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

Crossings occur where two tracks cross, and consist of four frogs, with the corresponding guard rails, as in fig. 147.

Fig. 147.

ELEVATION OF THE EXTERIOR RAIL.

293. The motion of a train of cars around a curve is accompanied by a tangential force, depending in amount upon the velocity of the train and the radius of curvature. This force tends to throw the cars from the track; and is counteracted by elevating the exterior rail.

The centrifugal force of any body in motion in a curved line is shown by the formula

WV²
32R.

Where W is the weight in lbs.

V the velocity in feet per second.

R the radius of curvature,