Wizlish You're both missing the key point here -- interestingly, although the report goes into some discussion of it, it's pretty evident the reporter doesn't really understand what's involved, and goes into the detail that in part is confusing Euclid (some of which appears to me to have some political aspects, perhaps talking up Administration policies and actions that turn out to have little if anything to do either with the proximate cause of the derailment or any practical measures to prevent a repetition, but I digress slightly)*.
You're both missing the key point here -- interestingly, although the report goes into some discussion of it, it's pretty evident the reporter doesn't really understand what's involved, and goes into the detail that in part is confusing Euclid (some of which appears to me to have some political aspects, perhaps talking up Administration policies and actions that turn out to have little if anything to do either with the proximate cause of the derailment or any practical measures to prevent a repetition, but I digress slightly)*.
This was a REVERSE DETAIL FRACTURE, originating on the underside of the railhead and with little, if any likelihood of being caused by any aspect of properly-defined rolling contact fatigue. There is specific mention of how difficult detection of this kind of defect is (relative to things like gauge-corner cracking, shelling/flaking, and other aspects that can be scanned or monitored easily by devices and techniques for the actual 'rolling contact' stressed areas. There is a mention -- only as a reference to something I haven't found yet -- that a "20% defect" turned up in the ultrasound records, but this seems to have transmogrified into only 5% in some later parts of the discussion (one being the detail about 25-mph train speed not constituting excessive for a defect of the claimed magnitude). The report also mentions something about RDF tending to cause a more likely catastrophic progression to breakage, although I saw no source reference -- I'm not really concerned because buslist and perhaps others can easily provide the references or summarize them for us.
What I am concerned about here is that the discussion about 'harmonic loading' or special stresses set up, or supposedly set up, by unit oil train consists will be re-opened with the excuse that such factors mitigate some 'greater likelihood of RDF' (I am not sure what physical argument would be used, and I'm not saying there can't be one, just that it is MUCH less likely than the stated probable cause, a fabrication or handling defect in the lower 'corner' of the railhead that propagated and then proceeded quickly to failure).
The great red flag here is that it opens up a whole new can of worms to people who are concerned about track integrity, particularly insofar as there appears to be no effective testing for RDF defects or crack progression other than interpretation of data whose methodology, processing, and interpretation is largely skewed in favor of RCC analysis. God help us if Schanoes' 'Schumenthal' gets hold of this as a place to enforce new regulations, or FRA decides more oversight procedures to detect RDF should be mandated as emergency orders or whatever. On the other hand... yes, I think this MIGHT need to be more carefully detected and tracked.
*And before any of the usual suspects start whining about 'experts' having worded everything in this report, consider the last part, which says
EuclidIf the type and size of rail defect was known to be not in danger of breaking, why did it break?
That's not what the report said, what the report said was that those types of defects were not considered serious enough to fail. That means in most cases they don't progress to failure, this one did. There doesn't appear to be any obvious reason documented why it failed. The anwer probably has to do with a combination of the specific metalurgy of the rail at that point, combined with the specific stresses on the rail. Replicating that specific set of circumstances would be very difficult.
Bottom line is that the train being an oil train had nothing specific to do with the cause of the derailment. It was a broken rail.
Dave H. Painted side goes up. My website : wnbranch.com
The final report on the cause of the Lynchburg, VA oil train wreck has been released.
http://www.roanoke.com/news/virginia/ntsb-says-broken-rail-likely-caused-lynchburg-train-derailment/article_8aba3f76-cb8d-543f-8799-3f6e5e4b48cf.html
NTSB Report:
http://www.ntsb.gov/investigations/AccidentReports/Reports/RAB1601.pdf
In the summer of 1973, I worked on a N&W section gang on the ex Wabash in Fort Wayne. I got to work one morning and the foreman and assistant were not there. Nobody knew where they were. They showed up out an hour later and advised there was a derailment west of town. As we approached a crossing near the derailment, the gates went down and a train went by at max track speed.
During the night, a wheel had derailed and tore up 4 miles of track before re-railing on an old farm crossing. The train speeding by had not received the slow order yet. They speculated it was the rear wheel of an auto rack car.
The track was slightly out of line in a few spots and we spent the next week replacing damaged bolts, spikes and creepers.
I do not remember all the details, but when I was going from Memphis to Chattanooga in 1964 on the Southern's day train, I noticed, as I was standing at the rear, that many ties on the stretch between Stevenson and Wauhatchee had been cut into in the middle. The flagman told me that a car had been derailed and was dragged along for some distance, cutting the ties.
Johnny
Larry, thanks for the reminder- I read Mr. Kiesels's description at least three times, knew that the last E was for Explosion, and forgot to add that to my post.
I was being a bit facetious with my last sentence- obviously this is a very complex subject with many variables and I didn't want to imply that those valves were the only one. I do remember seeing pix at Lac Megantic of rail punctures in some tank car heads. IIRC, that was one of the few derailments that happened on stick rail.
I did want to say, at the risk of obliterating the last bones of this poor horsie, a major contributor to these incidents may be something as simple as a valve handle that did not meet it's specificiations to break off when it should have.....
There is the probablity that some of the other derailments which 'appear' to have broken rails as part of the cause, may have had breaching from that break, or other breaks that were not visible in the available pix posted to the 'net. I think the Galena incident on BNSF started at a switch at the south end of the yard, but it hasn't been determined yet if trackwork was the main cause for that derailment, afaik.
I haven't read the Lynchburg reports, but will download and pore over them with great interest.
dehusman Now do you understand why when there was all the clamor for the exotic brake systems I was advocating for better rail/track defect detection?
Now do you understand why when there was all the clamor for the exotic brake systems I was advocating for better rail/track defect detection?
I think you need both. Even though those two wrecks were caused by rail failure, my exotic brake system may have prevented each wreck from burning.
RDG467Fix the valve handle, save the BLEVE.
BLEVE - "Boiling Liquid Expanding Vapor Explosion"
BLEVEs occur when two things happen:
1. Something heats up the container, and thus the product inside that container.
2. Something causes the container to fail. Usually the failure is directly related to the fire impingment. Firefighters are trained to get copious amounts of water on said point, if possible.
Your description is fairly accurate.
While the valve may well be one factor in providing the fuel for a fire, there are many others, including structural failure of the container as a result of the incident. This is the reason for head shields and the thicker metal called for in the new standards.
Mr Kiesel gets one important thing backwards - BLEVE's are a result of the incident, not the other way around. Statements like his are the cause of illogical panic - "rolling bombs."
Keep the cars on the rails and the problem will be negligible. Every Bakken incident so far has initially been due to failures wholly unrelated to the product being carried.
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...
WilliamKiesel Prevention must be zero tolerance, absolute; given the nature of Bakken crude oil.Bakken crude oil is a stratified multi constituent liquid. Its weight is such that something like 28,000 gallons are the weight limit for a 30,000 gallon tank car. Visualize the 2000 gallons as about 36 drums of 55 gallon capacity. That's quite a bit of empty space inside a tank car. It is about 269 cubic feet. What is the factor of cargo sloshing in the tank cars? What are the fluid dynamics for a stratified liquid such as Bakken crude? How does the distributed inertia and viscosity of Bakken crude contribute to unstable vehicle dynamics and rail/ wheel interaction? Might skin friction result in the tank due to sloshing creating localized heating, stress and failure? Are boiling liquid expanding vapor events (BLEVE) causing the derailments?Are the braking dynamics of ordinary air brakes contributing to slosh and a series of events leading to failure? Is there an optimal speed of operation for Bakken crude? Is there a maximum number of tank cars not to be exceeded? Is the draft gear and energy absorption of the tank cars adequate for handling Bakken crude.These are the questions must be examined. The inherent problem with railroad tank cars is that they are stupid. That is, there are no sensors on the tank cars to identify what the cargo is doing and how it affects vehicle dynamics. Knowing what is going on n the tank is first and foremost needed. FRA PHMSA announcement simplly dela with stupid vehicles, rail tank cars. Given the potential and reality for catastrophe smart railroad cars need to part of the problem solving.
Prevention must be zero tolerance, absolute; given the nature of Bakken crude oil.Bakken crude oil is a stratified multi constituent liquid. Its weight is such that something like 28,000 gallons are the weight limit for a 30,000 gallon tank car. Visualize the 2000 gallons as about 36 drums of 55 gallon capacity. That's quite a bit of empty space inside a tank car. It is about 269 cubic feet. What is the factor of cargo sloshing in the tank cars? What are the fluid dynamics for a stratified liquid such as Bakken crude? How does the distributed inertia and viscosity of Bakken crude contribute to unstable vehicle dynamics and rail/ wheel interaction? Might skin friction result in the tank due to sloshing creating localized heating, stress and failure? Are boiling liquid expanding vapor events (BLEVE) causing the derailments?Are the braking dynamics of ordinary air brakes contributing to slosh and a series of events leading to failure? Is there an optimal speed of operation for Bakken crude? Is there a maximum number of tank cars not to be exceeded? Is the draft gear and energy absorption of the tank cars adequate for handling Bakken crude.These are the questions must be examined.
The inherent problem with railroad tank cars is that they are stupid. That is, there are no sensors on the tank cars to identify what the cargo is doing and how it affects vehicle dynamics. Knowing what is going on n the tank is first and foremost needed.
FRA PHMSA announcement simplly dela with stupid vehicles, rail tank cars. Given the potential and reality for catastrophe smart railroad cars need to part of the problem solving.
16 pages of discussion until someone said the magic 'word'- BLEVE. However, as I understand the situation, BLEVE's occur after the derailments, and the initial cause may be as simple as valve handles which are TOO Strong.
Here's my logic: The unloading valves on the bottom of the cars have handles roughly 3 feet long. These handles are supposed to break away in derailments where the bottom of the car contacts the R-o-W. That's an AAR/FRA requirement. If it doesn't, it either opens the valve or tears it off the car, causing a breach.
In a roll over, that valve is much less likely to be the issue. Then you have to look at top fitting protection. If insufficient, the loading valve and/or relief valve can be torn from the car, again causing a breach.
Once this happens to *about* five cars and enough oil leaks out, the next issue becomes a 'pool fire'. The oil vapor (and other vapor components) are burning, but not explosively, since the oil isn't pressurized. If the pool fire is burning under a non-breached car for a long enough period, the BLEVE scenario begins.
As the oil heats up and expands in the tank car, the internal pressure rises, opening the relief valve at it's preset pressure. This sprays pressurized, atomized oil, which can be ignited into a 'blow-torch' until the pressure relieves and the relief valve shuts.
Now, there's less liquid in the tank to absorb the heat of the pool fire. So, the tank skin begins to heat up more rapidly, along with the remaining oil in the tank. It's possible that the relief valve may open again, repeating the cycle.
Eventually, the oil level in the tank gets low enough to allow the steel above the oil level to thermally fatigue (as long as the pool fire is still heating the tank). Once that ruptures, the release of pressure allows the rest of the oil to flash over to vapor and the expanding mixture ignites, making the large explosions seen in post-derailment videos.
Fix the valve handle, save the BLEVE.
(My apologies if similar info comes up later in the thread, I haven't gotten to the end yet.)
oltmannd Broken rail: http://news.yahoo.com/officials-reveal-cause-west-virginia-train-derailment-125703936.html
Broken rail: http://news.yahoo.com/officials-reveal-cause-west-virginia-train-derailment-125703936.html
As I recall from FRA stats, rail and roadbed problems are the leading cause of derailments.
C&NW, CA&E, MILW, CGW and IC fan
-Don (Random stuff, mostly about trains - what else? http://blerfblog.blogspot.com/)
Due to close clearances of the Great Northern tunnel under the city center and abundance of crossings nearby on the waterfront, trains do not travel fast enough to have a multiple car fire/explosion like we have seen elsewhere. They never have. There is no risk that requires operational changes.
It isn't about the trains, it is about the oil, which is a four-letter word in the PNW. (Except, of course, when one is burning it themselves.)
The stadiums are right next to King Street Station, and Sounder runs game day specials. Safeco Field's roof extends out over the tracks. LPG trains and other even more explosive chemicals have been running through there long before the stadium was built. If exploding trains were a huge danger, why did the designers still build over the tracks?
But, isn't the stadium close to public transportation, which should reduce street traffic to/from the stadium? By the way, what is the source of the fuels for public transportation?
Perhaps the powers that be should have told them not to build the stadium there.
Norm
BaltACD Remember this about the media. They have nothing to sell but fear! And they do a good job of it.
Remember this about the media.
They have nothing to sell but fear! And they do a good job of it.
Never too old to have a happy childhood!
1. This is right next to King Street Station and trains run through its approach switches. Trains NEVER move more than 25 MPH through there, and at that speed they wouldn't even rupture, even if DOT-111s.
2. Great Northern tunnel underneath the streets and skyscrapers of downtown Seattle is a far bigger risk.
3. Interbay derailment was a split switch in a yard at 5 MPH. No risk of spill, fire, explosion, etc. That fender-bender won't kill you.
4. What is the "Transcontinental Route"? It's Stevens Pass or the Scenic Subdivision. The SP&S is on a transcontinental route, too. Please, go to the effort to get correct information. Iron Triangle exists for good reason; BNSF isn't stopping it.
5. Risk is far larger for TIH gasses.
Really poor article overall. Go 'Hawks!
The Butlerhttp://www.komonews.com/news/local/BNSF-declines-to-stop-running-oil-trains-past-Seahawks-games-330172941.html
If they're so worried about oil trains why did they build the stadium next to a mainline? They're like the idiots who build at the departure end of a major runway and then complain about noise.
James
Wizlish ... In partial defense of my entirely non-serious location for the manifold: if the oil is kept at some reasonable temperature to make it ready to flow upon arrival, this will automatically keep water mixture in tankage 'within' the oil volume at proper temperature also, while minimizing the number of penetrations needed in the actual tank shell and the insulation and heating arrangements needed externally. Someone like Midland Mike is much more conversant than I am with the specific methods used to make the oil fluid, but not excessively 'hot', for best terminal handling.
...
In partial defense of my entirely non-serious location for the manifold: if the oil is kept at some reasonable temperature to make it ready to flow upon arrival, this will automatically keep water mixture in tankage 'within' the oil volume at proper temperature also, while minimizing the number of penetrations needed in the actual tank shell and the insulation and heating arrangements needed externally. Someone like Midland Mike is much more conversant than I am with the specific methods used to make the oil fluid, but not excessively 'hot', for best terminal handling.
My experience is in the oil fields of Michigan, so I am somewhat familiar with cold weather oil operations. The crude oil comes from the well already somewhat warm (relative to winter temperatures) and then goes immediately to a production facility, which usually involves a heater treater to separate the oil/water phase of the production fluid. The downhole pump can somewhat emulsify the oil/water mixture, so heat is what helps to separate them out. It was brought up earlier, as to what an oil train fire might do to a tank car whose contents were emulsified by the safety process under discussion. I don't know how the chemicals would affect things, but otherwise the tendency would be for the demulsifying and offgassing.
The crude oil is stored at the well production facility only until there is a truckload to haul out. The oil does not have much chance to cool. I don't believe that after a few hours in the truck, that there would be a problem unloading the crude. Michigan light crude has about the same viscosity as Bakken Crude. You would have to ask someone at a refinery if they have problems unloading tank cars of cold Bakken, but I doubt it. Heavy crudes are often carried in tank cars with steam coils, for loading/unloading.
EuclidI had no intention of choosing the “right thing” to look at. So I find it odd that you would take issue with that point. My point is to look at one thing out of many.
Aw, it was just a rhetorical device in English, to indicate you were looking at the surfactant when the water is far, far more important to the design.
In any case, his original design clearly shows where he intends the external tankage to go, and how it would be arranged.
I only tossed the invention by Iman Chalibi on the table in case you or others wanted to comment about it. I have no stake in it. I am not defending it. Like you and others, I see lots of practical problems with the idea. I am just adding my thoughts about the storage tank to the list of comments because nobody has mentioned it.
But if you are going to add thoughts, at least add complete ones, which aren't already covered in the source material better than you're commenting on them.
When I suggested a saddle tank or saddle bag, that's just a general description of an external tank. Specifically, the best location would be on either side of the lower half of the oil tank
Note that's not where the inventor put them. I think he is depending on gravity as part of his dispersal system, but I can't be sure because too many of the details are left out of his presentation to tell. As noted, you would not want to put the water there. I do agree that if you want external tankage for the water+surfactant, the location you describe is a very reasonable place to put it.
... why stuff the extra equipment of this invention into the payload tank when it can be hung on the outside where it will be easier to inspect and maintain?
For the reasons I gave, to start with.
It is perfectly possible, of course, to keep all the emulsification stuff external to the tank volume, and do it in the manner you propose. That is probably the likeliest way a Canadian company would construct it. You will need insulation and tank heating, including tracers for the lines going to the nozzles into the tank. You might want to speculate on how many nozzles there would need to be, where they would be located and aimed, what their spray pattern would be, etc.
What would you use as the driving agent for a system where the water is held in external tanks in this location? How would you communicate the driving agent to the water -- put it under hydrostatic pressure, pump it, entrain it? How quickly would you need to accomplish the emulsion mixing, and would you prioritize any parts of the internal volume (e.g., ends or bottom periphery of the tank first)?
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