tree68 EuclidThis information would be developed by a central processor that would know where the derailment is located, and so it would know where to split the braking function.And how, pray tell, will the processor know which car is where? If a car is bad-ordered and set out, how will the processor make the necessary adjustments? If the processor has to talk to each individual car, what will be the response time for the data to all the cars? Will there be some form of confirmation to the processor so it knows all cars have received the instructions? If you're talking wireless, what kind of range will the main processor and the individual cars have? If you're talking car-to-car relay via radio, what will be the failsafe if one car's processor fails?
EuclidThis information would be developed by a central processor that would know where the derailment is located, and so it would know where to split the braking function.
If the processor has to talk to each individual car, what will be the response time for the data to all the cars? Will there be some form of confirmation to the processor so it knows all cars have received the instructions?
If you're talking wireless, what kind of range will the main processor and the individual cars have? If you're talking car-to-car relay via radio, what will be the failsafe if one car's processor fails?
The processor would be independent of the cars and it would speak to all of them. I would expect the processor to talk to the cars and the cars would talk to the processor to confirm the receiving of commands from the processor. This much is part of the ECP brake systems currently under development.
Sensors to monitor brake performance are part of ECP, and additional sensors are contemplated because the communication cable of ECP is an essential component, and once incorporated, it can be used for other things like bearing temperature sensors. In the case of my proposal, there needs to be derailment sensors in addition to brake performance sensors. I would also consider other sensors. Considerable development would be needed for the derailment sensors. They might be a combination of sensors to monitor alignment, vibration, sound, etc.
The processor would have to know where all the cars are, and it would know that by the sensors sending information from each car. If a car were set out; the processor would detect that loss of that car and its position in the train, and then compensate for the lost car in its organization.
I don’t expect response time to be a problem, but I might need a little help wiring this thing up. A lot of thought and R&D would have to go into the automatic braking program. That is probably about the greatest area of development work needed.
You should be discussing this with a computer/electronic engineer and programer to see if it's even possible and what equipment would be required, and the cost of the system. My guess is it's going to be much more complicated and cost prohibitive than you may think. Even if it can be done with computers the cost may kill the idea. The law of diminishing returns may find the cost far above and beyond the benefits.
Norm
Norm,
It will cost a lot of money. But it has to be designed and developed to find out how much it will cost. You have to start with a concept. It takes a lot of investment just to find the cost. And the cost can be brought down as manufacturing moves forward. Along with the costing, there has to be an accurate analysis of how much money this will save.
This system will save money in preventing broken trains, spilled oil, and damage litigation. That is the engineering objective. But I believe it will also save money by putting the brakes on regulation. That is the marketing objective.
In my opinion, making tank cars a little stronger over the next several years is not an adequate response to offset the problem that is coming at the industry. It seems like a mighty high stakes wager that oil trains will be lucky.
I would prefer to leave the decision as to pulliing a way from a midtrain or rear derailed tank car as quickly as possible or stopping the whole train as quickly as possible in the hands of the engineer. I can imagine a scenereo where pulling away fast would cause more harm than good.
daveklepperI would prefer to leave the decision as to pulliing a way from a midtrain or rear derailed tank car as quickly as possible or stopping the whole train as quickly as possible in the hands of the engineer. I can imagine a scenereo where pulling away fast would cause more harm than good.
Dave Klepper,
Either pulling away as fast as possible or stopping as fast as possible will do more harm than good.
The intention of the automatic derailment response that I am proposing is not to pull away from the derailment. That would perhaps reduce the number of cars involved by getting them clear of the pileup. However, pulling away requires that a drawbar breaks and the cars ahead of the derailment separate from the cars running on the ground.
Once that separation happens, the stage is set for the cars on the ground to pile up into a heap. So you don’t want to pull away. And you also don’t want to slow the head end down by excessive braking. You want to keep the cars ahead of the derailment moving freely, but not so freely that their inertia pulls the train in two somewhere ahead of, or within the derailment. The optimum condition would be for the car ahead to pull on the derailed cars enough to keep them roughly in line; and prevent the cars behind the derailed cars from pushing so hard that they buckle or jackknife the derailed cars.
Generally, there are three basic scenarios in a mid-train derailment:
1) The cars behind the derailment run in with hard compression against the cars ahead of it.
2) The cars behind the derailment resist the pull of the cars ahead of the derailment.
3) The cars ahead of and behind the derailment keep their rolling inertia matched so that the cars running on the ground are not compressed or pulled so hard that they separate.
What I am proposing is intended to yield result #3. That result is also possible with conventional air brakes, but rare. With conventional air brakes, scenarios #1 and #2 are the most likely.
Unlike what I am proposing, the full-train dynamiting brake response to a derailment and pileup is typical with conventional airbrakes due to the first parting of an air hose pair. That response does stop the train as quickly as possible, but it can worsen the effects of a derailment, particularly if it leads to scenario #1.
So what I am suggesting will stop the train quickly, but not as quickly as the automatic dynamiting response of conventional air brakes. I want to reduce the stopping deceleration somewhat in order to balance the forces through the derailment for the purpose of achieving scenario #3, and avoiding scenarios #1 and #2.
NO Again you don't know the facts. With magnetic track brakes on each car, there is no pile-up to speak of because each car brakes to a stop as fast as an automobile brakes to a stop in an emergency. You are assuming the normal current air-brake procedure, where the drop in pressure travels from the break-in-two to the rear at less than 1000 ft/sec. With the electrical control it passes from the front to the rear at the speed of light, the normal speed of an electrical impulse. And the magnetic track brakes will stop the cars as quickly as the derailed car will stop unless the derailed car has hit something solid or moving in the other direction, and the Frailey suggestions should minimize that. Your program will lead to your "1" in many cases, because you do not have any guide as to how quickly the derailed car will stop and cannot plan in advance the suitable compromize braking effort. Soil and roadbed conditions widely. My program wil usually lead to no, 2, which I consider an excellent result, that the cars on the track prevent the derailed car from going very far!
In fact, your example of the Milwaukee freight car that traveled four miles, would have been a very minor incident with my system. The train would have stopped completely, the whole train, the crew would get out the rerailing frog, pull the car with one truck derailed back onto the track, proceed very slowly, to the next siding, and set off the problem car for attention by the car department before anyone tried to move it further.
On further thought, only two axle generators are necessary, each one on the outer axle of the trucks, the outer axle to facilitate the very-seldom-requried mainentnance.
Just to clarify something, I am not assuming the normal current air-brake procedure, where the drop in pressure travels from the break-in-two to the rear at less than 1000 ft/sec. I have explained several times in this thread that I am proposing the use of ECP brakes, and that they are controlled by electrically powered valves on each car which are controlled by electronic signals sent through a wire. So I am talking about the same speed-of-light control that you are referring to in association with track brakes.
With a train experiencing a derailment, I agree that it would be beneficial to stop every car as quickly as possible. The quicker it all stops, the less opportunity for damage. However, if the quick stop force is not uniform throughout the train, it can cause more damage than if the stop were slower. In the case of track brakes, I understand your point that they provide greater stopping adhesion than brake shoes against wheels. The simultaneous application may indeed provide uniform stopping force throughout the train, and therefore, neither compress against the derailing cars from the rear, nor pull too hard on the derailing cars from the front.
But I am not sure that this effect is guaranteed to occur just because brakes are applied with the same force to all cars at the same time. The train may be running with part moving up grade and part moving down grade. This undulating profile would be likely to influence the rate of deceleration in different parts of the train despite uniform braking force throughout the train.
Incidentally, I need to restate my scenarios #1-3 in a preceding post. I said #3 is the desired outcome; however, it actually needs to be scenario #2; as long as the pull on the derailing cars is not so great that it pulls the train in two. This pull is needed to help keep the derailing cars in line as they are subjected to a lot of skewing forces while running on the ground.
Scenario #3 is valid, but it needs some clarification. If the braking deceleration in the cars ahead of, and behind the derailing cars were uniform, there would be no compression or tension on the derailing cars due to unequal braking deceleration.
Yet, as mentioned, there needs to be some tensile pull on the derailing cars; so on the face of it, scenario #3 seems like it would be insufficient. However, even though the braking deceleration ahead of and behind the derailment is equal, the derailing cars themselves will provide resistance, and that resistance will cause the cars ahead of the derailing cars to be pulling on the derailed cars.
So, scenarios #2 and #3 need to be re-written to make these points clear.
I am not saying your idea of stopping as quickly as possible won’t work. It is a different approach to the problem. Just ECP brakes alone might go a long way in preventing pileups just because of their simultaneous application. Aside from shorter stopping distance, I have no idea of the ramifications and tradeoffs of using track brakes on a freight train.
I see we are coming to agreement. I already posted that I am not recommending track brakes for loose car railroadiing, because of weight and rolling resistance differences between car and car. I am assumiing unit trains of identacle cars loaded close to exactly the same way, well maintained, and with identacle brake eqhipment, regularly iinspected to insure that the brakes perform the same way on every car. Small one or two percent differnces can be tolerated and pose any undue forces on couiplers. But I am assuming that the whole train acts as a unit, and under those circumstances, stoping the entire train behind the point of accident is certainly by far the safest procedure. For the portion of the train forward of the accident (assuming there is break-in-two at the accident), the override button will provide the engineer to judge this situation and do what is necessary to minimze any damage first to people and then to property. And the whole system uses off-the-shelf comoponents; all the technology exists now. Brakes: adapted from MU commuter rail and light rail technologies. Derailment detection: adapted from wheel-slip control.
daveklepper I am assumiing unit trains of identacle cars loaded close to exactly the same way, well maintained, and with identacle brake eqhipment, regularly iinspected to insure that the brakes perform the same way on every car.
I am assumiing unit trains of identacle cars loaded close to exactly the same way, well maintained, and with identacle brake eqhipment, regularly iinspected to insure that the brakes perform the same way on every car.
That's a very shaky assumption. Unit trains are determined by the origin-destination and the billing, not by the equipment and there is no attempt whatsoever to match braking performance. The cars in an oil train are part of a pool and while its likely that certain groups of cars are moved together on successive trips there is no guarantee that they will remain on the train or route. It is relatively rare for all cars on a unit train to be exactly the same.
The only way they would remain together is if you make them equipment that is not compatible with other equipment so there is no choice but to run them together (an example are the Georgetown rock trains that can only be run in dedicated train sets.)
There is no test that measures the braking force of a car and there is no current requirement other than what is required on a normal brake test.
For the portion of the train forward of the accident (assuming there is break-in-two at the accident), the override button will provide the engineer to judge this situation and do what is necessary to minimze any damage first to people and then to property.
You will also have to assume that this train will be interchanged between two or more railroads over the course of a trip and may have more than one set of engines on it.
Dave H. Painted side goes up. My website : wnbranch.com
There is nothing really that unusual about what I am proposing. It is just a new combination of practice that is already a part of real world railroading. The computer controlled brake derailment function is no big deal compared to a host of other ideas being seriously proposed by the FRA. It is also no big deal compared to all the technology planned for PTC.
ECP brakes are a radical breakthrough, and yet the basic concept has been around for a long time. But the march of technology has finally made the execution practical. The industry takes ECP brakes seriously because it offers important advantages over conventional air brakes. So, there is a desire to universally replace conventional air brakes with ECP brakes.
However, there is a problem that I believe will prevent that from happening. The problem is the sheer size of the universal application of the current system. Replacing that system must be a relatively quick and concerted effort because the benefits of ECP brakes do not really kick in until all or most cars are equipped. But a fast changeover is a financially staggering challenge. And during the changeover, the new system has to be compatible with the old system. This further drives up the cost of the new ECP system. And then once the changeover is complete, all of those extra compatibility features become instantly obsolete with a lot of life still remaining in them.
In reading the Booz Allen Hamilton report on ECP brakes, one can sense the irresistible enticement of ECP, but in reading about the challenge of conversion, one can sense that the universal conversion is a bridge too far. The industry realizes this, and so there have been proposals to add the system only to specialized unit trains where the cars stay together. That way, the advantages of ECP brakes can be realized in that select service without converting the entire U.S. and Canadian rolling stock and locomotive fleet.
Just in terms of marketing against this current oil train fireball problem, ECP brakes would be a good match with oil trains just for the public and regulatory perception of a major safety advancement for oil trains. They are often unit trains just as the industry was planning to equip with ECP brakes. This would not be so much an engineering breakthrough as it would be a natural application of what was basically the plan all along. But it would be a powerful tool for improving the image of oil trains at a time that it is desperately needed.
Then if you combine with the ECP, the special feature that I am proposing, along with some other features involving enhanced inseparability of couplers, you have a truly advanced system of safety that will mitigate the chance of rupturing tank cars in the case of many derailments. If it were not for ECP brakes, what I am proposing would not be possible. There is no way it could be done with conventional pneumatically controlled air brakes.
My oil train concept would benefit all freight trains, but again, because of the need to combine it with ECP brakes, and the challenge they pose to universal application, this derailment control concept would be best targeted just to oil trains because that is where it is needed most by far.
The objections are valid, and we are talking only at this point of specialized equipment, an entire train kept together as a unit. Yes it can be coupled to other equipment, but then its special featurs would no longer be operable. We are talking about a complete train, with its own assigned locomotives. There already are such unit trains in operation, and some operate on more than one railroad.
It may be that after experience with this special equipment, ways will be found to adopt its special features to interchanged equipment, but that would be considerably in the future. Possibly for test purposes, one complete tank-car train would be constructed, number of cars dependent on the specific market and lane, number of diesel units based on the lane's railroads' own power for load figures, plus one for spare, plus a few spare tankcars as well. One goal is a train that is practicalliy derailment-free, break-in-two-free, as close to indestructable as possible, and that, even if 100 cars long, can stop approximately in the distance a private auto can stop at the same speed, without any stringing on curves, buckly, severe running in of slack, and a really easy train to handle.
By the way, for those proposing a dedicated unit train that has drawbars and not couplers, how are you proposing it be loaded and unloaded? The operations I have seen break the train up into smaller cuts and load and unload those, and don't have a 100 car capacity loading or unloading rack.
Does your design require that the loading and unloading facilities be also completely rebuilt to accommodate the train?
dehusman By the way, for those proposing a dedicated unit train that has drawbars and not couplers, how are you proposing it be loaded and unloaded? The operations I have seen break the train up into smaller cuts and load and unload those, and don't have a 100 car capacity loading or unloading rack.
This is a very valid point -- years ago, I'd have said it could be done via something like the Tank Train, but that approach doesn't work for a great many combinations of payload and unloading requirements.
Presumably the consist can be broken into sets with couplings that are more robust than a 'standard' interchange coupler, and that preserve the breaking and torsion strength of the drawbar/anticlimber setup. There is even some justification, if going to 'nonstandard' couplers that incorporate special ECP or track-brake connections, in making them 'especially strong' for this special service...
Is there a particular cut length that optimizes loading utility and service flexibility -- say, a ten-pack? This could rather easily be incorporated into the design...
Myf concept, based partly on Euclid's input, definitely does not use drawbars. There would be spare equipment. I would ask for the best possible mu-type couplers that incorporate the air and electrical connections, yet can when required mate with standard Janey MCB couplers. I would vote for individiual double-truck, tankcars, just the most robust design possible, with the brake, alternator-derailment responder, and battery equipmennt discussed.
dehusmanBy the way, for those proposing a dedicated unit train that has drawbars and not couplers, how are you proposing it be loaded and unloaded? The operations I have seen break the train up into smaller cuts and load and unload those, and don't have a 100 car capacity loading or unloading rack. Does your design require that the loading and unloading facilities be also completely rebuilt to accommodate the train?
What Dave Klepper is proposing differs considerably from what I am proposing, so I won’t speak for him. What I am proposing requires a captive consist because it uses ECP brakes, and they will not be in universal use throughout the freight car fleet. I am proposing solid, semi-permanent drawbar connections. This would provide the maximum strength with the least weight, eliminate slack, and eliminate the electric cable connectors which have proved to be a somewhat problematic feature of ECP brakes. However having one separable coupler joint and one pair of electric connectors that would allow breaking the 100 car train in two would not be a problem.
I don't care if the train is brand new, things happen. A stuck valve, cracking wheel, broken safety device, grade crossing accident, bad brake pad, any number of issues that can and do happen to a car.
In most of the Mid West, especially where they originate these trains, how the hell you going to repair that? How are you going to get repair equipment to the car with snowdrifts up to your neck?? If the car cannot be repaired on-spot, what now with your permanent drawbars? No unit train will fit in a RIP track where lifts and equipment are.
And no railroad would purchase them, instead putting that upon the customers bill, so long as facilities are in place on the respective lines that can properly handle them.
Pipe Dream.
The semi-permanently coupled car idea actually dates at least back to 1998, when UP started running trains between the San Ardo oil field and Wilmington. Per the sidebar in the March 2014 issue of trains:
...the train, which consist of 78 tank cars, in six strings of 13 semi-permanently connected groups.
But... This is a very specific move of about 300 miles, between places set up to handle the consist. It's also running in California, with little chance of the weather the northern tier trains will encounter 3-4 months of the year.
I would imagine the equipment uses standard railroad brake systems.
Then, again, I could be mistaken - it's possible that the "semi-permanent" connection is a hose, not a drawbar....
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...
tree68 I would imagine the equipment uses standard railroad brake systems. Then, again, I could be mistaken - it's possible that the "semi-permanent" connection is a hose, not a drawbar....
I don’t think the semi-permanent coupling would be a showstopper. It might require doing some things differently, but whole train concept that I am proposing is not business as usual, to say the least. This sort of coupling is not common is because there has not been a good reason to use it. Yet, there are several positive benefits to the train concept that I am proposing that are provided by the use the semi-permanent drawbars as follows:
1) Semi-permanent drawbars eliminate slack for better train control which is highly beneficial for a train such as I am proposing with an ultra-sophisticated, enhanced ECP brake system intended to mitigate the destructive effect of a derailment.
2) Semi-permanent drawbars eliminate the electric/electronic connectors which have proven to be a weak point in the ECP brake system.
3) Semi-permanent drawbars eliminate the air hose couplings which are prone to leaks.
4) Semi-permanent drawbars provide the strongest coupler method which has the greatest ability to stay connected during derailments; a characteristic that is crucial to the train concept I am proposing.
In 1970, the Duluth Messabe & Iron Range RR used semi-permanent drawbars to connect ore cars in sets of four. The advantage cited was “fewer couplers and air-hose connections resulting in easier handling and fewer breakdowns.” It is from this reference:
http://books.google.com/books?id=cYs_kM1qAOgC&pg=PA24&dq=reason+for+dm%26ir+quad+cars&hl=en&sa=X&ei=OEr4UsjLDs2FyQGm9YDgDg&ved=0CDYQ6AEwAA#v=onepage&q=reason%20for%20dm%26ir%20quad%20cars&f=false
There may applications for both ideas, Euclid, but the kind of modern coupler used on mu cars has the same advantages that drawbars do, in that they are stronger, have far less play, and carry the electrical and air connections.
There are, of course, major savings in first cost and in maintenance through the use of drawbars. However, for the first test train, I woujld recommend couplers on all cars, so the train can be tested in a variety of haxmat liqiuid applications' lanes, with the number of cars exactly suited to the test situation.
Something I see being totally ignored in this thread is finding defects on cars that can prevent derails. I'm referring to an article in the March issue about BNSF installing and testing detectors that evaluate truck performance while a train is on the move. What they are testing is much more comprehensive than the average hotbox detector. It appears one of those sophisticated detectors could have found the broken axle that derailed the grain train in the North Dakota accident. Wouldn't installing such detectors be more practical and less costly than redesigning a train?
Norm48327 Something I see being totally ignored in this thread is finding defects on cars that can prevent derails. I'm referring to an article in the March issue about BNSF installing and testing detectors that evaluate truck performance while a train is on the move. What they are testing is much more comprehensive than the average hotbox detector. It appears one of those sophisticated detectors could have found the broken axle that derailed the grain train in the North Dakota accident. Wouldn't installing such detectors be more practical and less costly than redesigning a train?
As I have mentioned, onboard detectors or sensors will be a key component of the oil train concept that I am proposing. To start with, it needs derailment sensors as an essential ingredient to the design. Those would probably detect a derailment occurrence based on several different inputs such as car alignment with the rest of the train, vibration, truck tracking, and sound. Some of this input might actually begin before a car derails.
There are a variety of onboard sensors that have been considered for trains, but they all require a means of data transmission. Because ECP brakes require a data transmission cable for control, that cable is also then available for all the sensors that might be applied to the train. So this expanded use of the cable is considered to be one of the big benefits of ECP. It opens the door to the extensive application of onboard sensors.
Never too old to have a happy childhood!
Gentlemen...I have no knowledge concerning the braking discussion taking place here...However just one comment.
The statement: with magnetic brakes on ea. {railroad}, car it brakes to a stop in an emergency as fast as an automobile does in an emergency.
A modern automobile can brake to a stop with full effort applied thru it's braking system in a very short order. Example: From 60 mph to 0 mph in a range of 100 ft. to perhaps 125 ft...!!
Quentin
As mentioned before, where does all of the kinetic energy go when a sudden stop occurs? Most of the proposals made tend to sound like a lot of the "gee-whiz" technology that could be found in the pages of "Popular Science".
With magnetic track brakes, it goes into friction between the magnetic shoe and the rail. Rail wear? Sure.
Certain PCC operated lines in Brooklyn developed corregated track at car stops because the emergency feature was being used routinely instead of being reserved for emergencies. A stop was put to this practice. In addition to the rail not liking it, neither did the standing passengers.
And yes, it will stop a 100-car freight train as quickly as an automoble can stop -if all cars are identacle and all brakes adjusted the same way.
daveklepper With magnetic track brakes, it goes into friction between the magnetic shoe and the rail. Rail wear? Sure.
I thought at least some of this was eddy-current braking. ISTR some of the streetcar brakes working this way, with nonfrictional contact being touted as an advantage. Surely that makes better sense than mutual magnetic attraction with a friction acting at right angles?
And have you actually calculated the amount of magnetic current, and the path for the lines of force, necassary to provide orthogonal clamping force of the designed magnitude when the only available material for the magnet to attract is... a rail section? What's saturation for a length of rail?
When I run some preliminary numbers and compare them against the mass of loaded freightcars, I do NOT see 'automobile-like' stopping distances. Can you provide some sample physics, including required currents (and friction material on your track shoe or sled) for substantiation?
I repeat (perhaps erroneously) that I expect some leverage transfer of car weight onto the frictions before a system of track brakes actually produces short stopping distances -- this would use 'electromagnetism' more for the deployment and release control than to exert the force to induce friction. Not saying that would be a good idea as a default emergency-brake option...
CLARIFICATION FOR THIS THREAD:
I made an original proposal for a new oil train concept to address the rising regulatory response to the public safety concern about exploding oil trains. My concept is detailed on page one of this thread.
There have been many comments and questions, and along the way, Dave Klepper has proposed his own concept for accomplishing what my concept intends to accomplish. I am certainly willing to consider Dave’s proposal, but so far, I prefer my approach to the oil train safety improvement.
I do not fully understand Dave’s proposal, and I have several questions about it that I will post soon. But in the meantime, I will clarify that I am not proposing magnetic brakes with the objective of stopping the train as quickly as possible. That is part of Dave’s proposal.
While I don’t expect the industry to jump onboard my concept, I do want to lay it out in the public domain. I am working on a fully detailed and illustrated presentation article to explain it further. This is not science fiction or pie in the sky. It is just a new combination of basic railroad technology. It is certainly far less grandiose than universal PTC, for example.
The point of my proposal is to prevent or reduce the pileup effect of a derailment at speed. Such pileups have the potential to produce an enormous crushing force that is capable of rupturing tank cars even if they are strengthened to the newly planned standards of crashworthiness.
As a pileup grows in size, it becomes more and more unyielding. The string of cars rolling in behind the pileup are still on the rails and perfectly guided into the heap like a baseball into a catcher’s glove. The force has nowhere to go other than being dissipated in the complete crushing of cars. It is like the effect of a freight train crashing into another freight train inside of a tunnel.
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