Weight
2
c.
Their low maintenance requirements.
2
d.
The low traffic density of the yard.
2
e.
Their ease in handling.
12.
On your section, the walls of a certain cut have presented a constant problem
because of erosion and crumbling. At present, the slope is one unit horizontal
to one unit vertical. The procedures that would solve the problem are:
2
a.
Change the slope to 1 1/2 horizontal to 1 vertical.
2
b.
Install a lateral drainage system on top of the sub-grade.
2
c.
Construct a French drain.
2
d.
Introduce plant growth.
2
e.
Erect a retaining wall.
Multiple Choice
(Each question in this group contains one and only one correct answer. Circle the
alternative that represents your choice.)
3
13.
Severe scouring has occurred in a drainage ditch cut through soil. To correct
this condition, you would:
A.
Introduce plant growth.
B.
Increase the gradient.
C.
Construct a double ditch.
D.
Pave the ditch.
3
14.
Although subballast may not be used on your line, you should know how,
why, and when it should be used. It:
A.
Should be omitted when the top ballast consists of slag.
B.
Reduces the unit pressure on the roadbed.
C.
Is primarily used on low-traffic, branch-line track.
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