BuslistPlease read your reference more carefully! It states that the FRA requires full brake pressure in less than 10 seconds, NOT that 10 seconds is required. So the 16 seconds is a worst case situation. It also says that emergency braking "applies the brakes as quickly as possible " . Note this guy is a plaintiff's expert witness trying to get $ from the railroads in grade crossing incidents. Biased?
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 the train will come to a complete stop.
Much as I may hate to say it, I found the explanations of brake-system operation and train dynamics to be objectively correct and well-worded, and I saw only one instance of potential 'bias' (where he said that the .57 seconds might have allowed one more car to get across the crossing before the train would hit it...)
Euclid Buslist Euclid 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. For the time being, the conclusion is that the stopping distance for Westinghouse brakes is very close to being equal to the stopping distance for ECP with both in the emergency application. Yet I know I have seen a reference somewhere recently that mentioned flow restrictors affecting the emergency application as well as the service application of Westinghouse brakes. Here is a reference to Westinghouse stopping distance: http://www.tarorigin.com/art/Jbentley/ It claims that for the Westinghouse brakes to fully apply on a 5,526-ft. long freight train, it takes 16 seconds. The larger part of that (ten seconds) is the time required for the air to flow from the reservoir to the brake cylinder on each car. So, according to that, it is not true that the only factor affecting stopping distance is the sequential propagation time for Westinghouse brakes. Obviously the railroads do not want to spend the money to comply with the ECP mandate, so I take their claims about braking performance with a grain of salt. It may be that the railroads are downplaying the stopping performance of ECP in the emergency braking application, and exaggerating the stopping performance offered by distributed power in the emergency braking application. Likewise, the ECP manufacturers have a great stake in exaggerating ECP advantages. Their agenda may indeed be sufficient to bamboozle the USDOT.
Buslist Euclid 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?
Euclid 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?
Please read your reference more carefully! It states that the FRA requires full brake pressure in less than 10 seconds, NOT that 10 seconds is required. So the 16 seconds is a worst case situation. It also says that emergency braking "applies the brakes as quickly as possible " . Note this guy is a plaintiff's expert witness trying to get $ from the railroads in grade crossing incidents. Biased?
wanswheel, quoting the FRA"The availability of graduated release will permit greater reliance on dynamic braking in mountain grade territory, reducing thermal inputs to wheels."
Want to bet that this opinion has changed somewhat following the 17 Mile Grade 'incidents'?
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.
Ricky W.
HO scale Proto-freelancer.
My Railroad rules:
1: It's my railroad, my rules.
2: It's for having fun and enjoyment.
3: Any objections, consult above rules.
Euclid Dave, 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. He also said this as quoted by the article I linked above: “ECP brakes can reduce how long it takes a train to stop,” Foxx said. “They can prevent cars from slamming into each other, they can decrease the number of cars that derail, they can greatly reduce the probability that tank cars will puncture. This is proven technology.” He was referring to the superior stopping power of ECP helping to mitigate the damage in a derailment after the derailment begins. The point that you make about additional FREDS reducing stopping distance equivalent to ECP is essentially the same point being made by the railroads as they oppose the ECP mandate. But the railroads say this is already being accomplished by distributed power creating more holes in the brake pipe during an emergency application. But, as I understand it, this improved stopping performance is very small no matter whether it comes from ECP compared to Westinghouse; or whether it comes from distributed power on Westinghouse compared to Westinghouse without distributed power. 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.
Has Foxx stated what the sight line was to the derailing car(s) of the grain train as the oil train approached? When trains meet or pass each other, the sight lines in many cases are severely restricted by curvature (and the curves themselves do not have to be severe). Just like life, one second everything is fine, the next catastrophy.
Any engineer that would use any form of Service brake application upon viewing an approaching derailment situation, won't maintain his engineers certification very long.
Never too old to have a happy childhood!
zugmann Euclid 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. 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.
Euclid 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.
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.
Johnny
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.
As a railroader, I kind of like it when we create ideas where you don't have to dump the train. By that point, something has already gone wrong.
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
daveklepperANY TECHNICAL REASON WHY ADDITIONAL FREDS SHOULDN'T BE THE WAY TO IMPLEMENT ELECTRONIC BRAKING INSTEAD OF CONVERTING THE FLEET?
If we are discussing using them for service braking?
1. Need to redesign them. EOTs are for monitoring and emergency braking only.
2. 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.
3. 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.
4. 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?
5. For the cost of all this - it may be cheaper just to get ECP brakes.
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.
Dave H. Painted side goes up. My website : wnbranch.com
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.
EuclidBut 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.
BuslistThe 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.
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.
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.
Euclid Wizlish, The only relevance of the 30-70% figure is that it is NEVER presented with the qualifier that it only applies to the service applications. That leaves people to naturally assume that ECP also yields some large reduction of stopping distance to the emergency application as well as to the service applications. Yet that is not true.
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.
Probably an attitude of "If you have to be told, you really wouldn't understand". I'll relate to a mentor of mine who would say "as any school boy knows"
Sorry for for the double post
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.
Probably an attitude of "If you have to be told, you really wouldn't understand"
EuclidWhy should I care about the number of feet it takes to stop?
Because THAT'S THE ONLY DAMN THING THAT MATTERS HERE!
I could say this with the greater emphasis it deserves, but this is about as much as the Forum formatting tools provide.
If you have a service stop 70% shorter than what conventional air brakes provide, then you might well be looking at comparable distance to what a conventional emergency-brake application might provide. If you actually looked at the numbers, that is, which you seem more than usually reluctant to do for some unaccountable reason.
I think it is established without doubt that emergency braking is considerably more dangerous than even full-rate service braking, especially if some cars in the consist are derailed or damaged. So if ECP's controlled, proportional, graduated-release service brake stopping distance is at all comparable to 'conventional' emergency stopping distance, you'll have something important even before discussing differential braking ability or antilock-type wheelslide prevention.
That's just my 25 cents' worth, but I do think going round and round wondering about qualifiers is getting you even more nowhere than usual.
EuclidHere is the answer as I understand it: Both are true, but each has a qualifier. ECP brakes decrease train stopping distance by up to 70% with a “service” application of brakes. ECP brakes decrease train stopping distance by up to 1% with an “emergency” application of brakes.
This is cute but you're missing the correct qualifier:
1) What is the stopping distance in feet (or meters or whatever) represented by that "70% shorter stopping distance"?
2) What is the stopping distance in feet represented by 'big-holing the Westinghouse' with ECP braking?
(You can then start getting into a discussion of things like ECP brake systems being able to detect and relieve wheelslide on particular cars when the brakes are in 'emergency', which I think bears some consideration if "safety" is a legitimate Government goal for improved brake systems. But until we have actual numbers to use, the ECP 'pro' and 'con' factions are essentially talking past each other...
BaltACD Can't speak to Amtrak or the various commuter agencies of today, however back in days before Amtrak, the B&O used Electro-Pneumatic Braking on their passenger trains. I suspect what is now termed ECP is being used on all passenger equipment today, however, what the inter-operatability is between the different carriers equipment is, I have no idea. ECP in a freight enviornment is a totally different animal than it is in a passenger enviornment. In the freight enviornment, cars are expected to run continuously between their mandated major air brake inspections (which I think is 5 years or more) with only brake shoes being replaced as necessary. Freight equipment will operate over multiple carriers and varying territories. In the passenger enviornment all cars get a major mechanical inspection every day or before every multi-day trip, with all defects (big & small) being attended to, as well as passenger eqipment operating in narrowly defined runs.
Can't speak to Amtrak or the various commuter agencies of today, however back in days before Amtrak, the B&O used Electro-Pneumatic Braking on their passenger trains.
I suspect what is now termed ECP is being used on all passenger equipment today, however, what the inter-operatability is between the different carriers equipment is, I have no idea.
ECP in a freight enviornment is a totally different animal than it is in a passenger enviornment. In the freight enviornment, cars are expected to run continuously between their mandated major air brake inspections (which I think is 5 years or more) with only brake shoes being replaced as necessary. Freight equipment will operate over multiple carriers and varying territories.
In the passenger enviornment all cars get a major mechanical inspection every day or before every multi-day trip, with all defects (big & small) being attended to, as well as passenger eqipment operating in narrowly defined runs.
The passenger electric brakes are a totally different beast. ECP is in essence a LAN running the length of the train that also carries the power bus to run the valves. It was difficult finding the chips that could handle the coms demand in a high voltage environment.
So as not to hijack ECP discussion, here is a link to the newest derailment thread. http://cs.trains.com/trn/f/111/t/247048.aspx
EDIT: and I see the link will not load correctly again.... Let's try again.
Nope, one more time.... Hey, now it works!
What benefit does ECP provide that will improve daily operations for the railroads?
Improved stopping distance in and of itself offers very little from what I can see. Any engineer that's worth his salt can provide good train handling with existing equipment. Shorter stopping distances may have value for commuter trains, where time is important, but there is no need for a freight train to make transit-variety stops.
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...
dehusman And Euclid's been the head cheerleader for ECP on this list.
And Euclid's been the head cheerleader for ECP on this list.
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