Ed, in your picture, I noticed that the rail is held in place by the use of both spikes and “rail hold downs” (those curvy shaped things). Do those things have a name?
I will accept that the use of rail anchors causes a redirection of expansion because of the compressive forces that it imposes on the rail, but I guess that I would like to understand the physics behind that a little bit better.
So, to sum up, rail anchors have two purposes. The redirect the expansion forces caused by heat on the rail away from the longitudinal, and they prevent the rail from moving longitudinally from train forces.
If your rails (jointed or CWR) are held down by cut spikes, you will have lots of anchors.
The type of rail anchor shown initially (plated) is a common channelock type.
If you have pandrols or D-E clips, the need for anchors are eliminated.
Anchors loose their grip with age and wear, thus the “pitched” anchors you saw. Some anchors can be slightly reformed and reapplied, but it is no longer cost effective.(costs more in energy and labor to recondition the anchor than to get new ones)
The application of anchors is totally dependent on the type of rail applicacation (cwr and jtd), where it is (curve/tangent) and that railroad’s standard anchor pattern. Guaranteed you will find every tie anchored 250 feet in advance of switches and road crossings to hold gauge and to keep the rail from running in the switch. If an anchor is failing, it will slide and no longer remain snug up against the side of the tie.
Thank you, mudchicken.
I’ve noticed that when pandrols are used with concrete ties, they always have some type of (insulating?) substance between the pandrol and rail. Looks like a blob of plastic.
Data…
The lead you see in the photo has steel ties every third tie to hold gauge in the curve which is behind, or to the left of the weld…and there is a crossover to the right about ten feet past the weld, so rail anchors are on every single wood tie.
Last place in the world you want a car on the ground is in the middle of your switching lead crossover!
The pads are to prevent the harmonics and the vibration from the rail degrading the surface of the concrete tie…wood ties with fish plates can absorb the vibration as they sit.
Ed,
Let’s see if I’ve got a handle on this now.
In your photo, there are steel ties to ensure gauge integrity. (Steel and concrete ties must, of necessity, use pandrols instead of spikes). In addition, the wooden ties all have rail anchors to prevent longitudinal movement of the rail, protecting the integrity of the crossover. And the plastic(?) that is used with concrete ties is to protect the integrity of the tie from vibration damage.
Got it. Thanks to all. [4:-)]