicle stuck on the track or a washout. As long as you have it figured out.
Euclid How fast would you be going? Maybe a shove move would not have PTC protection. I think the idea is concentrate on the higher speeds of restricted speed where people can get killed in collisions more easily. Or maybe the sensors are all mounted stationary, lineside, and just blanket the entire railroad with sensing coverage. Their functionality could probably be extended if they were covering the entire property 24 hours a day. It would not require a train to show up in order to sense a problem like a vehicle stuck on the track or a washout.
Shoving moves can hit the upper limit of restricted speed; CN's rules allow us to shove at up to 25 MPH with someone on the point as long as other applicable rules are complied with.
Of course one would never shove that fast when operating at restricted speed, our upper limit is 15 MPH.
Just wanted to show that shove moves are not just creeping around all day, and can hit the "higher speeds of restricted speed".
Greetings from Alberta
-an Articulate Malcontent
I understand the point about curves. People cannot see around them. For now, I don't expect optical sensors to see around curves either. I only expect optical sensors to do what humans cannot do at least as an immediate objective. But I think that as things are perfected, optical sensors may indeed surpass human scrutiny of the track ahead.
I am sure they will be able to see small objects as well as large objects like freight cars. And they will in fact see around curves if they are mounted stationary, along the right of way instead of carried on the locomotive.
If mounted along the track, they will also be able to handle shove moves at any speed. I expect all of this to come to pass even if it is not here today or in the current mandate. My only point is that I don't think PTC is fundamentally incapable with providing a lot, if not all protection during moves at restricted speed. All you do is tell PTC you want restricted speed, and it does the rest.
And so what if PTC can fail? Signals can fail, but nobody thinks signals are worthless just because they can fail.
Euclid And so what if PTC can fail? Signals can fail, but nobody thinks signals are worthless just because they can fail.
PTC is not worthless, but it is not a catch-all Godsend either.
These sensor plans sound very expensive, and will require a lot of ongoing maintenance in some very tough environments. It may end up being cheaper to keep a human employed to tackle these sort of situations.
Handing out night-vision binoculars to Conductors would have much of the same effect.
I think PTC could do more. The limitation currently is more the mandate than the concept.
One example is the moving block that would have been within the mandate but the chosen overlay system doesn't support it.
To provide moving block PTC needs to know were the preceeding train's rear end is to brake in time to prevent a rear end collision.
So the PTS concept would allow to prevent collisions between trains under restricted speed. It is not implemented. Non-railroad related are a different story.
I think PTC would be able to integrate a system that detects if a road crossing at grade is occupied by vehicles. Detection can be by radar scanner, infrared light barrier or induction loops. Here a radar scanner with 3 reflectors (2 visible):http://www.ostbahn.org/ecmf_edul/bue57_318a.jpghttp://www.ostbahn.org/ecmf_edul/bue57_318b.jpgFor cost reasons it is unlikely that this system gets implemented. I just post it to show that, at least in my opinion, Euclid's assumption is right that the current PTC is more limited by the mandate and its realization than the PTC's possibilities itself.Regards, Volker
Euclid That would require total optical sensing that could tell if anything was out of place and required stopping short of.
Like I said, we're seeing how well that's working out with driverless cars...
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...
PTC is not a perfect solution to preventing collisions and derailments. And it is true that it is often promoted that way. In any case, it will move ahead because the mandate forces the decision. I also agree that the sensors I mention will be very expensive. A comprehensive array of fixed location sensors along the track would certainly be a brave new world of technology.
Along with the optical sensors, would come new non-optical, special purpose sensors that would continuously monitor all rails for breakage. Sensors would also monitor all track alignment, and all track deflection as trains pass over it. Sensors would monitor all train movement to detect derailments the instant they happen. As Volker mentioned, sensors will see any fouling of all grade crossings. Basically every element of hazard or anomaly along the railroad will be detected and saved in the database.
Indeed, this surely will be expensive, and that’s an understatement. But I do not see PTC as something that is one day completed. A final completion is a view created by the mandate and its dictated completion date. In reality, I expect PTC to never be completed because it will always be in a state of improvement and extension in capability.
Much of that is the result inherent in the mandate. A federal mandate on a gigantic industry with deep pockets is a gravy train for developers and suppliers of PTC. These people will push PTC down any road they can dream up. And mandates predicated on improving safety are bulletproof. So PTC development being pushed by a mandate will never end because it will never be finished. In addition to extensions of application, parts will become obsolete technology as fast as new parts can replace them. So PTC will be a perpetual work in progress with unlimited cost and funding.
rdamonI am not sure how well optical sensors would work with the amount of vehicles who run red crossing signals.
I gave the example of grade crossing protection only to show that the PTC concept can provide more than is mandated currently. I think grade crossing protection with detection systems and PTC is only suitable for vehicles stuck on the tracks. You can't stop a train for every truck crossing the tracks before the gates close but within the train's stopping distance.
You can't protect people that try to beat the train, as pedestrians or in a vehicle.
As mandated PTC was not required to avoid collisions under restricted speed. Designed differently as stand-alone system, but within the mandate, PTC could have been calibrated to avoid this collision.Regards, Volker
Euclid I understand the point about curves. People cannot see around them. For now, I don't expect optical sensors to see around curves either. I only expect optical sensors to do what humans cannot do at least as an immediate objective. But I think that as things are perfected, optical sensors may indeed surpass human scrutiny of the track ahead.
Unless the curve is severly obstructed, humans can see around rail curvature, since their radii are much larger than roadways. Urban areas, mountains, cuts, and foliage being the primary obstructions which I'm thinking of.
You get a sensor! You get a sensor! EVERYONE gets a sensor!
zugmann You get a sensor! You get a sensor! EVERYONE gets a sensor!
Some are already too sensitive ;)
rdamon zugmann You get a sensor! You get a sensor! EVERYONE gets a sensor! Some are already too sensitive ;)
Do they come with a mechanic to recalibrate them?
They can't even keep our locomotive fridges set to the proper temperature, and the dial (if it even exists) is hidden somewhere inaccessible to the crew.
Even if we could find the dial I doubt we would be allowed to touch it without contacting the Diesel Doc first.
I suspect any PTC sensor system would fare about as well.
And just backtracking a bit here, wasn't this fatal crash between two pieces of railway equipment?
Even the current diet-PTC system should have seen the two heading towards each other and taken some sort of action.
Or was PTC not cut in yet in that area?
SD70Dude And just backtracking a bit here, wasn't this fatal crash between two pieces of railway equipment? Even the current diet-PTC system should have seen the two heading towards each other and taken some sort of action. Or was PTC not cut in yet in that area?
If an equipped train (and I don't know how the Herzog equipment is equipped) is making shoving or switching moves, PTC enforcement is temporarily suspended. PTC on the other train does not know why a signal (whether a permissive red or authorized past an absolute) is requiring restricted speed. All PTC "knows" is that restricted speed is required.
I think we need a thread on what PTC (currently) can and can't do.
Jeff
A rare bug in PTC can cut out the automatic air brake valve on a moving train without first making a penalty brake application.
SD70DudeAnd just backtracking a bit here, wasn't this fatal crash between two pieces of railway equipment? Even the current diet-PTC system should have seen the two heading towards each other and taken some sort of action.
Wasn't it you who posted the following:
jeffhergert PTC enforces the top end of restricted speed. It will make a penalty application if speed rises above 21MPH. (I've noticed the PTC speedometer, that goes by GPS, is usually 1 to 2 mph slower than the locomotive's speedometer.) Since PTC doesn't know where the obstruction is in the block, it can't stop you short. It only keeps the collision at a relatively slow speed. But still fast enough to cause damage that can lead to, and has led to, fatalities. It will query the position of facing point switches. Which requires the engineer to select the correct position. If no position is selected or the open position is selected, the PTC will then stop the train short. Jeff To refresh everyone's memory.
jeffhergert PTC enforces the top end of restricted speed. It will make a penalty application if speed rises above 21MPH. (I've noticed the PTC speedometer, that goes by GPS, is usually 1 to 2 mph slower than the locomotive's speedometer.) Since PTC doesn't know where the obstruction is in the block, it can't stop you short. It only keeps the collision at a relatively slow speed. But still fast enough to cause damage that can lead to, and has led to, fatalities. It will query the position of facing point switches. Which requires the engineer to select the correct position. If no position is selected or the open position is selected, the PTC will then stop the train short. Jeff
PTC enforces the top end of restricted speed. It will make a penalty application if speed rises above 21MPH. (I've noticed the PTC speedometer, that goes by GPS, is usually 1 to 2 mph slower than the locomotive's speedometer.) Since PTC doesn't know where the obstruction is in the block, it can't stop you short. It only keeps the collision at a relatively slow speed. But still fast enough to cause damage that can lead to, and has led to, fatalities. It will query the position of facing point switches. Which requires the engineer to select the correct position. If no position is selected or the open position is selected, the PTC will then stop the train short.
To refresh everyone's memory.
As I understood it was a rear end collision and the overlay PTC system doesn't know the location of the rear end of the preceeding train (rail train in this case)Regards, Volker
I was trying to reconcile that with the fact that a MOW truck appeared to be "leading" the rail train's "shove" move, and one would think MOW equipment should be PTC-GPS-equipped.
If MOW equipment is not equipped, and/or if the GPS part of PTC is all or even partly disabled while shoving doesn't that defeat a big part of PTC's raison d'etre?
A pretty serious bug in my opinion. That bit about cutting out the Automatic brake by itself is even worse!
None of this relieves whomever was at fault from their responsibility to properly operate at restricted speed.
SD70DudeI was trying to reconcile that with the fact that a MOW truck appeared to be "leading" the rail train's "shove" move, and one would think MOW equipment should be PTC-GPS-equipped.
I understood, that the Herzog truck were the rear end but perhaps I have overlooked something.
Be it head end or rear end, the class 1's PTC as an overlay system only can enforce the signal indications. As it is FRA certified it must fulfill all legal requirements.
I still haven't found were the law exempts restricted speed from PTC control except max. speed though.
I find it unsatisfying.Regards, Volker
The biggest red flag should be how both trains ended up on the same track... PTC or no, that simply should not have happened.
tree68The biggest red flag should be how both trains ended up on the same track... PTC or no, that simply should not have happened.
You are completely right.
On the other hand PTC was mandated to reduce the impact of human errors. Apparently not this kind of error.Regards, Volker
VOLKER LANDWEHR tree68 The biggest red flag should be how both trains ended up on the same track... PTC or no, that simply should not have happened. You are completely right. On the other hand PTC was mandated to reduce the impact of human errors. Apparently not this kind of error.Regards, Volker
tree68 The biggest red flag should be how both trains ended up on the same track... PTC or no, that simply should not have happened.
I recently read, I think in Railway Age, that the AAR figures that PTC is designed to prevent 4% of all railroad incidents that happen. The ones that don't happen everyday, but make the headlines on the nightly news when they do.
In congested (normal) mainline operations it is a regular occurrence for two trains to end up on the same track in close proximity to each other, so long as they are both proceeding in the same direction.
What is not not normal is for them to be heading towards each other.
Under our (Canadian) rules both trains would of course be operating at restricted speed, and for the rail train to change direction or enter a controlled block toward the stack train both movements would have to be given written authorities by the Dispatcher to "protect against" each other, and also protect against the foreman operating the Brandt-type truck.
All 3 parties would then have to talk to each other before either train would be allowed to move.
And I cannot emphasize this enough, none of that relieves either train crew from having to operate at restricted speed.
Maybe BNSF's rules are different, but it is far more likely that someone forgot about their authority limits and failed to properly obey restricted speed. The details of how that happened should be very interesting.
Has Chico's grapevine said anything more on this subject?
Restricted speed. Does the concept of 1/2 the visible distance come from the idea of 2 restricted speed trains approaching each other at the max restricted speed of the track being able to stop just inches from each other ?
blue streak 1
Yes
blue streak 1Restricted speed. Does the concept of 1/2 the visible distance come from the idea of 2 restricted speed trains approaching each other at the max restricted speed of the track being able to stop just inches from each other ?
That is the concept. The maximum allowed speed applies to locations with unrestricted vision. The more restricted the vision, they slower 1/2 the range of vision becomes. Just because the rule states 20 MPH as the maximum, doesn't authorize 20 MPH when operating over territory with 10 degree curves that cannot be seen around. If your vision is 1000 feet, a speed that will permit stopping the train in 500 feet is required.
Never too old to have a happy childhood!
SD70DudeIn congested (normal) mainline operations it is a regular occurrence for two trains to end up on the same track in close proximity to each other, so long as they are both proceeding in the same direction.
That would also assume that both trains were operating at normal speeds (as governed by the appropriate signal indications, etc.).
As I see it, the issue here is that the work train should have had some sort of working limits established, which would preclude other trains not involved with the work at hand from being on said track.
Situational awareness has been mentioned, but I would think that the only thing the IM train needed to be aware of was the possibility of a work train being on an adjacent track. The IM should have had clear sailing, other than reacting properly to the work train on the adjacent track.
Instead, they found the work train "in their lane..."
If - The rail train was actively dropping rail - NO other train should have been occupying that particular track segment.
If - The rail train was making reverse move one of two conditions should have been in place - the rail train should have been granted permission to work in BOTH directs within the track segment or IF it was making a one time reverse move it should have been granted specific permission to make that move. No other trains should have been permitted to follow it on the track segment.
In this particular incident - absent of any other information. I would have to throw the ultimate cause of this incident to poor Dispatching that may have been caused by poor communication and job briefing between the Rail Train and the Dispatcher. With the Rail train moving into that specific track segment, the Dispatcher should have set a Track Block using his CADS equipment. A Track Block prevents the Dispatcher from 'mindlessly' lining a signal for a following or opposing train into the track segment. A side function in creating the Track Block is identifying the reason the Track Block is being created to protect. The crux of the incident is - Did the Rail Train notify the Dispatcher they were going to be working in the track segment and would require protection. If they did - the Dispatcher is on the hook; If they didn't then the Rail Train crew is on the hook, as in the absence of information to the contrary the Dispatcher would expect the Rail Train to act like any other through train and line other trains to follow it.
Balt: You are getting closer to what's left Chico's tribe in shock. The operating and maintenance folks BOTH can't understand how a regular train was allowed inside working limits of a work train and work equipment. There is another issue out there still not resolved, but I'm off the normal territory trying to clean up a CSX mess that EHH only compounded. I won't get home for days.
Everybody is wondering why somebody didn't shut it all down. (or were they not aware of each other and the road freight being allowed into track time and limits?) Any experienced railroader's skin has been crawling over this; PTC is irrelevant here for the most part.
(*) I wouldn't be surprised if the problem goes higher than just the trick DS.
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