P/N 7010-0344
Chapter 5
5-1
Grading Applications
Sonic Stringline
Figure 5-1.
Setting Up a Sonic Stringline
On a typical project, hubs or laths, offset from the edge of the road,
provide the grade information for the operator. This information
needs to be transferred from the ground to the operator. This is
commonly done by a grade setter using a hand level, a 4 man crew
pulling a string across the road and marking cuts, placing "blue tops"
or hubs at finished grade, or some other similar method. In any of
these methods, the operator has grade information at the stakes -
every 25 or 50 feet.