The point you are missing is that qualifier is NEVER mentioned is that the folks to which this stopping distance information is important already know that (or should), these reports are not written for the general public.
We look at operational stopping distance to plan block lengths, signal aspects etc. This is how the railway operates day to day, not based on emergency brake application. Emergency stopping distance is irrelevant to these planning issues as A we can’t plan for them and B it doesn’t effect the design of the railway in any way.
Probably an attitude of “If you have to be told, you really wouldn’t understand”
The point you are missing is that qualifier is NEVER mentioned is that the folks to which this stopping distance information is important already know that (or should), these reports are not written for the general public. I suspect if someone read the report rather than the executive summary it would be obvious.
We look at operational stopping distance to plan block lengths, signal aspects etc. This is how the railway operates day to day, not based on emergency brake application. Emergency stopping distance is irrelevant to these planning issues as A we can’t plan for them and B it doesn’t effect the design of the railway in any way.
Probably an attitude of "If you have to be told, you really wouldn
I wish to address the ECP vs. Westinghouse comparison with regard to emergency braking and service braking. With Westinghouse, it does take time for the main pipe reduction to travel from the locomotive to the rear of the train. So the chances for a pile-up under some but by no means all situations is definitely increased. So on face there is an advantage to ECP in emergencies. But one does not need ECP to overcome the dissadvantage of normal Westinghouse. Distributed power narrows the advantage considerable, but also a proper FRED at the end of consists that dumps the air at the end or simply reduces pressure appropriately would do as much good as distributed power. And there may be a way of attaching some kind of intermediat FRED say every ten cars along the length of the train and get practically the full advantage of ECP, including service braking, without the need to convert the fleet to ECP! Would this be an idea the car builders and railroads find worth exploring? The device would hang on a grab iror on the rear of the car and have two connections for two air hoses.
Absolutely, I understand and agree with that. The emergency application has nothing to do with the design of the railway, planning for block lengths, signal aspects, etc. All of that is based on service application stopping distances.
But that is not what the USDOT is concerned about in their mandate for ECP on oil trains. Their concern has nothing to do with service braking applications and everything to do with emergency application.
They want ECP to stop trains quicker in order to avoid collisions and to reduce the number of cars getting shoved into a derailment pileup. Service braking is irrelevant to these emergency issues. Only the emergency braking application is relevant t
Sounds like the USDOT has absolutely no clue about train brakes at all. But hey, let’s insert more gadgets! That’ll work.
Oh well. We’ll make do with whatever gets thrown down the pipeline. That’s what we do. Then the people in charge can pat themselves on the back for doing a great job.
THEY MAY BE MORE CONCERNED WITH POSSIBLE PILEUP THAN WITH STOPPING DISTANCE. DOES ANYONE SEE ANY TECHNICAL REASON WHY ADDITIONAL FREDS SHOULDN’T BE THE WAY TO IMPLEMENT ELECTRONIC BRAKING INSTEAD OF CONVERTING THE FLEET?
CONDITIONS FOR A PILEUP WITH WESTINGHOUSE WITHOUT A DERAILMENT INSTIGATION: STEEP DOWNHILL AND SHARP CURVE.
Part of the problem with this whole discussion is nobody has clearly defined what the real problem is, there are multiple “problems” as seen by various people and entities and they don’t all coincide. Different agendas drive different views to the point that some of the stakeholders have actually lost track of what the “real” problem is. So each of the stakeholders has different solutions which don’t solve or even address the “problems” as seen by other stakeholders.
Then on this list we come up with all sorts of “solutions” that may or may not have been considered in light of all the factors, and on top of that there is debate on how to overcome all the limitiations and baggage the “solutions” bring with them. The result is 19 ot 20 pages of confusing mismash.
Before we start putting an EOT every 5 cars, do you even know if it will do anything to help the situation? What problem do you think distributed EOT’s will solve? It won’t meet the Federal requirements in any case.
If we are discussing using them for service braking?
Need to redesign them. EOTs are for monitoring and emergency braking only.
Need to have a way to reprogram them to the same number, or have to have the head end box be able to accept 10+ different EOT ID numbers at the same time. Currently an engine can link up to only one.
You will need an entire department to manage EOT distribution. Since not all trains are equal, you will get lots of EOTs in one terminal, and not enough in another.
Rules for EOT failures have to be re-examined. If you are carrying around 12+, what happens if one fails? Will you be limited to 30mph and prohibited from running heavy grades?
For the cost of all this - it may be cheaper just to get ECP brakes.
They are concerned with mitigating the pileup by reducing stopping distance. Secretary of Transportation, Anthony Foxx said this as paraphrased by the article I linked above:
Foxx maintained that the [ECP] brakes could prevent a repeat of incidents like a December 2013 collision in which an oil train slammed into a derailed grain train, setting off a series of explosions outside Casselton, N.D.
He was referring to ECP brakes reducing stopping distance. His point was that quicker stopping offered by ECP might have stopped the oil train before it collided with the fouling grain train in the Casselton wreck.
I understand there are FREDS in use on some railroads that do operate as remote control brake controllers, and that is the type that would be modified to attach to two air hoses instead of just one. Obviously the idea has to tested on a test train. The tests would determine how many cars can be located between devices without loosing the electronic brake advantage. But obviouly such a device is a lot less expensive than just adding midtrain power for braking control. The good feature is no modification of the existing fleet is required. And generally a portable device that is hung on a grab iron is less expensive than the same device installed pementanly on the car.
And there is no reason why such a device could not be comopatible with installed devices, although obviously wire-controlled devices instead of radio controlled would require that electronic-brake cars either be bunched at the head end or controlled by a separate portable radio-contolled device. It might turn out to be only an interem soluton, but still one worth considering and testing.
They are concerned with mitigating the pileup by reducing stopping distance. Secretary of Transportation, Anthony Foxx said this as paraphrased by the article I linked above:
Foxx maintained that the [ECP] brakes could prevent a repeat of incidents like a December 2013 collision in which an oil train slammed into a derailed grain train, setting off a series
Ok, so it might stop a little quicker, but the focus? Stopping 500 yards quicker does not solve jumping the tracks… And, that 1-1/2 miles, minus 500 yards (speculation on how much shorter.) would not be helpful if, as in the collision of two trains in N.D. mentioned above, the sight line was only 1000 yards away… ECP maybe helpful in some conditions, but is not the miracle cure the opponents of this traffic want.
The focus should start on preventing derailments, and preventing the exploding crude. Sure, help with stopping distance, but focus on the real problems, the crude itself being volatile, and the leaving the tracks.
And, no, it will not prevent all issues. Nothing will prevent every single derailment from occurring. They will still occur when things go wrong, nothing will change this. Can it be made safer? Yes. “Bullet proof” and “idiot proof”? No. So, even with ECP, safer tank cars, better track work, etc… will not bring the miracle cure that people want. It just will not, and cannot, happen the way everyone wants.
The conclusion is still pending final review before I will accept it. If the conclusion is correct, then the USDOT is wrong. They have promised to have one of their technical experts call me to answer my questions.
For the time being, the conclusion is that the stopping distance for Westinghouse brakes is very close to bei
The Department of Transportation, Federal Railroad Administration (FRA), Office of Safety has a requirement to acquire contractor services to conduct a cost benefit analysis of Electronically Controlled Pneumatic (ECP) Brake systems for freight service. Both business and safety benefits shall be analyzed. As a result of this analysis, the most effective implementation strategy of ECP brake system freight operations in the United States must be determined…
In either case, the improved stopping power is relatively modest, and not likely to produce the safety enhancement effects that the Secretary of Transportation cites in the quotes above.
And how many replies and time required to write them for this conclusion to be finally be reached?
The conclusion is still pending final review before I will accept it. If the conclusion is correct, then the USDOT is wrong. They have promised to have one of their technical experts call me to answer my questions.
Perhaps I might quote directly from the reference:
“The Federal Railroad Administration, under CFR Part 49, specifies the maximum time each car can take to achieve maximum braking. On trains operating at 70psi brakepipe pressure this maximum application time is 10 seconds. So, our hypothetical 5,526’ freight train would take 16 seconds to attain full emergency braking. During this 16 seconds the train will have steadily increasing brake application taking effect between 1.5 (the time for braking in the first car to begin) to 16 seconds (the time the last car achieve full braking)”
I think this is adequately clear for anyone to comprehend. What might help would be a graph of deceleration (or actual braking effort) against time, showing the rate of change of deceleration first as the brakes are set up to engage, and then as they progressively come on.
I, for one, found the analysis he provided of the hypothetical grade-crossing collision highly interesting, as both his explanation and the resulting ‘numbers’ have a bearing on the present “discussion”. Note that if I understand what he has said correctly, the difference between putting the train in emergency and NOT APPLYING THE BRAKES AT ALL translates into barely more than half a second’s time at the hypothetical point of impact, more than half the way to the calculated point t