Effect of Adhesion Limits
See also: Traction (engineering)Adhesion is caused by friction, with maximum tangential force produced by a driving wheel before slipping given by:
- Fmax= coefficient of friction x Weight on wheel
Usually the force needed to start sliding is greater than that needed to continue sliding. The former is concerned with static friction, referred colloquially to as 'stiction', or 'limiting friction', whilst the latter is called 'sliding friction'.
For steel on steel, the coefficient of friction can be as high as 0.78, under the best of conditions (= utopic laboratory condition, on railway realty: 0.35 -0.5 ), whilst under extreme conditions it can fall to as low as 0.05. Thus a 100 tonne locomotive could have a tractive effort of 350 kilonewton, under the ideal conditions (assuming sufficient force can be produced by the engine), falling to a 50 kilonewton under the worst conditions.
Read more about this topic: Rail Adhesion
Famous quotes containing the words effect of, effect and/or limits:
“To get time for civic work, for exercise, for neighborhood projects, reading or meditation, or just plain time to themselves, mothers need to hold out against the fairly recent but surprisingly entrenched myth that “good mothers” are constantly with their children. They will have to speak out at last about the demoralizing effect of spending day after day with small children, no matter how much they love them.”
—Wendy Coppedge Sanford. Ourselves and Our Children, by Boston Women’s Health Book Collective, introduction (1978)
“Whenever any form of government shall become destructive of these ends, it is the right of the people to alter or to abolish it, & to institute new government, laying it’s foundation on such principles & organising it’s powers in such form, as to them shall seem most likely to effect their safety & happiness.”
—Thomas Jefferson (1743–1826)
“The element running through entire nature, which we popularly call Fate, is known to us as limitation. Whatever limits us, we call Fate.”
—Ralph Waldo Emerson (1803–1882)