Cutting The Trenches
There are ditching-machines that do efficient
work. The best are costly. Most of the work on farms will continue to
be done with ditching-spades. The ground should be moved when wet, so
that labor can be saved.
A line should be used to secure a straight side to the trench. The
grade should be obtained by means of a system of strings. If two light
poles be pushed into the ground at each 100-feet station, one on either
side of the proposed trench, and a string be drawn across at a point
5-1/2 feet above the bottom of the proposed trench, these strings will
be in line on a grade 5-1/2 feet above the grade the drain will have.
As the cut at the station is known, the height of the string above the
top of the stake is easily determined. These strings will reveal any
inaccuracy in the survey. The workman can test every part of the bottom
of the trench by use of a rod 5-1/2 feet high, the top end being
exactly in line with the strings when the lower end is placed on the
correct grade of the trench. This device is better than running water
where grades are slight.
A drain scoop should be used in bottom of the trench to make a resting
place for the tile that will prevent any displacement by the soil when
the trench is filled.
Next: Depth Of Trenches
Previous: Establishing A Grade