guidance on digging and travel speeds for the type of
ditcher used.
Obstructions
Where boulders, heavy roots, or pipelines could be
met, you should adhere to the following guidelines:
. Both walking and wheel speeds should be slow.
. Soft boulders are cut through by the teeth.
Depending on how buried a hard boulder is, it may be
pulled to the surface or forced forward. This is because
the deeper boulder not only is held down by a greater
weight of dirt but also the direction of the tooth contact
tends to force it forward, rather than up.
. The wheel will usually ride over embedded
boulders that cannot be removed by the ditcher. If a large
boulder is near the surface of the cut, it may stop the
forward motion of the machine; in which case, power
should be cut off promptly.
. If a boulder is pulled to the surface, it may land
in an inconvenient spot, forward of the wheel and
between the tracks. You may have to lift the wheel into
transporting position, work forward until clear of the
rock, push it out of the way, and backup until the wheel
can be lowered to the ditch bottom. If the boulder is too
large for the wheel to clear, release the wheel drive
clutch so the wheel can turn as it is pulled over it.
. When the wheel is lifted above grade to clear any
obstruction, it maybe worked back to grade at the other
side in the same way the cut is started.
. Turn with caution while digging. Slight turns
cause the wheel to move sideways in the trench. If the
buckets have long side teeth or side-cutting bars and the
earth is soft, you can make a gradual turn without
damaging the wheel assembly. Sharp turns may cause
severe damage, such as bending the wheel frame,
bending the wheel itself, or pulling the wheel frame off
the vertical track.
LADDER DITCHER
The boom on the ladder ditcher (fig. 9-67) cannot
be brought closer than about 35 degrees to the vertical.
Figure 9-67.—Ladder ditcher.
9-31
