EuclidFred Frailey has some good information and discussion about the odds of certain magnitudes of oil train wrecks occurring.
You may have read that the Canadian government is requiring rail shippers of crude to take out insurance against the risk of derailment damage. You can bet that the Marsh & McClellan actuaries are trying to calculate the risk of another OMG incident - a Lac-Megantic or that Amtrak train plowing into the train of crude oil splayed across the right of way.
Let's see: A year or so ago in a blog, at someone's suggestion, I plowed through FRA accident stats and concluded we should expect six noticeable derailments of crude oil trains a year. Well, that's about what is happening.
What I don't know how to calculate the odds of a truly catastrophic incident, a la Amtrak or Lac-Megantic. But this is really a form of Russian Roulette. Spin the chamber often enough -- derail enough crude oil trains over time -- and a bullet will someday be in the chamber.
Your odds of having that day dawn diminish when you decrease the rate of derailments. We need to 1) seriously slow these trains down (the CSX train in West Virginia was doing 33 mph, and six days later the fire is still burning) or 2) take better care of our track and equipment.--Fred W. Frailey
C&NW, CA&E, MILW, CGW and IC fan
Ah, now that the 'pump has been primed' with our somewhat not too serious comparisons why don't we build pipelines?? Ask our President!!
diningcar Mr. Willison, you wouldn't be thinking about the threat of bombs being detonated in our shopping malls would you. If one, or more, of these occur a train derailment will be relagated to page 15 next to Ann Landers.
The Chatsworth, Calif. passenger train wreck that resulted in the PTC legislation killed about 25, after the NS Granite, SC chlorine car wreck that killed about 9.
The risk is clearly out there. To ignore or minimize it by thinking, saying, or acting like all such future incidents will occur out in the middle of nowhere is contrary to recent experience, and hence foolhardy.
- Paul North.
LIONS do not reply to PRIMATES
ROAR
The Route of the Broadway Lion The Largest Subway Layout in North Dakota.
Here there be cats. LIONS with CAMERAS
Mr. Dining car... Silly silliy comparison. Terrorism to transportation safety and regulation issue. Really
CSX is rerouting some oil trains onto NS's old Virginian.
http://www.dispatch.com/content/stories/national_world/2015/02/21/oil-trains-quietly-rerouted-after-derailment.html
Mr. Willison, you wouldn't be thinking about the threat of bombs being detonated in our shopping malls would you. If one, or more, of these occur a train derailment will be relagated to page 15 next to Ann Landers.
Thier is a silent majority that will not allow continued disasters. The big one in the us has yet to happen. If it does things will get ugly. It won't be tree huggers or the media, just out rage ordinary Americans.
ROBERT WILLISONThe general public understand and accepts reasonable risk.
The media and their agenda are the ones who will not let go of the issue.
ROBERT WILLISONNothing can be made 100% risk free. New tank cars can be and will be built to higher standards. A better tank car will be built to meet the needs of all the stakeholders in this issue.
New tank cars can be and will be built to higher standards. A better tank car will be built to meet the needs of all the stakeholders in this issue.
There is no technical problem in building a tank car that will survive high speed derailments. Nothing can be perfect, but 99% perfect may be attainable. But there is one problem. Such a tank car will be so heavy that it won’t carry enough oil to make the shipment worthwhile.
Jeff, I think you hit it on the head. The general public understand and accepts reasonable risk. Nothing can be made 100% risk free.
New tank cars can be and will be built to higher standards. Thier are too many stake holders here including the railroads, shippers and the end users of the product not to develop a better car.
Most can remember when an air bag was consider an unneeded and costly government regulation. Every one knows the air bag won't save you if drive over a cliff. Over time they have saved many a life.
A better tank car will be built to meet the needs of all the stakeholders in this issue.
But time is ticking, and needs to be done in responsible time frame.
Modeling the Cleveland and Pittsburgh during the PennCentral era starting on the Cleveland lakefront and ending in Mingo junction
Jeffhergert posted the following link:
Railway Age article on this subject.
http://www.railwayage.com/index.php/safety/oil-train-mishaps-reveal-tank-car-strengths-and-limitations.html?channel=60
Jeff
From that link:[snip] "...The oil industry has argued that railroads are to blame for not keeping their trains on track, a contention accepted by the Federal Railroad Administration and its sister agency the Pipeline and Hazardous Materials Safety Administration, which have chosen to ignore the matter of “hot oil” being loaded directly from wells to tank cars without first cooking off the explosive dissolved gases.
Such heat treatment is routine in Texas, from where equally volatile light crude has been shipped by rail for years without a single explosive incident.
The oil industry says there is a ready market for the extracted gases in Texas, but none in North Dakota. Therefore, say the producers, the explosive gases are best shipped to refineries while still dissolved in the crude. Otherwise, they would have to be shipped away by rail or flared into the atmosphere..."[snipped] { I added the emphasis to the linked article and its information}samfp1943
It would seem that the blame, and the solutions to the problematic transportation of the Bakken Crude is writte in this article; So far the FRA(?) has mandated that the speed of the trains carrying Bakken Crude have been limited to 45 mph. New tank car specifications have been orded and they are being delivered...The problem seems to be the entrainded gases in the crude, the treatment before shipment has been apparently 'deemed' too costly or environmentally unfriendly, and the burning off is not allowed(?) so it is shipped as is, to be extracted in the existing refineries of the Gulf Coast.
Why could not the gases be 'extracted', then shipped in seperate shipments to facilities that could use them? They might have to be concentrated ( as a liquid(?); or as a compressed gas(?) in thier own tank cars.
CShaveRR Please recognize that there is no coupler construction possible at all that will withstand jackknifing when you have 143 tons of pressure on each fist snapping the pencil, as it were. The couplers are fine--there was a picture making the rounds a couple of weeks (or months) ago of a string of acid tank cars that tipped over as a unit in a yard (MRL?). It's a safe assumption that these cars weren't moving at 40-50 mph when one of them tipped.The new tank specs (DOT-116) will have even thicker shells than the CPC-1232 cars. But use the Titanic-vs.-iceberg analogy. Think this shell is going to withstand a jagged rock hitting it at 40 mph? Uh-uh.Now, as to these derailments of Baaken crude. The explosiveness is caused by gases contained in the crude, which have historically been stripped from crude before shipment and flared off or put to use (they could be shpped separately in pressure tank cars if the demand were there). That's it, in a nutshell (or a CPC-1232 shell): the railroads have been doing their part, designing safer equipment and operating it over well-designed trackage. There will be failures, there will be breaches. It should be the responsibility of the shippers to take the same precautions regarding explosive gases that have been, and are being, taken elsewhere in the country. If open flares have become problematic, railroads have a solution for that, too.
Please recognize that there is no coupler construction possible at all that will withstand jackknifing when you have 143 tons of pressure on each fist snapping the pencil, as it were. The couplers are fine--there was a picture making the rounds a couple of weeks (or months) ago of a string of acid tank cars that tipped over as a unit in a yard (MRL?). It's a safe assumption that these cars weren't moving at 40-50 mph when one of them tipped.The new tank specs (DOT-116) will have even thicker shells than the CPC-1232 cars. But use the Titanic-vs.-iceberg analogy. Think this shell is going to withstand a jagged rock hitting it at 40 mph? Uh-uh.Now, as to these derailments of Baaken crude. The explosiveness is caused by gases contained in the crude, which have historically been stripped from crude before shipment and flared off or put to use (they could be shpped separately in pressure tank cars if the demand were there). That's it, in a nutshell (or a CPC-1232 shell): the railroads have been doing their part, designing safer equipment and operating it over well-designed trackage. There will be failures, there will be breaches. It should be the responsibility of the shippers to take the same precautions regarding explosive gases that have been, and are being, taken elsewhere in the country. If open flares have become problematic, railroads have a solution for that, too.
I just threw that exception in the case of equal squeeze in there as a qualifier. What I mean is this: Say that a laboratory experiment was conducted where a loaded and sealed tank car is placed in a larger enclosed tank of water or other liquid. Then say the pressure of that liquid in the larger tank was raised. The tank car would be squeezed evenly all over its surface. The oil inside would be practically non-compressible because it is a liquid.
So the loading on the steel wall of the tank car, would be simply compressing the steel between the building pressure in the larger outer tank, and the inner backing of the non-compressible oil in side of the tank car. There would be no force that would try to burst the tank car.
But if you had a loaded and sealed tank car, and squeezed it in a giant vise, the vise compressing the tank walls in just limited areas would raise the internal pressure of the oil, causing it to force outward in the tank areas not being directly squeezed by the vise jaws. Eventually the rising internal pressure would burst the walls outwards in some area not directly backed up by the squeeze of the vise jaws. It would be like hand squeezing a water balloon until it bursts. All train wrecks will squeeze tank cars unevenly, like the giant vise example.
I feel that the only factor that would prevent a tank car from being burst in that manner in a train wreck would be if the pressure applied were simply not high enough. I believe that there is the potential for that squeeze to be great enough to burst a tank car in many train derailments. But it will depend on the focus of kinetic energy in an oncoming string of cars forcing into the heap of cars as the size of that heap grows, thus increasing the resistance of the heap to the oncoming cars plowing into the heap.
Bingo. By the time you put enough pressure on the car the shell will either puncture or be creased and crack. If the car is engulfed in a fire the shell will be weakened from the heat, the contents will be superheated and THAT pressure will cause the car to burst.
Dave H. Painted side goes up. My website : wnbranch.com
EuclidDo you mean that it cannot happen in a train wreck? I ask the question because obviously it is possible to burst a car if the squeeze pressure is high enough (assuming that the squeeze is not evenly distributed on the car’s exterior).
Emphasis mine.
If the "squeeze" is not evenly distributed on the car's exterior, that would tend to suggest the very high possibility of mechanical failure of the tank. I would opine that any "bursting" due to outside pressures would likely be secondary to the physical failure of the tank due to puncture, crease, or other physical insult.
DOT111A's had a design strength of 500 PSI. One would assume that the newer CPC-1232 cars would have at least the same, and possibly a higher burst strength. I'm not even going to begin to guess what kind of a reduction of the volume of one of those cars would require to reach an internal pressure of 500 PSI.
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...
You must also consider other causes of tank failures. In a tank car derailment, valves and fittings can be broken-off, leading to leakage. If it catches fire, it may lead to a confined vapor explosion.
That cars rupture is obvious. I am saying that the mode of failure that cars are squeezed and cause the internal pressure in the cars to become so high the cars burst is not correct. That a car can impact another car and puncture the tank car is possible. That a car can impact another car, crease the tank and cause the tank wall to crack at the crease is possible.
We waste millions of electrons with fanciful "solutions" to modes of failure that don't occur. All coupling systems have to have enough movement in them to allow two coupled cars to negoiate a curve or a switch. If a car can negoiate a switch, one end of the car can diverge enough for the wheels to go off the ends of the ties, Once the wheels leave the ties you lose control of keeping the train upright and in line. Once the cars leave the ties, where they end up is a matter of the weight of the cars, the speed of the cars, the condition of the ground, the shape of the terrain and the number of obstructions in the way.
Murphy Siding Euclid dehusman Here a trick you should try, get two cans of soda. Take one and drink the soda. Squeeze the empty can in your hand. Does it crush? Now take the full can of soda. Squeeze that in your hand. Does it crush? Thats the difference between a loaded and empty container. Are you saying that the fact that a person cannot crush a full soda can with their hand proves that a full tank car cannot be crushed in a train wreck? Are you saying that the fact that a person cannot crush a full soda can with their hand proves that a full tank car can be crushed in a train wreck? It sounds just as silly when I put words in your mouth.
Euclid dehusman Here a trick you should try, get two cans of soda. Take one and drink the soda. Squeeze the empty can in your hand. Does it crush? Now take the full can of soda. Squeeze that in your hand. Does it crush? Thats the difference between a loaded and empty container. Are you saying that the fact that a person cannot crush a full soda can with their hand proves that a full tank car cannot be crushed in a train wreck?
dehusman Here a trick you should try, get two cans of soda. Take one and drink the soda. Squeeze the empty can in your hand. Does it crush? Now take the full can of soda. Squeeze that in your hand. Does it crush? Thats the difference between a loaded and empty container.
Are you saying that the fact that a person cannot crush a full soda can with their hand proves that a full tank car can be crushed in a train wreck? It sounds just as silly when I put words in your mouth.
In response your question: No I am not saying that.
The question I asked of Dave is not silly at all, and it does not put words into his mouth, as you say. You would not think my question is silly and that it does put words into his mouth if you bothered to understand the question and its context. What I asked for is a clarification of what Dave’s analogy is intended to show.
A full soda can and a full tank car are both cylinders. If you squeeze either one hard enough, it will burst. I interpret Dave’s analogy as attempting to show that, since you cannot hand squeeze full soda can hard enough to burst it, that proves that a train wreck cannot squeeze a full tank car hard enough to burst it. After all, the bursting of tank cars was the topic for which he offered the analogy.
I fail to see that the conclusion is proven by the analogy. But Dave does not tie the analogy directly to tank cars. He only compares a full soda can to an empty one. In that respect, I agree with his point that a full soda can is harder to crush than an empty one. I was just asking him to tie his analogy to tank cars. There is nothing silly about it. Apparently the point and the logic totally escapes you.
Thanks to Chris / CopCarSS for my avatar.
Eucliddehusman Are you saying that the fact that a person cannot crush a full soda can with their hand proves that a full tank car cannot be crushed in a train wreck?
Try stomping on the full can with a hard soled boot, and see if it maintains it's complete integrety. With enough force, the weak spot will be found.
Never too old to have a happy childhood!
dehusmanHere a trick you should try, get two cans of soda. Take one and drink the soda. Squeeze the empty can in your hand. Does it crush? Now take the full can of soda. Squeeze that in your hand. Does it crush? Thats the difference between a loaded and empty container.
CShaveRR ... Now, as to these derailments of Baaken crude. The explosiveness is caused by gases contained in the crude, which have historically been stripped from crude before shipment and flared off or put to use (they could be shpped separately in pressure tank cars if the demand were there). ...
...
Now, as to these derailments of Baaken crude. The explosiveness is caused by gases contained in the crude, which have historically been stripped from crude before shipment and flared off or put to use (they could be shpped separately in pressure tank cars if the demand were there). ...
Bakken crude has always used gas seperation, apparently to varying degrees, and a recent ND regulatory order to standardize it is being implemented. However, the seperating process is only for the 4 lightest components of the crude, and while it should decrease flammability incrementally, there will still be plenty of bang left in crude vapors confined in a tank car.
BroadwayLion It is not all that hard to crush a railroad tank car...
It is not all that hard to crush a railroad tank car...
Unfortunately that is not a a crush in the same context we are discussing. That was an empty tank car that had been steam cleaned, thus heated inside, then sealed and when the interior cooled, caused a drop in internal air pressure allowing the external air pressure to collapse the car. The cars we are talking about are not empties, they are loads. We are not talking about collapsing a car (reducing internal pressure) we are talking about bursting a car (increasing internal pressure).
Here a trick you should try, get two cans of soda. Take one and drink the soda. Squeeze the empty can in your hand. Does it crush? Now take the full can of soda. Squeeze that in your hand. Does it crush? Thats the difference between a loaded and empty container.
Euclid In a mid-train derailment, as the first cars accordion, they continue to be pushed along sideways by the cars coming ahead on the rails behind them. As the accordion continues, it builds a heap that becomes increasingly more resistant to the forward shove of the oncoming cars behind them. If the heap builds enough resistance, and if there are still say 10-40 cars behind it on the rails, their rolling kinetic energy will apply enough force to crush the first car contacted in the heap. The crushing will burst the car.
In a mid-train derailment, as the first cars accordion, they continue to be pushed along sideways by the cars coming ahead on the rails behind them. As the accordion continues, it builds a heap that becomes increasingly more resistant to the forward shove of the oncoming cars behind them. If the heap builds enough resistance, and if there are still say 10-40 cars behind it on the rails, their rolling kinetic energy will apply enough force to crush the first car contacted in the heap. The crushing will burst the car.
You keep saying this. Please provide one documented (NTSB or FRA report) example where the force of derailment caused a car to burst due to pressure from other cars against it. Puncture, yes. Heated and burst, yes. Pile of loaded cars and burst, no.
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