Murphy Siding If you have 100 tank cars screeching to a halt, isn't that enough transfer of forces to simply peel up the track...and derail the train?
If you have 100 tank cars screeching to a halt, isn't that enough transfer of forces to simply peel up the track...and derail the train?
Murph,
The formula I found for kinetic energy is somewhat above my pay grade, but a quick run through of one 286,000 lb car at 60 MPH found that energy to be, pardon the pun, in TONS; many of them. The braking force necessary to stop just one car in a short distance far exceeds the capabilities of both air and magnetic brakes. The latter would simply rip uo the rails.
Norm
Some replies don't seem to refer to what I actually wrote. Any derailment will immediately apply both the normal airbrakes and the magnetic track brakes. If the engineer wishes to press an override button for an immediate release, he may do so. With well-maintained uniform equipment, there should be very little slack action, and depending on what the derailed car encounters, there can be littlle or zero accordianing. Or stringing.
Track structure. I did have one personal experience on a PCC car coming to an emergency stop on very weed-grown undermaintained lightweight track. There was no track damage. After a bunch of passengers lifted the offending vehicle that the PCC would not have cleared off to the side, we started up and proceeded as if nothing happened. Admitadly, a PCC is way way lighter than a 100-car loaded oil train, but the trackj structure was also way way lighter. After any cleanup, obviously the entire track structure from the point of rear-car first brake application should be inspected, but whatever damage is suffered is small change compared meeting a train on an opposing track, heading into buildings, or whatever. I probably exaggerated when I said stopping distance like a private automobile, and more realistic would be halving the current stopping distance, still very worthwhile. There would be no brakes not contolled by electricity in an emergency, except possibly those on the lead locomotives. In normal operation the engineer would and should be given the option of using or not using electric control, the options primarily to control slack action.
I think with respect to Lac Megantic, the brakes applying thte moment one car left the rails, this would have averted the disaster. Of course! But we also know that if any brakes on all cars had been applied at any time before or up to the derailment, the disaster would not have occured. What is true is that if the string of tankcars had been left alone with a dead locomotive, all without any airbrakes, the air in all airtanks having leaked off, and the train started rolling, at least the magnetic track brakes would have applied on all cars once there was a derailment, and the disaster would have been avoided or sharply mitigated. The electfically controlled airbrakes would have "applied", but without any air-pressue from the airtanks, they would have been ineffective, and only the magnetic trackbrakes would have applied. Remember, each tankcar does have a battery and two axle-driven alternator-generators which double as sensors for derailment detection.
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Dave H. Painted side goes up. My website : wnbranch.com
tree68So it appears that we're all in agreement that differential braking won't work. Semi-permanent drawbars won't make a difference because they still have to have enough play for the train to go through turnouts and around fairly sharp curves. The play necessary to do so will allow a car to skew if the forces pushing on it from behind are great enough - and probably enough to force it off the rails and into an accordian if the cars ahead of it have stopped fairly abruptly. Most, if not all, hazmat tank cars already have shelf couplers, which have the same effect as the suggested drawbars. Thing is, the only thing keeping the trucks on the cars is gravity. I'd say the whole idea is "busted," as they say on Mythbusters.
Semi-permanent drawbars won't make a difference because they still have to have enough play for the train to go through turnouts and around fairly sharp curves. The play necessary to do so will allow a car to skew if the forces pushing on it from behind are great enough - and probably enough to force it off the rails and into an accordian if the cars ahead of it have stopped fairly abruptly.
Most, if not all, hazmat tank cars already have shelf couplers, which have the same effect as the suggested drawbars. Thing is, the only thing keeping the trucks on the cars is gravity.
I'd say the whole idea is "busted," as they say on Mythbusters.
You know what they always say: “Build a better mousetrap and the world will beat a path to your door with a list of reasons why it won’t work.”
The stronger drawbars are not intended to directly prevent jackknifing or accordion action. Those effects are prevented by pulling on the train to keep it stretched tight. The stronger drawbars are necessary to withstand that pull.
The pull on the cars comes from differentiating the braking so the cars behind the derailment have more braking than the car ahead of it.
It is not rocket science. It won’t prevent derailments. It won’t prevent all damage. But it will help to limit the damage; just like shelf couplers and head shields do.
The trick, is to build a better mouse trap without reinventing the wheel.
Thanks to Chris / CopCarSS for my avatar.
I srill say if there is no break-in-two, then stopping the whole train as quickly as posible in the event of a derailment is uniformly the safest procedure. This assumes no jacknifing and thus electrically-appllied brakes with all brakes acting unifromly. If there is a break-in-two. then the engnineer should have the option of immediately releasing the emergency appllication on the front section only and handling this section as suites the particular circumstances, including, in some case, allowing the emergency brakes on the front section to continiue. If the derailment occurs in the middle of a fire, then obviously he is going want to get-the-h__l out of the place as quickly as possible. If whatever danger caused the derailment back in the train is minor compared to a danger a half mile down the line, he may wish to allow the emergency brake application to continue.
And I want the test train to be equiped with indivdiual couiplers for each car to have the train suite the applciiation exactly - as well as minimizing ovefall effects of any car sbad-ordered for any reason.
I think differentially applied brakes can create more problems and be far less safe than stopping as quickly as possible, safely and uniformly.
I have restated my original premise from the beginning of this thread to eliminate some of the features and add clarity.
THE EUCLID SYSTEM OF DERAILMENT DAMAGE MITIGATION FOR OIL TRAINS
BASIC ELEMENTS:
1) Cars semi-permanently coupled with extra strength solid drawbars; either in full trains, or in multiple car-sets which are separated by standard knuckle couplers and separable air hoses.
2) Truck anti-pivot safety chains.
3) Electronically controlled pneumatic brakes (ECP brakes).
4) Cars equipped with sensors to monitor temperature of running components, vibration, sound, motion, etc.
5) Cars equipped with derailment sensors to detect a derailment the instant it begins.
6) A controller that initiates a “smart emergency” automatic response upon detection of a derailment by the derailment sensors. This response applies less braking on the cars ahead of the derailment than it does on the cars behind the derailment. The system varies these brake applications according to train tonnage, train speed, location of the derailment in the train, and location of the train on the line.
The purpose is to keep tension on the cars ahead of the derailment and on the cars that have derailed in order to keep the derailed cars in line with the track as much as possible.
< ------~~~------ >
Nice proposal without a lot of specifics, why doesn't this proposal include some real engineering to support it
There are sitiuations where differential braking will cause more problems than solve, such as derailmenet on a bridge, where the differential may create additinal strain.
daveklepper There are sitiuations where differential braking will cause more problems than solve, such as derailmenet on a bridge, where the differential may create additinal strain.
I would opine that the magnetic braking might fall into the same category.
The track structure is intended to keep the rails in guage - ie, limit side-to-side movement. Lengthwise, the rails are allowed to move.
Trying to stop a heavy train almost instaneously from 30+ MPH would likely cause the rails to slide in their anchors, until they found a weak spot in the structure. That might be a switch or a curve, or even just a rail joint. At that point, it's gonna look like a sun kink on steroids and cars that might have otherwise stayed on the rails are going to be on the ground.
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...
I think a reasonable compromise could be found where the magnetic track brakes would contribute usefully to stopping power For starters i would use models used on transit vehicles without trying to increase their power to account for the added weight of a loaded tank car. Based on my experience with transit use, I doubt the harm you mention would occur -- unless there was repeated use in the same spot .
Euclid should learn that not all railroad is on straight track. A derailment on a curve can often result in stringing, and differential braking as Euclid proposes would make it a certainty. Fast and uniform braking would reduce this tendincy.
daveklepperIf there is a break-in-two. then the engnineer should have the option of immediately releasing the emergency appllication on the front section only and handling this section as suites the particular circumstances, including, in some case, allowing the emergency brakes on the front section to continiue.
But if a train breaks in two, you are assuming the front half is staying on the rail. There may be derailed cars that will only be seen by an inspection (barring some sort of derailment detecting device that bucky euclid alludes to - curious how that will work).
So you release the emergency application, take off, and promptly toss a derailed oil tank car off a bridge, or down an embankment on top of someone's car? If something happens that breaks a train in two, you don't just want to keep going and hope everything is ok.
And loading these cars up with computers, sensors, and microschips - that is going to add a lot of work to car inspector/maintainer jobs.
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
Euclid 6) A controller that initiates a “smart emergency” automatic response upon detection of a derailment by the derailment sensors. This response applies less braking on the cars ahead of the derailment than it does on the cars behind the derailment. The system varies these brake applications according to train tonnage, train speed, location of the derailment in the train, and location of the train on the line.
I always shudder at the use of the term "smart" for something that adds a lot of extra steps, sensors, and software to what should be an immediate and direct response, IMO. Open the brake pipe, (KAPOW!), and you come screeching to a halt. You want to add that stuff to regular applications? I'm cool with that... but seriously, with an emergency application, keep it simple. If I need an emergency stop, I want the stuff to stop for a very important reason.
zugmann daveklepperIf there is a break-in-two. then the engnineer should have the option of immediately releasing the emergency appllication on the front section only and handling this section as suites the particular circumstances, including, in some case, allowing the emergency brakes on the front section to continiue. But if a train breaks in two, you are assuming the front half is staying on the rail. There may be derailed cars that will only be seen by an inspection (barring some sort of derailment detecting device that bucky euclid alludes to - curious how that will work). So you release the emergency application, take off, and promptly toss a derailed oil tank car off a bridge, or down an embankment on top of someone's car? If something happens that breaks a train in two, you don't just want to keep going and hope everything is ok. And loading these cars up with computers, sensors, and microschips - that is going to add a lot of work to car inspector/maintainer jobs.
That is exactly why I want the train to automatically stop as unifromly and as quickly as possible. If the engineer presses the override button to get out of place fast, he must have a very very good reason to do so, and be able to know that his or her doing so is going to reduce property and human life damage. That is why I do not want differntial braking automatically or anything automatically except stopping the train as quickly, uniformly, and safely as possible. Euclid wants to trust a computer to make such decisions, but I prrefer an engineers who can look back at the train, read all the information at the time of the emergency, and usually let the train brake to a stop, doing something different only when he is reasonably cerain it is the best thing to do. Noe that the front section staying on the rail will be noted on the engineer's computer display, because all cars have derail sensors, not just the car that derailed behind the break-in-two.
daveklepperNoe that the front section staying on the rail will be noted on the engineer's computer display, because all cars have derail sensors, not just the car that derailed behind the break-in-two.
How would these work?
Also, after an emergency application, you do have to recharge the airline and reservoirs on the cars. Unless the system re-figures how the airbrakes are set up. This is some heavy stuff we're getting into. Way above my paygrade.
zugmannI always shudder at the use of the term "smart" for something that adds a lot of extra steps, sensors, and software to what should be an immediate and direct response, IMO. Open the brake pipe, (KAPOW!), and you come screeching to a halt. You want to add that stuff to regular applications? I'm cool with that... but seriously, with an emergency application, keep it simple. If I need an emergency stop, I want the stuff to stop for a very important reason.
I know what you mean about the term, smart. It is actually a green buzzword that I find annoying, but I use it to tweak the green movement as pushback against their agenda that is attached to this oil train fireball crisis. You could call this a Smart Oil Train.
But as far as keeping it simple by going right into emergency, my system is intended to prevent the train from going into emergency. I don’t want the train to come to a screeching halt. You get that automatically, whether you want it or not, in the case of a derailment with conventional air brakes. In many cases, that emergency braking exacerbates the derailment damage and promotes a pileup.
Dave Klepper is advocating that the key to reducing derailment damage is to stop the train as fast as possible. I disagree with that.
Imagine Euclid's train on your bridge, but a curved bridge, with the derailment at a center car, stringing, drawbars insead of couplers, and the one car pulling the entire train off the bridge. What is below? A highway? Houses? A river?
CSSHEGEWISCHNice proposal without a lot of specifics, why doesn't this proposal include some real engineering to support it
Thanks. I understand that this proposal needs to be verified by engineering, but that comes later. The first task is to simply explain it clearly in terms of the objective and how it will be accomplished. It is that age-old problem. Everybody needs details to understand something, but brevity is the most understandable.
Euclid, it produces a pileup only because the braking isn't uniform, but startsat front with the rear keeping moving. You are throwing what is called a red herring, something not applicable to electric control of braking. It will not produce a pileup with electric braking and uniform braking, whether or not magnetic track brakes supplement the electrically controled air brakes.
EuclidIn many cases, that emergency braking exacerbates the derailment damage and promotes a pileup.
so your system will differentiate from a UDE (undesired emergency application) and the "oh ----" application (or desired emergency application?)
So my point being, when I pull the big red handle int he cab, am I at the mercy of sensors, computers and software? Or do I just make a direct 90lb reduction? I know, I know, newer engines already have electronic air brakes, but that's one computer as opposed to 80+ on an oil train.
Maybe I missed it somewhere in this thread, but how will these derailment sensors detect a derailment?
I dicussed this thoroughly. It is off-the-shelf technology differently applied. The front and rear axles on each tankcar would have alternator-generators, keeping the car's battery charged via rectifiers, although in normal operation head-end power would do the job. The second purpose of these alternators is to allow the usual EMD or GE locomotive slip-protection control to yell to the locomotives display and to activate the braking system if big enough differences exist between between the front and rear axles of the car, which I assure you always happens in a derailment.
zugmannEuclidIn many cases, that emergency braking exacerbates the derailment damage and promotes a pileup. so your system will differentiate from a UDE (undesired emergency application) and the "oh ----" application (or desired emergency application?) So my point being, when I pull the big red handle int he cab, am I at the mercy of sensors, computers and software? Or do I just make a direct 90lb reduction? I know, I know, newer engines already have electronic air brakes, but that's one computer as opposed to 80+ on an oil train.
My system will not react to either the UDE or an intentional emergency application. It only reacts to a derailment the instant it begins. It does that by detecting a derailment by a derailment sensor on each car that can distinguish one end of the car from the other. There are no computers on the cars; only the derailment sensors plus a variety of other sensors.
Those other sensors monitor the performance of the ECP brakes and perform other supplementary monitoring functions such as bearing temperature. Those other sensors are not a fundamental necessity for my system, but they are simply added protection. The only computer for all of this is on the engine.
The differential braking feature of this system activates automatically upon detection of a derailment, but it can be manually overridden if the engineer suddenly finds a need to stop faster than the stop provided by the system.
Incidentally, with ECP brakes and far fewer air hose couplings, there will be fewer UDEs with this system.
Again, the only reason for the USUAL pile-up in an emergency brake application is non-uniform braking. With uniform braking no pile-up will occur because of the braking. And Euclid's differential braking system is certain to cause stringing on curves (if there is a derailment), which will result in additlional cars being derailed.
Eucllid may respond with "my seonsors will sense the curve and remove the differential braking." But if this is a safe stop on a curve, then it will also be safe on straight track and the differentiall ffeature is not necesary anyway!
Euclid ...only the derailment sensors plus a variety of other sensors.
I think you'll find that this means that there will be a computer on each car.
If each car sends data for every single sensor, that digital trainline will get pretty busy. Having a computer on each car means that the car can track the sensors and only send data when something is amiss, or periodically as a "keepalive" signal ("I'm still here!").
Tree68. With you completely on that score. With the battery, head-end-power connection, and two axle generators, there is zero problem in powering the speciallized computer.
All electronics should have 100% redundancy, check each other continually, and warn if there are discrepencies.
daveklepper Again, the only reason for the USUAL pile-up in an emergency brake application is non-uniform braking. With uniform braking no pile-up will occur because of the braking.
Again, the only reason for the USUAL pile-up in an emergency brake application is non-uniform braking. With uniform braking no pile-up will occur because of the braking.
Really? Do you have any actual data to support that statement (since it seems foundational to all the proposals here)?
So if I have a uniform train of very similar cars loaded in a similar fashion with very similar brake systems and the train goes in emergency, they won't pile up?
(hint search Google images for "coal train wrecks")
dehusmandaveklepperAgain, the only reason for the USUAL pile-up in an emergency brake application is non-uniform braking. With uniform braking no pile-up will occur because of the braking. Really? Do you have any actual data to support that statement (since it seems foundational to all the proposals here)? So if I have a uniform train of very similar cars loaded in a similar fashion with very similar brake systems and the train goes in emergency, they won't pile up?
daveklepperAgain, the only reason for the USUAL pile-up in an emergency brake application is non-uniform braking. With uniform braking no pile-up will occur because of the braking.
The statement you quoted from Dave Klepper is not foundational to all proposals here, as you say.
Uniform braking is a basic component of Dave Klepper’s proposal, but not of my proposal. I could have uniform braking if it were needed because ECP brakes permit it, but my concept relies fundamentally on differentiated braking in two distinct zones. For the most part, the braking would be uniform within each of those zones.
Regarding you example of a uniform train of very similar cars loaded in a similar fashion with very similar brake systems:
If those similar brake systems are conventional air brake systems; and if the train goes into emergency; there will not be uniform braking, as your example assumes. Dave Klepper's comment about the USUAL pile-up assumes the conventional air brake systems where emergency braking is not uniform in its application throughout the train.
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