If there’s any interest, MSNBC’s Rachel Maddow briefly interviewed Anthony Foxx (second link), after a fairly lengthy set-up (first link). Lots about oil trains, practically nothing about brakes, though.
http://on.msnbc.com/1ILJRoY
http://on.msnbc.com/1ILGhv0
In the wake of the new tank car rules, here is the pivotal question about ECP brakes:
Do ECP brakes decrease train stopping distance by up to 70%—OR—do they decrease train stopping distance by up to 1%?
Here 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 “
And Euclid’s been the head cheerleader for ECP on this list.
The US has the best form of government that MONEY can buy.
I haven’t the stomach for reading the entire thread. It seems to me the point of ECP is to obviate the need for emergency brake applications (which may cause aforementioned pile-ups) by having safer, controlled, 70% shorter distance stops with service applications.
Euclid: You implied that you were quoting USDOT when you wrote "… allow train operators to stop faster if there was an obstacle on the tracks.” It sounds enough like government bureaucratize to be from USDOT. I assume by “train operators” they mean engineers.
Question for the many engineers on this forum: “How many times in your career have you stopped your train because of an obstacle on the track?” And a companion question: “How often are you able to stop your train because of an obstacle on the track when you are moving at track speed?”
All this talk about air brakes. Yet dynamic braking and throttle modulation are the preferred ways to handle trains. I guess ECP would help in severe grade territory to some extent, but they act like we need it to be safe.
shrugs
I can stop fine with what we have now. Perhaps we need to focus on skills and training and less on fancy gadgets.
Let’s look at it this way. Some hotshot engineer races to a stop signal, figuring his ECP brakes will let him stop 70% faster. But the E in the ECP fails. No problem, as you still have the ol’ standard backup airbrake. Only problem? It’s 70% worse. Dump it and pray I guess. I would never trust ECP to be 70% faster just because of that. It’s like using dynamics - you always have to be prepared in case they crap out.
Chuck,
The quote I posted above with comments from the USDOT is from the N.Y. Times today. Last Friday, the following comments are attributed to Secretary of Transportation, Anthony Foxx after the mandate was announced. This is the link: http://www.politico.com/story/2015/05/obama-safety-regulations-train-oil-derailments-117550.html#ixzz3ZNbTCQWb
Here are the comments quoted:
Foxx maintained that the 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.
“I conclude that the USDOT (astoundingly) fails to understand the qualifiers to the answer.”
Are you saying that the people who deal with this on a daily basis don’t know what they are talking about? Certainly sounds like it.
Norm,
Yes, that is exactly what I am saying. It is either that or the railroad industry does not know what they are talking about. I think that the DOT was duped by a long standing exaggeration of ECP stopping power that has been intentionally implied, as I detailed in the second post on this page. Some of the railroad industry itself has contributed to this exaggeration before this mandate was in the offing. Unfortunately for them, they probably helped convince the DOT that ECP was the answer. So the exaggeration came back to bite them.
I bet the railroads’ resistance to ECP is almost entirely about postponing an enormous expense, like standardizing a new gauge or something. FRA seized the opportunity to capitalize on concern about oil trains to force-feed a little ‘improvement’ they’ve long believed in.
Excerpt from 2009 FRA update on ECP
“FRA continues to believe that ECP brakes provide numerous safety and business benefits over conventional air brake systems. ECP brake technology provides simultaneous and graduated application and release of brakes on all rail cars within a train, resulting in shorter stopping distances. Trains equipped with ECP brakes provide locomotive engineers with better train control, lowering the risk of derailment…
“The final rule requires that ECP brake systems fully comply with existing indu
Yes I have. I just figured this out last night after spending a day trying to get an answer from the FRA, Wabtec, and New York Air Brake to explain the two conflicting claims of reduced stopping distance for ECP brakes. It was the comment by Buslist yesterday that pushed me in the right direction. As I recall, nobody else here has mentioned it so far in this thread.
Prior to the prospect of this mandate, even the railroads were on the same bandwagon as everybody else. Canadian railroads reported great improvements in stopping distance without mentioning that it only involved service applications of braking. They have only reversed their position since the prospect of an ECP mandate developed recently.
And from that point, leading up to the mandate, and even after the mandate, every reference from the railroad industry has failed to clarify the point about the claim of 70% shorter stopping time with ECP.
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.
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.
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!
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.
This is cute but you’re missing the correct qualifier:
-
What is the stopping distance in feet (or meters or whatever) represented by that “70% shorter stopping distance”?
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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…
Wizlish,
The qualifier to the stopping time and distance of ECP versus Westinghouse is whether the application is an emergency application or a service application. It relates to the difference in the design of the service application in each of the two brake types. The qualifier simply explains the discrepancy between the claims that ECP stops up to 70% quicker than Westinghouse, and that ECP stops about 1% quicker than Westinghouse. The qualifier explains the 69% discrepancy in the conflicting claims.
Why should I care about the number of feet it takes to stop? I think I have explained as clearly as possible, assuming that my understanding of the flow controls is correct according to my reasoning in the last post of the previous page. Certainly nothing I have seen from the USDOT or from the AAR has explained it at all.
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.
Wizlish,
The service stop of ECP is up to 70% shorter than that of Westinghouse. But here is the point: The emergency stop of the two brake types is practically identical. That is why I don’t care about the number feet represented by the 70% figure. Even that percentage figure is said to vary from 30-70%. It does not make any difference to the point I am making.
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.
There may be a small stopping time advantage of ECP over Westinghouse due to the quicker propagation time, but the industry is claiming that distributed power can reduce that advantage to near zero. So the only stopping time advantage of ECP lies w