RAILROAD CONSTRUCTION 
331 
per hour. Tlie elevation for track of another gauge is approxi- 
mately in proportion to its relation to the standard-gauge. 
An average day's work for surfacing a new roadbed when about 
8 inches of dirt are used as ballast, is three rail lengths per man, 
while on swamp work when from 12 to 15 inches of dirt ballast 
are used, it is one rail length. 
Cost of Construction. — The cost of construction per mile on 
logging railroads varies widely even in a given region. The two 
Speed/mOes per Hour 
5 10 15 20 23 30 
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Fig. 111. 
Diagram Showing the Customarj^ Elevation of the Outer Rail, 
in Inches, for Various Degrees of Curvature. 
factors that chiefly influence it are topography and the character 
of the bottom on which the road is to be built. 
Construction is cheapest in the flat pine forests of the extreme 
southern States, where a minimum of grading is required. On 
the other hand the rough topography of some of the Pacific 
Coast country often requires heavy grading work and high trestles 
and the roads must be built more carefully for transporting the 
large and heavj^ timber. Swamps such as are found in the 
cypress region also necessitate a heavy expenditure because 
the main roads have to be built on piling. 
