Grade
Percent of ruling grade = 1.5
Curvature
Sharpest or ruling curve 100
To use the formula for CTL given in the preceding paragraph, you
must first find values for DBP, W, RR, GR, and CR.
a. Drawbar pull. Your locomotives have a continuous tractive
effort of 36,000 pounds from which 20 pounds per ton of total
locomotive weight must be subtracted to get DBP. Thus:
b. Weather factor. In table III, you find that between 11 and
20 F. a locomotive loses 20 percent of its hauling power;
therefore, the weather factor is 80 percent. This means that the
locomotive is able to exert only 80 percent of its normal hauling
power.
c. Rolling resistance. In table II, you find that the rolling
resistance is 7 pounds per ton of train on a track rated fair to
poor. The value you must use for RR then is 7.
d. Grade resistance. Paragraph 2.7 explains that grade
resistance is equal to 20 pounds per ton of train multiplied by the
percent of ruling grade, which is 1.5 for your railway division.
When you multiply 1.5 by 20 you get 30the value for GR.
e. Curve resistance. Curve resistance is found, as explained in
paragraph 2.8, by multiplying 0.8 pounds per ton of train per degree
of curve. In this example, 0.8 multiplied by 100 gives you a CR
value of 8.
f. Using the formula. Substitute the values you have found for
the factors in subparagraphs a through e in the formula for GTL as
follows:
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