1.1.
GENERAL
Through gravity, friction, and inertia, our physical environment imposes certain
limitations on movement. To effect movement, these forces must be overcome by the
expenditure of energy. The various modes of transport have been developed to overcome these
restrictions in different ways. Each mode has its individual characteristics. Those of railroads
enable them to move large numbers of persons and great quantities of freight between any two
points on the rail line with comparative ease and high speed. Railroads are able to do this
because they employ cars rolling on flanged wheels over steel rails. These two elements, flanged
wheels and steel rails, as shown in the sketch, are the essential elements of rail transportation. A
student of any phase of railroading must thoroughly understand the characteristics of railways
resulting from the use of rails and flanged wheels.
Chapter 1 discusses the fundamentals of railroad engineering. In
it you
study how the railroads meet operational difficulties presented
by
the terrain over which they travel. And you become familiar
with such terms as grade, alinement, profile, gage, cross
level, surface, and track clearance; and their relationship
to
railroad engineering and to the job of the track supervisor.
1.2.
MEETING OPERATIONAL PROBLEMS
A set of flanged wheels rolling on two steel rails is guided along the path of those rails
and does not have to be steered. A number of cars supported by these wheels can, therefore, be
grouped to form a train and be operated as a unit by one crew. Not only does such an operation
reduce labor requirements but also enables railroads to use large, efficient prime movers--
locomotives--to move the groups of cars rather than less efficient individual power units applied
to each car.
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