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.
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.
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.
Overmod, please refrain from citing me within gratuitous criticism of other people.
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.
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
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.
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
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/
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.
BaltACDWhat 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.
I guess that's another example of the newsworkers reporting what they thought they heard rather than what Union Pacific actually said.
Has there been any work done since the Fabyan Bridge accident to figure out what a 'critical' number of fastener failures per unit distance is (in different curve and resistance circumstances) for these Pandrol-clip systems, and more importantly, how quickly the situation starts to deteriorate beyond that number? It might be that even with regular quarterly testing, track that passes a lateral 'simulated' test conducted by a relatively light vehicle might progress to dangerous 'invisible' damage before that is recognized either by subsequent testing or 'alert' crew recognition of some external sign in locomotive riding or train motion.
I was particularly concerned by that picture (in R12E0008) of the 'rolled steel plate' with shiny fretting polishing on its entire underside. I have to wonder whether there is some dynamic between some characteristic of the spring clips and the motion of the tieplate that is permitted when the lags slacken or break -- something that might facilitate very large and perhaps harmonic force that would 'progress' a track to failure long before a simple lateral force test would indicate.
Moreover, we might recall that almost at the outset of coverage of this story,
Spokesman Justin Jacobs said Saturday the track near Mosier, about 70 miles east of Portland, had been inspected at least six times since March 21. It was most recently checked last Tuesday, and within the past month, the company had used a detector car to check for imperfections as well as a geometry car to inspect the ground along the track.
Raquel Espinoza provided a little more detail in the original report wanswheel linked (between 2:15 and about 3:30) which indicated that Union Pacific's frequent 'safety inspections' essentially concentrated on rail integrity (through 'ultrasound' detection) and line and surface integrity (via the geometry car) -- 'everything aligned properly'. There was no indication whether the geometry car was measuring transient motion (lateral or vertical) that might indicate either a loss of vertical clamping authority or lateral 'pinning' against transverse excursions, but it would seem to follow that if there were, the tests did not disclose the damage in any form that triggered specific followup or remediation, even though the track was being 'inspected twice a week ... in excess of Federal requirements'.
https://www.fra.dot.gov/Page/P0636
http://www.ensco.com/userfiles/file/Products_Services_PDF/07_Rail/12.0060-Deployable-Gage-Restraint-Measurement-System.pdf
EuclidThere you go. Lag bolts failing in consecutive ties just like the CN wreck. Just as I speculated.
Yes, after you speculated several other things, speculated the UP was trying to cover up something, stated it didn't make any sense, after I had to explain it to you, after the UP clarified their statement and said the same thing that I had to explain to you, yes after all that, your last speculation superseding all your previous speculation, that matched what other people, including the UP, had been saying for days was correct.
Congrats.
Dave H. Painted side goes up. My website : wnbranch.com
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? It'll be interesting to see how this is done, or if the increased inspection frequency starts causing more problems than it tends to address...
It'll be interesting to see how this is done, or if the increased inspection frequency starts causing more problems than it tends to address...
Never too old to have a happy childhood!
Euclid There you go. Lag bolts failing in consecutive ties just like the CN wreck. Just as I speculated.
There you go. Lag bolts failing in consecutive ties just like the CN wreck. Just as I speculated.
A hero. Not the hero we deserved, but the hero we needed.
It's been fun. But it isn't much fun anymore. Signing off for now.
The opinions expressed here represent my own and not those of my employer, any other railroad, company, or person.t fun any
EuclidI see that in this coverage, they are still referring to a lag bolt failing as though just one failed and caused the wreck. That seems to be a major point of confusion in the story.
"They" seems to be the media, not UP.
It is not uncommon to refer to a system failure in the singular, as in "a significant number of injuries in automobile collisions are caused by a failure to wear a seatbelt."
All of those people weren't injured due to one person's failure to wear a seatbelt.
I suspect that UP might feel that all of the lags that failed had something in common, be it corrosion, wear, location, whatever. Inasmuch as the lags are part of the track securement system, "the lag bolt" is apparently part of the problem, and may well be the proximate cause of the derailment.
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...
Electroliner 1935 I have a concern that these bolts could be of defective manufacture. I am aware of subpar bolts being sold in the past and they did not meet the strength requirements. I would hope that the UP has a QA department that test a random sample. Is the cause of failure known?
I have a concern that these bolts could be of defective manufacture. I am aware of subpar bolts being sold in the past and they did not meet the strength requirements. I would hope that the UP has a QA department that test a random sample. Is the cause of failure known?
Although not industry required, I would assume that UP would require the manufacturer of these bolts be AAR M1003 certified. This in essence turns the entire rail industry into its QA department. Failures of this type are not that uncommon if indeed this installation is similar to the CN one. A good argument for the use of the GRMS inspection system.
challenger3980But Yep, I guess you were right, and UP should have consulted you from the begining.
Yep, if you want to know the cause right away hire an armchair expert. Of course their story is subject to change and modification faster than a politician's.
Norm
Euclid wanswheel Excerpt from KREM Spokane/Coeur d’Alene, Jun. 11 http://www.krem.com/news/broken-lag-bolt-caused-train-derailment-up-officials-say/239795087 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. "As the trains move around the curve, they apply a lateral force to that rail, shoving that rail out. What holds that rail intact are those lags," said a Union Pacific spokesperson. "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." The point of derailment was about three-tenths of a mile east of where the rail cars piled up off the track. Union Pacific officials said the lag bolt would have been detected by a gauge restraint measurement system but that test is only done once every 18 months. That test will now be done four times a year, officials said. I see that in this coverage, they are still referring to a lag bolt failing as though just one failed and caused the wreck. That seems to be a major point of confusion in the story.
wanswheel Excerpt from KREM Spokane/Coeur d’Alene, Jun. 11 http://www.krem.com/news/broken-lag-bolt-caused-train-derailment-up-officials-say/239795087 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. "As the trains move around the curve, they apply a lateral force to that rail, shoving that rail out. What holds that rail intact are those lags," said a Union Pacific spokesperson. "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." The point of derailment was about three-tenths of a mile east of where the rail cars piled up off the track. Union Pacific officials said the lag bolt would have been detected by a gauge restraint measurement system but that test is only done once every 18 months. That test will now be done four times a year, officials said.
Excerpt from KREM Spokane/Coeur d’Alene, Jun. 11
http://www.krem.com/news/broken-lag-bolt-caused-train-derailment-up-officials-say/239795087
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.
"As the trains move around the curve, they apply a lateral force to that rail, shoving that rail out. What holds that rail intact are those lags," said a Union Pacific spokesperson. "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."
The point of derailment was about three-tenths of a mile east of where the rail cars piled up off the track.
Union Pacific officials said the lag bolt would have been detected by a gauge restraint measurement system but that test is only done once every 18 months. That test will now be done four times a year, officials said.
I see that in this coverage, they are still referring to a lag bolt failing as though just one failed and caused the wreck. That seems to be a major point of confusion in the story.
Guess someone has lost their reading powers.
I thought that you initially speculated/ were convinced/adamant that it was caused by a UDE, which again you were convinced that UP was trying to cover up with a rail fastner failure "Red Herring"
But Yep, I guess you were right, and UP should have consulted you from the begining.
Doug
May your flanges always stay BETWEEN the rails
Gosh Euclid, if you take another bow without a lag you’ll break a bolt.
Excerpt from Oregon Public Broadcasting, Jun. 11
http://www.opb.org/news/series/oil-trains/oregon-mosier-oil-train-derailment-union-pacific-rail-fastener-failure/
The Union Pacific Railroad says it has completed its investigation into an oil train derailment in the Columbia River Gorge…
“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…
The Federal Railroad Administration is conducting its own investigation of the derailment.
I should not have used the term Lag Screw Spike because I am not sure of its scope. It may only refer to lag screws that have their heads bearing on the rail base. So 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.
And yes, by all means, somebody please tell us what kind of rail securement is in place on the line through Mosier. I would like to know if it uses lag screws in any manner.
What is the Ultimate Goal? Or was, 2 years ago.
http://railtec.illinois.edu/Crosstie/2014/presentations/Track%201%20-%20Concrete%20Crossties%20and%20Fastening%20Systems%20Track/Session%201-2_Fastening%20System%20Design%20Priorities/Ashmore%20-%20UIUC%20-%20Fastening%20System%20Design%20Priorities.pdf
[quote user="Euclid"]
[quote user="Norm48327"]That article was written about a different rail securement system than is common in the US. Please tell us in your "experience" you've seen it used in North America. I don't think that system is relevant to this discussion. Yes, I'm aware lag screws are used in some cases.
https://en.wikipedia.org/wiki/Rail_fastening_system[/quote]
I am not sure where it is used. It is similar to, but not identical to the one used on the CN where this wreck occurred. See this report and look at photo #4:
http://www.tsb.gc.ca/eng/rapports-reports/rail/2012/r12e0008/r12e0008.asp
I have no idea what system is in place on the line through Mosier. But my only point is the use of lag screw spikes. They appear to be common in several different systems with other details varying.[/quote]
First: The 'lag screws' in the Canadian example are not the same thing as "spikes"; they are used to secure the baseplates that implement Pandrol-style clip retention of the rail in the (somewhat defectively engineered) wood-tie variant of that sort of system, the elastic clips performing all the rail hold-down functions just as they do in the concrete-tie version.
The only place I have seen lag screws used in place of spikes for rail retention was on the ex-Erie main line in the section where it divided at Glen Rock into two separate 'double-track' mains for commuter service. Here the construction was 'typical' spiked tieplates, with at least one lag screw driven down in place of a conventional spike (ISTR one screw and one spike per plate, but I wasn't paying as much attention to 'how many' as to the novelty of the screws). I did not think to check how this worked on curves (though I photographed on Sullivan's Curve many times!) That was to my knowledge unusual construction in the early '70s, and I don't recall seeing it on other main lines subject to much greater load or higher speed.
I think it's pointless to extend any analysis of Pandrol systems to spiked track, or to speculate that the "fastener" described in the Union Pacific spokesperson's report is a lag screw of this kind without confirming that a spring-retention fastening system was in use on the track through Mosier. There are people here (mudchicken being the likely best qualified) who KNOW the answer to that question, and could put this whole silly digression to bed with a word.
Personally, I have disliked the Pandrol 'conversion' systems as very ill-considered for the length of time I have known about them. Spring-clip retention works nicely for concrete ties, where the clips are reliably and firmly held in the tie structure, and theoretically should work in the kind of wood-tie conversion system where the plates are bushed accurately to the shanks of bolts that are threaded into large tee-nuts (sorry if there's a better technical term for these that I should use for track) in the 'bottom' of the tie, to give reliable preload and clamping force even when the grain of the tie opens up or weathers and admits water along the shaft of the bolts -- I know of nowhere in the United States that system is in use. Some of the pictures in R12E0008 graphically illustrate exactly the sorts of failure I'd expect a wrongheaded 'analogy' system to exhibit, and I would suspect that Union Pacific among others would go straight to concrete ties if they were going to adopt elastic fastening with or without elastomer cushioning under the rail base. But it's looking increasingly as if that's what the UP spokesmen are talking about.
And yes, it was Euclid that brought up the Pandrol system secured by lag bolts, and understood that there were precedents where a great many of those bolts failed progressively, without being effectively detected, in order to produce an ultimate failure.
On the other hand, he also decried the idea it was a 'fastener' failure and said UP was mentioning that only to avoid having to discuss a UDE causing the derailment...
Probably no help, UP website has a page about customer's track.
https://www.up.com/cs/groups/public/@uprr/@customers/@industrialdevelopment/@operationsspecs/@specifications/documents/up_pdf_nativedocs/pdf_up_std_0460.pdf
https://www.up.com/customers/ind-dev/operations/specs/track/
[quote user="Norm48327"]
That article was written about a different rail securement system than is common in the US. Please tell us in your "experience" you've seen it used in North America. I don't think that system is relevant to this discussion. Yes, I'm aware lag screws are used in some cases.
https://en.wikipedia.org/wiki/Rail_fastening_system
[/quote]
I have no idea what system is in place on the line through Mosier. But my only point is the use of lag screw spikes. They appear to be common in several different systems with other details varying.
Our community is FREE to join. To participate you must either login or register for an account.