Fig. 26.—Six-wheeled Switching Locomotive. By the Schenectady Locomotive Works.
From the illustrations, Figures 28, 30, and 31, it will be seen that when so many wheels are used, even if they are of small diameter, the wheel-base must necessarily be long, so that a limit is very soon reached beyond which the number of driving-wheels cannot be increased.
Improvements in the processes of manufacturing steel, which resulted in the general use of that material for rails and tires, have made it possible to nearly double the weight which was carried on each wheel when they were made of iron. The weight of rails has also been very much increased since they were first made of steel. Twenty or twenty-five years ago iron rails weighing 56 pounds per yard were about the heaviest that were laid in this country. Now steel rails weighing 72 pounds are commonly used, and some weighing 85 pounds have been laid on American roads, and others weighing 100 pounds have been laid on the Continent of Europe.
Fig. 27.—Mogul Locomotive. By the Schenectady Locomotive Works.
Fig. 28.—Ten-wheeled Passenger Locomotive. By the Schenectady Locomotive Works.
Fig. 29.—Consolidation Locomotive (unfinished).
