Stihl MSA 160 C Instruction Manual page 47

11 Operating the Saw
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.
11.4.4 Cutting the felling notch
The felling notch determines the direction in
which the tree falls. Country-specific standards
for making the felling notch must be observed.
► Position the saw so that the felling notch is an
right angles to the direction of fall and the saw
is close to the ground.
► Make the horizontal cut.
► Make the angle cut at 45° to the horizontal cut.
► If the wood is sound and long-fibered:
Observe the following points when making
sapwood cuts:
– The cuts must be the same at both sides.
– The cuts must be at same height as bottom
of felling notch.
– The width of the cuts is 1/10 of the trunk
diameter.
The trunk does not splinter when the tree falls.
0458-701-9821-G
11.4.5 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
11.4.6 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.
11.4.7 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.
English
2
47