BaltACD Overmod I will tell you the 'speculative' thing I want to know, in deep and procedural technical detail: UP said they were inspecting these 'fasteners' every 18 months, but will now be doing it 'four times a year'. How are they proposing to inspect lag screws driven down into wood ties? Pull them all out? Clamp onto the heads and use ultrasound? Back them off and use a camera to detect signs of rust or corrosion, or induce a magnetic field with dye sprayed on them to catch 'shank' stress raisers? What will they do if they break off a substantial number of them - cut out around them with a 'tube saw' and then drive in a treated plug?And what gets poured down into the hole in the tie when they back one of these screws out? Is any inspection of conditions inside the hole made, in addition to inspecting the screw? What UP said was that their 'Gauge Restraint Test Vehicle' had been inspecting the territory every 18 months and in the future that test vehicle will test the territory quarterly. The test vehicle applies lateral forces to the rails and measures the track structures resistance to turning the rail over - creating a record of forces applied and restistance and movement obtained - these values are then compared to the standards UP (and the other carriers that use similar testing equipment) have developed over the years. If not enough resistance and too much movement is measured, immediate actions are taken as necessary fix the situation. If the situation is measured to be bad enough, the track will be taken out of service until repairs are made.
Overmod I will tell you the 'speculative' thing I want to know, in deep and procedural technical detail: UP said they were inspecting these 'fasteners' every 18 months, but will now be doing it 'four times a year'. How are they proposing to inspect lag screws driven down into wood ties? Pull them all out? Clamp onto the heads and use ultrasound? Back them off and use a camera to detect signs of rust or corrosion, or induce a magnetic field with dye sprayed on them to catch 'shank' stress raisers? What will they do if they break off a substantial number of them - cut out around them with a 'tube saw' and then drive in a treated plug?And what gets poured down into the hole in the tie when they back one of these screws out? Is any inspection of conditions inside the hole made, in addition to inspecting the screw?
I will tell you the 'speculative' thing I want to know, in deep and procedural technical detail:
UP said they were inspecting these 'fasteners' every 18 months, but will now be doing it 'four times a year'.
How are they proposing to inspect lag screws driven down into wood ties? Pull them all out? Clamp onto the heads and use ultrasound? Back them off and use a camera to detect signs of rust or corrosion, or induce a magnetic field with dye sprayed on them to catch 'shank' stress raisers? What will they do if they break off a substantial number of them - cut out around them with a 'tube saw' and then drive in a treated plug?And what gets poured down into the hole in the tie when they back one of these screws out? Is any inspection of conditions inside the hole made, in addition to inspecting the screw?
What UP said was that their 'Gauge Restraint Test Vehicle' had been inspecting the territory every 18 months and in the future that test vehicle will test the territory quarterly.
The test vehicle applies lateral forces to the rails and measures the track structures resistance to turning the rail over - creating a record of forces applied and restistance and movement obtained - these values are then compared to the standards UP (and the other carriers that use similar testing equipment) have developed over the years. If not enough resistance and too much movement is measured, immediate actions are taken as necessary fix the situation. If the situation is measured to be bad enough, the track will be taken out of service until repairs are made.
Actually GRMS measures dynamic gage widening independent of if its due to rail rotation or translation.
Excerpt from CBS News, June. 11
http://www.cbsnews.com/news/railroad-reveals-cause-of-fiery-oregon-oil-train-derailment/
Union Pacific spokesman Justin Jacobs said Saturday that the company filed a report Friday with the Federal Railroad Administration citing one or more broken bolts as the cause of the June 3 derailment.
"We are unaware of any time when this has happened in the past," Jacobs said. "This is an unusual failure."
He said there's no evidence of malevolent activity by anyone to damage the tracks.
"There's nothing to indicate that would be the case," he said.
The type of bolt that broke is unique in that it's only used on curved sections of track, Jacobs said. He noted the train was going 26 mph in a 30 mph zone so it's not clear why the bolt failed. As a result, he said, the company is now in the process of checking similar bolts in curved sections of its 32,000 miles of track in 23 states…
Jacobs said bolts in that section of track, following the derailment, have been replaced with heavier duty bolts.
He also said inspections have been increased in the Columbia River Gorge from once every 18 months to four times a year. He said the broken bolt possibly escaped detection because the break occurred out of sight. He said the testing going on now on the company's network of tracks is much more labor intensive and will detect broken bolts.
http://koin.com/2016/06/10/broken-lag-bolt-caused-train-derailment-in-mosier/
Euclid was all over the place with his theories. Not to boast, but I posted this on page 1 of this thread:
I would only add that the derailment and release of oil may have had nothing to do with any form of braking if its cause was faulty trackwork: summer? kinks? or loose spikes/broken ties, etc.
C&NW, CA&E, MILW, CGW and IC fan
schlimm Euclid was all over the place with his theories. Not to boast, but I posted this on page 1 of this thread: Posted by schlimm on Sunday, June 05, 2016 1:52 PM I would only add that the derailment and release of oil may have had nothing to do with any form of braking if its cause was faulty trackwork: summer? kinks? or loose spikes/broken ties, etc.
Posted by schlimm on Sunday, June 05, 2016 1:52 PM I would only add that the derailment and release of oil may have had nothing to do with any form of braking if its cause was faulty trackwork: summer? kinks? or loose spikes/broken ties, etc.
But you did not provide any relevant detail of the 'faulty trackwork' itself, and in the event none of the causes you actually speculated were accurate.
Euclid, on the other hand, clearly said this (Saturday, June 11, 3:56)
my only point has to do with the use of lag screws in any type of rail mounting system including acting as cut spikes and bearing directly on the rail base. The details of the overall system they are used in is beside the point in my mind because the only issue is the ability of lag screws to break inside the tie and go unnoticed as they did in the CN wreck. While we don’t know even if lag screws are used on the line through Mosier, that type of hidden progression of individual breakage leading up to a sudden and unexpected catastrophic failure seems like it fits what happened in Mosier. For a line that is inspected every few days, I cannot see how suddenly, between inspections, 75 cut spikes somehow popped out of the ties or broke under the head. So I am speculating that the Mosier wreck was caused by the failure of some type of lag screw system where the lag screws broke and went unnoticed like they did in the CN wreck.
While we don’t know even if lag screws are used on the line through Mosier, that type of hidden progression of individual breakage leading up to a sudden and unexpected catastrophic failure seems like it fits what happened in Mosier.
For a line that is inspected every few days, I cannot see how suddenly, between inspections, 75 cut spikes somehow popped out of the ties or broke under the head. So I am speculating that the Mosier wreck was caused by the failure of some type of lag screw system where the lag screws broke and went unnoticed like they did in the CN wreck.
"If all those lags are broke for so many ties in a row, it allows that rail to spread out, which allowed the wheel to fall in. We had one wheel down at the point of derailment."
(Note the context: Euclid was replying to a criticism of mine, and the words he used in the reply make it extremely unlikely he 'went back and edited' this or his previous post about R12E0008 after he read the KREM report to "prove he was right")
wanswheel then posted the OPB story (at 4:30) that contained
“The fastener system that connects the railroad tie to the rail is what failed in this incident and is what caused the derailment,” said company spokesman Justin Jacobs. Multiple metal fasteners, called lag bolts, failed in consecutive rail ties. That caused the rails to spread apart as the train rolled over them
Multiple metal fasteners, called lag bolts, failed in consecutive rail ties. That caused the rails to spread apart as the train rolled over them
And it was only after that (4:35) that Euclid made his "boast", which now seems much less braggadocious than folks are making it seem:
There you go. Lag bolts failing in consecutive ties just like the CN wreck. Just as I speculated
Now, I'm going to hear groaning and perhaps even death threats, but there is something more than a bunch of lag bolts failing to produce this derailment. Recall from Raquel's and Justin's previous statements that all previous inspections (including the detector and geometry passes within the previous 30 days) hadn't shown anything needing a response. Recall the 'Cortex' report which showed no defects associated with any lag-screw system. Recall that the immediately previous train reported nothing out of the ordinary.
Something made the track more or less abruptly fail -- catastrophically, not just at one or two bolts -- under the middle of that oil train, enough to put one rail far enough out of gauge to 'drop a wheel' and that led (I'm still waiting for the exact sequence of events after that) to a severe pileup. I'm concerned that a 'rail securement system' that can progress so dramatically, and with so little warning, to failure might have more implicit design flaws than acknowledged at this point.
Note that I am not saying 'there had to be some causal factor, like the vaunted mystery UDE, or things we've discussed earlier like truck skew or side-bearing hangup, that kicked enough energy into the track 'in the wrong way' to make it fail as described. I'm not ruling out that there was, or wasn't, such an event --but I'm sure saying let's apply Occam's Razor to that possibility until we have the detailed FRA, and perhaps UP, tech reports. (Yes, I do wish the NTSB would investigate, and perhaps Congressional "pressure" may yet get that to happen...)
That leaves a sudden and dramatic change in track geometry, unpredicted by multiple, overlapping, frequent and supposedly definitive testing. And I find that ominous, and in light of the Fabyan Bridge accident, no longer a unique 'fluke' of probability or circumstance. That's a prediction I will make now.
I assume that this train was westbound and the derailment occurred at the curve along East Lake. Most of the photographs of the pileup in the news appear to have been taken looking west from the overpass for Hwy. 30.
This would mean that the derailment dragged one or more derailed cars for about 1,500 feet before the jackknife pileup finally occurred.
Overmod, please refrain from citing me within gratuitous criticism of other people.
Overmod Now, I'm going to hear groaning and perhaps even death threats, but there is something more than a bunch of lag bolts failing to produce this derailment. Recall from Raquel's and Justin's previous statements that all previous inspections (including the detector and geometry passes within the previous 30 days) hadn't shown anything needing a response. Recall the 'Cortex' report which showed no defects associated with any lag-screw system. Recall that the immediately previous train reported nothing out of the ordinary. Something made the track more or less abruptly fail -- catastrophically, not just at one or two bolts -- under the middle of that oil train, enough to put one rail far enough out of gauge to 'drop a wheel' and that led (I'm still waiting for the exact sequence of events after that) to a severe pileup. I'm concerned that a 'rail securement system' that can progress so dramatically, and with so little warning, to failure might have more implicit design flaws than acknowledged at this point.
Overmod,
As I understand it, there is no currently used method of inspection that will detect the broken lag screws such as used on the Mosier line or the ones that caused the CN wreck in 2012.
As you know, the screws break from the sideways force on the rails induced from a curve. I suppose one benefit of the screws is their better holding ability which makes them ideal to maintain the gage on curves.
However, the holding ability of the screw threads in wood, becomes moot if the force rises high enough to simply break the bolt above the threads.
In the CN wreck report, it says that screws broke individually over the time of passing of many trains; perhaps years of time. The more screws that break in a given space, the greater the loading on the remaining unbroken screws becomes. So the rate of screw breaking accelerates. As this develops it reaches the point where perhaps several screws then break during the passage of just one train. Finally, at some point, a train breaks enough screws so that the total number of broken screws over time is no longer able to withstand the gage widening force of a train. It is the proverbial straw that breaks the camel’s back.
So the hidden, individual screw breaking finally leads to a catastrophic failure, and no inspection currently used can see this coming.
I agree with your point above about a need for an inspection that can detect this problem. Another solution would be to develop a lag screw that will not break, but this is probably not possible within any practical basis. In lieu of an unbreakable screw, the fatigue failure of the screws could be determined, and then the total cumulative train force could be recorded. That way, they could keep track of the screw life and replace them before their time runs out.
This U.P. Mosier wreck appears to have an identical cause to that of the CN wreck. With the knowledge gained in the CN wreck, it seems strange that the issue could sneak up on anybody as it apparently did at Mosier.
As I understand it, there the only way to inspect for this problem with lag screws is to check for gage widening as a precursor to a catastrophic failure of lag screws.
The following is from the TSB report of the 2012 CN derailment at Fabyan Bridge:
If the screws are tight on the rolled plates, the clamping force produces friction between the plate and the tie, providing lateral resistance to gauge-widening forces in the curve. If the screws are loose, they act as pins, providing the sole lateral resistance. When this happens, the flat bottom rolled plates move under load and can break (Photo 8). Failure of the screws is usually due to a combination of shear and bending, as all screws do not receive even loading.
In this occurrence, a number of lag screws in the vicinity of the POD broke off in the tie. The breaks, which occurred over a considerable period of time, were due to fatigue at the transition point between the shank and the threads, where the cross-sectional area is reduced. Even with broken lag screws, there was little indication that the curve was under stress, as track gauge was maintained by the lag screws that did not break. The remaining intact lag screws experienced much higher lateral curving forces. The derailment occurred when the remaining screw fasteners were insufficient to resist the lateral curving forces; the high rail then rolled under the train, resulting in wheels falling into gauge at the east end of Fabyan Bridge.
**********************************************
Incidentally, the reports from U.P. say that one or more lag screws failed and caused the wreck. So there is still an indirect reference to ONE bolt failing. I don't know how there can be any doubt that would necessitate the quantification of "one or more." In the CN wreck, 74 lag screws failed.
Exactly where and how do you allege I have done this? Tell me where and I will take it out of a secondhand quote.
You were mentioned in my posts only only to establish a timeline, as a matter of historical record .. or are you now asserting that you didn't officially post something at a particular time if you don't like how it's subsequently used to substantiate or illustrate something?
Have I supposedly misquoted anything in one of your provided links, or referred to you in any way that attributes an opinion to you that you have not yourself first expressed? I try very carefully to avoid that, and I have a long track record of objectivity as an editor and director in so avoiding it.
A couple of comments in line -- note that some of this is my own opinion but I think it is factually based; correct me if otherwise.
EuclidThis U.P. Mosier wreck appears to have an identical cause to that of the CN wreck.
I would not make a blanket statement. Both wrecks appear to have lag-bolt issues (in a Pandrol-style spring-clip system) as contributing factors. But as you note (I'll say a bit more in a moment) there appears to be a key difference: there were clear warning signs of deterioration at Fabyan Bridge, but none -- despite the presence of several kinds of reasonably alert maintenance -- at Mosier.
Furthermore, according to Jacobs the 'proximate cause' of the derailment was a gauge widening only great enough to drop one wheelset. One of the things to emerge from the FRA investigation will be just how many 'lag-screw failures' would be needed to permit lateral excursion and/or roll of one rail relative to the other sufficient to drop the wheelset entirely within the gauge. I expect that will be more than 'one or two plates' worth'. I do not really expect the problem to be as widespread as the 74 documented failures that triggered the actual derailment event on CN, but (as noted) I'm beginning to worry that comparatively small initial events may lead to catastrophic failure in ways that other track securement systems might not.
The test is not for 'gauge widening' per se, it has to be for gauge widening upon application of lateral or overturning force -- remember that the geometry train didn't catch anything 'within the past 30 days', so passive measurement of track geometry is most likely not producing whatever effect caused the Mosier derailment. The CN test by contrast not only detected a number of gauge widenings before the accident, but typified them (as your citation indicated) as 'near-urgent'.
If the screws are tight on the rolled plates, the clamping force produces friction between the plate and the tie, providing lateral resistance to gauge-widening forces in the curve.
Note that this is one of the places the design fails some basic mechanical design -- where you are relying on fastener tension to provide lateral resistance between two smooth faces, some elastic provision like Belleville or lock washers needs to be provided to keep the surfaces clamped. In this system, the elastic clamping between tieplate and rail base does nothing for tie securement, and anything that creates even slight space between tie face and rolled plate bottom may cause shifting of the plate over against the shank of the screw. This might both deflect the metal and distort the edge of the hole in the tie, admitting water and contaminants. Even a small amount of looseness in the lags -- from whatever cause -- reduces the effective clamping force to zero, and at that point the loading on the screws becomes as you note, but there is more to the issue. The clips are still providing spring action to give elastic shock absorption to the rail, except now the effect is to magnify the shock between the tieplate and the shoulders on the lags, a kind of 'hammer blow' that increases asany of the 'clearances' increase.
... the flat bottom rolled plates move under load and can break (Photo 8). Failure of the screws is usually due to a combination of shear and bending, as all screws do not receive even loading.
My immediate concern with the 'rolled-plate' version of the system was that, unlike the cast plate, there were no features on the bottom of the tieplate that provided lateral 'keying' against lateral movement. (I did not think the features present on the cast plates were very substantial or shaped well, but at least they were present.) Note the picture that shows polish and scratching across the entire base of a plate! You'd best believe this shows not only substantial lateral movement with contaminants present, but shows the movement persisted for a substantial length of time. I suspect there was a design assumption along the general lines that having four lags per plate would prohibit all but a 'clearance' amount of lateral shift, and relative tolerance of rolling force, hence no perceived need for keys on the underside of the plate.
In this occurrence, a number of lag screws in the vicinity of the POD broke off in the tie. The breaks, which occurred over a considerable period of time, were due to fatigue at the transition point between the shank and the threads, where the cross-sectional area is reduced.
I am not fully convinced that this is the sole reason for breakage, or that there is some structural design defect in that area of a standardized lag screw. On the other hand, I have seen precisely this kind of problem completely ignored by engineers (in the crankpins of the original Precor elliptical exercise machine). In both cases, interestingly enough, a stress-originated failure was complicated by multiple stress-raisers forming at points of corrosion originated by 'foreign materials' in a wet environment
Even with broken lag screws, there was little indication that the curve was under stress, as track gauge was maintained by the lag screws that did not break. The remaining intact lag screws experienced much higher lateral curving forces.
These are important points to remember, together. It is not exactly a contradiction to what you said above, because what you meant was that there was little VISIBLE sign of the curve being under stress, a plurality of screws (whether still clamping or loose but acting as pins) holding the plates in rough gauge no matter how far they were deflected or bending. Naturally, the fewer the fasteners taking up the particular vectors of load, the more failures were induced, leading to some acceleration of deterioration which -- unsurprisingly -- proceeded to the point of failure.
I consider it instructive to note that the reported prompt failure at Fabyan Bridge here was not a lateral gauge failure (as alleged at Mosier so far) but a rolling failure, where the vertical clamping integrity of the lags was lost for a sufficiently long span to allow the railhead to roll out and dump wheelsets into the gauge. Whether or not the subsequent effects of the wheelsets forcing rails apart laterally was the same in both cases will probably not be determined until the FRA investigation is reasonably far along.
... there is still an indirect reference to ONE bolt failing. I don't know how there can be any doubt that would necessitate the quantification of "one or more." In the CN wreck, 74 lag screws failed.
I don't think there is a way to drop a wheelset into the gauge without some combination of plates being loose, screws deflecting laterally, and screws pulling up vertically, perhaps on both sides and not just the more-heavily-loaded rail in a curve. Again, it will probably be wise to wait for more specific detail from forensics before making more speculation about particular mechanisms.
Remediating loose fasteners may be as complex as trying to test them for looseness or corrosion. Spikes can be easily pulled and redriven, and their holes plugged easily; tension on lag screws can't be determined properly by backing and retightening them (any more than torque-to-yield bolts can be 'tested' by torquing them backward) and any tensioning can only be done by putting a proper rotational tool on them -- there is no inspection of the shank, threads, material, etc. without physically unscrewing them, and that is likely to damage any tie wood in directions other than optimal for vertical clamping ... repeatedly.
EuclidIncidentally, the reports from U.P. say that one or more lag screws failed and caused the wreck. So there is still an indirect reference to ONE bolt failing. I don't know how there can be any doubt that would necessitate the quantification of "one or more."
Because it overs all the bases. Why are you obsessing over the "one" part? This was, by all appearances, a lag screw failure. Not "one" lag screw failure, but a failure of lag screws securing the track in place.
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...
tree68 Euclid Incidentally, the reports from U.P. say that one or more lag screws failed and caused the wreck. So there is still an indirect reference to ONE bolt failing. I don't know how there can be any doubt that would necessitate the quantification of "one or more." Because it overs all the bases. Why are you obsessing over the "one" part? This was, by all appearances, a lag screw failure. Not "one" lag screw failure, but a failure of lag screws securing the track in place.
Euclid Incidentally, the reports from U.P. say that one or more lag screws failed and caused the wreck. So there is still an indirect reference to ONE bolt failing. I don't know how there can be any doubt that would necessitate the quantification of "one or more."
My concern over the mention of one or more lag screws failing is that they either know that it was only one; or they know that it was more than one. They have even said it was several. So why say "one or more"? I am sure that they have counted them by now, so why don't they tell us what the number was? If they need to cover their bases, they can use the word "approximately" ahead of the number.
I don't believe this amounts to a message referring to a lag screw as meaning a class of lag screws, although that misunderstanding has also entered the discussion as seen in the article where experts doubt that one broken lag screw would derail the train. They based their whole argument on the literal interpretation of "one" as meaning one.
As clarification of that point, the article that I cited yesterday said this:
MOSIER, Ore. – A broken lag bolt on the track caused an oil train to derail near Mosier on June 3, Union Pacific officials said in a town meeting Friday night.
OvermodOvermod wrote the following post 4 hours ago: schlimm Euclid was all over the place with his theories. Not to boast, but I posted this on page 1 of this thread: Posted by schlimm on Sunday, June 05, 2016 1:52 PM I would only add that the derailment and release of oil may have had nothing to do with any form of braking if its cause was faulty trackwork: summer? kinks? or loose spikes/broken ties, etc. But you did not provide any relevant detail of the 'faulty trackwork' itself, and in the event none of the causes you actually speculated were accurate.
Picky picky. Faulty trackwork is accurate and my post was one week ago.
This thread is getting more and more entertaining.
_____________
"A stranger's just a friend you ain't met yet." --- Dave Gardner
schlimm Picky picky. Faulty trackwork is accurate and my post was one week ago.
' Faulty trackwork' is indeed accurate, and you are to be commended for posting the statement a week ago (when Euclid was still off on the UDE 'conspiracy theory'). However, the problem I had was with the end statement in your post earlier today, which I did not quote
Sometimes even us non-experts have better hunches than the resident rail experts here.
I took that as both a 'dig' at Euclid's presumption to be a 'rail expert' and as a claim that your hunch as to the technical details of the faulty trackwork were 'better' than his. And here, arrogance is not in order.
For better or worse, Euclid did 'discover' both the type of construction that uses "bolts" to secure trackwork and the precedent in Canada for that type of trackwork to fail. That was corroborated by later objective news reports, one of the exhibits used in the Mosier community meeting, and statements by UP "expert" Jacobs.
On the other hand, none of the 'better hunches' in your actual post a week ago is even close to the actual cause of the derailment -- not sun kinks, not broken ties, certainly not loose spikes as there were no spikes in the faulty trackwork at all.
It's the last statement that causes the 'pickiness', not the fact that you were correct in a broad sense back a week ago before Euclid figured things out for a while. I now see he is back on the 'single bolt' hypothesis -- which is based only on improper comprehension by Oregon officials in a series of press releases, as far as I can tell; UP made it clear at the meeting that it was a fastener SYSTEM that caused the problem, and has repeatedly discussed how multiple fasteners had to fail to produce the dropped wheelset... etc. So perhaps it was a fluke that he figured out something right, against considerable mockery and opposition as he did so. But in all fairness, you essentially mocked him for getting it right, and implied you were better at understanding the specific faulty trackwork when you were not. That was the source of the pickiness.
Euclid schlimm wanswheel Euclid a failed fastener is referring to ONE fastener. Excerpt from KATU Portland, Jun. 11 http://katu.com/news/local/officials-multiple-broken-fasteners-led-to-mosier-oil-train-derailment-explosion Union Pacific officials told KATU News Friday night they believe multiple loose fasteners on the track led to the crash. So now we have the UP spokesperson (who must be getting this from UP experts) saying what some of us non-experts have been saying? Yes, us non-experts can cover a lot of ground quickly with our freedom to speculate.
schlimm wanswheel Euclid a failed fastener is referring to ONE fastener. Excerpt from KATU Portland, Jun. 11 http://katu.com/news/local/officials-multiple-broken-fasteners-led-to-mosier-oil-train-derailment-explosion Union Pacific officials told KATU News Friday night they believe multiple loose fasteners on the track led to the crash. So now we have the UP spokesperson (who must be getting this from UP experts) saying what some of us non-experts have been saying?
wanswheel Euclid a failed fastener is referring to ONE fastener. Excerpt from KATU Portland, Jun. 11 http://katu.com/news/local/officials-multiple-broken-fasteners-led-to-mosier-oil-train-derailment-explosion Union Pacific officials told KATU News Friday night they believe multiple loose fasteners on the track led to the crash.
Euclid a failed fastener is referring to ONE fastener.
a failed fastener is referring to ONE fastener.
Excerpt from KATU Portland, Jun. 11
http://katu.com/news/local/officials-multiple-broken-fasteners-led-to-mosier-oil-train-derailment-explosion
Union Pacific officials told KATU News Friday night they believe multiple loose fasteners on the track led to the crash.
So now we have the UP spokesperson (who must be getting this from UP experts) saying what some of us non-experts have been saying?
Yes, us non-experts can cover a lot of ground quickly with our freedom to speculate.
OvermodOvermod wrote the following post 1 hours ago: schlimm Picky picky. Faulty trackwork is accurate and my post was one week ago. ' Faulty trackwork' is indeed accurate, and you are to be commended for posting the statement a week ago (when Euclid was still off on the UDE 'conspiracy theory'). However, the problem I had was with the end statement in your post earlier today, which I did not quote Sometimes even us non-experts have better hunches than the resident rail experts here. I took that as both a 'dig' at Euclid's presumption to be a 'rail expert' and as a claim that your hunch as to the technical details of the faulty trackwork were 'better' than his. And here, arrogance is not in order.
I was not making a dig at Euclid; I suggest you try reading more accurately and in context. I was not dealing with specifics, just a hunch that the crash's cause was trackwork, not brakes. I never pretended to be an expert anymore than he did/does. I don't know if you are an actual expert or a railroader or just another non-expert observer. However, you seem to be acting as some self-appointed judge of the postings. I'm not aware of any announcement by the forum moderators of your new reponsibilities.
One broken bolt that missed detection sounds better than say 75 broken bolts. But I see that the report of ONE broken bolt can either minimize the problem or accentuate it depending on how you look at it. Quote from the link:
“Mosier Fire Chief Jim Appleton, who fought the blaze after the derailment, said he appreciated Union Pacific's maintenance and safety procedures but the risk of one broken bolt resulting in such a disaster or potentially worse disasters means regulators should not allow shipments of crude oil to travel by train through the area.”
I would like to know what happened right after a wheel dropped into the gage. It would seem this derailment happened on the inside of the curve at East Lake (north side) as the train would naturally crowd the outer rail (south side). For various reasons, I speculate that the derailed wheel ran in line, but on the ties for some considerable distance, such as 1500 ft. for instance.
This running would be between the point where the first wheel derailed to the point where the pileup and fire occurred. Bear in mind that at the start of this 1500 ft. of travel, when the wheel dropped off the rail, the opposite wheel is still running on the rail in the proper position (although tipped out of perfect rail contact).
I doubt that the gage had widened over this entire 1500 ft. of distance. You would be considering thousands of screws being broken if that were the case.
More likely, the gage widened in a rather short distance of say a few hundred feet; say at the curve at East Lake. Then a wheel fell off of the rail on the inside of its rail where the gage widened.
It seems to me that the next wheel to follow would also drop off the rail in the same spot. Each wheel in succession would drop off the rail, so that many cars would be running with wheels on the derailment side all running on the ties, and pressing against the inside of their rail.
But, in a relatively short distance, the widened gage would close back to normal. Where do those derailed wheels go then?
There would be a big squeeze contest between the derailed wheel shoving against the inside of its rail, and the flange running normally for the wheel still on the rail on the opposite side. I would guess that the derailed wheels pressing against side of their rail would possibly cause a reaction force that would cause the opposite wheel flange to climb the rail, and derail to the outside of that rail.
If that did not happen, then the derailed wheels, as the gage closed to normal, would displace their rail off of its position on the ties. The first derailed wheel would shear off all of the hardware connecting the rail to each tie, one-by-one.
EuclidI would like to know what happened right after a wheel dropped into the gage.
The train derailed.
EuclidBear in mind that at the start of this 1500 ft. of travel, when the wheel dropped off the rail, the opposite wheel is still running on the rail in the proper position (although tipped out of perfect rail contact).
And how would you know that? Once one rail tips over there is nothing restraining the wheels to stay on the other rail and the "derailed" wheel is now lower than the other wheel so gravity is pulling things towards the side of the track where the rail is turned over. Plus ther is more drag on the derailed wheel which slows that side of the truck down causing the truck to "steer" towards the turned over rail.
EuclidI doubt that the gage had widened over this entire 1500 ft. of distance. You would be considering thousands of screws being broken if that were the case.
Dude, the wheels of the cars are between the rails. Unless you think that gauge is between 5 and 6 feet, I gaurantee the guage was compromised.
Once the wheel hits the tie it begins tearing things up. It will shove the rail sideaways or turn the rail over.
EuclidThere would be a big squeeze contest between the derailed wheel shoving against the inside of its rail, and the flange running normally for the wheel still on the rail on the opposite side.
No. No contest whatsoever. The wheels win. Once the rail turns over only one flange might be in contact with the rail. There is no "squeezing", squeezing requires a force from both sides and there is nothing to provide the force from one side.
EuclidIf that did not happen, then the derailed wheels, as the gage closed to normal, would displace their rail off of its position on the ties. The first derailed wheel would shear off all of the hardware connecting the rail to each tie, one-by-one.
Bingo, the derailed wheel is tearing stuff up on the ties until bends the rail enough that the rail breaks or the wheels dig in and then stuff piles. up.
Dave H. Painted side goes up. My website : wnbranch.com
dehusmanBingo, the derailed wheel is tearing stuff up on the ties until bends the rail enough that the rail breaks or the wheels dig in and then stuff piles. up.
Exactly!
dehusman Euclid I would like to know what happened right after a wheel dropped into the gage. The train derailed. Euclid Bear in mind that at the start of this 1500 ft. of travel, when the wheel dropped off the rail, the opposite wheel is still running on the rail in the proper position (although tipped out of perfect rail contact). And how would you know that? Once one rail tips over there is nothing restraining the wheels to stay on the other rail and the "derailed" wheel is now lower than the other wheel so gravity is pulling things towards the side of the track where the rail is turned over. Plus ther is more drag on the derailed wheel which slows that side of the truck down causing the truck to "steer" towards the turned over rail.
Euclid I would like to know what happened right after a wheel dropped into the gage.
Euclid Bear in mind that at the start of this 1500 ft. of travel, when the wheel dropped off the rail, the opposite wheel is still running on the rail in the proper position (although tipped out of perfect rail contact).
I still wonder what the specified sheer strength of the bolts is and what tests have been done to confirm that the bolts met that spec. There was back in the 80's if I recall a rash of venders supplying bolts that didn't meet specifications.
Electroliner 1935 I still wonder what the specified sheer strength of the bolts is and what tests have been done to confirm that the bolts met that spec. There was back in the 80's if I recall a rash of venders supplying bolts that didn't meet specifications.
I think this derailment could lead to a big controversy about strength of materials, engineering, and overall approach. And if this basically duplicates the CN wreck, it will raise even more questions.
It does open the door to the development of a lag screw testing machine. All that is needed is a pull on each screw to make sure that it has not separated due to breakage.
The beauty of the cut spike is that it always tells you what it is doing.
schlimmHowever, you seem to be acting as some self-appointed judge of the postings. I'm not aware of any announcement by the forum moderators of your new reponsibilities.
Good point. Assuredly no one died and left me in charge of some truth police. And it does not matter to the actual topic of discussion even if they had, and I were.
I now see that nobody's going to figure out how the single-bolt tale got started, either; I'm not sure whether quoting Chaos News bot coverage of a media story reporting a press release that has misconceptions in it is sophisticated sarcasm, but it sure is too complex for me to comment any further on.
One note to the latest controversy between Euclid and Dave: in some cases it should be possible for a wheelset that has dropped into a short wide-gauge 'hole' to pop back up -- into guiding, or maybe into derailment 'over the high side' -- if there is enough lateral restoring force exerted by the rails on the wheelrim faces and outer tread corner. But it should be noted that each following wheelset will be dropping down into the same 'hole' and tending to lengthen the wide spot or turn over a rail, and the resistance 'felt' by the parts of the train both before and behind that area will likely be increasing.
What remains to be seen is whether there is 3/8 of a mile of fully 'widened-out' gauge between the original point of failure (which was the original few broken bolts that allowed the first wheelset to drop) and the point where the bulk of the accordioning is observed -- which is how I thought this accident was being described -- or if the accordioning started 3/8 of a mile 'behind' the point of derailment (as the derailed part "dug in" and the rear part's momentum started running in the slack...) Until I get that clarified (and it may well be known; it's just obfuscated by lousy news coverage and what passes for press releases) I'll withhold further comment.
Overmod What remains to be seen is whether there is 3/8 of a mile of fully 'widened-out' gauge between the original point of failure (which was the original few broken bolts that allowed the first wheelset to drop) and the point where the bulk of the accordioning is observed -- which is how I thought this accident was being described -- or if the accordioning started 3/8 of a mile 'behind' the point of derailment (as the derailed part "dug in" and the rear part's momentum started running in the slack...) Until I get that clarified (and it may well be known; it's just obfuscated by lousy news coverage and what passes for press releases) I'll withhold further comment.
I don't follow what you are saying in the above quote.
Incidentally, my comment that Dave replied to above was just an observation of what I assumed would have happened. It was not intended to prove anything. It assumes that the gage widened and dropped a wheel inside of its rail. That is the way it is described by U.P., and it it is also what is shown in their graphic. I don't recall anyone from U.P. saying that the rail tipped over, so I assumed that it just shifted sideways. What I am suggesting is that the wheel fell off the rail in the wide gage, and then acted sort of like a can opener and extended the wide gage all the way to the point of pileup.
In any case, what I find most interesting is that this pileup appears to have been preceded by a relatively long derailed-dragging event. If so, there was plenty of time to stop the train if the derailment had been detected.
EuclidIn any case, what I find most interesting is that this pileup appears to have been preceded by a relatively long derailed-dragging event. If so, there was plenty of time to stop the train if the derailment had been detected.
1500' = 25 60' cars. Not very long at all, especially if the train was moving at anything above a snail's pace. And that's if the rail just overturned at one small spot, and not for a few car lengths.
PS: don't put any type of "expert" tag on me. Cause I sure as heck ain't one.
The opinions expressed here represent my own and not those of my employer, any other railroad, company, or person.
[quote user="zugmann"]
Euclid In any case, what I find most interesting is that this pileup appears to have been preceded by a relatively long derailed-dragging event. If so, there was plenty of time to stop the train if the derailment had been detected.
PS: don't put any type of "expert" tag on me. Cause I sure as heck ain't one./quote]
30 MPH = 44 feet per second1500 feet = 34.1 seconds
Never too old to have a happy childhood!
Another question, my experience with most tie plates was that they had ridges that would dig into a tie and help hold it in place on the tie, Earlier, someone spoke about rolled plates. Do these have anything other than the bolts to maintain their position? Also, has anyone learned about the cause of the bolt failure? Is it corrosion, wear, pulled apart (under tension) or shear (from side forces like the plate cutting it). The UP slide indicated that the bolt was in place but the top was separated from the bottom. Thus the rail had NO horizontal restraint nor vertical but the weight of the train. Horizontal force causes the rail to slide to the outside. If all the force is on the bolt, it could overload it and cause it to shear. This is the failure but I don't think they have stated the bolts failure mode or cause. Two crashes indicates that stronger bolts may not be the solution.
Are these Pandrol systems better?
I just found one answer in Euclid's post of the Canadian report.
Photo 6. Cast plate (left) and rolled plate (right) ↑
Photo 7. Bottom of plates (Note: lugs on bottom of cast plate [left] and smooth bottom of rolled plate [right]) ↑
So the rolled plate cannot provide any horizontal restraint to the structure and ALL the horizontal forces are on the bolts. I think this is a significant factor.
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