I suspect that the lag screws were subject to the phenomenon mentioned by a metallurgist (I forget whether it was on this forum or elsewhere - but that's not important) - metal might fail in 100 years, or it might fail tomorrow.
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...
The Oberbau K had a poplar board pad beneath the rail. The clamping plate was pressed to the rail by spring washers. Everything else was rigid in the beginning. The spring washers on the ribbed plate lag screws came after WWII, the elastomer rail pad even later.
The first accident was Nuremberg-Stein in Germany. The poplar board had decayed, the lag screws got loose and broke from bending fatugue: https://www.eisenbahn-unfalluntersuchung.de/SharedDocs/Downloads/EUB/Untersuchungsberichte/2009/017_Nuernberg-Stein.pdf?__blob=publicationFile&v=4
The other accident was Duesseldorf. I remembered it wrong. The screw got loose without breaking because of a decomposed tie: https://www.eisenbahn-unfalluntersuchung.de/SharedDocs/Downloads/EUB/Untersuchungsberichte/2013/052_Duesseldorf_Derendorf.pdf?__blob=publicationFile&v=4
Both problems were overlooked during regular maintenance.
And here is the Canadian report: http://www.tsb.gc.ca/eng/rapports-reports/rail/2012/r12e0008/r12e0008.asp
I read somewhere that lag screws were first used with spring washers in North America and that the new Arema standard is without spring washers. Is that correct? The Vossloh KS 24 linked above seems to reflect this.Regards, Volker
BaltACD VOLKER LANDWEHR What I didn’t understand after the Mosier, OR was that UP gave the impression being surprised that lag screws would break. There were reports from Canada in 2014 and Germany 2014 and 2009. In all these cases the reasons were negligent maintenance and fatigue of material. Regards, Volker So - what would non-negligent maintenance look like? Applying torque to each lag screw fastener to a specified value and see that the lag screw doesn't run away because of a broken shaft or stripped threads in the wood or lag screw. That is a lot of fasteners to be tested on a periodic basis.
VOLKER LANDWEHR What I didn’t understand after the Mosier, OR was that UP gave the impression being surprised that lag screws would break. There were reports from Canada in 2014 and Germany 2014 and 2009. In all these cases the reasons were negligent maintenance and fatigue of material. Regards, Volker
So - what would non-negligent maintenance look like? Applying torque to each lag screw fastener to a specified value and see that the lag screw doesn't run away because of a broken shaft or stripped threads in the wood or lag screw. That is a lot of fasteners to be tested on a periodic basis.
BaltACDSo - what would non-negligent maintenance look like? Applying torque to each lag screw fastener to a specified value and see that the lag screw doesn't run away because of a broken shaft or stripped threads in the wood or lag screw. That is a lot of fasteners to be tested on a periodic basis.
Perhaps negligent maintenance is the wrong word. Nevertheless the defects weren't found during maintenance.
To find a broken lag screw you don't need torque. It still can be laborious. Look at the end of the Canadian report.If I understood correctly the lag screws in the ribbed plate don't use spring washers. One way from my point of view would be to use spring washers. With a broken screw the head would sit about 0.5'' higher.Regards, Volker
[quote user="CSSHEGEWISCH"]
I'm not an engineer but I would think that barbed spikes would also be a bear to remove when replacing ties or rails. They would also be expensive to produce./quote]
I'm sure a mechanical spike puller would have no problem and if the tie is going to be scrapped those barbs would be of no consequence.
Norm
VOLKER LANDWEHR BaltACD So - what would non-negligent maintenance look like? Applying torque to each lag screw fastener to a specified value and see that the lag screw doesn't run away because of a broken shaft or stripped threads in the wood or lag screw. That is a lot of fasteners to be tested on a periodic basis. To find a broken lag screw you don't need torque. It still can be laborious. Look at the end of the Canadian report.
BaltACD So - what would non-negligent maintenance look like? Applying torque to each lag screw fastener to a specified value and see that the lag screw doesn't run away because of a broken shaft or stripped threads in the wood or lag screw. That is a lot of fasteners to be tested on a periodic basis.
To find a broken lag screw you don't need torque. It still can be laborious. Look at the end of the Canadian report.
If you don't need torque, what do you need - a spike puller?
Never too old to have a happy childhood!
I would imaging things like ultrasonic, magnetic or eddy currents could be used ..
For many metals my understanding is that the fatigue life is well known and easily calculated. Steel is one.
Aluminum on the other hand doesn't show signs of fatigue, even when x rayed. There's likely others.
Corrosion adds an unpredictable factor. The use of road salt and the like might account for as many failing road bridges in this country as it does. It's probably a factor in why so many railroad bridges are lasting twice or longer than the design expected.
Modeling the Cleveland and Pittsburgh during the PennCentral era starting on the Cleveland lakefront and ending in Mingo junction
rdamonI would imaging things like ultrasonic, magnetic or eddy currents could be used ..
Remember trackmen and track inspectors doing routine inspection and maintenance are from the Track Supervisor's (Roadmaster) basic force. They tend to be less educated than more technical positions. Imaging technology would likely be beyond their technical expertise.
Convicted OneReviewing vintage 1949 issues of Trains magazine recently, I came upon an advertisement (promotion really) by Erie railroad patting themselves on the back for innovation, for developing the threaded rail spike. Copy of ad below. I don't believe I've ever seen anything similar, yet on the surface bthis seems like a great idea. Why did this not catch on?
I don't believe I've ever seen anything similar, yet on the surface bthis seems like a great idea. Why did this not catch on?
- PDN.
CSSHEGEWISCHI'm not an engineer but I would think that barbed spikes would also be a bear to remove when replacing ties or rails. They would also be expensive to produce.
This patent description-type page may be of interest (not vouching for it, though):
http://www.pages.drexel.edu/~garfinkm/Spike.html
Paul_D_North_JrThere was a ... rectangular sheet metal tube with a pointed end that fit over the spike. Flutes were formed into each side of it, kind of like mini-louvers - cut and bent outwards. As I recall, the theory was that driving the spike into it would force the flutes outward and into the tie. I don't recall how the interface between the surfaces of the spike and this widget would be improved, though
That is not the Garfinkle spike, which is one bent piece with the teeth on the inside; the legs bend out and the enhanced barbed grip is on the 'wedge' formed between the diverging legs. One disastrous thing about this is that once driven it and its tie are 'forever' -- no taking up rail, no reusing the tie, no disposing of the tie without sharp metal edges where you'd removed the formed 'head'. I thought of improvements to it, a collar of malleable metal just under the shank to preclude lateral motion relative to the tie plate, or forming it with four legs to lock longitudinally as well as axially, before I figured out the whole idea was a boondoggle compared to simple pad and clip systems a la Pandrol.
It might be noted that a Garfinkle-like device is a good alternative to the worthless lags in the Pandrol Wood-tie fixation system ... assuming you can keep the plate located properly as the device is driven, something unlikely to happen just by holding the plates on the rail base with their clips. Theoretically you could dowel a lag hole and then use a Garfinkle with only nominal reduction of effective grip, and it would be simple to detect both unsettling or relative motion between head and plate with high-speed machine vision. So there may be a use for this after all.
The sleeve device sounds a bit like the Schiro approach, but using a head on the sleeve to actually hold the rail, with the spike being a convenient way to lock the sleeve in position A bad idea if so; these would fail by cracking under the head in ways that could be detected little more readily than compromised lags.
Robotic devices to locate, 'see', and test the fit of screw fasteners would be possible to build. So would equipment comparable to spike pullers -- albeit slower and needing more special attention. I was always told the incremental cost of the screw and necessary washer and perhaps 'chair' exceeded that of properly installed and maintained spiked track for most cost-effective American applications, anything high-speed in my era being assumed to involve concrete and elastic fixation almost by default...
ruderunnerFor many metals my understanding is that the fatigue life is well known and easily calculated. Steel is one.
Fatigue is not a fixed lifespan. The bearable number of load changes depends on the installation situation and the load combination. If the lag screw is tightened correctly their upper part has a press fit in the wood. If the screw loosens this fit can get lost and the bending moments inscrease leading to a shorter fatigue lifespan.Regards, Volker
BaltACDIf you don't need torque, what do you need - a spike puller?
The men walking the track in Germany had a large wrench. I think you can hear from the sound if a screw is loose or broken when you hit it with the wrench. But these people haven't worked with nothing else than rail fasteners with lag screws.
Today the work of is done by exclusivly by geometry cars. When anomalies are found a track gang is sent.
The were tests in the USA too that a number of missing fasterners doesn't lead to too much gauge widening in 1986: www.rta.org/assets/docs/ComprehensiveRail/sec12/missing%20fasteners%20vs.%20gage%20strength.pdf
Other tests described the gauge strength of different systems: http://www.rta.org/assets/docs/ComprehensiveRail/sec5/gage%20widening%20strength.pdfRegards, Volker
Volkner over here the engineers have a simple problem solver they love to use for complex problems. We outside the enginering world call it the KISS principle or Keep It Simple Stupid. Here is something to think about in WW2 German tanks were considered the best in the world especially the Panther and Tiger 1 and Tiger 2 series. However what won the war sheer numbers of T-34's of the Soviet Army and M4 Sherman tanks made here in the USA. 20K tanks made by Germany verus 35K Shermans of all types and 85K T-34's alone by the Soviet Union. We out produced your nation with a tank while not quite as good as the Panther or Tiger models could overwhelm them in sheer numbers. Ours where easy to fix in the field yours where nightmares to repair. To replace a busted roadwheel on a Sherman required just a wrench a jack and the replacement. On both the German designs it had to go back to heavy maintance to get it done do to the overlapping roadwheel deisgn.
Our track workers like things simple for one reason less tools they need to carry around in the field. Most track workers can fix a broken rail with the tools they carry and do it quickly no need to worry if the bolt is tight enough if the spike is down they know it is tight.
Shadow the Cats ownerVolkner over here the engineers have a simple problem solver they love to use for complex problems. We outside the enginering world call it the KISS principle or Keep It Simple Stupid.
I know this principle. I think it doesn't fit everywhere. I wouldn't like to see a real high-speed train running at 200 mph on spiked rail. With today's power tools rail, geometry cars maintaining rail fasteners with lag screws doesn't have to be more complicated than with spiked fasteners.
I know we have a different philosophy than you. You have another saying: If it isn't broke don't fix. We say: The better is the enemy/death of the good. An example: IBM distributed and supported Lockheed's CADAM CAD-software in Europe. When IBM asked for further development Lockheed thought it good enough. In the end IBM Europe switched to Dassault's (French mititäry aircraft manufacturer) CATIA CAD-software.
You choose one way we a different one.
As I said before German track workers were able to handle the Oberbau KS fasterners containing lag screws with hand tools they carried with them. At least temporarily as the lag screws are finaly pre-stressed to about 25 to 30 kN (5500 to 6600 lbs). Regards, Volker
Shadow the Cats ownerWe outside the enginering world call it the KISS principle or Keep It Simple Stupid.
We in the engineering world called it the same thing. Of course, that was wrapped up in the concept of engineering economics, lifespan analysis, etc., but we still called it KISS. No disrespect to Gene Simmons.
Volker,
One thing I have not seen in this or prior discussions on the subject of threaded spikes was a report on the metalurgy of them. Perhaps I missed it along the way but it should have been made available to those of us who have an interest in whether or not those threaded spikes met the appropriate standards for strength, their ability to hold their position in relation to the tie and rail and their ability to withstand any corrossion they may encounter. Should you find a report expressly explaining the above concerns please post it.
I don't believe any system of rail securement will ever be foolproof in the long run but wonder if the threaded spikes used on Union Pacific were thoroughly vetted prior to their installation. I would like to think UP MOW engineers did their homework befor approving them.
One other factor May be the difference in loading of rail cars in Europe vs those in North America. I don't know load limits in Europe but ours are 286,000 pounds per car with exceptions for Schnabel cars and six axle cars.
Norm48327One other factor May be the difference in loading of rail cars in Europe vs those in North America. I don't know load limits in Europe but ours are 286,000 pounds per car with exceptions for Schnabel cars and six axle cars.
286K headed to 315K
Norm48327One thing I have not seen in this or prior discussions on the subject of threaded spikes was a report on the metalurgy of them.
Norm,
you didn't miss anything. What I found is e.g. that Pandrol uses spike screws according to ASTM 66, hot forged, normal 65,000 psi: www.pandrolusa.com/wp-content/northamerica/screwSpike-1.pdf
Vossloh states: Some types of screw spike we produced are ASTM A66-87 screw spike, UIC864-1 screw spike (Ss series Ss8, Ss23, Ss25, Ss35, Ss36, DHS35 etc), 3V screw spike meet to NF F50-006, to name just a few.http://www.bsrailway.com/rail-fastening/vossloh-fastening-system.shtml
The UP Mosier, OR derailment was never investigated by the NTSB. The is a short preliminary FRA Report: https://gorgefriends.org/assets/images/issues/2016_06_03_Preliminary_Factual_Findings_Report_Mosier_Union_Pacific_FINAL.pdf
It states on the last page: Volpe, one of the Department of Transportation’s research centers, is testing the metallurgy of the broken bolts.
I haven't found neither the final report nor Volpe's results.UP must have made its own investigation but I haven't found it.
The German load limits are 50,000 lbs per axle. On the other hand we have speeds of up to 200 mph. The Vossloh KS-24 is limited to 150 mph. In Sveden and Norway the ore railroad from Kiruna to Narvik has 66,000 lbs per axle.
Here is a presentation about gauge widening with indications in the field: https://www.wheel-rail-seminars.com/archives/2015/hh-papers/HH-02%20WRI%202015%20Wolf%20Wide%20Gage%20HeavyHaul%20-%20with%20watermark.pdf
Regards, Volker
Paul_D_North_Jr CSSHEGEWISCH I'm not an engineer but I would think that barbed spikes would also be a bear to remove when replacing ties or rails. They would also be expensive to produce. There was a sleeve or sheath-type thing ( ) that was marketed for this purpose. I can't remember the name of it - maybe mudchicken can remember. Anyway, it was a rectangular sheet metal tube with a pointed end that fit over the spike. Flutes were formed into each side of it, kind of like mini-louvers - cut and bent outwards. As I recall, the theory was that driving the spike into it would force the flutes outward and into the tie. I don't recall how the interface between the surfaces of the spike and this widget would be improved, though. This patent description-type page may be of interest (not vouching for it, though): http://www.pages.drexel.edu/~garfinkm/Spike.html - PDN.
CSSHEGEWISCH I'm not an engineer but I would think that barbed spikes would also be a bear to remove when replacing ties or rails. They would also be expensive to produce.
There was a sleeve or sheath-type thing ( ) that was marketed for this purpose. I can't remember the name of it - maybe mudchicken can remember. Anyway, it was a rectangular sheet metal tube with a pointed end that fit over the spike. Flutes were formed into each side of it, kind of like mini-louvers - cut and bent outwards. As I recall, the theory was that driving the spike into it would force the flutes outward and into the tie. I don't recall how the interface between the surfaces of the spike and this widget would be improved, though.
PDN: Hope you aren't talking about those Huck-Bolt related headaches in curve tie plates and switch plates....That stuff works in insulated joints (i-bonds)and insulated switch plates, but the permanence of the fastener is its own undoing when you add-in Pandrol or D-E clips
MC: No, neither one of those. As I recall, lock spikes were invented by Bethlehem Steel Co., and there were 3 different types (shape of the hairpin part). The Huck Bolt type of thing had a different name back then. I installed approx. 8 dozen in the joint bars of the approaches to a new manganese casting double-curved crossing frog in 1982 (then B. F. Goodrich Co. plant, Pedricktown (Penns Grove), NJ - N 39.76355 W 75.41981) with the cooperation of the plant engineer to try to maximize the service life of everything associated with it. I was there a couple years ago and most of them were still there. I wouldn't do it again, though, for the 'special tooling needed' reasons you mention.
The spike thingy I roughly described is from the 1980's or 1990's, so long ago I doubt that even with a photo or sketch either of us would remember the name of the manufacturer or the trade name for it. It was designed to improve the holding power of spikes in marginal or spike-killed ties. I'm sure there were many ads in Railway Track & Structures, but my copies from back then are long gone.
Only other thing I can think of were threaded camcars with a little square-ish spring clip instead of a washer. The thought was, if you were even thinking of those (like around crossings with downed ties) it was already time to change out the wood tie. (also jokingly referred to as belts and suspenders band-aids)
Wasn't there a movie showing fleeing prisioners removing screw spikes ? The train ?
Burt Lancaster in 'The Train'.
Semper Vaporo
Pkgs.
blue streak 1 Wasn't there a movie showing fleeing prisioners removing screw spikes ? The train ? Yes, "Von Ryan's Express" starring Frank Sinatra (1965)
blue streak 1 Wasn't there a movie showing fleeing prisioners removing screw spikes ? The train ?
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