Stihl MSA 120 C Instruction Manual page 75

12 Operating the Saw
F Stabilizing strap
The stabilizing strap supports the tree and helps prevent
it from falling prematurely. The width of the stabilizing
strap is 1/10 to 1/5 of the trunk diameter.
G Holding strap
The holding strap supports the tree and helps prevent it
from falling prematurely. The width of the holding strap is
1/10 to 1/5 of the trunk diameter.
12.3.5 Plunge cutting
Plunge cutting is a technique required for felling.
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► Begin cut with the lower portion of the guide bar nose –
with chain running at full speed.
► Cut until depth of kerf is twice the width of the guide bar.
► Swing the saw into plunge-cutting position.
► Perform the plunge cut
12.3.6 Choosing right felling cut
The choice of felling cut depends on the following factors:
– Natural lean of the tree.
– Limb structure of tree.
– Damage to tree.
– Soundness of tree.
– Snow load.
– Direction of slope.
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– Wind direction and speed.
– Neighboring trees.
There are different variations of these factors. Only two
types of tree are described in this manual.
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1 Normal tree
A normal tree stands vertically and has a uniform crown.
2 Leaner
A leaner stands at an angle and has a crown that points
in the direction of fall.
12.3.7 Felling normal, small diameter tree
A normal tree is felled with a felling cut and stabilizing strap.
This felling cut must be performed if the tree diameter is less
than the guide bar's length.
► Shout a warning.
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