ICFR – Chainsaw Safety and Operating Handbook
26
Figure 19: Technique to reduce butt wastage
10.11.2.7 t
rees
that
spLit
Under normal circumstances splitting can be minimised
using the following technique:
•
Firstly, make the directional notch as for the
standard technique. Then cut "ears" at each side
of the stem at an angle of not less than 45°. These
cuts must not exceed the guide bar width.
Figure 20: “Ears”
In veneer logs side splitting can be minimised using
the following technique:
•
Firstly, make the directional notch as for the
standard technique. Then make side cuts on the
stump parallel to, and at the same level as the
bottom cut of the directional notch, and no deeper
than the guide bar width.
Figure 21: Side cuts
10.11.3
f
elling
techniqueS
uSing
wedgeS
Important:
It is recommended to use machine
assisstance for trees with a profound lean as wedges
are limited in changing the felling direction. (Refer
to section 10.13).
Wedges should be used in the following situations:
10.11.3.1 f
eLLing
Large
trees
with
no
or
sLight
Lean
This technique can be used where the diameter of the
tree exceeds the guide bar length. The wedge will
ensure that the desired felling direction is achieved.
Use the following method:
•
Step 1:
Make the directional notch as for the
standard technique.
•
Step 2:
Select the side of the tree from which
the first part of the felling cut will
be made. If the tree has a slight
lean, or if there is rot or something
in the crown that could dislodge
as the tree falls, make the first part
of the felling cut from that side by
inserting the chainsaw, leading with
the bottom edge of the guide bar to
avoid kickback.
•
Step 3:
Continue the cut until the right hinge
width is reached. Saw back about the
width of the guide bar.
•
Step 4:
Continue with the first part of the
felling cut. Place a wedge in the cut.
•
Step 5:
Saw the second part of the felling cut
up to the hinge. Tap the wedge in as
the cut proceeds. Always finish the
second part of the felling cut on the
safe side of the tree.
