Euclid So if the top level measure only provides 80% of the solution, I think other measure are justified if they address the remaining 20%.
To turn that a bit - the 80/20 'rule' also applies to expenditures. When comparing the top level solution to the remainder, I'd opine that dealing with the top level solutions will only take up 20% of the total cost of reducing the problem to an acceptable minimum. The remaining 20% of the solution will thus take up 80% of the costs.
Oh my gosh! Tree's saying we should just give up!
Hardly.
But in business, the law of diminishing returns does hold sway. At some point, the cost of fixing a problem exceeds the cost of dealing with the problem when it does occur.
"Five nines" reliability is a common goal in many pursuits. But five nines isn't good enough if that .00001 happens in your front yard. I get that, and I'm sure everyone else does, too.
So we look at relative return. Taking care of the big stuff - track, defect detection, you-name-it, benefits the entire operation, not just trains of crude. Conventional braking systems handle train control just fine for almost all trains running today.
As Bucky notes, there are myriad potential causes of derailments, so when do we say "good enough?" Obviously a zero derailment rate is desirable. I'm sure the railroads would like that even more than the public. But when does the the cost of removing all potential derailments exceed the return on investment?
ECP has been around for a number of years. Unlike electronic devices, and PTC, the incidents so far haven't sparked a similar knee-jerk reaction from any regulators for the use of ECP. That could well be because ECP likely wouldn't have had any effect on the outcomes.
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...
Good points Larry, and I do understand the 80-20rule. That said no one yet knows with any certainty how much derailment sensors may cost, or differential braking or whatever else may develop.
So which likely costs more, outfitting the fleet of cars and locos with a couple thousand dollars in parts, or relaying all track in the continent with concrete ties and weldedrail?
This is why I'm looking at things that dont require a fundamental changes to cars,infrastructure,or locomotive's. Ecp is a major change to braking.
And again this isn't limited to oil trains. These could be tested on coal or wheat trains too.
Modeling the Cleveland and Pittsburgh during the PennCentral era starting on the Cleveland lakefront and ending in Mingo junction
Larry,
I understand and agree with your point about diminishing returns. My point that I think you are responding to is my response to deusman’s point on the previous page. His point is that there is no reason to try to control a derailment when it is possible to just prevent them. I think that is flawed logic. He brought up the analogy to air bags earlier. In applying his point about preventing derailments instead of controlling them, this would be how it would fit the air bag analogy:
There is no point in putting air bags in vehicles when the problem can be solved by careful and lawful driving. And yet we have air bags because, although careful and lawful driving would render air bags unnecessary, it will never be effective enough to solve the problem.
And I do not believe his point was that detection and inspection will solve the bulk of the problem. His point was that because preventing derailments is a higher level of prevention than limiting damage after a derailment occurs, we should just do that higher level. That I think is flawed logic.
Also, my 80%:20% ratio is just an arbitrary number for illustration. I do not assume that improving wayside detection and track inspection necessarily will solve the problem 80%. So I would not assume that a cost benefit analysis would necessarily favor that safety measure.
Incidentally, I agree that the industry has to look at return on investment. But while the investment is quantifiable, I doubt that any two people would agree on what the return is. The “return” is just a game of chance, and as we have learned, that game includes the chance of enormous loss in death and injury, it also includes the potential loss of the oil business. How much do you invest to limit your risk?
Incidentally also, I have not suggested that the only acceptable outcome is zero fireball wrecks. I have used the phrase, “reducing the problem to an acceptable level.” My references to solving the problem 100%, or addressing the remaining 20%, are only as reference points to explain the logic. I think that the objective will be met by reducing oil train wrecks to a level that the public accepts, rather than reducing it to zero. Of course zero would cost infinite money and be impossible to achieve.
EuclidHis point is that there is no reason to try to control a derailment when it is possible to just prevent them.
I don't think that was his point at all. What I understood him to be saying was that there is little reason to concentrate, or obsess, on developing complex and expensive systems that may or may not mitigate severe oil-train accidents when the money and effort involved would be better spent on prevention. I took the point of his 'three-alarm fire' metaphor to be illustrating this.
By extension:
He brought up the analogy to air bags earlier. In applying his point about preventing derailments instead of controlling them, this would be how it would fit the air bag analogy: There is no point in putting air bags in vehicles when the problem can be solved by careful and lawful driving. And yet we have air bags because, although careful and lawful driving would render air bags unnecessary, it will never be effective enough to solve the problem.
The analogy I think he is making is more that you don't put in 13 air bags, active rear-wheel steering, TPMS, radio cruise control, active bumpers, Chobham armor and springs all over the car when a much better approach will be a combination of proper training, prudent operation, proper road and vehicle maintenance, etc.
Note that this does NOT say that some level of improvement in oil-train design is overkill, just that there comes a point -- dhusman thinks it comes more quickly than I do -- at which a derailment of any particular magnitude on an oil consist will snowball into danger REGARDLESS of any cost-effective measures you might apply to the train, and perhaps regardless of any measures that don't themselves price oil-by-rail out of any market if implemented.
The problem is that the public perception IS that fireball wrecks should be, and must be, reduced to zero. That's not just an opinion of the moment driven by self-serving journalism or whatever. Politicians are going to use this as a golden opportunity to cram in all sorts of bells and whistles of legislation and unfunded mandates -- take the history of PTC legislation after a couple of MUCH less terrifying wrecks as a case in point. And there is little advantage, or opportunity, in reducing the incidence of derailments by any of the honest means that is done. (And a good Democrat will add that railroads should already have had their six-standard-deviations of quality control for track integrity in place already...)
To me there's no question that oil trains can be made safer if by some chance they derail. There's also little question that no amount of armoring the cars or their connections will accomplish much of that safety, or (in my opinion) throwing their brake valves indiscriminately into emergency as promptly and powerfully as even a discriminating derailment detector can manage will.
Any system applied to a train will apply only to oil trains, at least to start. Any argument about applying components like ECP to all interchange cars, or perhaps even to entire locomotive fleets, is really a red herring. It's possible that if ECP is mandated for oil trains the cost of a proper system, or one that is nominally compatible with 'regular' one-pipe brake systems, will be reduced enough to make it attractive for other unit or semi-unit services, but it is far less essential there than it is for the oil service. Likewise any 'gizmo' system for discriminating derailments (up to five-nines or whatever confidence is needed) is not needed beyond oil consists, no matter how useful it might be now or in future on PIH hazards, liquefied gas fuel, or other places.
Where I see the near-term interest is how the cost of applying mandated systems to oil trains gets passed along to customers vs. absorbed by the carriers ... and perhaps more importantly, whether the mandated requirements are a proper inducement to the shippers to perform proper degassing, etc., of their volatile crude before shipping. THAT to me is really the most important part of making these oil trains 'safer', and as often happens in this kind of situation, arranging the economics to make the 'right thing' the least expensive option ought to produce the right effects.
As long as we can keep it from being a grandstanding unfunded-mandate sort of arrangement!
wanswheelDOT press release about oil trains http://www.fra.dot.gov/eLib/details/L16335
Euclid WizlishThe FRA says this: “These are important, common-sense steps that will protect railroad employees and residents of communities along rail lines.” It is meaningless without clarifying how much protection there will be. How exactly will lowering the speed limit to 40 mph protect people?
WizlishThe FRA says this: “These are important, common-sense steps that will protect railroad employees and residents of communities along rail lines.”
WizlishI am more concerned that turning down the threshold on defect detectors might lead to something other than the desired effect -- what are the actions that have to be taken when a detector 'flags' an axle?
On may detectors they are interconnected so the system detects when an axle is trending hotter, that information is alerted, the dispatcher contacts the trains and the train sets the car out.
I am now wondering whether what is desirable here is actually a coordination between detectors (and some standard for calibrating them) so that there is knowledge when a wheel on a particular axle is deteriorating progressively somehow.
20 year old technology. Its already in place on most class 1's. It applies to all trains. Oil trains are only about 4-5% of trains and oil isn't that dangerous so railroads want solutions that address a broader range of trains.
Dave H. Painted side goes up. My website : wnbranch.com
dehusman Wizlish I am more concerned that turning down the threshold on defect detectors might lead to something other than the desired effect -- what are the actions that have to be taken when a detector 'flags' an axle? On many detectors they are interconnected so the system detects when an axle is trending hotter, that information is alerted, the dispatcher contacts the trains and the train sets the car out.
Wizlish I am more concerned that turning down the threshold on defect detectors might lead to something other than the desired effect -- what are the actions that have to be taken when a detector 'flags' an axle?
On many detectors they are interconnected so the system detects when an axle is trending hotter, that information is alerted, the dispatcher contacts the trains and the train sets the car out.
By extension and from what you said, the same procedure applies to impact detection. The immediate question is whether 'dialing down' the detector threshold as the FRA release indicated would result in a serious increase in the number of cars needing to be set out enroute.
I suspect it isn't practical to lower thresholds 'just' for the 4-5% of the traffic that represents trains carrying at least one car of crude oil, although I suppose if the decision to set out cars is at a dispatcher's discretion much of the same effect can be obtained. Presumably the detectors provide actual scaled impact-force data, with the 'threshold' being just a setpoint that triggers an alarm, rather than just tripping if the threshold shock is exceeded. Do dispatchers have on-demand access to those data?
Are there wayside detectors that analyze the shock waveform and characteristics generated by individual wheelsets or wheels, and discriminate between different types of potential damage -- for example by using broad-spectrum microphones bonded to the rail??
I concur that 'improvements' in wayside detection represent an advantage for all traffic, not just oil traffic, but part of what I am wondering is whether 'improvements' mandated to (ostensibly) make oil traffic "safer" have positive, or negative, or mixed implications for the cost-effective flow of other traffic.
The reaction to the DOT release is amusing. Its like watching people who have never filled out a form 1040 try and redesign the tax code.
The HTUA's have been around since just after 9-11. They are the standardway that the regulations identify major urban areas. There are dozens of regulations that refer to them.
Y'all have got the detector thing exactly backwards. If you kid has a fever they tell you to take them to the doctor if its above 102 or 103 degrees. If they LOWER the threshold, then you take the child to the doctor when the fever is 100 or 99 degrees. You lowered the threshold but response became more restrictive. If they lowerthe threshold then if the detector used to fault at 100 mm then the fault will now hit at 95 mm or whatever. The threshold is lower, but its more restrictive.
Euclid always thinks every announcment is a signal they are going to spring some secret new thing and suprise everybody. That's not how it works.
Euclid I did not miss the part about the 40 mph speed limit applying only in High Threat Urban Areas. Although I did wonder where those areas were, and why they are “high threat.”
Generally I concluded that the report is symbolism over substance intended to convince the public that it is doing its job to address this safety issue. It leaves me to conclude that the main thing that is protecting residents of communities along rail lines is the odds of derailments happening elsewhere.
I realize that there will be less destructive energy as the speed is lowered, but I don’t see how 40 mph is going to help much. Either 40 mph or 50 mph has more than enough energy to breach many tank cars in a pileup.
Considering the wrecks in Casselton, Alabama, Virginia, W. Virginia, Illinois, and the two in Ontario; how fast were these trains running when they derailed?
Considering the first sentence, could it possibly be more indecisive? “Preliminary investigation” of one recent derailment “indicates” that a mechanical defect “involving” a broken tank car wheel “may” have “caused” or “contributed” to the incident.
I see this report as intended to convey a sense of ramping up concern in order to set the stage for new tank car rules that are going to surprise the stakeholders.
We'll have to disagree on this -- except I do think there are forces in government that are setting up to do more or less what you say. Many in Congress would be delighted to exercise power in dictating to railroads what is 'necessary' to achieve 'safety' whether or not the solution is cost-effective, practicable, or even safe (let alone safer than better alternatives). All you need to do is compare the history of mandated PTC to see how this happens.
I thought the NPRM bent over backward NOT to make it look as if more extreme "solutions" were coming, or that a camel's nose was being thrust into anyone's particular tent at present. If the speed restriction were to 20 mph, or applied to all track mileage irrespective of popultion, I'd have been more inclined to agree, but this does look more like an attempt at common sense and practical measures to me. But as usual with these NPRMs, YMMV.
To be honest, the only way a system like yours will ever be built is if the United States Government mandates it, tests it, and subsidizes some or all of the detail design via grants. So I am not quite sure why you're attacking a tendency by that government to take grander or more sweeping action to fix the perceived dangers from volatile-crude trains...
dehusmanY'all have got the detector thing exactly backwards.
How so?
The detector will have a vibration or shock threshold -- a better 'temperature' analogy would have been your thermostat, not a fever. When the setpoint is exceeded, the device issues an alert. Lower threshold = less vibration or whatever needed to trigger the alert.
And the more likelihood that a given train will have at least one car that triggers at the lower threshold, and the affected car will have to be set out at some (possibly inconvenient) point. I suspect there is the usual war between the operating and MOW department over where the thresholds for a given railroad's detectors will be set -- remains to be seen if there is too much false-positive action and the thresholds have to be 'adjusted' quietly and behind the scenes after the publicity has died down...
Wizlish I suspect there is the usual war between the operating and MOW department over where the thresholds for a given railroad's detectors will be set -- remains to be seen if there is too much false-positive action and the thresholds have to be 'adjusted' quietly and behind the scenes after the publicity has died down...
always a 3-way war: operating (engineer and conductor zombies), mechanical (car dep't) and engineering (track goblins). I believe the newer detectors can tag a car if a journal or wheel is running hotter than usual, but not as hot as to cause a need for immediate set-out. Pretty hi-tech stuff anymore.
BaltACD would know better than me.
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
What war?
The engineering department doesn't really care where the thresholds are set. Its ithe operating and mechanical departments that have the dog in the hunt. They will determine the threshold based on data and set them accordingly.
A question of perspective: how much does the industry spend each year on derailment cleanups? Not just hazzardous loads but all derailments? Including lost time to rerail a couple cars that picked a switch and lost revenue from having to shut the line down for days to clean up a more major accident? Damaged and lost lading? litigation and settlements/judgements? Those are just a few of the costs involved in any derailment. How much does that add up to?
Not an easy question to answer. Someone woud really have to be "in the know" to provide real answers but I suppose educated guesses could work here.
And how do those costs compare to added safety improvements? Upgraded right of way and keeping it in better condition costs how much per year? Not including repairs from derailments (if the derailment didn't happen, the repairs woudn't be needed) Is adding things like ECP really that expensive compared to one major derailment (LacMegantic for example)? How many derailments would cost more than ECP? Most are knocking my derailment sensor idea as cost prohibitive but none of us even have any idea how much such a system would cost, not even me. But I feel that the cost would be much less than others think.
Without actual number to put things into perspective though, it's really an argument about nothing. That's not to say that keeping the costs minimal isn't beneficial, actually the cheaper the better in order to gain acceptance. And by way of mass production the more production the cheaper it could become.
EXample: the Lincoln show car that eventually became the original Batmobile, cost FoMoCo somehwere near 5 million dolllars (in the late 50's), was sold to Barris for less than $2000 and now is stil worth less than a fraction of what it cost to build (I believe current value is about $500k). But the production versions of that Lincoln sold for well under $5000 and enough were sold to justify it's production expenses.
Point being, prototype costs are always much higher than production costs.
And to be clear, I agree that derailment prevention is the best way to handle things. If derailments didn't happen how much could be saved in car costs? Tanks coud be built, maybe, with only 1/4" steel for example. What about lower insurance premiums? Higher track speeds? No drailment cleanups? Other savings? Could those saving offset the expense of making trackwork derailment proof?
For that matter can track be made derailment proof? No, not even with an unlimited budget.
So given that derailments can still happen, why not explore avenues of crash control/mitigation? By limiting the severity of those derailments, many of the costs associated with one can certainly be reduced. Enough to offset the cost? Maybe, we don't know yet.
And now that the government is noticing and taking some action, time is growing short for the industry to sort out its own problem. Best to get a handle on it before the government decides whats best. FWIW I don't believe the latest news from on high is bad, it actually seems rather prudent. I'm not sure how patient they will be though before handing down something not practical.
ruderunner And how do those costs compare to added safety improvements? Upgraded right of way and keeping it in better condition costs how much per year? Not including repairs from derailments (if the derailment didn't happen, the repairs woudn't be needed) Is adding things like ECP really that expensive compared to one major derailment (LacMegantic for example)?
And how do those costs compare to added safety improvements? Upgraded right of way and keeping it in better condition costs how much per year? Not including repairs from derailments (if the derailment didn't happen, the repairs woudn't be needed) Is adding things like ECP really that expensive compared to one major derailment (LacMegantic for example)?
Here is a perfect example of why I keep bringing up using DATA, addressing the CAUSE and not firing shotguns in the dark.
ECP would not have prevented Lac Megantic. Not a single penny of the money spent on ECP would have yielded a benefit for Lac Megantic.
Load/empty sensors would not have prevented Lac Megantic. Not a single penny of the money spent on load/empty sensors would have yielded a benefit for Lac Megantic.
Euclid's differential braking would not have prevented Lac Megantic. Not a single penny of the money spent on differential braking would have yielded a benefit for Lac Megantic.
For a cost benefit basis all of those schemes, if you are trying to prevent Lac Megantic, would have been 100% waste. All expense, zero benefit.
That's why railroads take a broader approach and look at more than the cause du jour that everybody is in a tizzy about. When you look at the big picture, what you do and how you do it is different than just reacting to last thing the evening news covered.
dehusmanECP would not have prevented Lac Megantic. Not a single penny of the money spent on ECP would have yielded a benefit for Lac Megantic.
Don't be dumber than you have to be.* Any sensible ECP system would have responded to falling trainline pressure by applying the train brakes. I think we are all agreed: brakes on = no Lac Megantic accident. Admittedly this is a fringe benefit of having the ECP system, and not just some additional valves and wiring to actuate release quicker... but the additional features are part of the "money spent on ECP" (and in the case of Lac Megantic even you can't deny it would have been money well, well spent.)
*(Yes, that was a little strong, but Dave has been a bit arrogant in his claims that many contributors to this thread are ignorant of real-world train systems, and he should have known better than to miss this so badly...)
It seems Euclid is on the same page as me. Perhaps I should have used Lynchburg as an example or some other wreck.
That said, wizlist I'm not sure Dave is wrong about ecp not stopping the wreck. In my understanding, once the air is gone even ecp wouldn't have held the train. OTOH would PTC have been a benefit? Probably not. Even great trackwork wouldn't have helped. But runaway trains is such an anomaly, why even think about it.
How many derailment happen every day? And not just the ones that make the news...
I believe everyone here is taking things a bit too literally. I'm trying to discuss concepts of things that may make improvements, not saying this is how it has to be and its the only way. I see Euclid doing the same, trying to develop a concept but everyone doesn't seem to be even attempting to follow the idea, rather they would rather argue over finedetails. Sure the details will be important, but at this time the idea or concept is more important.
Don't know that that would happen. Is that functionality on each individual car (if a car senses an air drop it sets the brakes on itself) or is it part of the locomotive control valve functionality (the locomotive senses the drop and sets the brakes on the train)? Since there was no system and there is no ECP system currently in use on the US freight network, I couldn't swear how one would work.
I would think having an individual car set the brakes on just itself would be a bad thing.
If its part of the locomotive control valve, then what happens when all the engines are shut down before the air pressure drops? After all, before the engine caught fire, the train line was pressurized. The only running engine caught fire. That engine was shut down. Subsequent to that the train line pressure dropped. With all the engines shut down, which engine is going to be the one that tells the train to set its brakes?
Even if the air bled off and the train brakes set, there is nothing to say that they wouldn't have bled off and let the train roll free. That's why the rules require handbrakes because the train brakes can't be relied upon to hold a train. It might have delayed the runaway for a couple more hours, which might have reduced the fatalities, but there is no guarantee that it would have held the train all night.
As I understand it, the engineer of the MM&A oil train left the automatic brake released and held the train with just the indenpendent brake and some hand brakes. So apparently the leak-down only involved the independents. The train line and the car reservoirs remained pressurized, and the automatic brake remained released as the train ran away once the independents leaked down.
This is why so many people could not understand how the car reservoirs all leaked down and released the car brakes in only a few hours. The car reservoirs did not have to leak down in order to release the car brakes. The car brakes were already released while the reservoirs and train line were fully charged.
dehusmanDon't know that that would happen. Is that functionality on each individual car (if a car senses an air drop it sets the brakes on itself) or is it part of the locomotive control valve functionality (the locomotive senses the drop and sets the brakes on the train)? Since there was no system and there is no ECP system currently in use on the US freight network, I couldn't swear how one would work.
I'm going by the systems that have been developed (some of which have been tested in service) for ECP on freight trains. You will know more of these than I do. My present opinion is that ECP systems as generally designed and applied to passenger trains aren't comparable to what is required for a 'good' freight system, either for unit-train service or as prospectively designed for loose-car or loose-block railroading. But I would think any ECP system designed by a competent engineer would have some limit valve that would set the air if trainline pressure dropped below a reasonable limit, no matter how slowly pressure bled off to reach that limit.
I can think of very few things as asinine as that would be; it's bad with conventional brakes when one car 'decides' to set itself in emergency ('dynamiting') and takes the rest of the train with it eventually...
I leave aside the discussion of what a bonehead Pepsi move it was to leave all the locomotives of a consist 'dead' with only the independent and a wholly insufficient number of handbrakes set. The Canadians involved will have to live with that, and I leave it to them to do that, but shoulda-woulda-coulda is not really appropriate in this discussion, and it brings up the very important point of whether the 'safety' valve in a given locomotive unit will function with that unit isolated or shut down.
As noted in the accident report, many locomotives in fact have a specific valve in the trainline that is meant to detect falling pressure, and at some absolute setpoint this valve opens and dumps the air. I don't remember exactly, but I think that at least one engine in the MMA consist involved at Lac Megantic was set up to have this valve but it was either disconnected or removed. If this is an important issue to document I'll look up the specific references. Randy Stahl is likely to know all about this and I hope he will comment (assuming he hasn't already gotten terminal MEGO syndrome from this thread and has stopped following it...)
In answer to your question: EVERY locomotive in a consist ought to have one of these valves, and 'which one is the one that tells the train to set its brakes' is the first one whose valve triggers. If a given engine doesn't trip, the next one would, and so on. (If I remember correctly, this valve was supplied with battery power even with the locomotive isolated and the prime mover shut down, so even 'dead' units would have the safety feature; IIRC you would have to pull the master battery shutoff, a separate thing on both EMD and GE locomotives, to deactivate it. (Perhaps ironically, wasn't this what those firemen did?) The valve should certainly stay shut when an equipped locomotive is being handled dead-in-train, and it shouldn't contribute enough parasitic drain when 'live' to run a parked locomotive battery down and present proper start/restart, but if this were a concern I'd expect the battery shutoff would have been used.
Even if the air bled off and the train brakes set, there is nothing to say that they wouldn't have bled off and let the train roll free. That's why the rules require handbrakes because the train brakes can't be relied upon to hold a train.
Thing is, the brakes were tested, and I believe it was demonstrated that the train would have held easily for at least 2 to 3 days. The only length of time involved at Lac Megantic would have been up until dawn, when the 'American' engineer showed up to take the train (and discovered what a mess awaited him! The point is that even if the train brakes had started bleeding off to the point the train started to move, it would still have shoes applied to all the cars, plus of course the 'seven brakes' less the axle left out by the defective QRB valve. I think you will agree that it would be unlikely that in the relatively short distance down to Lac Megantic the train would have reached the speed corresponding to the 'boiling point' where outgassing from the shoes destroys effective braking effort at about 22-23 mph.
It might have delayed the runaway for a couple more hours, which might have reduced the fatalities, but there is no guarantee that it would have held the train all night.
Of course there is no 'guarantee' that the train involved in the Lac Megantic accident wouldn't have rolled down and exploded, but I don't recall anyone with experience claiming that if the train air had in fact been set, even with the reduced reservoir pressures corresponding to the point the 'safety' valve triggered at about 40 psi or so, the train would have rolled down that night. I still am uncomfortable with the fact that part of a safety device -- the air turbine in the EOT device -- was the proximate cause both of the significant fall in trainline pressure and the slow-enough fall of pressure that kept the brake system from normally going into emergency by sensing differential between reservoir and trainline pressures. (I would tongue-in-cheek note that if Euclid put a little turbine on every car, the aggregate drop WOULD have put the 'legacy air' in a compatible ECP/standard hybrid system into emergency, right quick, under the conditions that prevailed for the Lac Megantic accident...)
Euclid As I understand it, the engineer of the MM&A oil train left the automatic brake released and held the train with just the indenpendent brake and some hand brakes. So apparently the leak-down only involved the independents. The train line and the car reservoirs remained pressurized, and the automatic brake remained released as the train ran away once the independents leaked down. This is why so many people could not understand how the car reservoirs all leaked down and released the car brakes in only a few hours. The car reservoirs did not have to leak down in order to release the car brakes. The car brakes were already released while the reservoirs and train line were fully charged.
Take another look at the report. http://tsb.gc.ca/eng/rapports-reports/rail/2013/r13d0054/r13d0054.asp
There's a chart (table 1) on that page with the data downloaded from the engine. The brakepipe did bleed off before the train ran off.
Even with ECP, you set handbrakes when parking a train. Period. End of story. Railroading 101. Never rely on the air to hold an unattended train.
After I wrote my response I realized that the whole arguement was moot. The train would not have gone in emergency when "the air bled off", because the train would have already been in emergency and the air would have never had a chance to bleed off the train line.
As soon as the last engine was shut down, the train line ECP control signal would have gone dead. That should have signaled the cars to go in emergency, because they don't know whether that signal loss was caused by an engine shutdown or the train parting. I wil agree that with ECP the train would have been placed in emergency. The question remains, for how long? A pessimist would say that since nothing else went right that night it would have bled off, an optimist would say it would have held long enough for the relief crew to get there and restart the engines.
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