In my previous posts I lightly covered: The various combinations of these forces define the train driving regimes. These are the following (not sure if all the railway networks are defining theme in the same way): A particular case of this regime is where the falling gradient is so steep that it requires the train…
And then we have the braking force – the third type of force that influences the train movement. As with the others, this force also depends on speed – mainly due to the speed variation of the friction coefficient (μ) for various brake systems (the forces K that trigger the friction are generally the same):
Before reading this, I recommend reading the previous post – The Traction Force – including its disclaimer. When a railway vehicle is required to move on track, it needs to overcome a series of resistance forces. We can call the resultant R of all these forces “the running resistance of the vehicle”. If we consider…
I’m on my way to explain the principle curvature equivalent gradient. As this is related to a discipline I enjoyed, I choose to go the long way and start with the FORCE. But, before that, a few words of caution: Disclaimer Take this post, and any other that I will write on this subject, with…
… or – How to convert a curve into an angle? In the track design handbook we have a too complex formula that refers to “degree of curvature”. Before discussing about the equivalent gradient, let’s see first what this is – what is the degree of curvature? This measure is used in United States in…
Disclaimer – this includes a back-of-the-envelope calculation. Take it with a pinch of salt. If a steel beam is exposed to an increased temperature, it will tend to expand. If there is nothing to oppose that expansion, then the beam increases in length by ΔL. If, however, the beam’s ends don’t allow this expansion then…
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As demonstrated in a previous post here: https://pwayblog.com/2015/10/29/11-82_cant-deficiency-un-compensated-acceleration-pway/ , the cant deficiency is the conventional representation of the uncompensated lateral acceleration. And since cant deficiency is an acceleration, we can easily represent it as a percentage of g, the gravitational acceleration. The formula that relates the cant deficiency D to un-compensated lateral acceleration is: The…
A railway track blog 