To Fell A Tree; To Free A Badly Fallen Tree; To Cut Trees And Branches That Are In Tension - Zenoah GZ381 Manual De Usuario

2. Remove any undergrowth from the base of the tree.
3. Check the area for obstacles such as stones,
branches and holes so that you have a clear path of
retreat when the tree starts to fall. Your path of
retreat should be roughly 135 degrees away from the
intended felling direction.
1. Danger zone
2. Retreat path
3. Felling direction
(Fig. 72)

To fell a tree

Felling is done with three cuts. First you make the
directional cuts, which consist of the top cut and the
bottom cut, and then you finish with the felling cut. By
placing these cuts correctly you can control the felling
direction very accurately.
WARNING: Unless you have special training
we advise you not to fell trees with a
diameter larger than the bar length of your
chainsaw!
To make the directional cuts
1. Start to make the directional cuts by making the top
cut first. Aim with the chainsaw's felling direction
mark (1) toward a goal further forward in the terrain,
where you would like the tree to fall (2). Stand on the
right-hand side of the tree, behind the chainsaw, and
cut with a pull stroke.
2. Make the bottom cut so that it finishes exactly at the
end of the top cut. (Fig. 73)
The directional cuts should run 1/4 of the diameter
through the trunk and the angle between the top cut and
bottom cut should be 45°.
The line where the two cuts meet is called the directional
cut line. This line should be perfectly horizontal and at
right angles (90°) to the chosen felling direction.
(Fig. 74)
To make the felling cut
The felling cut is made from the opposite side of the tree
and it must be perfectly horizontal. Stand on the left side
of the tree and cut on the pull stroke.
1. Make the felling cut about 3-5 cm (1.5-2 inches)
above the bottom directional cut. (Fig. 75)
2. Set the spiked bumper (if one is fitted) just behind
the felling hinge.
3. Use full throttle and advance the saw chain/guide
bar slowly into the tree. Make sure that the tree does
not start to move in the opposite direction to your
intended felling direction.
4. Drive a wedge or breaking bar into the cut as soon
as it is deep enough. (Fig. 76)
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5. Finish the felling cut parallel with the directional cut
line so that the distance between them is at least
1/10 of the trunk diameter. The uncut section of the
trunk is called the felling hinge. The felling hinge
controls the direction that the tree falls in. (Fig. 77)
WARNING: All control over the felling
direction is lost if the felling hinge is too
narrow or non-existent, or if the
directional cuts and felling cut are badly
placed.
(Fig. 78)
6. When the felling cut and directional cuts are
complete the tree should start to fall by itself or with
the aid of a felling wedge or breaking bar. (Fig. 79)
When the felling cut and directional cut are complete the
tree should start to fall by itself or with the aid of a felling
wedge or breaking bar.
Note: We recommend that you use a bar
that is longer than the diameter of the tree,
so that you can make the felling cut and
directional cuts with single cutting strokes.
See instructions under the heading
Accessories on page 39 to find out which
lengths of bar are recommended for your
chainsaw.
There are methods for felling trees with a diameter
larger than the guide bar length. However these
methods involve a much greater risk that the kickback
zone of the guide bar will come into contact with the
tree.
(Fig. 80)

To free a badly fallen tree

It is very dangerous to remove a trapped tree and there
is a high accident risk. The safest method is to use a
winch:
• Tractor-mounted
• Portable
WARNING: Never try to fell a tree that is
trapped and never work in the risk zone of
the hanging trapped tree.
(Fig. 81)
To cut trees and branches that are in
tension
1. Figure out which side of the tree or branch that is in
tension and where the point of maximum tension is,
for instance where it would break if it was bent even
more. (Fig. 82)
2. Decide which is the safest way to release the tension
and whether you are able to do it safely
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