rdamonThat could add up quickly on a long train ...
... if you released them all at the same time with a single command, rather than sequencing them via addressed commands over the power bus. (Which is part of my interest in zug's RCO box system.)
Suspect that a 'trainlined' version would be designed to be compatible with the ECP 220V line rather than straight locomotive standard voltage, which was no doubt chosen 'because it was there'.
RME zugmann http://www.grahamwhite.com/main/product.php?C1=15&P1=170&P2=-1 I stand happily corrected. Some of our remote power even have it programmed so you can set or release the above power handbrakes from the RCO box. Do you have a link either to the provider of the programmed equipment or to a description of the system you're using? It shouldn't be difficult to adapt that code or its API to work with 'trainlined' versions of handbrakes, or to recognize properly-equipped manual applications that have been fitted with appropriate sensors...
zugmann http://www.grahamwhite.com/main/product.php?C1=15&P1=170&P2=-1
I stand happily corrected.
Some of our remote power even have it programmed so you can set or release the above power handbrakes from the RCO box.
Do you have a link either to the provider of the programmed equipment or to a description of the system you're using?
It shouldn't be difficult to adapt that code or its API to work with 'trainlined' versions of handbrakes, or to recognize properly-equipped manual applications that have been fitted with appropriate sensors...
From the website ...
That could add up quickly on a long train ..
Zug the current system is to bleed air from the brakes am I correct maybe keep the air on the parking brakes until the train is made up then release it. The system would be complete with gladhands shutoffs and such. So when switching pump up the parking brakes close all the gladhand shutoffs on both service and the new parking brakes. Then when your done switching pop the valves open and bang there goes the air for the parking brakes. How hard is it to hook up an airhose to move a car then know when it is moved the brakes are not going to back off like they can with the current system or be released by vandals. This system would have stopped the runaway in Canada of the crude oil train why No air pressure in the line the brakes would have come on trainwide and stayed on. If there is a failure in the chamber that does provide the braking force it is a simple swap it out and go not see what part of it has failed. Yes it would take some adjustment for the railroads to get used to however the labor savings just in lost time accidents from not having people fall off cars in the winter would be worth it from releasing handbrakes.
Shadow the Cats ownerIt would take another brake valve in the cab 1 extra valve a car one extra spring loaded cylinder a car and locomotive and that's it for the air side. Then a system to override it for moving the car or being without air in it.
So how do we hump cars?
And what about all the industries that need to move railcars around on their property? Unless that's what you mean with the last sentence? Sounds a bit complicated.
Now roadrailers did have spring brakes from what I understand. And caused massive headaches when they acted up.
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
oltmanndMRs are nominally 140 psi, freight train brake pipe is 90 psi.
On a pure ECP system? That's what I was talking about ... the 'normal operation' refers to normal operation of pure-ECP consists with proper control equipment on the locomotives.
With ECP might not need as high a brake pipe.
Why would you not want the highest possible delivered volume at best approximation of main-reservoir full recharge pressure?
All the air line 'needs' to do on an ECP system is provide makeup air for what is valved to the equipment on the cars. A break-in-two will also separate the 220V power/data cable, and that event can trigger a more 'intelligent' response than a sonic signal propagating from the separated connection would likely do.
I do not think a 'conversion kit' ECP valve arrangement would be configured to allow pass-through of sonic signals from a parted 'pressure-only' trainline to the (retained) mechanical triple valve. (The same trainline would be used for one-pipe functions, specifically including big-hole emergency, when the valve is locked in the 'conventional' position, so it is at least feasible to incorporate a valve that responds to pressure differential regardless of selected mode.) That might be a good question to ask the tech staff at one of the manufacturers. I'll look into it in more detail.
RME believe we have had discussions about 'motorizing' handbrakes (really wheel brakes; I doubt there's any reliable way to apply and release a 'pump' brake as found on many locomotives).
http://www.grahamwhite.com/main/product.php?C1=15&P1=170&P2=-1
RME"Yes, but" it's a bit more complicated. The trainline is used as a source of continuous 140psi air in normal operation.
Just to be clear, now, all the MRs on the consist are MUed and the trainline is fed (slowly) from the brake valve on the lead unit. MRs are nominally 140 psi, freight train brake pipe is 90 psi. With ECP might not need as high a brake pipe. Also, the concept of "emergency" might be able to go away. All you need is break-in-two protection. Doesn't have to be trainline initiated...necessarily.
-Don (Random stuff, mostly about trains - what else? http://blerfblog.blogspot.com/)
BaltACDOne thing that when people think about ECP in braking - they are overlooking that air pressure is what provides the braking power. Electronic controls do not do anything about the necessity of recharging the resevoirs (where the power actually resides). Yes, you can initiate an application or release at near the speed of light - but the resevoirs will get recharged at the speed of the trainline air pressure increase.
You can recharge much faster with ECP. Currently, the air is throttled into the trainline slowly so that it doesn't "pretend" to be a control signal. If you take the control function out of the trainline, you can charge very rapidly and keep it charged regardless of brake valve state.
EuclidHowever, the electronic control of ECP removes the control function from the pneumatics of the conventional train line or brake pipe. So with ECP, the train line has the communication and control function removed from it, and it is left with only the purpose of charging air to the car reservoirs.
"Yes, but" it's a bit more complicated. The trainline is used as a source of continuous 140psi air in normal operation. When brakes are applied, it will take some time to recharge the reservoirs from this source, but it happens continuously (the main reservoir essentially becoming a 'buffer' between air being passed to the brake cylinder and supply from the high-pressure line). There is no need for accelerated release (and concomitant loss of any reliable graduated release) as the electronics can control cylinder pressure directly.
Now, for emergency braking, the same action as in one-pipe braking is used: the triples open fully to apply as much reservoir pressure as the system permits, as quickly as possible. The action is a tad quicker with ECP because all the triples open at essentially the same time (the speed is about .93C if I remember right), rather than each triple starting its cycle as the sonic signal triggers it while propagating down the trainline, but the actual difference first for full application of shoes to wheels and then for the train to stop is comparatively minor (and is the reason why there is only about a 3% observed improvement for ECP over one-pipe for emergency braking, while full service shows much more radical improvement).
Euclid It would not be difficult to develop a freight train securement brake that could be set or released from one control in the locomotive cab. It could be incapable of any accidental full application while moving and would be operated solely by compressed air. It would also be incapable of losing its set by air leakage. This improvement would require some extra equipment with its cost. There would also be maintenance cost. It would also be one more thing that can fail and cause delays. It may be easier to execute with ECP brakes, but I have not thought that through.
It would not be difficult to develop a freight train securement brake that could be set or released from one control in the locomotive cab. It could be incapable of any accidental full application while moving and would be operated solely by compressed air. It would also be incapable of losing its set by air leakage. This improvement would require some extra equipment with its cost. There would also be maintenance cost. It would also be one more thing that can fail and cause delays.
It may be easier to execute with ECP brakes, but I have not thought that through.
I should add to this description of the ideal, simple, single control, securement brake: This system does not wind up the hand brakes. It has absolutely nothing to do with the handbrakes. It works at the level of the basic braking foundation. If the securement braking is set, and someone sets a handbrake, nothing changes with the winding of the brake wheel. If the securement braking is released, and someone sets a hand brake, the handbrake goes from released to set in the conventional manner.
The speed of light electronics with ECP is only for the controlling and not for the supply of air, as you say. However, the electronic control of ECP removes the control function from the pneumatics of the conventional train line or brake pipe. So with ECP, the train line has the communication and control function removed from it, and it is left with only the purpose of charging air to the car reservoirs.
Relieving the conventional pneumatic train line of the control function allows it to deliver air to the reservoirs full time. There is no need to stop charging reservoirs when a service application is made by lowering the train line pressure as a control function, for instance. So the train line can charge reservoirs faster than a conventional pneumatic train like can.
schlimmYou are not taking into account the costs of long delays in traffic flow caused by these maneuvers even if a derailment does not occur. Before automatic airbrakes and couplers were mandated the cost per car of implementation was objected to as well.
The issue here is not spending about $3 trillion or whatever the inflated figure is -- it's spending a large fraction of that amount on a spring-brake system of very dubious utility instead of implementing ECP properly, with a much wider range of synergistic benefits and the ability to work correctly in one-pipe service with a simple configuration change until whole blocks of rolling stock converted to ECP can be assembled and operated.
As we discussed several years ago, it has become technically possible to implement electromagnetic track 'emergency' brakes that will actually take substantial momentum off an 'equipped' consist without relying on friction tread braking at all. I'd prefer implementing such a thing, dollar for dollar, over anything involving spring activation of tread brakes -- and I'd prefer ECP over both of them.
I believe we have had discussions about 'motorizing' handbrakes (really wheel brakes; I doubt there's any reliable way to apply and release a 'pump' brake as found on many locomotives). There have been many proposals over the years for doing this; the Loughridge chain brake of pre-Civil War memory essentially wound up a customized sprocket-equipped version of brakewheels. One catch is that any power assist in application is likely to make manual release extremely difficult; another is that power application and release may interfere with a crew's manual actions while leaving that crew responsible for the way the brakes were set. In both cases you have mechanical fiddling with the foundation of levers and rods that the air-brake cylinders will move to perform any trainlined power-brake function, and coordinating the degree of mechanical application (through whatever form of slack adjustment comes to be used) between 'power hand' and 'power air', particularly with regard to how the brakes are released, may be (is, in my opinion) a mechanical exercise best left to the theoretical.
Euclid schlimm RME This is completely aside from the safety questions inherent in any kind of locking 'safety brake' that applies itself automagically when there is some nominal failure condition. Think about the bigger picture. It's 2017 and we're talking about applying and releasing manually 50 or more sets of handbrakes as though it were ~1920! But now there is a crew of two as opposed to many more able bodies back then at the front and rear of a much shorter train. It would not be difficult to develop a freight train securement brake that could be set or released from one control in the locomotive cab. It could be incapable of any accidental full application while moving and would be operated solely by compressed air. It would also be incapable of losing its set by air leakage. This improvement would require some extra equipment with its cost. There would also be maintenance cost. It would also be one more thing that can fail and cause delays. It may be easier to execute with ECP brakes, but I have not thought that through. In any case, rolling stock changes that affect the standard practice are almost impossible to introduce because the change has to be implemented on such a vast number of freight cars in order maintain the standard practice. For this reason, I doubt that even the compelling ECP brakes will ever become standard practice in the U.S.
schlimm RME This is completely aside from the safety questions inherent in any kind of locking 'safety brake' that applies itself automagically when there is some nominal failure condition. Think about the bigger picture. It's 2017 and we're talking about applying and releasing manually 50 or more sets of handbrakes as though it were ~1920! But now there is a crew of two as opposed to many more able bodies back then at the front and rear of a much shorter train.
RME This is completely aside from the safety questions inherent in any kind of locking 'safety brake' that applies itself automagically when there is some nominal failure condition.
Think about the bigger picture. It's 2017 and we're talking about applying and releasing manually 50 or more sets of handbrakes as though it were ~1920! But now there is a crew of two as opposed to many more able bodies back then at the front and rear of a much shorter train.
It may be easier to execute with ECP brakes, but I have not thought that through. In any case, rolling stock changes that affect the standard practice are almost impossible to introduce because the change has to be implemented on such a vast number of freight cars in order maintain the standard practice.
For this reason, I doubt that even the compelling ECP brakes will ever become standard practice in the U.S.
One thing that when people think about ECP in braking - they are overlooking that air pressure is what provides the braking power. Electronic controls do not do anything about the necessity of recharging the resevoirs (where the power actually resides). Yes, you can initiate an application or release at near the speed of light - but the resevoirs will get recharged at the speed of the trainline air pressure increase.
Never too old to have a happy childhood!
RMEThat does not change either the mechanical consequences of equipment failure, or the required cost per car/locomotive to provide 'automatic' "parking-brake" application.
You are not taking into account the costs of long delays in traffic flow caused by these maneuvers even if a derailment does not occur. Before automatic airbrakes and couplers were mandated the cost per car of implementation was objected to as well. And monster trains in length and weight also hav a cost as well as a savings of labor.
C&NW, CA&E, MILW, CGW and IC fan
schlimmThink about the bigger picture. It's 2017 and we're talking about applying and releasing manually 50 or more sets of handbrakes as though it were ~1920! But now there is a crew of two as opposed to many more able bodies back then at the front and rear of a much shorter train.
That does not change either the mechanical consequences of equipment failure, or the required cost per car/locomotive to provide 'automatic' "parking-brake" application.
As an aside: a proper ECP system ought to allow addressable 'retainer' operation, which can quite easily integrate with other equipment on a car (such as continuously-reading load cells) to produce better than just an approximation of maximum safe braking on an individual-car basis, with knowledge of the characteristics of the overall consist.
There's no formal reason why this facility couldn't be used as a 'parking brake'. Or, by extension, why an ECP-equipped car with reasonable on-board reserve power couldn't have its brakes modulated, within limits, from an addressable system on a RCO panel in a yard.
That beats all heck -- in my opinion -- out of anything kludged to handbrake wheels, at likely comparable cost.
RMEThis is completely aside from the safety questions inherent in any kind of locking 'safety brake' that applies itself automagically when there is some nominal failure condition.
The problem is (and has been) that for such a system to work, it would have to be consistently applied across the range of interchange equipment, and on all operating locomotives. Figure out the rough cost of the changes you propose per car and per locomotive, and simple multiplication will tell you why it hasn't been done in the rail industry.
This is completely aside from the safety questions inherent in any kind of locking 'safety brake' that applies itself automagically when there is some nominal failure condition. The spring that is required to put the equivalent of 15psi of retarding force on a loaded railroad car is very strong compared to what is needed for rubber-tired OTR vehicles, and additional indicators would need to be supplied so that rail people could determine whether the spring brake was applied AND producing full effect through the brake foundation rigging -- that's neither simple nor trivial. Then you need a reliable way to pull the spring brake off without compromising the wind-on handbrake that's also required. (See the discussion of the locomotive brake application in the Lac Megantic wreck threads to get some idea of what would likely be involved in getting that to work; again, it would have to be standardized across a very large number of interchange cars to mean much operationally.)
Personally, I don't think there's a lot more capital involved in doing one of the 'adapter plate' conversions to ECP functionality, which gives fairly simple switch convertability between ECP and regular one-pipe operation, and of course there are vastly more advantages from ECP than from a spring.
This is where I think the OTR industry airbrake system would be a huge advantage. Now before you scream hear me out. We relay also on pressure changes to apply the brakes also. Now here is where our system is different. We have a second system with its own air supply from the air compressor that applies and releases all the parking brakes on the system. However our parking brake system uses a spring that requires air pressure to even be released. To maybe make it possible for it to work on the railroads have the handbrake wheel act as a manual override for when the air system in removed. Think about it below a certain pressure all brakes come on and it could prevent accidents like this from ever happening again. With our brakes on a loss of pressure situation the parking brakes apply they are normally 60 percent of the brakes of the vehicle. Now after the loss of pressure is fixed. Before releasing the parking brakes we can apply the service brakes to hold then release the parking brakes since we have that second air line feeding it.
It would take another brake valve in the cab 1 extra valve a car one extra spring loaded cylinder a car and locomotive and that's it for the air side. Then a system to override it for moving the car or being without air in it.
Okay, I see. (regarding Balt's comment on conventional graduated release)
schlimmHowever, I do have a question: would electronically controlled pneumatic brakes (ECP - not electro-pneumatic) work better?
With the very limited amount of information we have: I suspect that if there was a significant problem with one-pipe Westinghouse, there would have been a problem with the air line supplying any current system of ECP (and added to that, the possibility that the integrity of the signals or power on the electric trainline would be impaired).
The usual sort of "damage accommodation" I have seen with ECP involves the ability to isolate or cut out brake operation on deflicted individual cars. The point to remember here is that ECP still depends on reasonable air pressure and volume in its trainline to work, and I suspect that if its trainline were unreliable, exactly the same kind of those-shoes-aren't-hell-and-a-half-to-change power handbrake 'retaining' might have been tried.
As a note to Euclid, graduated release is a specific feature of modern ECP systems, one of the touted advantages of that system. Since the air trainline is used only for air supply in all service braking, it is comparatively simple to command reduction of a given degree in some or all brake cylinders, and by extension to proportion the degree of a running release; if individual cars are addressable logically, it becomes possible to apply or release the actual 'set' with some precision and relatively little lag.
One of the things I think is going to come out of the investigation: was power braking on the front part of the train actually achieved at some point in the manipulations (it almost would have to be in order for even buffoons to think about moving a train that size downgrade) and the "number of handbrakes" adjusted to provide some semblance of equivalent braking for the rear of the train? If that is so, then I wonder if the crew would be able to 'modulate' graduated release to match the effect of the fun happening on the back of the train ... seems clear to me they were ignorant of the heating and sliding going on there in spite of buff force on the empties building up.
Of course it's also possible that the ECP system would flatly refuse to be kludged to that degree, and not allow its feet to be moved. In that case the train would be sitting there for a considerable time ... but that doesn't seem to be too unusual in recent 'precision railroading' operations
Euclid tree68 I suspect conventional graduated release would also have helped. What is that?
tree68 I suspect conventional graduated release would also have helped.
What is that?
A feature that exists on passenger car braking systems, not freight. Freight brakes can be applied in increasing pressures. When they are released - it is a full release.
Passenger braking can 'reduce the pressure' of the application and thereby have a partial release.
tree68I suspect conventional graduated release would also have helped.
schlimm However, I do have a question: would electronically controlled pneumatic brakes (ECP - not electro-pneumatic) work better?
I'm no expert on ECP - but I would opine that if they allowed the train to recharge while the brakes were applied, then yes, they would work better. I suspect conventional graduated release would also have helped.
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...
RME Euclid I am only asking what normal practice is since it is being suggested here that taking the train down the hill with hand brakes set is normal every time a train like this one stops on the grade. I don’t believe it is normal practice at all. I think that's a fair question. I do not think it is normal practice; in fact, I don't think it is sensible practice. The real problem here is that, until we have much more 'hard' information, we can't know why the railroaders involved made and approved what seems such a dumb choice, and then executed the move in what evidently was such a dumb way. The more information I hear about this, in fact, the dumber it seems. This is not a relatively simple miscalculation like letting a train with insufficient dynamics get up to brake-fade velocity. It required a Plan.
Euclid I am only asking what normal practice is since it is being suggested here that taking the train down the hill with hand brakes set is normal every time a train like this one stops on the grade. I don’t believe it is normal practice at all.
I think that's a fair question. I do not think it is normal practice; in fact, I don't think it is sensible practice. The real problem here is that, until we have much more 'hard' information, we can't know why the railroaders involved made and approved what seems such a dumb choice, and then executed the move in what evidently was such a dumb way.
The more information I hear about this, in fact, the dumber it seems. This is not a relatively simple miscalculation like letting a train with insufficient dynamics get up to brake-fade velocity. It required a Plan.
I don't know the answers as I have no knowledge beyond the report. However, I do have a question: would electronically controlled pneumatic brakes (ECP - not electro-pneumatic) work better?
EuclidI am only asking what normal practice is since it is being suggested here that taking the train down the hill with hand brakes set is normal every time a train like this one stops on the grade. I don’t believe it is normal practice at all.
Deggesty Will someone please take this horse out before it is beaten to death?
Will someone please take this horse out before it is beaten to death?
Beating the horse? You have got to be kidding! A thousand posts about hating EHH, and no worry about the horse there.
Here nobody has even touched the horse yet. This horse ought be quite pleased with so many people tip-toeing around it.
Johnny
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