When a train is going up a grade, the locomotive drive wheels apply a force to the rail. This force tends to pu***he rail and track structure downhill. What prevents this[?]
As a former Railroad track man, I can answer this. A piece of track hardware often
overlooked by people talking about track (rails, ties, spikes and tie plates) is called
the rail anchor. It is a steel item that comes in various configurations but are all
similar in that they take the form of a ‘C’. They can be applied either by wrench or
sledge, (NOT spike maul). They attach around the base of the rail adjacent to
the ties (wooden ones-modern concrete ties have different systems) and due
to spring tension remain there. These provide resistance to the rails sliding by
their numbers (lots are used) and locations-right next to the ties. Hope that this
explanation is clear enough.
[#welcome] to the forums.
To continue on with GN-Rick’s answer, rail anchors are used on just about everything above FRA Class 1 track, and in some situations on Class 1 as well. They are also particularly useful on curves, where a combination of forces tends to try and slide the rail in the tie plate. The anchor is used with wood crossties that are spiked. It is driven onto the rail on the side of the tie where the track force is applied; i.e., the uphill side on a grade, and usually both sides on tangent and curves.