Husqvarna 120, Operator'S Manual

Page: 17 / 328

To use the tree felling technique
WARNING: You must have experience to
fell a tree. If possible, engage in a training
course in chainsaw operation. Speak to an
operator with experience for more
knowledge.
To keep a safe distance
1. Make sure that persons around you keep a safe
distance at a minimum of 2 1/2 tree lengths. (Fig. 61)
2. Make sure that no person is in the risk zone before
or during felling. (Fig. 62)
To calculate the felling direction
1. Examine in which direction it is necessary for the
tree to fall. The goal is to fell it in a position where
you can limb and cut the trunk easily. It is also
important that you are stable on your feet and can
move about safely.
WARNING: If it is dangerous or not
possible to fell the tree in its natural
direction, fell the tree in a different
direction.
2. Examine the natural fall direction of the tree. For
example the tilt and bend of the tree, wind direction,
the location of the branches and weight of snow.
3. Examine if there are obstacles, for example other
trees, power lines, roads and/or buildings around.
4. Look for signs of damage and rot in the stem.
WARNING: Rot in the stem can mean a
risk that the tree falls before you
complete the cutting.
5. Make sure the tree has no damaged or dead
branches that can break off and hit you during
felling.
6. Do not let the tree fall onto a different standing tree.
It is dangerous to remove a caught tree and there is
a high accident risk. Refer to To free a trapped tree
on page 18
. (Fig. 63)
WARNING: During critical felling
operations, lift your hearing protection
immediately when the sawing is
complete. It is important that you hear
sounds and warning signals.
To clear the trunk and prepare your path of
retreat
Cut off all branches from your shoulder height and
down.
1. Cut on the pull stroke from the top down. Make sure
that the tree is between you and the product. (Fig.
64)
2. Remove undergrowth from the work area around the
tree. Remove all cut off material from the work area.
3. Do a check of the area for obstacles such as stones,
branches and holes. You must have a clear path of
retreat when the tree starts to fall. Your path of
retreat must be approximately 135 degrees away
from the felling direction.
1. The danger zone
2. The path of retreat
3. The felling direction
(Fig. 65)
To fell a tree
Husqvarna recommends you to make the directional
cuts and then use the safe corner method when you fell
a tree. The safe corner method helps you to make a
correct felling hinge and control the felling direction.
WARNING: Do not fell trees with a diameter
that is more than two times larger than the
guide bar length. For this, you must have
special training.
The felling hinge
The most important procedure during tree felling is to
make the correct felling hinge. With a correct felling
hinge, you control the felling direction and make sure
that the felling procedure is safe.
The thickness of the felling hinge must be equal and a
minimum of 10% of the tree diameter.
WARNING: If the felling hinge is incorrect or
too thin, you have no control of the felling
direction.
(Fig. 66)
To make the directional cuts
1. Make the directional cuts ¼ of the diameter of the
tree. Make a 45°-70° angle between the top
directional cut and bottom directional cut. (Fig. 67)
a) Make the top directional cut. Align the felling
direction mark (1) of the product with the felling
direction of the tree (2). Stay behind the product
and keep the tree on your left side. Cut with a
pull stroke.
b) Make the bottom directional cut. Make sure that
the end of the bottom directional cut is at the
same point as the end of the top directional cut.
(Fig. 68)
2. Make sure that the bottom directional cut is
horizontal and at a 90° angle to the felling direction.
To use the safe corner method
The felling cut must be made slightly above the
directional cut.
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