I have though about this for a while but never ask the question, are the spike holes pre drilled in the tie? Looks like the spike would just pull out. How does this work?
Spikes work in wood ties because they compress the wood fibers as they are driven into the tie. The wood fibers then push back against the spike, preventing it from being easily extracted – until the wood deteriorates and looses this ability. Concrete is not easily compressible like wood nor resilient like wood, so this method does not work.
Thus concrete ties don’t use spikes, they use either a screw-type fastener or a resilient fastener.
The screw-type fastener (uncommon in the U.S.) consists of a large lag screw with a square or hex head that is screwed into a wood or plastic insert. The screw compresses the insert, the insert expands into the hole cast into the concrete tie. The insert is thus being compressed just like the wood in a wood tie, and pushing back against hard unyielding objects, the screw and the tie. The friction of this compression is what resists pull-out. The lag screw passes through a flat steel clip that has one edge over the base of the rail before it goes into the insert. That clip holds the base of the rail down. Screw-type fasteners are OK for low-density, low-load railroads. They are not a very good system, but they are cheap. Concrete ties with screw-type inserts can be manufactured in a very crude factory with very poor quality control and labor education, and still work. I’ve used a lot of them overseas. The plastic inserts are barely OK, but the wood inserts terrible – they eventually dry out or rot out, and then the rail can’t be lifted any more by a tamper because the ties won’t come with it.
The resilient fastener consists of a spring steel clip (of various designs). One end of the clip is inserted into a steel “shoulder” that is
As new rail would be installed over concrete ties using the fastener, Pandrol clip…Does it take a special tool {or machine}, to insert the “clip” and “load it”, down onto the rail…?
You can put on a Pandrol clip with a sledge hammer (and knock it off with a sledge too), but there are also machines that do this.
RWM
In a word, yes. The tool used depends on the type of clip being used. Hopefully the machines are all working so we don’t have to put on many by hand. When it comes to declipping it’s the same story: a different declipper for every kind of clip… They wouldn’t want to make it too easy on us by only having to carry one kind of clipper/declipper with us.
Truth be told putting Pandrols on with hammers is a lot easier said than done. We use what we call “T tools” which are are lever devices that keep the clip lined up on the tower. As you pull down on the handle toward yourself the clip slides into place They’re very simplistic and quite effective. As for removing Pandrols, a sledge hammer works very well, but a machine works even better. Of course, you always have foremen who believe the hammer should be used to remove Pandrols because it saves the machine from having to perform its work. Never mind that the machine can work faster than ten guys with hammers.
See the various “pages” at:
and - although these are for the installation and removal of the “FastClip”, not the “e-clip” - esp.:
http://www.pandrol.com/index.php?/products/installation_with_handtools/
and
http://www.pandrol.com/index.php?/products/installation_with_machines/
and also:
- PDN.
I only did it in countries where we didn’t have any machines!. We didn’t even have hi-rails because the railway was afraid they’d be driven home and never come back.
No comment on the foremen. [:P]
RWM
When using a sledge hammer, you want to make sure you hit it correctly the first time. It’s a spring, if you don’t seat it with one swing, it might hurt more than your pride. [B)] Fortunately, I got to practice by myself on a lonely yard track with no witnesses. After a lot of practice, I could install a clip (on steel ties) with a 3# hammer if I hit it “just right”.
If I remember right, the track crews I worked with settled on using the T-tool to put a good amount of “push” or “pull” on the clip to start to seat it and hold it in place, but not to actually get it all the way “home”. Then another guy would use a hammer to drive it the rest of the way in - the constant pressure on the T-tool was used to keep it moving in the right direction, and prevented it from springing back or zinging off someplace as you guys reference. Also, the T-tool if used by itself took a lot of upper body strength applied “just right” to do it in one stroke. Their method took 2 guys, but was a lot more certain and productive, less tiring, and less prone to disruption from the unpredictable ricochets of the spring clips and then having to go get them, etc.
- Paul North.
Walking 20 feet each way was the best exercise I got that day.[banghead] As I got into the “swing of things”, I did a lot less walking.[8D]
I wrote apost titled this vey thing a-while ago. The rails are just “clamped” to the tie itself I belive.