While walking down the middle of my local mainline yesterday, I noticed some sections of rail were fastened by spikes, and other sections had the rail fastened by what looks like thick paper clips (bent metal clips). What’s the difference, and why would the RR use different fasteners on the same line?
keep asking keep learning
They are called Pandrol clips, bet they were on steel or concrete ties…
Quicker and cheaper, easier for machines to install.
You most likely were looking at a section of track that was replaced, for what ever reason.
Ed
Actually, all the ties were wood, and the clips were on an older section of track with the spikes on a recently upgraded section. It was a NS line.
Are you saying that they put the wrong fasteners on the wrong ties? Wouldn’t it make more sense to place the clips on the newer track? Do you think I should flag down a train the next time I am walking down the middle of the tracks and warn the crew about the wrong fasteners?
keep asking keep learning
You may be referring to the clips that are placed over the base flange of the rail on either side of ties (not every tie) to keep the rails and the ties from sliding relative to one another. They’re not fastening the rail to the tie, the spikes and tie plate are doing that.
Just my guess based on your description.
Regards
Ed
Type Pandrol into your search engine.
Look at the clips they show…
If its not those your talking about, I go with the Mexico Ed, its the expansion clips your looking at.
They clip inside the rail, right up next to the ties, and help keep the track from developing a sun kink by controling expansion of the rail.
As for flagging down a train, please dont…
The engineers and the MOW guys wouldnt make such a mistake, for what ever reason, what they laid down is what they want there.
Ed in Texas
I too, have seen Pandrol clips (or something like them) used on wood ties. I want to say I’ve seen them where they’ve put in new rail on curves. I’ll have to look has we have a gang relaying rail on a curve over by Cedar Rapids.
Jeff
Are you talking about rail anchors like these:
http://www.akrailroad.com/track_assemble.html
Or Pandrol clips like these:
http://www.railway-technology.com/contractors/rail/pandrol/
Now I want to ask, why would you and why are you walking down the middle of the tracks? This whole section smells funny to the Mookie’s nose. I wonder if you really are that naive and not just pulling on someone’s pants leg… Don’t toy with the good people of this forum - you won’t win.
Mookie
They didn’t use the wrong fasteners, either works.
The clips (and there are several types) are replaceable without damaging the ties and actually clamp the rail down so perform some of the functions of a rail anchor. Many times clips are used in curves where the rail wears out before the ties, so the railroad can replace the rail frequently without damaging or " the ties.
Don’t walk down the middle of the tracks and don’t step on the rail.
Dave H.
Terry, If you are really so naive that you are willing to walk down the middle of the track and flag down a moving train; please do. And may God rest your soul. If you do survive, I for one will not anwer your letters from Juvenille Detention.[X-)]
For future reference, I don’t suggest walking down the Middle of a track, you might just get hit by a train.[;)]
Oh, so that’s why I see them used in the New York City subway.
BTW, does anyone know what the weight of a rail used for subways?
If Terry_C would tell us the precise location of his ‘wanderings’ we could probably tell him which of the technologies he was seeing.
It’s pretty clear to me from the description that he’s talking about rail anchors.
Pandrol clips on wood ties would seem to be to be a triumph of available surplus capital over common sense. The wood ties themselves provide the resilience which, on concrete or metal, is provided by the springs in the Pandrol clips; the hold-down fitting that secures the clip to the ties will require greater anchoring integrity – into threads or a fitting inserted by cutting or drilling into each tie (let’s hope they aftertreated the holes with some sort of preservative!) – and will see both higher peak loads and leverage load than spikes. I might also mention that all the Pandrol clips I’ve seen have been designed to reduce the friction loading between rail and clip, sometimes to the extent of putting plastic rollers over the part of the clip that bears on the rail. This is hardly something that would be effective at keeping rail from expanding longitudinally to control sun kink; rather, the clips assist in this respect by restraining the rail from moving in directions that affect gauge and lining integrity when it expands (btw this, to me, is a far more sensible idea than brute-force longitudinal anchoring)
Presumably the use of spring clips on curves would be to reduce lateral shock loading or to provide ‘automatic’ resumption of full clamping tension after high curve loading that might progressively ‘start’ spikes. It would be interesting to see the attachment plates and clips that are used in such installations.
Probably mudchicken can clear us all up, but… you do need longitudinal anchoring on rail (even or perhaps especially CWR) whether you are using Pandrols or spikes; as overmod notes, Pandrols really don’t do much longitudinal anchoring. The longitudinal is partly for thermal expansion, partly for tractive forces – but the end result, in both cases, is that on grades the rail will creep – slowly, slowly, but oh so surely – down grade, with an increase in the likelihood of kinks toward the bottom (particularly in sags) and tension breaks near the top (particularly on crests). Which are generally not happy events…
…I see Pandrol clips installed along with spikes on NS here in Muncie with continous rail and on a curve as it passes through the city…
You’re putting us all on, right?[:(!] You can’t be serious.
If you are serious, then yes, you should flag down a train the next time you’re walking down the middle of the tracks. Hopefully, the crew – if they are able to stop in time – will have the good sense to call the police, who will place you under arrest for trespassing and reckless endangerment.
Amen Mookie & Dave::
Walking between the rails is a good way to get planted in the ballast section, PERMANENTLY.
Besides Pandrol’s “e” clips, D-E Safelok Clips are becoming common (Kozzie has seen these for years. The Aussies did well to come up with these.)…You are most likely going to see Pandrols in curves, turnouts/switches, crossing frogs and bridges where forces play havoc with the ability to hold the rail in place and not “spike kill” the tie.
…Look at it it this way Terry, if a conventional cut spike gets lifted up, it stays up. Too many of these gone bad in a curve and there can be problems. (The rail can rotate in the plates and a wheel could fall-in as in wide-gage, if it gets really bad.) A pandrol clip (“Pretzel” clip) never stays “up” unless it breaks - which is rare …
The railroad industry is still looking for a better way to fasten pandrol tie plates to the t wooden ties without spikes, screws and/or hairpins (Gals, you don’t want to fool with these 6 inch hairpins, a.k.a. compression clips).
Mudchicken
[banghead][banghead][banghead]
…As I mentioned in above post on the Pandrol clips…I also noted the plates had fasteners with a square head like they were a fastener with threads and turned into the tie to do their fastening.
I feel safe walking down the track where I was talking about. Trains only go 25-30mph and there are only 2-3 trains per day. Its uphill so you can hear the trains comming for a long time. I’m not talking about walking down the northeast corridor here guys. Besides, I’'m really good friends with the local crews and rr police in this area an when they see me railfanning they stop and say hi–no way they will ever arrest me. In fact, I sometimes walk with the local track inspector down the tracks, he walks the tracks once per week. Maybe I should ask him the question about the difference because he has always been really nice to me not mean like some of you.
keep asking keep learning
Are you familiar with the Darwin Awards?[}:)]