Technical specifications of locomotives often include tractive effort curves, which show the relationship between tractive effort and velocity.
The basic shape of the graph is shown schematically (diagram right). The line AB shows the operation at the maximum tractive effort, the line BC shows the relationship of continuous tractive effort being inversely proportional to speed.
Tractive effort curves will often have graphs of rolling resistance superimposed on them—the intersection of the rolling resistance graph and tractive effort graph gives the maximum velocity (i.e. when the net tractive effort is zero).
Read more about this topic: Tractive Force
Famous quotes containing the words effort and/or curves:
“And in counterpoint, from other windows,
the effort to be merry—ay, maracas!
Msibilant, intricate—the voices wailing pleasure,
arriving perhaps at joy, late, after sets
have been switched off, and silences
are dark windows?”
—Denise Levertov (b. 1923)
“For a hundred and fifty years, in the pasture of dead horses,
roots of pine trees pushed through the pale curves of your ribs,
yellow blossoms flourished above you in autumn, and in winter
frost heaved your bones in the ground—old toilers, soil makers:
O Roger, Mackerel, Riley, Ned, Nellie, Chester, Lady Ghost.”
—Donald Hall (b. 1928)