7j43k Backshop Some people need to remember that this is a hobby forum and that is why we are here. Too many think that this is their professional engineering forum and are driving people away because of it. So it's OK with you if people make things up and present them as facts? It THAT a "hobby"? Is that what you do in your hobby? Ed
Backshop Some people need to remember that this is a hobby forum and that is why we are here. Too many think that this is their professional engineering forum and are driving people away because of it.
Some people need to remember that this is a hobby forum and that is why we are here. Too many think that this is their professional engineering forum and are driving people away because of it.
So it's OK with you if people make things up and present them as facts?
It THAT a "hobby"?
Is that what you do in your hobby?
Ed
PS--People give "opinions" all the time. There's no law against it. This isn't a court with sworn testimony and expert credentials.
Delete
Lithonia OperatorI don't get it. It says the engineer waited about 15 seconds (after going into emergency) before pinging the EOT. It was a forty-car train, and I would have thought that the entire train would have been at full braking within about five seconds after going into emergency in the cab. Not so?
It does not give any rational for why he did not trigger the EOT but the brake pipe pressure reduction is reflected in the times given. And it is NOT instantanious. While it would have reduced the damage, the accident was under way.
I'm still in agreement with Chuck that this is very similar to the Florida case. Track on a curve on a fill. Heavy previous train. Rails subjecf to temperature strains.
I wonder what if any is indicated by the two rails being bowed apart that are above the three cars on their sides . They have obviously been pulled out of their spikes and are not held to their ties
Euclid Get over it.
Get over it.
Choice A: Admit to making an error (done), admit to being sloppy and vow to run a much tighter ship (blown off).
Choice B: Get defensive and angry (and not do A).
GOOD choice!
_____________
"A stranger's just a friend you ain't met yet." --- Dave Gardner
7j43k 7j43k I cannot understand why you would mis-attribute these things. It brings into question everything you assert. You do sloppy work. And you should be ashamed of it. Euclid Ed, Yes, you are correct.
7j43k I cannot understand why you would mis-attribute these things. It brings into question everything you assert. You do sloppy work. And you should be ashamed of it.
I cannot understand why you would mis-attribute these things. It brings into question everything you assert.
You do sloppy work. And you should be ashamed of it.
Euclid Ed, Yes, you are correct.
Ed,
Sloppy misattributions designed to lend more authority to speculations.
Thank you for providing the link for your source.
NTSB ("They") were not quoted as saying the "most likely explanation" was heat. THAT was attributed to Russ Quimby, a former NTSB employee.
The ONLY things NTSB (Landsberg) stated was:
"We have experts that are studying the camera footage frame by frame to make sure that we see exactly what the engineer saw--or maybe didn't see,..."
In reference to ties stacked nearby on the side of the tracks: "That will be one of the questions that we look at, maintenance will be a really big concern for us. We don't know, at this point, exactly what happened, whether it was a track issue, whether it was a mechanical issue with the train. So all of these things are open."
The NTSB did not "suggest" a heat problem. There is NO comment about heat in the above quotes. Nor did the article attribute any such thing to the NTSB or one of their employees.
The NTSB at NO TIME said anything about a heat problem in the above linked source. I cannot understand why you would mis-attribute these things. It brings into question everything you assert.
Here is the link:
https://www.usatoday.com/story/news/nation/2021/09/27/amtrak-derailment-montana-under-investigation-three-people-killed/5886070001/
Euclid NTSB says they have not ruled out any cause, including human error. But they have said little about what causes would be possible. Only two causes have been speculated by them. The one that NTSB suggested in the most detail is a track buckle caused by heat. They said that is the "most likely explanation." They said this derailment has all the “earmarks” of that cause. They also described those earmarks and how they fit this derailment.
NTSB says they have not ruled out any cause, including human error. But they have said little about what causes would be possible. Only two causes have been speculated by them.
The one that NTSB suggested in the most detail is a track buckle caused by heat. They said that is the "most likely explanation." They said this derailment has all the “earmarks” of that cause. They also described those earmarks and how they fit this derailment.
Could you please supply a link to those statements?
The following post has been edited for clarification 10/3/21:
NTSB says they have not ruled out any cause, including human error. Two causes have been speculated by various experts in the field.
The one cause that has suggested in the most detail is a track buckle caused by heat. It has been characterized as being the "most likely explanation." It was said that this derailment has all the “earmarks” of having been caused by track buckle caused by heat. The experts also described those earmarks and how they fit the details of this derailment.
I put a straightedge underneath the rails, and found that one spot. If y'all think it's not there, or is inconsequential, I can live with that.
SD70Dude Track is an industrial thoroughfare, not a Japanese rock garden.......
Track is an industrial thoroughfare, not a Japanese rock garden.......
It's not even that, when there's a train on the ground.
7j43k SD70Dude A slight dip in the rails underneath anything heavy is normal. I'm sure. How come it's only under one of the wheels?
SD70Dude A slight dip in the rails underneath anything heavy is normal.
A slight dip in the rails underneath anything heavy is normal.
I'm sure. How come it's only under one of the wheels?
Looks pretty even to me. The track in the photos looks as good or better than our mainline.
You may be surprised to learn that ballast is not finely placed, tamped and groomed on a daily basis, and small imperfections are ok.
Greetings from Alberta
-an Articulate Malcontent
diningcar My old eyes cannot detect this dip, Perhaps you are correct and the NTSB will elabor ate.
My old eyes cannot detect this dip, Perhaps you are correct and the NTSB will elabor ate.
I feel better now I could not see it as well.
The effects of a telephoto lens often make this look worse in photos than it actually is.
Regardless of the cause of this derailment, the equipment's behaviour and number of injuries and fatalities is very similar to this VIA derailment from 1997.
https://www.bst-tsb.gc.ca/eng/rapports-reports/rail/1997/r97h0009/r97h0009.html
Here's an interesting photo showing the siding. I do agree it needs work:
I also detected a dip in the rail underneath the second wheel on the lead unit.
Here's another:
It's a CTC siding, by the way.
Sun kinks?
Fred M Cain Ed, I agree with your synopsis and coverage of the Australian sun kink...
I agree with your synopsis and coverage of the Australian sun kink...
I tried finding an accident report or at least more data, and didn't come up with much (except that bit about the containers being overweight).
I don't see the event as "sun kink". I see it as a track maintenance failure with likely excess stress on the track, by speed and/or weight.
Note that the trailing flats appeared to stay on the track, and wiggled on through.
Silly NTSB investigators. Trains.com detectives solved this one in 48 hours!
The opinions expressed here represent my own and not those of my employer, any other railroad, company, or person.
dpeltier If you were to take this to the extreme - say, if you welded the base of the rail to a plate cast into a concrete tie - then the track structure would act more like a rigid frame and less like two separate rails, and then you would get vertical buckling before you got horizontal buckling. Which is to say, you would never get either kind of buckling. What you would get is a whole lot of cracked concrete ties - you need to isolate the concrete from the rails to prevent the concrete from breaking under the impact loads of a train going over. Dan
If you were to take this to the extreme - say, if you welded the base of the rail to a plate cast into a concrete tie - then the track structure would act more like a rigid frame and less like two separate rails, and then you would get vertical buckling before you got horizontal buckling. Which is to say, you would never get either kind of buckling. What you would get is a whole lot of cracked concrete ties - you need to isolate the concrete from the rails to prevent the concrete from breaking under the impact loads of a train going over.
Dan
I suspect sucessful railroad track is finely balanced between rigidity and flexibility, similar to a wood-frame house in an earthquake zone.
(A structural engineer suggested NOT making a certain wall in this house rigid, for that reason.)
I speculate that if they had any idea why the train derailed, we would be hearing about it. The full report will probably be available in two years, but it is not unusual to have some idea of cause almost immediately. And there will be a preliminary report in a few weeks. Often the cause is self-evident when the accident occurs. Or it is at least partly so, as in the case of a train upsetting from overspeed through a curve, but not knowing the reason for the overspeed.
In this case, however, the investigators seem to be stumped. If a car truck had collapsed or broke an axle, they would find that right away. They also have their clues and witness marks to tell them the story, and yet they are drawing a blank. How hard can it be? The train was running at high speed and all at once, it went on the ground for no known reason.
A sun kink has been considered, and its effect is visually obvious. But, there is the question of whether the damage caused by a sun kink would be evident if the sun kink caused a derailment.
This is because like sun kinks, derailments often tear up track, plow up the ballast, and bend rails in large bows. If a sun kink caused a derailment, the derailment damage would be added to the sun kink damage, and both damage results would look similar. Or more specifically, the obvious damage inflicted by a sun kink would likely blend into the damage caused by the derailment.
In all the news coverage, I have yet to see a meaningful photograph that sheds light on the derailment action.
Yet, the evidence available is consistent with a the effect of a sun kink, while there is no other cause that I can think of that the available evidence points to.
Tasmania is a separate island and is also one of six states in the Commonwealth of Australia.
I agree with your synopsis and coverage of the Australian sun kink although I think it was actually in Tasmania. I think that Tasmania is actually a separate country from Australia although I'm not sure. Perhaps it's just a province but it's on an island separated from the mainland.
Anyhow, I read somewhere that trackwork had recently been done on that curve and the track hadn't completely "settled" yet. Prbly they should've kept a 10 MPH speed restriction on it but that's water over the dam.
In any event, I believe that particular line was later closed and today is out of service although the last I knew, no moves had been made to dismantle the line. There was a group fighting to get it coverted into either a commuter rail or light rail transit line but their efforts have as yet not succeeded.
Overmod Before this goes on too much further, consider the force restraining 'buckling' in the vertical plane, restricted by rail weight and fastening integrity to tie weight; force restraining movement in the longitudinal direction (controlled as noted by rail anchors and fastening including Pandrol clips when present); and lateral motion (tie friction; ballast end shoulders, etc.)
Before this goes on too much further, consider the force restraining 'buckling' in the vertical plane, restricted by rail weight and fastening integrity to tie weight; force restraining movement in the longitudinal direction (controlled as noted by rail anchors and fastening including Pandrol clips when present); and lateral motion (tie friction; ballast end shoulders, etc.)
Generally, forces restraining rail in the vertical direction are only relevant if the rail is going to buckle vertically (up-and-down), not laterally (side-to-side). I don't believe I've ever heard of this happening. The cross-section of a 136# rail is such that the resistance to up-and-down buckling for a single rail is 7-8 times greater than it's resistance to side-to-side buckling. That overcomes any of the other factors having to do with lateral or vertical restraint.
Just for the sake of being thorough (maybe event pedantic), I would point out that there is one other factor that contributes to resistance to track buckling, which is the rotational stiffness of the rail fasteners. In a track buckle, the ties normally displace laterally but don't skew very much, while the rail obviously winds up with some sharp curves (hence the term "sun kink"). That means that, in the horizontal plane, the rail has to rotate relative to the tie. The fasteners may or may not resist this rotation. As Dr. Arnold Kerr put it in _Fundamentals of Railway Track Engineering_: neglecting the rotational resistance of the fasteners "may be justified for tracks with cut-spike fasteners that have been loosened by extensive traffic. It is definitely not the case for tracks with... [elastic fasteners]."
BaltACD
C'mon, SPECULATE! You know you want to.
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