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:
“A readiness to believe ill of others, before we have duly examined it, is the effect of laziness and pride. We are eager to find a culprit, and loath to give ourselves the trouble of examining the crime.”
—François, Duc De La Rochefoucauld (1613–1680)
“As soon as I suspect a fine effect is being achieved by accident I lose interest. I am not interested ... in unskilled labor.... The scientific actor is an even worker. Any one may achieve on some rare occasion an outburst of genuine feeling, a gesture of imperishable beauty, a ringing accent of truth; but your scientific actor knows how he did it. He can repeat it again and again and again. He can be depended on.”
—Minnie Maddern Fiske (1865–1932)
“To the extent to which genius can be conjoined with a merely good human being, Haydn possessed genius. He never exceeds the limits that morality sets for the intellect; he only composes music which has “no past.””
—Friedrich Nietzsche (1844–1900)