tdmidgetSince there is no such thing as No 7 or 8 oil your post is just BS. This whole "sloshing" is a joke.
You are misreading what he wrote. The "#" sign is a symbol for "pound".
What he said was:
If oils weighs 7 to 8 pounds per gallon, tank cars would have to be about 14% oversized(?) in order to carry 7 pound oil and 8 pound oil. If oil weight varies, is every tank car weighed after it's filled?
Dave H. Painted side goes up. My website : wnbranch.com
Not only manifest trains, but that statement leads me to believe their stat includes switching derailments too. A single wheelset off the rails in a yard is a far cry from multiple cars off the rails. And is likely not caused by track defect as much as running through an open switch or too hard of a coupling.
Take those out of the equation and I'd expect you track defects will account for a much higher percentage of derailments. Again I have one simple question, how does that 59% compare to other unit trains?
Midget, #7 isn't the same as 7#. One would be a type of oil(non existent as pointed out) the other is the weight of a gallon of oil.
Modeling the Cleveland and Pittsburgh during the PennCentral era starting on the Cleveland lakefront and ending in Mingo junction
Murphy Siding If oils weighs 7 to 8 pounds per gallon, tank cars would have to be about 14% oversized(?) in order to carry 7# oil and 8# oil. If oil weight varies, is every tank car weighed after it's filled? Side note: My father was an over the road trucker. He hauled a lot of cement out of the S.D. Cement plant in the 70's/80's. They had a terrible loading process that took many hours. They would load a truck to what *looked* like the right amount, and then weigh it. Then they ineveitablly had to blow some back out because it was overweight. Then weigh it. Then add more. Then weigh it. Then blow some off etc... When the truckers asked why loading train cars with cement didn't require the same process, they were told that they just knew how much to put in each rail, and besides, "everyone knows the railroads are way overbuilt anyway". This was in the era where the Milwaukee Road and the CNW were both falling apart in S.D.
If oils weighs 7 to 8 pounds per gallon, tank cars would have to be about 14% oversized(?) in order to carry 7# oil and 8# oil. If oil weight varies, is every tank car weighed after it's filled? Side note: My father was an over the road trucker. He hauled a lot of cement out of the S.D. Cement plant in the 70's/80's. They had a terrible loading process that took many hours. They would load a truck to what *looked* like the right amount, and then weigh it. Then they ineveitablly had to blow some back out because it was overweight. Then weigh it. Then add more. Then weigh it. Then blow some off etc... When the truckers asked why loading train cars with cement didn't require the same process, they were told that they just knew how much to put in each rail, and besides, "everyone knows the railroads are way overbuilt anyway". This was in the era where the Milwaukee Road and the CNW were both falling apart in S.D.
Since there is no such thing as No 7 or 8 oil your post is just BS. This whole "sloshing" is a joke.
When it comes to writing reports, especially reports by governmental agencies with an agenda, 'facts' get cherry picked to push the agenda.
Figures lie, liars figure!
Never too old to have a happy childhood!
I think part of the problem is the people who don't know much about derailments think 59% track caused is a big problem and some of the people on this list who have prototype exerience don't think it is an unexpected percentage.
Also I would question the way things were calculated after reading the TSB report that everybody seems to be quoting. They seem to be using 3 accidents as examples that support their argument, but only two of the trains were "oil trains". The third was a mixed train with empty equipment that had a couple empty oil cars involved in the derailment. Including that train in the discussion doesn't support the argument that unit oil trains are a problem. How many of the other "oil trains" that had track related derailments weren't really "oil trains"? how many were manifest trains that just happened to have a oil car or two in them and had a derailment?
ruderunner: You make untenable claims. "Sloppy journalism" when I clearly showed you that the LA Times article accurately.exactly quoted the TSB. Now you say "The 59% more likely to derail due to track defects line is a bit of a red herring. Sure there are far more derailments caused by other than track problems, man happen in single car low speed switching. "
The Times says "A review of 31 crashes that have occurred on oil trains since 2013 puts track failure at the heart of the growing safety problem. Track problems were blamed on 59% of the crashes, more than double the overall rate for freight train accidents, according to a Times analysis of accident reports."
Sure, it would be good to compare the rate of rack-caused crashes with non-switching freights and also with other unit trains. But having a rate for oil unit trains (18 of 31 crashes) that much larger is not just a staistical fluke nor is it sloppy journalism. It certainly is of a magnitude that it raises a red flag and is worthy of more analysis. Why don't you do so?
C&NW, CA&E, MILW, CGW and IC fan
schlimm ruderunner The quotes for the story are IMHO ambiguous and tend to support the headline of dangerous oil trains. But when actually read, they say nothing at all. At least nothing concrete, just a flashy headline. "Oil trains are damaging track!" Or "Unit trains wear track out faster.". Whoicvh is the attention grabber headline? Considering that oil train wrecks are the hot ticket to headlines, guess which gets printed? Also schlimm, so what is your beef with wizlist wanting to apply the scientific method? You seem to want to take the questionable quotes from nthe story as gospel, did you write the story? Did you interview the "experts" cited in the story? Are you certain hat the writer didt just ask their neighbor who's great grandfather worked for some railroad in Pennsylvania? Wouldn't that neighbor be asn expert to the writer who has likely never seen w freight train? Without seeing the data actually referenced (if any was) for this story, or who the quotes are actually attributed to, we are all just guessing and pointing fingers. Had you actually read my earlier post you could have judged for yourself on the basis of facts instead of your wild imagination. My post shows clearly that the writer of the article directly (and accurately) quoted the TSB report. They are identical. Acquiring the data from the TSB would be nice, but I doubt if they would send it to anyone besides the credentialed experts at FRA and/or NTSB, and probaably did so earlier. I am willing to accept the investigators' report because there is no reason to doubt its veracity, IMO. The investigators are more expert on the topic than anyone on this forum, AFAIK. But since many of the posters such as yourself seem to have a pre-existing agenda of attacking anything that questions the safety of unit oil trains, it's not surprising that what is clear and factual gets questioned or labeled as sloppy, ad nauseam.
ruderunner The quotes for the story are IMHO ambiguous and tend to support the headline of dangerous oil trains. But when actually read, they say nothing at all. At least nothing concrete, just a flashy headline. "Oil trains are damaging track!" Or "Unit trains wear track out faster.". Whoicvh is the attention grabber headline? Considering that oil train wrecks are the hot ticket to headlines, guess which gets printed? Also schlimm, so what is your beef with wizlist wanting to apply the scientific method? You seem to want to take the questionable quotes from nthe story as gospel, did you write the story? Did you interview the "experts" cited in the story? Are you certain hat the writer didt just ask their neighbor who's great grandfather worked for some railroad in Pennsylvania? Wouldn't that neighbor be asn expert to the writer who has likely never seen w freight train? Without seeing the data actually referenced (if any was) for this story, or who the quotes are actually attributed to, we are all just guessing and pointing fingers.
Had you actually read my earlier post you could have judged for yourself on the basis of facts instead of your wild imagination. My post shows clearly that the writer of the article directly (and accurately) quoted the TSB report. They are identical. Acquiring the data from the TSB would be nice, but I doubt if they would send it to anyone besides the credentialed experts at FRA and/or NTSB, and probaably did so earlier. I am willing to accept the investigators' report because there is no reason to doubt its veracity, IMO. The investigators are more expert on the topic than anyone on this forum, AFAIK. But since many of the posters such as yourself seem to have a pre-existing agenda of attacking anything that questions the safety of unit oil trains, it's not surprising that what is clear and factual gets questioned or labeled as sloppy, ad nauseam.
So the proper question to ask and answer is "are oil trains more likely to derail than other unit trains? And why?"
As an engineer who has ran oil trains, I have never once noticed any sloshing on the loaded trains or cars.
Partially loaded tanks, of course, but that's usually only when you're switching them at a customer, rarely on the mainline.
10000 feet and no dynamics? Today is going to be a good day ...
It may be just me, but it seems like it's been quite a while since the last incident. Warmer weather?
_____________
"A stranger's just a friend you ain't met yet." --- Dave Gardner
EuclidHowever, I would not rule out the possibility that both oil sloshing and a relatively higher center of gravity are producing higher dynamic loading on track that is unique to oil trains.
How do you reconcile your suppositions when, in the TSB report quoted above, one of the three examples of incidents cited in the report involved empty cars not in a unit oil train (low dynamic loading, no sloshing, no unit train).
What the incidents cited in the TSB report have in common is they occurred in the winter (low temps are a known factor in broken rails) or they involved joints or field welds (both are known weak spots in tracks).
Two things which I haven't seen mentioned in this thread:
1) The cars may not be a perfect cylinder. Many tank cars with bottom outlets are actually two cylinders welded together at a slight angle (2-3 degrees, perhaps), so that the lading flows towards the bottom outlet valve at the middle of the car. The middle of the tank is below each end, so that would tend to mitigate any sloshing effects, imho.
2) The trucks have these new-fangled contraptions called "coil springs", which would have to be totally compressed before any 'dynamic load impact' (DLI) would transfer to the track structure. There *may* be a temporary increase in dynamic axle loading on the front truck upon deceleration or slack run-in, but it would only be fraction of the numbers DEH presented earlier. DLI is more a function of flat-spotted wheels, as also mentioned earlier in the thread.
Note that my question was about tank cars versus various coal carrying cars. I'd suspect loaded coal cars would have a bit lower center of gravity than a loaded tank car.
FWIW, covered hopper cars had a bad reputation with respect to track, mainly because the 40' wheel base almost matched the 39' rail lengths. The low spots associated with the staggered joints induced severe rocking above 10 MPH.
As for sloshing, with a nearly full tank, the sloshing forces will be small when compared to momentum effects of the oil acting as a solid body.
erikem ...I wonder if the cg of a tank car might be a bit higher than a gondola or hopper car bearing coal as the coal cars carry some of the load below the tops of the trucks.
...I wonder if the cg of a tank car might be a bit higher than a gondola or hopper car bearing coal as the coal cars carry some of the load below the tops of the trucks.
http://www.tsb.gc.ca/eng/enquetes-investigations/rail/2015/r15h0021/r15h0021.asp
Preliminary indications are that track infrastructure failures may have played a role in each of the Gogama accidents and a 3rd accident that involved a mixed manifest train on the Ruel Subdivision near Minnipuka, Ontario on 5 March 2015. Petroleum crude oil unit trains transporting heavily-loaded tank cars will tend to impart higher than usual forces to the track infrastructure during their operation. These higher forces expose any weaknesses that may be present in the track structure, making the track more susceptible to failure.
Reading the TSB report I quoted a section above.
The above quote and various snippets of it have shown up in multiple posts above and media articles cited. Normally only the last 2 sentences is what gets quoted in the articles and posts, which would cause the casual reader to think that loaded oil trains were involved in all the derailments. But if you read the whole report, of the three trains and derailments discussed that were attributed to track defects, only 2 were loaded oil trains, the 3rd was a mixed freight train and a non-unit shipment of oil was involved and the cars were EMPTY. But they really don't address that and it is totally lost in the media repackaging of the report.
wanswheel http://www.latimes.com/la-bio-ralph-vartabedian-staff.html
http://www.latimes.com/nation/la-na-rail-accidents-20151009-story.html
ruderunner OK so are we perhaps all being duped by a report written by a "journalist" with an agenda? Maybe one who doesn't know the difference between an oil train and a unit train? Maybe they believe those terms are interchangeable?
OK so are we perhaps all being duped by a report written by a "journalist" with an agenda? Maybe one who doesn't know the difference between an oil train and a unit train? Maybe they believe those terms are interchangeable?
http://www.latimes.com/la-bio-ralph-vartabedian-staff.html
ruderunnerThe quotes for the story are IMHO ambiguous and tend to support the headline of dangerous oil trains. But when actually read, they say nothing at all. At least nothing concrete, just a flashy headline. "Oil trains are damaging track!" Or "Unit trains wear track out faster.". Whoicvh is the attention grabber headline? Considering that oil train wrecks are the hot ticket to headlines, guess which gets printed? Also schlimm, so what is your beef with wizlist wanting to apply the scientific method? You seem to want to take the questionable quotes from nthe story as gospel, did you write the story? Did you interview the "experts" cited in the story? Are you certain hat the writer didt just ask their neighbor who's great grandfather worked for some railroad in Pennsylvania? Wouldn't that neighbor be asn expert to the writer who has likely never seen w freight train? Without seeing the data actually referenced (if any was) for this story, or who the quotes are actually attributed to, we are all just guessing and pointing fingers.
The quotes for the story are IMHO ambiguous and tend to support the headline of dangerous oil trains. But when actually read, they say nothing at all. At least nothing concrete, just a flashy headline.
"Oil trains are damaging track!" Or "Unit trains wear track out faster.". Whoicvh is the attention grabber headline? Considering that oil train wrecks are the hot ticket to headlines, guess which gets printed?
Also schlimm, so what is your beef with wizlist wanting to apply the scientific method? You seem to want to take the questionable quotes from nthe story as gospel, did you write the story? Did you interview the "experts" cited in the story? Are you certain hat the writer didt just ask their neighbor who's great grandfather worked for some railroad in Pennsylvania? Wouldn't that neighbor be asn expert to the writer who has likely never seen w freight train?
Without seeing the data actually referenced (if any was) for this story, or who the quotes are actually attributed to, we are all just guessing and pointing fingers.
Wizlish,
Looking through the two TSB links, I saw several references to concerns regarding type 111 tank cars, a few references to broken joints and one comment that unit trains carrying oil may cause higher stresses on the track. I also consider the comment about stresses from unit oil trains to be ambiguous, it's not clear to whether the investigator thinks the increased stresses are due to weight as opposed to "sloshing" or perhaps the buffer cars (if any) between the locomotive and the crude oil cars. Having said that, I wonder if the cg of a tank car might be a bit higher than a gondola or hopper car bearing coal as the coal cars carry some of the load below the tops of the trucks.
I also second Paul North's comment about wnting some hard data on comparative forces on the track structure.
- Erik
Wizlish schlimm “Petroleum crude oil unit trains transporting heavily loaded tank cars will tend to impart higher than usual forces to the track infrastructure during their operation,” the safety board said in a report this year. “These higher forces expose any weaknesses that may be present in the track structure, making the track more susceptible to failure.” There is nothing ambiguous about that nor is it about semantics. I suspect you were about to make a point about Euclid saying this, but it got lost. But before I read your actual comment, there is at least one very substantial ambiguity in the statement itself, one which is also related to semantics: what is "higher than usual" supposed to refer to? Other petroleum crude oil trains that have less-heavily-loaded tank cars? Other 'usual' kinds of unit train? The 'usual' sort of train on the line in question? And this is at the heart of what we are supposedly discussing. I am quite certain the TSB folks know what they meant, and will confirm the intended meaning when they are asked. But you cannot tell what the 'reference' force level is from that statement as written. Which was one of the original points.
schlimm “Petroleum crude oil unit trains transporting heavily loaded tank cars will tend to impart higher than usual forces to the track infrastructure during their operation,” the safety board said in a report this year. “These higher forces expose any weaknesses that may be present in the track structure, making the track more susceptible to failure.” There is nothing ambiguous about that nor is it about semantics.
There is nothing ambiguous about that nor is it about semantics.
I suspect you were about to make a point about Euclid saying this, but it got lost.
But before I read your actual comment, there is at least one very substantial ambiguity in the statement itself, one which is also related to semantics: what is "higher than usual" supposed to refer to? Other petroleum crude oil trains that have less-heavily-loaded tank cars? Other 'usual' kinds of unit train? The 'usual' sort of train on the line in question?
And this is at the heart of what we are supposedly discussing.
I am quite certain the TSB folks know what they meant, and will confirm the intended meaning when they are asked. But you cannot tell what the 'reference' force level is from that statement as written. Which was one of the original points.
I never said there was anything ambiguous or having an issue with semantics regarding the TSB statement. The statement is as clear as a bell. I am just not convinced that the person making the statement meant to say what he did.
I would not be at all surprised if he meant that any loaded unit train would find more defects than a mixed manifest train or some other train generally lighter than a loaded unit train. He may have meant that, but just mentioned oil unit trains as an example of loaded unit trains in general simply because an oil unit train was the subject of the wreck he was reporting on.
wanswheel linked the TSB report this morning. I linked the safety letter a few minutes later. Here they are again --
TSB report R15H0021:
Safety letter associated with above report:
http://www.tsb.gc.ca/eng/medias-media/sur-safe/letter/rail/2015/r15h0021/r15h0021-617-04-15.asp
For reference, here is the link to the original L.A. Times story:
http://www.latimes.com/nation/la-na-crude-train-safety-20151007-story.html
Paul_D_North_JrWith such tentative words and phrases being used, as "tend to impart higher than usual forces" and "higher forces expose any weaknesses that may be present in the track structure, making the track more susceptible", this isn't even to the point of having a qualitative description to work from. - Paul North.
Amen.
Wizlishthere is emphatically nothing about oil-caused aggravating factors in the TSB report itself, or in the safety letter that came out of the investigation
Where is the TSB report or safety letter? Link?
Preliminary indications are that track infrastructure failures may have played a role in each of the Gogama accidents and a 3rd accident that involved a mixed manifest train on the Ruel Subdivision near Minnipuka, Ontario on 5 March 2015. Petroleum crude oil unit trains transporting heavily-loaded tank cars will tend to impart higher than usual forces to the track infrastructure during their operation. These higher forces expose any weaknesses that may be present in the track structure, making the track more susceptible to failure. Given the potential damage of a train derailment, particularly when petroleum crude oil unit trains are involved,
Again, pretty clear and the same wording is in theother TSB document as well as the LA Times article. If you still insist there is "nothing about oil-caused aggravating factors in the TSB report itself, or in the safety letter" then you and others who seem to object should read all three again.
Who said the TSB said the cause was sloshing? Posters, including myself have speculated that it might be a factor. And that point was made in the article along with weight and cold temperatures as factors or issues being examined by rail safety experts. The obvious meaning is just what it said, experts on rail safety not limited to the Canadians think those factors may explain the higher incidence of rail defects. "Issues that might be exaccerbating problems" and "causes" are clearly different in meaning.
Of the 31 crashes involving crude or ethanol since 2013, 17 were related to track problems and 12 a mix of other causes. The cause of the two other crashes remains unclear. The count is based on both final or preliminary government and railroad investigations that were collected by The Times under the Freedom of Information Act or in U.S., Canadian and railroad company filings.
About two-thirds of the accidents resulted in spills, fires or explosions, a record that has already prompted regulators to demand stronger tank cars and other safety measures.
Weight, oil sloshing and cold temperatures are among the issues that might be exacerbating the problem, according to rail safety experts.
Investigators at Safety Transportation Board Canada, which is investigating the eight accidents that have occurred in that country, are beginning to suspect that the oil trains are causing unusual track damage.
“Petroleum crude oil unit trains transporting heavily loaded tank cars will tend to impart higher than usual forces to the track infrastructure during their operation,” the safety board said in a report this year. “These higher forces expose any weaknesses that may be present in the track structure, making the track more susceptible to failure.”
Rick Inclima, safety director at the Brotherhood of Maintenance of Way Employees, also said that oil trains could be creating unique stresses on the track. “You can certainly get some rhythmic forces in ... oil trains that you might not see on a mixed freight train with cars of different sizes, weights and commodities,” he said.
I see something else interesting here, that I hadn't realized before.
One of schlimm's posts, back around the 12th, referenced this from the original L.A.Times story:
"Weight, oil sloshing and cold temperatures are among the issues that might be exacerbating the problem, according to rail safety experts."
This was immediately followed -- in the story -- by mention of the Canadian TSB and the quote we have been discussing.
Nowhere is there any indication of who the actual 'rail safety expert(s) who thought oil slosh might be a factor were. That leaves us making the assumption that it must be the TSB people saying that ... but there is emphatically nothing about oil-caused aggravating factors in the TSB report itself, or in the safety letter that came out of the investigation (where it assuredly would have been if the TSB thought it was significant to safety).
So in my opinion we were all fooled by an artifact of journalism into thinking the 'rail safety experts' and the TSB staff under Mr.Fowler were the same -- I think they are not.
This leaves us with quite a different potential question -- what is the Times reporter's source for the claim that slosh is a factor in oil- train derailments? And what are that source's grounds for believing slosh contributes materially to the risk of derailment? (Perhaps naively, I would rule out 'colder temperature' as a factor involving the oil load, as the oil should be more viscous at lower temps and slosh less ... and greater weight is of course what i've been saying all this time, and has nothing obvious to do with the load being oil.)
WizlishAs you well know, one version of argumentum ad hominem (it is also one of the better red-herring techniques) is to disparage the personal merits or qualifications of a person, rather than responding to the substantive merits (or lack of merits) of their opinions. That specifically applies to many of the insulting terms you have used in recent posts, and no attempt at pretending 'character' or 'motive' is 'above reproach' either justifies or excuses that.
Pointing out a person's lack of the necessary qualifications, such as training, education or experience, to judge a point in question is NOT an ad hominem attack, nor is it insulting since it is factual. It is not attacking you for any personal attributes.
Playing word games with a clear statement by the TSB and then calling it semantics is applying a gloss to a specious argument.
What is unclear? The qualifiers "tend" and "may" are typical of studies because of the inexactitude of any measures and thus conclusions. The comparison is with any other trains operating. Do you know for a fact that the only unit trains operating on those Canadian lines were oil trains? It is incumbent on you as someone who repeatedly challenges these TSB statements to support what you are saying with facts. And since you do not accept their statements, why don't you go find the TSB reports for the eight derailments?
greyhoundsI reason that this could be done with a wheel impact load detector.
The only thing about using WILDs is that it may be -- I think probably would be -- unlikely for a detector in a fixed location to be in 'just the right place' to pick up a critical shock level (above fixed load) that might only result from perhaps-momentary coincidence of several harmonics or resonances. That's not to say you shouldn't deploy WILDs to test oil-train consist behavior in general, just that I see a chance of false-negative results making it over into confirmation of a null hypothesis.
I think the suggestion of using one or more instrumented wheelsets (was it buslist who made that suggestion?) would be a better approach -- they might not have to be the expensive, fully-calibrated pieces of jewelry used at Pueblo, just some basic cell-phone-type accelerometer cores and associated circuitry at appropriate places on the wheels and/or axles that won't go out of range at high short-period g. Buffer the output and save a multiple-second 'snippet' around any shock over a certain g range -- this would perfectly mirror any shock going from the train into the track to be detected by a WILD, wouldn't it?
This might even be cheap enough to deploy semi-permanently on any potentially hazardous consist, and develop a correlative 'map' of track force vs. location, time, and other parameters. A little pattern analysis on the datastream might also identify frequency and amplitude of any developing resonance, and at least theoretically allow identification of complex interactions...
... and yeah,just buffer the datastream and dump it to an appropriately-equipped WILD whenever the car passes one...
Paul_D_North_JrI believe it was the English scientist Lord Kelvin (William Thomsen) who said that: "You start to understand a thing when you can describe it qualitatively [i.e., with words], but you really understand it when you can quantify it [i.e., with numbers]."
Yes. I think the concept that oil unit trains impact the rail and support structure more than other trains is a hypothesis. It's time to quit speculating and test the hypothesis.
I reason that this could be done with a wheel impact load detector.
https://www.youtube.com/watch?v=7CJycCggHgw
Although the "WILD" is intended to detect bad wheels it does so by measuring the impact on the rail. Put some "WILDs" along a stretch frequently used by oil trains. Measure the impact of the oil trains vs. the impact of other trains.
Maybe have the trains (oil and otherwise) brake significantly on the test mileage. That would provide some real data to work with.
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