E7 wrote:Big Jim wrote:Note that the rail sits in the flanges of the tie plate and that the spikes keep the tie plate in place.
Which gives rise to the question: Were tie plates used from the get go, or did they evolve along the way as a more efficient way to hold the rails to the ties?
No, early "tee" rail was nailed directly to the tie.
No, tie plates were not invented for effeciency, but to increase the bearing area of the train weight on the wooden ties.
As trains got bigger and heavier it was found the rails were cutting into the ties. Also, as Murph pointed out, the rails move quite a bit as a train rolls over them. This also causes wear in the ties. The tie plate provides a buffer between the moving rail and the tie.
There were two comments concerning whether the rails should move or not. I watched a train traverse a particularly soft section of roadbed and came to the conclusion that the rail system would be a lot more efficient if the rails did not move at all. The reason is, the weight of the train cars pushes the rail/tie/roadbed system down creating a depression the engines have not only to power themselves out of but they have to pull every car out of its own depression.
To make matters worse, the depression caused by the individual engines and cars stays under the wheels causing the engines and every car to be forever climbing out of its self-made hole.
Ships used to have the same problem with their bow wave... forever having it in front of them when in motion.
Modern ships have solved the problem. You will not see a container ship at full speed with a bow wave.
Instead, you will see the bow falling into a depression.
Edit 1: Changed, "ever car" to "every car."
Edit 2: Gave some motion to ships with bow wave (they do not have a bow wave if standing still.
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Edit 3: Created "Edit 2" note, which I forgot to do before pressing "Submit."
