Stihl MSA 120 C Notice D'emploi page 55

12 Operating the Saw
12.4.4 Basic information on felling cut
C
C Felling notch
The felling notch determines the direction of
fall.
D Hinge
The hinge helps control the falling tree. The
width of the hinge is 1/10 of the trunk diame‐
ter.
E Felling cut
The tree is felled with the felling cut. The fell‐
ing cut is 1/10 of the trunk diameter (at least 3
cm) above the bottom of the felling notch.
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.
12.4.5 Plunge cutting
Plunge cutting is a technique required for felling.
1
3
2
► 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.
0458-716-9621-E
C E
1/10
Ø
G
12.4.6 Selecting the Appropriate Felling Cut
The choice of appropriate felling cut depends on
the following conditions:
– The natural inclination of the tree
– The tree's branch formation
– Damage to the tree
– The tree's state of health
– If there is snow on the tree: the snow load
– The direction of slope
– Wind direction and speed
– Nearby trees, if any
There are different features of these conditions.
Only two features are described in this Instruc‐
tion Manual.
1
1 Normal tree
A normal tree is vertical and has an even
crown.
2 Leaner
A leaner stands at an angle and the crown
faces in the direction of fall.
12.4.7 Felling normal, small diameter tree
A normal tree is felled with a felling cut and stabi‐
lizing strap. This felling cut must be performed if
the tree diameter is less than the guide bar's
length.
► Shout a warning.
► Plunge the guide bar into the felling cut until it
is visible at the other side of the trunk,
12.4.5.
► Apply the spiked bumper behind the hinge and
use it as a pivot.
► Enlarge felling cut in direction of hinge.
► Enlarge felling cut in direction of stabilizing
strap.
English
2
1.
2.
55