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.
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.
Last try at explaining this to you.
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.
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.
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.
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
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.
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.
This forum software needs an "Ignore this user" button so we don't have to read Bucky's drivel.
Norm
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.
C&NW, CA&E, MILW, CGW and IC fan
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.
Your plan only succeeds if the train remains in tension.
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.
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.
Won't an organizatinal change, with people with credibility, do more and faster in that department?
Thus, Key Transportation, Inc.
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.
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!
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.
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.
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
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 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.
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.
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.
Well, yes, but more power then the train needs once it is in motion. This would be a waste of expensive locomotive assets.
dehusman 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? Maybe. Maybe not. http://www.businessweek.com/articles/2013-07-12/french-wreck-reveals-hidden-danger-in-its-vaunted-train-system
That wreck was an old (needs to be replaced) conventional equipment train on old track (also needs to be replaced according to the article). Apples and oranges.
daveklepperNote that oil trucks these days no longer have round tanks, they are oval. Possibly with the desire for increased capacity, the newest and safest tankcars will also have oval tanks, but long dimension vertical to take advantage of clearances available even on the more restricted existing freight routes.
That is an interesting thought. I gather that the oval tanks on highway trailers are to lower the center of gravity. But they would be slightly more complicated to fabricate possibly. I recall that Trains once had a small article about an idea to make tank cars rectangular in cross section.
You would lose the natural structural advantage of a cylinder, so the rectangular tank would have to have extra reinforcing members. However, it has the advantage of filling up the railroad clearance diagram where as a cylinder is like a round peg in a square hole regard the clearance diagram.
A really futuristic and advanced oil train would have tank cars shaped like fish belly gondolas. They would carry the load as low as possible for the lowest possible center of gravity. Unlike a fish belly gondola which has a flat floor and merely dropped side walls, the fish belly tank cars would have a floor that drops down to within maybe six inches above the rail. A train of those type of tank cars would have sailed right through Lac Megantic without leaving the rails.
Euclid ... A really futuristic and advanced oil train would have tank cars shaped like fish belly gondolas. They would carry the load as low as possible for the lowest possible center of gravity. Unlike a fish belly gondola which has a flat floor and merely dropped side walls, the fish belly tank cars would have a floor that drops down to within maybe six inches above the rail. A train of those type of tank cars would have sailed right through Lac Megantic without leaving the rails.
...
Once a fish-belly tank car lost its trucks, it would be like a rocking horse.
EuclidA really futuristic and advanced oil train would have tank cars shaped like fish belly gondolas. They would carry the load as low as possible for the lowest possible center of gravity. Unlike a fish belly gondola which has a flat floor and merely dropped side walls, the fish belly tank cars would have a floor that drops down to within maybe six inches above the rail. A train of those type of tank cars would have sailed right through Lac Megantic without leaving the rails.
The 'rail whale' tank cars had what amounted to a depressed center section between the span bolsters, for much this sort of reason. One problem is that this drops what is essentially a reinforced monocoque structure very close to things sticking up from the track, which might cause substantial damage a la Titanic even to multiple-compartment cars. That is not a criticism, only a concern.
Rectangular tanks were noted as a bad idea in the commentary to the Trains article: much more structural material needed for the enclosed volume; trouble getting product out of the 'corners' or getting the last part of the load out of the car; different baffling needed especially near the upper part of the car. A reasonably-rectangular (or oval) carbody bulit to 'load out' before it 'cubes out' would have the desired low center of gravity. Which leads me to think that perhaps an interim solution, shy of building Hundreds Of Expensive New Tank Cars, would be to build a slew of 40' tank modules, and drop them in existing (but obsolescent) well cars.
There is your low center of gravity, easy removal of damaged tanks for servicing, easy provision of heating lines, air lines, etc. for facilitation of loading and discharge -- etc. The well-car structure provides some of your collision bracing and structural protection (in addition to the armor, shock-attenuation, and structure in the enclosing 'container' frame that is provided for the tank module, in addition to what is already used for containerized tanks). Makes a certain amount of intermodal loading possible, too, for what that might be worth. It also makes adoption of full ECP braking, high-speed trucks with stabilizers, and other safety requirements relatively more cost-effective.
I will let you all argue forward and back about whether to allow some forms of stack on top of the oil modules (which might not reach full ISO interchange height... Personally, I'd run oil trains as fully dedicated blocks following current practices, with buffer cars and all the other operating precautions that go with an explosive liquid cargo. But other paradigms might be implemented, with proper care and attention...
When you change the type of car you end up changing the loading pattern, then not only does the shipper have to get all new equipment for transportation but has to build new racks or modify existing racks to load and unload the oil. $$$
Another consideration is that by moving it in containers you are shipping less per platform which means more cars or more trains to haul the same volume of oil (unless you doublestack it, a truly bad idea.)
The existing fleet can be replaced faster and more cheaply with new cars of conventional designs that are more secure and less likely to rupture. The problem is that the existing cars are built for a commodity with one set of characteristics and the commodity really has a different set of characteristics. We already have very successful designs for those characteristics, its just a matter of getting cars that match the actual characteristics (designs closer to flammable gas designs).
Overmod................ A reasonably-rectangular (or oval) carbody bulit to 'load out' before it 'cubes out' would have the desired low center of gravity. Which leads me to think that perhaps an interim solution, shy of building Hundreds Of Expensive New Tank Cars, would be to build a slew of 40' tank modules, and drop them in existing (but obsolescent) well cars. There is your low center of gravity, easy removal of damaged tanks for servicing, easy provision of heating lines, air lines, etc. for facilitation of loading and discharge -- etc. The well-car structure provides some of your collision bracing and structural protection (in addition to the armor, shock-attenuation, and structure in the enclosing 'container' frame that is provided for the tank module, in addition to what is already used for containerized tanks). Makes a certain amount of intermodal loading possible, too, for what that might be worth. It also makes adoption of full ECP braking, high-speed trucks with stabilizers, and other safety requirements relatively more cost-effective..................
There is your low center of gravity, easy removal of damaged tanks for servicing, easy provision of heating lines, air lines, etc. for facilitation of loading and discharge -- etc. The well-car structure provides some of your collision bracing and structural protection (in addition to the armor, shock-attenuation, and structure in the enclosing 'container' frame that is provided for the tank module, in addition to what is already used for containerized tanks). Makes a certain amount of intermodal loading possible, too, for what that might be worth. It also makes adoption of full ECP braking, high-speed trucks with stabilizers, and other safety requirements relatively more cost-effective..................
Thanks to Chris / CopCarSS for my avatar.
Murphy Siding Now that's an interesting thought. Would it be possible to take those existing (but obsolescent) well cars, and build them into tank cars? Kind of like recycling the good parts? They do it with locomotives. Think of something along the Cleveland class cruisers that became aircraft carriers in WWII.
Now that's an interesting thought. Would it be possible to take those existing (but obsolescent) well cars, and build them into tank cars? Kind of like recycling the good parts? They do it with locomotives. Think of something along the Cleveland class cruisers that became aircraft carriers in WWII.
'Makes sense. Thanks.
Building as many flamable liquid state-of-the art tankcars as quickly as possible does make more sense,
schlimm 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?
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?
Maybe quicker, but does it kill the economics? Having to replace the tank car fleet from scratch raises the cost of providing the service and can change the economic flow patterns of the product.
-Don (Random stuff, mostly about trains - what else? http://blerfblog.blogspot.com/)
daveklepperBuilding as many flamable liquid state-of-the art tankcars as quickly as possible does make more sense,
It only makes sense if it solves the problem. As I understand it, it will take until 2015 to just develop the standards for new tank cars. Won’t it take several more years before the existing fleet is replaced by the new safer tank cars? And how safe will they be?
That question is not even being asked let alone being answered in the public discussion. In Fred Frailey’s statistic of SIX serious oil train accidents per year, how many will there be if all tank cars were of the upgraded design? Would SIX change to THREE? Or would there still be FIVE?
How long will it take for the oil-by-rail traffic to double as the boom continues, and SIX accidents per year becomes TWELVE?
It only makes sense if it solves the problem, and solves it soon. Five years and a partial solution is too little, too late. With that plan, it becomes a game of Russian roulette placing at stake, innocent lives and the continuation of the oil by rail business.
The only way to win that game is if fate postpones those SIX accidents per year and saves them for some date way in the future after a real solution to the problem is implemented that will prevent fate from cashing in all those saved up accidents.
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