Ed,
I doubt that it was covered in the news, but I was there the day it happened, about 4 hours after it happened. The dragging car was in the middle of a long train, and crew on either end did not see it. It happend very early in the morning and may not have been light yet. It was an eastbound train that dragged the car from just west of Chanhassen, MN to near Tower E-14. It tore out two planked grade crossings along the way, one at Duck Lake Rd. and the other at Birch Island Road.
In talking to people involved with it the next day, there was no sense expressed by them that this was anything unusual.
The dead horse is still in pain!
Never too old to have a happy childhood!
Euclid tree68The car involved will go from whatever speed to zero MPH within a few feet, ... That is not true. I recall seeing a car on the Milwaukee that derailed from a burned off axle and ran on the ground for 4 ½ miles undetected. It broke the end off of every tie, clipped the corner off of every angle bar, and creased every tie plate for 4 ½ miles. That kind of thing happens all the time. The only way a car is going to dig in and stop in a few feet is if it is moving very slow, and is on its own with no cars on the rails behind it.
tree68The car involved will go from whatever speed to zero MPH within a few feet, ...
That is not true. I recall seeing a car on the Milwaukee that derailed from a burned off axle and ran on the ground for 4 ½ miles undetected. It broke the end off of every tie, clipped the corner off of every angle bar, and creased every tie plate for 4 ½ miles. That kind of thing happens all the time. The only way a car is going to dig in and stop in a few feet is if it is moving very slow, and is on its own with no cars on the rails behind it.
Cite the source for this story please.
“Memories” don’t count, reliable print sources do.
23 17 46 11
EuclidDo you think that everybody who has experience with derailments and trains agrees on everything?
I think a good many of us agree your premise has no basis in real-world railroading.
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...
dehusmanEuclidThere won’t be multiple dynamiters, as you suggest, because the system will not dynamite the brakes in the traditional sense of a rapid loss of train line pressure triggering a pneumatic chain reaction of emergency braking. There will be no brake actuation controlled by brake-pipe reduction since that is eliminated by the ECP approach. The brake pipe simply charges the car reservoirs. The ECP system does apply brakes on all cars simultaneously, as you mention. That is the beauty of ECP electronic control by wire versus the conventional air brake control by changes in the train line pressure. So if the train breaks in two (but doesn't derail) the brakes don't set up? There's a safety feature.
EuclidThere won’t be multiple dynamiters, as you suggest, because the system will not dynamite the brakes in the traditional sense of a rapid loss of train line pressure triggering a pneumatic chain reaction of emergency braking. There will be no brake actuation controlled by brake-pipe reduction since that is eliminated by the ECP approach. The brake pipe simply charges the car reservoirs. The ECP system does apply brakes on all cars simultaneously, as you mention. That is the beauty of ECP electronic control by wire versus the conventional air brake control by changes in the train line pressure.
Yes, that is a very good point. The break-in-two application is a safety feature of conventional air brakes. The concept I am proposing is an added feature to the ECP brake system that has been developed so far. The only way my feature takes action is if one of the sensors detects a derailment. If that happens, my feature kicks in and overrides the normal full train emergency braking feature. If the train breaks in two, the normal full-train brake application will occur.
But when the derailment sensor detects a derailment, it starts the new system that I am proposing. That system replaces the normal emergency response with a better response. It does eliminate a safety feature, but it replaces it with a better safety feature. It only does this once a derailment is detected.
That improved safety feature would be to split the braking control of the cars ahead of the derailment from the braking control of the cars behind the derailment. That way, it could control the two braking ranges independently. Mainly, it would brake the cars behind the derailment with more force than the cars ahead of the derailment. As I mentioned, the decision making in this specialized response would be fully automatic according to a program and a processor evaluating many different variables to control the derailment. However, the engineer would have the ability to override it with full-train braking if there were some extenuating circumstance that made that advisable.
Euclid, how about electrically applied and release brake control, and magnetic track brakes, for all special purpose unit trains?
Dave,
You are free to see all the flaws you want. Do you think that everybody who has experience with derailments and trains agrees on everything?
He hasn't tumbled to the fact that everybody who has had any experience with real derailments or trains see major flaws in the premise (and physics) of the plan.
Dave H. Painted side goes up. My website : wnbranch.com
Norm,
I had no intention of sidestepping your question. The 10,000 tons will simply follow the first car (the derailed car, if that is what you mean) until the brakes and general friction stops the train. Your question seems to indicate that you interpret me to be claiming that the entire trailing part of the train will stop on a dime to avoid crushing into cars ahead. That is not what I am proposing.
EuclidThat is may not be true.
Fixed it for ya.
All of Bucky's ideas here are predicated on a simple wheels-off-the-rail derailment. Any catastrophic failure (wheels, trucks, track) or outside force (ND) negates the whole thing. The car involved will go from whatever speed to zero MPH within a few feet, while the rest of the 10,000 tons continues at speed for several seconds, even with an emergency application of the brakes.
I know from experience that it takes greater than a train length to stop a four car passenger train from 30 MPH.
At 30 MPH (a great reduced speed for that hazmat train), the train is travelling at 44FPS, or roughly 2/3 car per second. Three seconds is two cars with no place to go, because the car in front of them has stopped dead.
And I still haven't figured out how this "stretched" thing works if the entire train is in buff (ie, in dynamics).
Nice job of sidestepping the question.
Norm
Norm48327Assuming the first car derails, and you have 10,000 tons trailing that car, how much energy do you think it would take to stop the remaining cars without decimating the first car? Train brakes can't possibly supply the necessary force.
It will take time for the brakes to stop the 10,000 tons trailing the derailed car, but the force of those trailing cars will not decimate the derailed car unless that car is blocked from forward movement.
It won’t be blocked from forward movement unless it becomes a part of a pileup of cars that have stopped moving as they jackknifed into the pile.
If all those cars could be kept moving, they would not pile up, and the 10,000 tons of trailing cars could just keep moving forward with not much interference. The way you keep those derailed cars moving is to keep them coupled and hold off on braking the cars ahead of them.
CSSHEGEWISCHEuclid seems to be ignoring one issue in his proposal, the law of conservation of energy: Energy can neither be created nor destroyed. A moving freight train contains lots of kinetic energy, which has to be converted to another form of energy when the train stops. In a normal brake application, the kinetic energy is converted into heat energy by the brakes and is dissipated into the atmosphere. In a derailment, that energy is going to have to go somewhere much more quickly, a lot of it is absorbed in the accordioning of a string of freight cars before they come to rest. The brake shoes and wheels would have to absorb a lot of energy very quickly to prevent this from happening.
I am not saying that my idea is stop the train abruptly at the onset of a derailment in order to prevent it from piling up cars. The idea is to keep the train stretched as much as possible during the derailment to prevent the accordion process as much as possible. The train will still take its normal distance to stop. If several cars are on the ground, they will add some stopping power, so the train will stop somewhat quicker than usual.
For an oil train, the accordion process is sure to rupture tank cars. Any rupture will spill oil. Any spillage will ignite. Once that happens the other un-ruptured tank cars are stacked up just like a bed of logs in a fireplace; all ready and eager to be ignited by the ruptured and burning car or cars.
Nope! Even with lots of sand, the cars with non-rotating wheels will SLIDE!!!! Every active railroader knows that. And you know whar? The braking force GOES DOWN as the wheels start sliding! Or do you propose two arc welder's attached to every freightcar truck?
What you want is magnetic track brakes. Allows PCC streetcars and modern light railcars to stop as quickly as rubber-tired personal automobiles. Used by West Penn Interurban cars in 1912. Highly impractical for interchange freightcars, but might be adopted along with electric control brakes for new fixed-consist unit trains. Was looking over the shoulder of a Jerusalem Light Rail operator accelerating south from a stop light north of Damascus Gate station when a tourist on a bicycle (tourists recognized in Jerusalem by their carrying a water bottle as if they are in the middle of the desert) swerved directly in front of us, about 12 - 15 feet in front. We went from 12mph to stop in about 5 feet, and I was pleasantly suprised to see that no standees that I could see landed on the floor. Lots of people grabbed the nearest handhold, including some seated passengers.
CSSHEGEWISCH Euclid seems to be ignoring one issue in his proposal, the law of conservation of energy: Energy can neither be created nor destroyed. A moving freight train contains lots of kinetic energy, which has to be converted to another form of energy when the train stops. In a normal brake application, the kinetic energy is converted into heat energy by the brakes and is dissipated into the atmosphere. In a derailment, that energy is going to have to go somewhere much more quickly, a lot of it is absorbed in the accordioning of a string of freight cars before they come to rest. The brake shoes and wheels would have to absorb a lot of energy very quickly to prevent this from happening.
Euclid seems to be ignoring one issue in his proposal, the law of conservation of energy: Energy can neither be created nor destroyed. A moving freight train contains lots of kinetic energy, which has to be converted to another form of energy when the train stops. In a normal brake application, the kinetic energy is converted into heat energy by the brakes and is dissipated into the atmosphere. In a derailment, that energy is going to have to go somewhere much more quickly, a lot of it is absorbed in the accordioning of a string of freight cars before they come to rest. The brake shoes and wheels would have to absorb a lot of energy very quickly to prevent this from happening.
Thanks to Chris / CopCarSS for my avatar.
BaltACDEuclidBaltACDWhere does the mechanical power come from to apply the brakes in this ECP system? It comes from compressed air fed to reservoirs through a brake pipe in the normal fashion. But it is controlled by electronic signals sent through a cable passing through the cars just like the brake pipe does. So the control does not depend on sensing changes in brake pipe pressure the way conventional air brakes work. In the add-on feature I am describing, when it kicks in to respond to a derailment, it will be able to tell each car how much braking to apply independently from all the other cars. So long as you have a system that requires pressure differential for it's power you have the potential for the valve that controls that differential to malfunction and perform in a undesired manner - the same as today's system, no matter how that valve is controlled. If it is made by man, it will fail eventually.
EuclidBaltACDWhere does the mechanical power come from to apply the brakes in this ECP system? It comes from compressed air fed to reservoirs through a brake pipe in the normal fashion. But it is controlled by electronic signals sent through a cable passing through the cars just like the brake pipe does. So the control does not depend on sensing changes in brake pipe pressure the way conventional air brakes work. In the add-on feature I am describing, when it kicks in to respond to a derailment, it will be able to tell each car how much braking to apply independently from all the other cars.
BaltACDWhere does the mechanical power come from to apply the brakes in this ECP system?
It comes from compressed air fed to reservoirs through a brake pipe in the normal fashion. But it is controlled by electronic signals sent through a cable passing through the cars just like the brake pipe does. So the control does not depend on sensing changes in brake pipe pressure the way conventional air brakes work.
In the add-on feature I am describing, when it kicks in to respond to a derailment, it will be able to tell each car how much braking to apply independently from all the other cars.
So long as you have a system that requires pressure differential for it's power you have the potential for the valve that controls that differential to malfunction and perform in a undesired manner - the same as today's system, no matter how that valve is controlled. If it is made by man, it will fail eventually.
Euclid BaltACDWhere does the mechanical power come from to apply the brakes in this ECP system? It comes from compressed air fed to reservoirs through a brake pipe in the normal fashion. But it is controlled by electronic signals sent through a cable passing through the cars just like the brake pipe does. So the control does not depend on sensing changes in brake pipe pressure the way conventional air brakes work. In the add-on feature I am describing, when it kicks in to respond to a derailment, it will be able to tell each car how much braking to apply independently from all the other cars.
Euclid There won’t be multiple dynamiters, as you suggest, because the system will not dynamite the brakes in the traditional sense of a rapid loss of train line pressure triggering a pneumatic chain reaction of emergency braking. There will be no brake actuation controlled by brake-pipe reduction since that is eliminated by the ECP approach. The brake pipe simply charges the car reservoirs. The ECP system does apply brakes on all cars simultaneously, as you mention. That is the beauty of ECP electronic control by wire versus the conventional air brake control by changes in the train line pressure.
There won’t be multiple dynamiters, as you suggest, because the system will not dynamite the brakes in the traditional sense of a rapid loss of train line pressure triggering a pneumatic chain reaction of emergency braking. There will be no brake actuation controlled by brake-pipe reduction since that is eliminated by the ECP approach. The brake pipe simply charges the car reservoirs. The ECP system does apply brakes on all cars simultaneously, as you mention. That is the beauty of ECP electronic control by wire versus the conventional air brake control by changes in the train line pressure.
Where does the mechanical power come from to apply the brakes in this ECP system?
Assuming the first car derails, and you have 10,000 tons trailing that car, how much energy do you think it would take to stop the remaining cars without decimating the first car? Train brakes can't possibly supply the necessary force.
Overmod,
This system will not prevent derailments. It will just prevent them from piling cars into a heap. The heap amounts to a very resistive obstacle. If it forms while the trailing cars are still coming on with considerable speed, the compressive force of those cars pressing into the heap will be overwhelming. I do not believe that the best standards of tank car strength being considered will be sufficient to protect them from rupture if they are caught in this squeeze between the oncoming trailing cars and the heap.
So I think it pays to think of a way to prevent the heap from forming. Certainly, there will be plenty of derailment damage even if the cars do not pileup into a heap. This concept is not intended to prevent damage. It is only intended to prevent tank car rupture by preventing the cars from piling into a heap.
The ECP brakes in this system will be controlled by wire, but will need some type of wireless backup for this derailment mitigation feature. There won’t be multiple dynamiters, as you suggest, because the system will not dynamite the brakes in the traditional sense of a rapid loss of train line pressure triggering a pneumatic chain reaction of emergency braking. There will be no brake actuation controlled by brake-pipe reduction since that is eliminated by the ECP approach. The brake pipe simply charges the car reservoirs. The ECP system does apply brakes on all cars simultaneously, as you mention. That is the beauty of ECP electronic control by wire versus the conventional air brake control by changes in the train line pressure.
As you mentioned, my concept, which includes ECP brakes, would also require derailment sensors on each car, and the information from them would have to be processed for the optimum brake response.
Design and test such a system. Then post the results.
dehusmanIt takes 5-10 sec for the brakes to apply once the brake valve starts the application. A train going 30 mph is traveling 44 ft/sec. That's between 220 and 440 ft before you can start to control the train. In that time between 4 and 8 more cars may have passed over the point of derailment and derailed. In that 5-10 seconds and several hundred feet, there is a strong probability that one or more cars will have skewed to the point that one or more wheels have reached the ends of the ties. As soon as that happens there is no braking force that you can apply that will keep the train streched in a straight line. Once the wheels get off the ties, they will present a huge amount of drag and will decelerate FASTER than the brakes can decelerate the train. It doesn't matter whether you have ECP or conventional brakes, the rear of the train can't decelerate faster than the derailed cars. At some point the air hoses on the derailed cars, whch are now dragging on the ties because the wheels are on or off the ends of the ties, will part, putting the train in emergency. When that happens you have lost control of the situation. You entire premise hinges on the conditions that only one car derails, it remains upright, in line, on its trucks, on tangent track, train line intact and there are no other external forces acting on it (switches, grade crossings, collisons with other vehicles, debris, etc). While that does happen, its an edge case. I have seen too many derailments with the wheels went from the POD to the ends of the ties in one car length or less.
At some point the air hoses on the derailed cars, whch are now dragging on the ties because the wheels are on or off the ends of the ties, will part, putting the train in emergency. When that happens you have lost control of the situation.
You entire premise hinges on the conditions that only one car derails, it remains upright, in line, on its trucks, on tangent track, train line intact and there are no other external forces acting on it (switches, grade crossings, collisons with other vehicles, debris, etc). While that does happen, its an edge case.
I have seen too many derailments with the wheels went from the POD to the ends of the ties in one car length or less.
With all due respect, I do not believe you are looking at the total picture of the system and response that I am describing. Instead, you are construction a scenario of failure based mostly on the conventional air brake system performance.
My premise does not (as you say it does) hinge on the condition that only one car derails, that cars remain upright, remain on their trucks, or that the train line remains intact. I do agree that the conditions of track curvature, or excess forces from encountering switches might defeat the system and cause an immediate jackknifing. It is not meant to prevent pileups in cases of collisions with other trains, or in the case of derailing the locomotives from various causes.
Sure it takes some time to move the brake linkage once the application has been signaled.
But until that happens, cars on both sides of the derailment are going to be rolling freely with no compression from the trailing cars that will tend to skew a derailed car. So, while the entire train is still rolling without braking, the dragging resistance of one or even several cars could easily be irrelevant to the momentum of the train. Having several cars on the ties does not mean that the system has lost control of the situation. I disagree with your basic premise that the first car to derail will create so much running resistance that it will decelerate the trailing cars faster than the braking can hold them back.
The response does not depend on putting the train into emergency upon the breaking of the first air hose. And the breaking of the first air hose will not put the train into emergency. The brakes are not controlled by brake line reduction.
I agree that certain circumstances will prevent this system from controlling a pileup. However, in the scenario that you paint as typical, a derailment happens and every car following that occurrence will derail at the same spot. Therefore, you conclude that several cars will be on the ground before any braking is initiated on the trailing cars. And with that many cars on the ground, you conclude that they will surely jackknife. I don’t believe that is a certainty if the train does not go into emergency, and if there is no braking initiated on the cars ahead of the derailment-- both of which will be the case.
It is trains moving at full speed that have the most energy that can be applied to causing a destructive pileup. But that same energy can be most effective in keeping the derailed cars in line and stretched despite their dragging resistance. Even the derailed cars retain the force of momentum. At the slower speeds, there is less momentum to accomplish overcoming of the dragging resistance, but that same lack of momentum will also mitigate the potential for a destructive pileup.
So, in my proposal, a braking response is initiated on the trailing cars the instant the first car derails. If it takes 5-10 seconds for that application to take hold, the derailed car or several derailed cars will drag. They may tip over. They may lose trucks. But they will stay stretched and generally in line even though braking on the trailing cars has not yet begun.
Even for as violent as this dragging process can be, it is not what causes the maximum resistance that is indicated by the severely compressed and flattened cars in a wreck. The resistance that makes that possible comes from piling up several cars into a heap. That heap becomes the immovable anchor that the enormous linear inertia of the trailing cars is directed against.
My point is to react to the derailment more proactively in order to prevent that pileup from beginning. It won’t prevent every pileup, but air bags in cars do not prevent every death or injury. I would expect this system to prevent a lot of pileups, and not just ones in rare occasions when things go just right.
I get very nervous about enabling wireless modulation of brake actuation entirely separate from brake-pipe reduction, on multiple cars simultaneously (which unless I'm mistaken is what the proposal entails).
Imagine the fun of MULTIPLE dynamiters all in a row... or perhaps spaced in a moving consist. Remember the old Three Stooges routine "see these two fingers... now you don't!"? That's going to be the situation for at least one drawbar, or Flatwheel City by the time the train grinds to a halt.
In order for the system to work correctly, there will have to be multiple sensors in the train, and more importantly, some form of processing (probably distributed) that determines the correct timing and duration of the ECP response, proportions it to the various ECP controllers on or between the cars, and then takes care of modulating the response. I see headaches.
It takes 5-10 sec for the brakes to apply once the brake valve starts the application. A train going 30 mph is traveling 44 ft/sec. That's between 220 and 440 ft before you can start to control the train. In that time between 4 and 8 more cars may have passed over the point of derailment and derailed. In that 5-10 seconds and several hundred feet, there is a strong probability that one or more cars will have skewed to the point that one or more wheels have reached the ends of the ties. As soon as that happens there is no braking force that you can apply that will keep the train streched in a straight line. Once the wheels get off the ties, they will present a huge amount of drag and will decelerate FASTER than the brakes can decelerate the train. It doesn't matter whether you have ECP or conventional brakes, the rear of the train can't decelerate faster than the derailed cars.
What I am suggesting with this new oil train concept is to control ECP brakes to change the in-train forces in a way that reduces the destructive nature of a derailment once it starts. I have never heard anyone else state this as an objective. I suspect that it has not occurred to industry experts.
The closest they have come is the recognition that ECP brakes will reduce in-train forces, and thus prevent those forces from causing a derailment. That is different from what I am proposing, which is to reduce the destruction caused by a derailment. This is accomplished by separating the braking performance between the cars ahead of the derailment and the cars behind it. So what I am talking about is actually creating new in-train forces to stretch the train. The purpose is to keep the train stretched through the derailing cars; as opposed to the usual scenario in which the cars run into the derailment under compression, and pile up into a heap.
This separating of the braking performance into two sections is done automatically once a derailment is located by a sensor. This sensing, reacting, and controlling the divided brake application would be a completely automatic function with many parameters factored in by a computer. These would be factors such as speed, tonnage, location of the train on the line, and location of the derailment in the train.
To get to what I am talking about, only requires a small modification to the basic control system for ECP brakes. The flexible ability to control ECP brakes is a fundamental advantage of the ECP system. What I am proposing is a natural addition to that fundamental advantage. ECP brakes facilitate the use of sensors, and it is indeed sensors that will be needed to add this extra derailment control feature to ECP brakes.
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