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

The line of traction of a locomotive ought to be as near as possible at the same vertical height as the driving wheel centres. If much below this the load will tend to lift the engine off from the leading wheels, upon the drivers as a fulcrum, thus increasing the adhesion and lessening the leading power.

Fig. 153.

If the traction bar (draw link) is above the wheel centres, it will tend to lift the rear of the engine from the rails.

Fig. 154.

The general form of engines used in America are shown in figs. 151, 152, 153, 154, and 155.

Fig. 155.

Fig. 151 is the express passenger locomotive.