Well, yes, but more power then the train needs once it is in motion. This would be a waste of expensive locomotive assets.
NorthWestWithout slack, could the train even be started? Motive power depends on not starting every ton of weight at the same time, ...
They can start without slack if the train has enough power for its tonnage.
A main difference is HSR ROWs are very straight, and have very large curves. Trains can move in a straight line when derailed, and have much less chance of flying off the ROW and becoming a missile.
Without slack, could the train even be started? Motive power depends on not starting every ton of weight at the same time, it is easier to overcome the starting resistance of one car at a time, not over 100.
schlimm I realize it is different (System, passenger, not freight, high speed) but I seem to recall reading somewhere that one reason the SNCF has not had a fatality on their TGV's to date is that even if they derail, the cars stay together and do not jack knife or separate or overturn, mostly continuing along the RoW forward until they stop. Shouldn't that principle at least be worth considering?
I realize it is different (System, passenger, not freight, high speed) but I seem to recall reading somewhere that one reason the SNCF has not had a fatality on their TGV's to date is that even if they derail, the cars stay together and do not jack knife or separate or overturn, mostly continuing along the RoW forward until they stop. Shouldn't that principle at least be worth considering?
Schlimm,
That objective is exactly what I am talking about for oil trains. However, I am not familiar with the methods used to achieve it with SNCF equipment. For oil trains, I am proposing to achieve that objective with sensors to detect a derailment, a smart braking system to respond to the sensors, and stronger, solid drawbars with no slack.
It would be very interesting to learn the engineering principles behind the SNCF approach to the problem, particularly how they prevent overturning.
C&NW, CA&E, MILW, CGW and IC fan
I'm wondering if the best safety enhancement to a petroleum carrying tank car (in addition to some reasonable structural improvements) would be a means of generating foam automatically in case of derailment. Not sure if the needed amount of foam would add a significant amount of weight.
A similar scheme could involve CO2 bottles that would release CO2 in case of a derailment. The idea is to slow down the start of the fire.
- Erik
As I recall, coupler knuckles are like shear pins that break so that the cars are not pulled apart. Even if you strengthen the cars so they won't pull apart, as soon as one or two cars derail, the engines which are already near the point of slipping, will not be able to keep the train moving forward to keep everything in tension.
BaltACDIf it is made by man, it can break. If it is made by God, it can break. Put the dynamic forces of a moving train against anything and it will break!
Well, drawbars don’t break in normal service. They withstand the dynamic forces of a train just fine. They are made strong enough to do the job. All I am suggesting is to give them a little more of a job to do, and make them a little stronger so they can do it.
They don’t have to be unbreakable in cosmic terms.
Euclid dehusman Euclid When a derailed car starts to dig into the ties and ballast, its forward motion would be arrested if the car were on its own and not coupled into the rest of a train. But if it is coupled into a train, the resistance has little effect on the total inertia of the rest of the train. You are correct, the car digging into the ballast has little effect on the movement of the TRAIN. it does have a huge effect on the movement of the CAR. That CAR slows down. When it does the forces become unbalanced and cause it to rotate, especially if the car is not perfectly in line. Your plan only succeeds if the train remains in tension. ONLY if the entire train remains in tension. ONLY if there is no increase in deceleration on the derailed car. ONLY if no subsequent cars derail at the point of derailment. ONLY if the derailed car does no further damage to the track. Dave, I don’t mind your criticism of this concept, and I think I understand your points completely. However you are mostly ignoring one key element of my concept. That is the fact that when the first car goes on the ground, the drawbar ahead of it won’t break. The car won’t be under compression, as you say. It will be under tension. It will not slow down because of being on the ground.
dehusman Euclid When a derailed car starts to dig into the ties and ballast, its forward motion would be arrested if the car were on its own and not coupled into the rest of a train. But if it is coupled into a train, the resistance has little effect on the total inertia of the rest of the train. You are correct, the car digging into the ballast has little effect on the movement of the TRAIN. it does have a huge effect on the movement of the CAR. That CAR slows down. When it does the forces become unbalanced and cause it to rotate, especially if the car is not perfectly in line. Your plan only succeeds if the train remains in tension. ONLY if the entire train remains in tension. ONLY if there is no increase in deceleration on the derailed car. ONLY if no subsequent cars derail at the point of derailment. ONLY if the derailed car does no further damage to the track.
Euclid When a derailed car starts to dig into the ties and ballast, its forward motion would be arrested if the car were on its own and not coupled into the rest of a train. But if it is coupled into a train, the resistance has little effect on the total inertia of the rest of the train.
When a derailed car starts to dig into the ties and ballast, its forward motion would be arrested if the car were on its own and not coupled into the rest of a train. But if it is coupled into a train, the resistance has little effect on the total inertia of the rest of the train.
You are correct, the car digging into the ballast has little effect on the movement of the TRAIN. it does have a huge effect on the movement of the CAR. That CAR slows down. When it does the forces become unbalanced and cause it to rotate, especially if the car is not perfectly in line.
Your plan only succeeds if the train remains in tension.
ONLY if the entire train remains in tension. ONLY if there is no increase in deceleration on the derailed car. ONLY if no subsequent cars derail at the point of derailment. ONLY if the derailed car does no further damage to the track.
Dave,
I don’t mind your criticism of this concept, and I think I understand your points completely. However you are mostly ignoring one key element of my concept. That is the fact that when the first car goes on the ground, the drawbar ahead of it won’t break. The car won’t be under compression, as you say. It will be under tension. It will not slow down because of being on the ground.
If it is made by man, it can break. If it is made by God, it can break. Put the dynamic forces of a moving train against anything and it will break!
Never too old to have a happy childhood!
Won't an organizatinal change, with people with credibility, do more and faster in that department?
Thus, Key Transportation, Inc.
It is true that the drawbars will need some swing to be able to go around curves, but I don’t see that swing allowance as being sufficient to permit the car to swerve so far out of line as to be able to begin jackknifing.
In the larger perspective, part of the purpose of this proposal is for the industry to show a new and advanced concept train that is bristling with new innovation. This could be presented at least conceptually within six months. And while the functional purpose of the concept would be to prevent pileups, the far greater purpose would be to show the world that the industry takes this seriously and is doing something big about it right now.
As I have mentioned, this is more of a perception problem than an engineering problem, and this new concept markets a perception of a robust solution to the problem in proportion to the degree that the problem is being marketed to the public perception by the media.
If the industry does not change the public perception, the regulators will change the rules. This wonderful oil traffic could be here today and gone tomorrow.
The only software needed is the old-fashioned kind - your eyes and brain telling you when you see a post with that moniker, ignore it.
This forum software needs an "Ignore this user" button so we don't have to read Bucky's drivel.
Norm
This is the way I am looking at this. The Lac Megantic wreck and the discovery of the volatile nature of Bakken oil have catapulted this issue of oil train safety into the limelight. It is a public safety problem and it needs to be fixed. But it is also a public perception problem because the public has seen the fireballs, and they are simply unwilling to accept the odds of it happening to their town even though those odds are vastly in their favor.
This public perception problem is a public relations problem for the oil companies in that the public refuses to compromise on the solution to the problem. They want the problem to go away. That means a 100% solution to the problem which is like the anti-breach certainty of a nuclear flask.
I don’t think the industry has any intention of going that far. I don’t think they can go that far without pricing oil out of the market. So they will be conservative in their solution to the problem. Perhaps they don’t even realize that there is a public relations problem in which the public unreasonably wants zero flaming oil train wrecks. It makes no difference that railroads haul things more dangerous than oil or things just as flammable as oil. News is like marketing, and this oil train problem has been packaged and sold to the public as though it were a product.
If the industry does not comprehend the depth of the problem they face, they may feel that an incremental increase in safety is an adequate response that will quell the public clamor. But the only real way out of this problem is for the industry to mount their own marketing perception to counteract the message instilled in the public by the media. And you don’t do that by adding a little more protection to tank cars. They need to fight fire with fire or they are going to get run over.
You can't control the uncontrollable. Keep the train in tension ?? Gimme a break , as soon as stuff hits the ground the drawbars and knuckles are going to bust on the power and the forward part of the train is going to go on its merry way, oh wait.. that means that the locomotive drawbars gotta be unbreakable too ?? Then you can deal with the prime mover and alternator becoming missiles after the hold down bolts and dowel pins break.
Just build a damn pipeline.
With all the new regulations and whatnot coming out only a few select railroads will profit from the oil moves. The railroads that don't run through towns or cities.. that's not going to be easy.. maybe we'll see some major capital spent on new railroads that go around populated areas? You know , making these rules and regulations is pretty damn easy when you spend your career sitting behind a desk, I guess you really can lose touch with reality. Maybe the best plan is just to leave it in the ground in N. Dakota.. pay at the pump America.
As for this discussion , stop feeding the damn troll. Let him be right, its pointless to argue. I promise NONE of his idea's will be implemented.
Last try at explaining this to you.
At 40 mph in less than 1 sec the train will have traveled one car length, the next car in the train will reach the point of derailment. At just under 2 sec after the first car derails there will be 2 cars over the point of derailment. When that happens you have lost the restraint that has been keeping the train in line, the wheels on the rails, the cars can move at angles to each other to the extent that the drawbars allow (and the drawbars have to allow some movement or the cars could never go through a switch).
Your plan only succeeds if the train remains in tension. Once the car hits the ground it begins decelerating faster than the train can brake. Based on the paper available on the internet, the derailed car can be decelerating over 3 times faster than the rest of the train. What that does is put the derailed cars in compression compared to the rest of the rear of the train. Compression forces will try to rotate the car around the Z axis. Being derailed there is nothing there to resist that, other than the stuff being plowed up. Every second one more car passes over the POD, and your chain in tension becomes a chain in compression, Once the connections between the cars go from tension to compression, the fat lady has sung.
The most immediate effect of that resistance is to cause the derailed car to be deflected out of alignment with the train due to the inertia of the train overpowering the resistance of the derailed car. If that deflection of the first derailed car can be prevented, it will prevent the chain reaction of more cars deflecting and creating an accordion pileup.
Have there been derailments where one end of one car derailed and the car went for miles, but because of shelf couplers it never dropped and because the train was in tension it kept the car in line on the ties? Sure. I've run across several of those derailments in the last 30 years. Are they typical? No.
You are proposing to spend a whole lot of money for an edge case.
It you want to look at something useful, here's an idea. On a locomotive the maximum power is when the wheels are just at the slipping point. AC locomotives pull more than DC locomotives because AC engines have better wheel slip control. Turn that arround, If the maximum pulling power is at the point of slipping, the maximjum braking power is at the point of slipping. Have your "smart" brakes track the speed of the car, the rotation of the wheels, the brake pressure on the shoes and the termperature of the wheels to apply the maximum braking force but not slide the wheels of the car. That would be something useful to improve the handling of the train the 99.99995% of the time its not derailed.
Dave H. Painted side goes up. My website : wnbranch.com
tree68 So for at least two of the three derailment/fire incidents of the recent past, your proposed system would have had no effect whatsoever. And it's unknown at this point in time what caused the Aliceville incident. Given that an emergency application applies the maximum possible braking force to all the cars, and that while not instantaneous, an emergency application still transmits through the train very quickly (each car also dumps the brake line, speeding the process), any other sort of brake sensing and application would have little additional effect. Virtually any catastrophic failure (wheel, truck, track structure) is going to have an immediate effect on the car involved, and very likely at least one of the adjacent cars. And they will almost immediately dig in, arresting their forward motion. Even if it were possible to sense the situation and cause the locomotive to advance the throttle, the response time of the prime mover won't be fast enough to keep the slack stretched. And if the locomotive is already in notch eight, there is no acceleration to be had. If the locomotives are in dynamics, there is about a ten second period required to go from dynamics to power, and by then things are pretty well piled up.
So for at least two of the three derailment/fire incidents of the recent past, your proposed system would have had no effect whatsoever. And it's unknown at this point in time what caused the Aliceville incident.
Given that an emergency application applies the maximum possible braking force to all the cars, and that while not instantaneous, an emergency application still transmits through the train very quickly (each car also dumps the brake line, speeding the process), any other sort of brake sensing and application would have little additional effect.
Virtually any catastrophic failure (wheel, truck, track structure) is going to have an immediate effect on the car involved, and very likely at least one of the adjacent cars. And they will almost immediately dig in, arresting their forward motion.
Even if it were possible to sense the situation and cause the locomotive to advance the throttle, the response time of the prime mover won't be fast enough to keep the slack stretched. And if the locomotive is already in notch eight, there is no acceleration to be had.
If the locomotives are in dynamics, there is about a ten second period required to go from dynamics to power, and by then things are pretty well piled up.
Larry,
Oil by rail traffic is on an upward trajectory. Fred Frailey has a blog that gives the odds of oil train derailments. Nobody knows how they will actually distribute or what amount of damage or injury may result. Certainly they can’t all be prevented by my concept or by the regulator’s plan to strengthen the cars. Also ramping up, is the public reaction to these fireball wrecks. So, each additional one does exponentially more damage to the industry.
My concept only depends on adding power if the derailment is very close to the head end, and it does take some time, as you say. Although in some cases, the engines will already be in power mode, so they just have to remain there as the derailment occurs.
The ECP brakes can apply maximum braking to the same force as the “emergency” mode of standard air brakes, and they can make that application instantaneously on all cars. Whereas standard air brakes take some time to propagate the application throughout the train.
My concept uses sensors to detect when a car derails, so braking can begin right at that instant. Many derailments start out with dragging the derailed wheelset. This may continue for a considerable distance before developing further to the point of parting the air hoses and dynamiting the brakes. Valuable time is lost in reacting to the derailment with braking.
With my concept, the application of brakes does not have to wait until air hoses part. It starts braking the instant a derailment begins. In this way, it may actually prevent a serious wreck by stopping the train in the beginning phase of the derailment.
When a derailed car starts to dig into the ties and ballast, its forward motion would be arrested if the car were on its own and not coupled into the rest of a train. But if it is coupled into a train, the resistance has little effect on the total inertia of the rest of the train. The most immediate effect of that resistance is to cause the derailed car to be deflected out of alignment with the train due to the inertia of the train overpowering the resistance of the derailed car. If that deflection of the first derailed car can be prevented, it will prevent the chain reaction of more cars deflecting and creating an accordion pileup.
rbandr,
A tank car that is as invincible as a nuclear cask is indeed what is needed. That is a container where breaching is completely unacceptable. It would be interesting to know how thick tank car walls would have to be in order to achieve that standard. I doubt that the planned strengthening standard will come close to the reliability of a nuclear cask. But it is not an engineering problem. It is an economic problem. Nuclear waste is handled in small quantities and the cost for absolute safety must be borne. But if oil tank cars are too strong, they will price the oil out of the market, so it will have to be left in the ground.
u can be sure that the federal test center in I believe it is pueblo Arizona is testing new improved designes all the time. they can make a cask to contain radioactive material to survive a direct hit from a locomotive. the question is always about cost. and also weight. it must work on both levels to get built and bought.
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...
dehusmanAll my brake concept does is control the braking on the cars ahead of the derailment rather than let them dynamite into emergency as is normally the case. ..... and remind me why that is a bad thing.
All my brake concept does is control the braking on the cars ahead of the derailment rather than let them dynamite into emergency as is normally the case.
It is a bad thing because the head end braking often causes it to decelerate faster than the hind end. So as the cars derail, they get shoved into a jackknifing condition by the trailing cars pressing ahead against the higher resistance of the leading cars. The best you can do is pull on the head end with the power, but the braking of the head end can offset that pulling power. And if you pull too hard, the head end can break in two. So the effect is limited. This is why it is better to control the braking ahead of the derailment rather than to let it dynamite into emergency.
Regarding your other point where you say, “Trust me, when the trucks start coming apart and gravity drives the broken trucks into the roadbed, the coefficient of friction of plowing up crossties is waaaaaaay higher than anything your brake system will be doing.”
Until you get a lot of cars on the ground, the coefficient of friction of plowing up the crossties is minuscule compared to the inertia of the rolling train. Holding back on the brakes for the leading cars retains their inertia for the purpose of pulling on the derailing cars. Heavy braking on the trailing cars removes their inertia so they cannot push into the derailment and start jackknifing cars. In addition to the pull of the head end cars due to their own momentum, power can also be applied. This would be particularly necessary where the derailment begins close to the head end, leaving too few cars ahead of the derailment to pull into the derailment with their own inertia.
The derailing cars that are plowing up ballast will be also losing their momentum just as they would with braking. So if you were to get say 15 of them on the ground, they would start to exercise a retarding effect on the derailed string of cars that would create resistance to the pull of the head end into the first cars in the derailment. That retarding effect of the derailed cars would blend with the retarding effect of the braking on the cars behind the derailment that are still running on the rails.
In other words, as the string of cars on the ground gets longer, yes its resistance can start to rival the resistance produced by the brakes on the trailing cars still on the rails. However, the resistance of those cars on the rails becomes less needed because it is replaced by the resistance of the cars dragging on the ground.
Regarding you points about other types of derailments not being addressed: I agree that this system will not work the same way every time or even be successful every time. It won’t help at all in head on or rear end collisions. It won’t work in a sideswipe at entering or leaving a passing siding. It would not have worked at Casselton because the engine of the oil train hit the derailed grain car. With the engine involved in the wreck, the derailment began right at the head end, so there would be no way for the leading part of the train to pull on the derailment. It would not work with a derailment on a bridge where the derailed train could fall off and drop into a ravine.
Euclid No car will stop dead in its tracks. The never do unless they hit something more massive than the car; or hit something moving in the opposite direction, like another train. Then maybe the car would completely disintegrate, thus stopping dead in its tracks.
No car will stop dead in its tracks. The never do unless they hit something more massive than the car; or hit something moving in the opposite direction, like another train. Then maybe the car would completely disintegrate, thus stopping dead in its tracks.
Ignoring the fact that trains hit massive things, cars get wedged sideways in things, etc., it doesn't take the car to stop, all it takes is a large difference in deceleration rates. Trust me, when the trucks start coming apart and gravity drives the broken trucks into the roadbed, the coefficient of friction of plowing up crossties is waaaaaaay higher than anything your brake system will be doing. The derailed car will be decelerating faster than the cars behind it. That differential in the deceleration rate causes things to go sideways. If you assume it won't happen, you will be disappointed.
tree68So if a car stops dead in its tracks (literally), all the other cars are going to be able to stop behind it with this braking system?
No car will stop dead in its tracks. The never do unless they hit something more massive than the car; or hit something moving in the opposite direction, like another train. Then maybe the car would completely disintegrate, thus stopping dead in its tracks. All my brake concept does is control the braking on the cars ahead of the derailment rather than let them dynamite into emergency as is normally the case.
Ok, but I would think if it derailed on a sharp curve (Lac Megantic), poor track (La Megantic), around a grade crossing (Lac Megantic), was hit in the side by another object (Casselton) or derailed on a bridge where there were no shoudlers (CSX Philadelphia) you would have a problem. As long as you think an oil train will never derail under those circumstances, in those places, I'd say your assumptions are solid.
Riddle me this.
When the train derails its a pretty good bet that every axle that passes over the point of derailment will also derail and the main track will be torn up (or be plowed up) from the point of derailment to the point the first derailed car comes to a stop. How does your braking algorithm work with a large part of the train bumping along the ties?
I have been involved with too many derailments to expect the optimal outcome to be the typical outcome.
So if a car stops dead in its tracks (literally), all the other cars are going to be able to stop behind it with this braking system?
There's not a braking system in existence (or otherwise in the works) that can accomplish that.
Stuff will come apart and break (including the car frames). The cars will "accordion." Unless the tanks are made of some material we haven't heard of, they may well be punctured by trucks, trackside structures, or those unbreakable drawbars.
In other words, very much like what happens now.
dehusmanThe entire plan hinges on the cars derailing and remaining upright, in line and on the track structure with the trucks under them.
It does no such thing. It depends only on the cars remaining coupled together. If they do that, they will stay relatively in line and on the roadbed. They don't need the trucks under them. They don't need to be upright.
The only purpose is to prevent the cars from piling up into a heap.
The point is that there is no heap of cars created with car after car being jammed into it by the string of trailing cars. That effect will rupture tank cars no matter how much armoring is added to the tanks.
The entire plan hinges on the cars derailing and remaining upright, in line and on the track structure with the trucks under them.
Everybody loves an optimist.
dehusmanWhat happens when the first cars derails, digs in and stops with 8000 tons of train behind it still moving?
The air brakes are what stop the 8000 tons behind still moving behind the derailment. Certainly, the accordion action and crushing of cars in a derailment does absorb energy, as you say. However, this is not desirable, nor is it an intentional part of the design as it is in automotive design, for example, where the crushing of the front of the car absorbs energy. That is intentional design to save the life of the driver. When freight cars crush in a derailment, nothing good results from it. It destroys equipment and cargo, ruptures tank cars, and threatens lives nearby.
So my point of this safe oil train concept is to avoid that. In a conventional train, air brakes stop the cars behind the derailment. They also stop the cars ahead of the derailment. But they do this by full emergency application in all cars, ahead of and behind the derailment. The response propagates through the cars toward the front and back of the train, starting from the derailment point. It is an automatic response that cannot prevented or overridden.
In my concept, the brake response is also automatic, but it is a “smart” response. It senses the derailment and varies the brake response according to what is needed. For example, it can apply any amount of braking to any car, completely independent of all other cars. In the case of a derailment, it senses the derailment, and applies braking to the cars behind the derailment. Those brakes are applied simultaneously and there is no slack action. It also applies brakes to the cars ahead of the derailment, but not as hard as the brakes are applied behind the derailment.
This difference in braking on both sides of the derailment creates tension as the inertia of the leading cars wants to run away from the trailing cars holding back with their heavier braking. This smart system will know just how much this braking difference can be maximized without pulling the train in two.
The resulting tension is the greatest on the cars ahead of the derailment and closest to the derailment site. If the cars in the derailing process can stay coupled together, this tension will extend right into the derailed cars while the train is still moving. If the derailed cars stay coupled, it makes no difference what happens to them. They can lose their trucks, tip over, snag rail, plow ballast, rip up ties, tear out crossings, and whatever. But if they stay coupled, eventually they will simply stop because of the braking drag on the cars behind the derailment. That is the desired outcome.
dehusmanit would be 5, closer to 10 years (or more with the technology) before is would be certified for use. Then the companies would have to buy them, so you might get a significant penetration into the fleet 20-25 years from now.
The revolutionary Airbus A380 went into design in 1997, test flights 2005, certification 2006-7, service entry Oct. 2007. Rather a lot more complicated and expensive than a tank car, yet 10 years from design to service, with 122 built so far. Is it just possible that a breakthrough tank car design might be somewhat quicker?
...... or you could just use the flammable gas design in service now as a basis. They are proven designs, heavier construction, available off the shelf and a good safety record.
If somebody gave you $100,000,000 right now and said go build one, it would be 5, closer to 10 years (or more with the technology) before is would be certified for use. Then the companies would have to buy them, so you might get a significant penetration into the fleet 20-25 years from now.
Since the companies can't wait that long (the existing fleet will be reaching the end of its lifespan) they will probably replace the current cars with the improved conventional design variants anyway, which will make them reluctant to buy the new cars since the improved designs will most likely be be sufficient.
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