Handbook of Railroad Construction; For the use of American engineers. / Containing the necessary rules, tables, and formulæ for the location, construction, equipment, and management of railroads, as built in the United States.

by George L. Vose

From a great number of experiments made by Mr. Clark, the relative resistance to the motion of inside and outside connected engines is as follows:—

Inside connections	17
Outside connections	14

The effect of curves, bad state of the road, and adverse winds, amounts (according to the same author) to the following percentages:—

Bad state of the road	40
Curves	20
Strong head and side winds	20
In all	80

The resistance due to grades depends entirely upon the rate of incline, and is quite independent of all other considerations. The relative effect of grades decreases with the absolute increase of resistance on a level. Thus common roads admit of steeper grades than do railroads, because the level resistance is much more upon the former than on the latter.

The exact determination of the resistance due to any grade depends upon the very simple mechanical principle, regulating motion upon the inclined plane. For each foot rise of grade per mile, the resistance per ton is

2240 × 1
5280.

Thus the resistance to one ton upon a forty feet grade is

2240 × 40
5280 or 17 lbs.

And if we are moving at thirty miles per hour the sum of all other resistances is, by the formula, or the table at the end of Chapter XIV., part I., 13.3 lbs. per ton; whence the whole resistance to the motion of one ton, at thirty miles per hour, upon a forty feet grade, is