English---22
115391326 Rev. 3 1/31/11
WORKING TECHNIQUES
Another very important factor, which does
not affect the felling direction but does affect
your safety, is to make sure the tree has no
damaged or dead branches that might break
off and hit you during felling.
The main point to avoid is letting the tree fall
onto another tree. It is very dangerous to re-
move a trapped tree and there is high accident
risk. See instructions under the heading Free-
ing a tree that has fallen badly.
Clearing the trunk and preparing your
retreat
Delimb the stem up to shoulder height. It is
safer to work from the top down and to have
the tree between you and the saw.
Remove any undergrowth from the base of
the tree and check the area for obstacles
(stones, branches, holes, etc.) 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 in-
tended felling direction.
(38)
Felling
Felling is done using three cuts. First you
make the directional cuts, which consist of
the top cut and the bottom cut, then you fin-
ish with the felling cut. By placing these cuts
correctly you can control the felling direction
very accurately.
Directional cuts
To make the directional cuts you begin with
the top cut. Stand to the right of the tree and
cut on the pull stroke. Next make the bottom
cut so that it finishes exactly at the end of
the top cut.
(39)
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.
(40)
Felling cut
The felling cut is made from the opposite
side of the tree and it must be perfectly hori-
zontal. Stand on the left side of the tree and
cut on the pull stroke.
Make the felling cut about 1.5--2 inches (3--5
cm) above the bottom directional cut.
(41)
The log is lying on the ground.
There is
little risk of the chain jamming or the object
splitting. However there is a risk that the
chain will touch the ground when you finish
the cut.
Cut all the way through the log from above.
Avoid letting the chain touch the ground as
you finish the cut. Maintain full throttle but
be prepared for what might happen.
(36)
If it is possible (can you turn the log?) stop
cutting about 2/3 of the way through the log.
Turn the log and finish the cut from the op-
posite side.
The log is supported at one end.
There is
a high risk that it will split. Start by cutting
from below (about 1/3 of the way through).
Finish by cutting from above so that the
two cuts meet.
T
he log is supported at both ends.
There is a high risk that the chain will jam.
Start by cutting from above (about 1/3 of
the way through).
Finish by cutting from below so that the
two cuts meet.
Tree felling technique
Safe distance
The safe distance between a tree that is to
be felled and anyone else working nearby
is at least 2 1/2 tree lengths. Make sure
that no--one else is in this “risk zone” be-
fore or during felling.
(37)
Felling direction
The aim is to fell the tree in a position
where you can limb and cross--cut the log
as easily as possible. You want it to fall in
a location where you can stand and move
about safely.
Once you have decided which way you
want the tree to fall you must judge which
way the tree would fall naturally.
Several factors affect this:
S
Lean of the tree
S
Bend
S
Wind direction
S
Arrangement of branches
S
Weight of snow
S
Obstacles within the reach of the tree: for
example, other trees, power lines, roads
and buildings.
S
Look for signs of damage and rot in the stem,
this makes it more probably that the tree will
break and start to fall before you expect it to.
You may find you are forced to let the tree
fall in its natural direction because it is im-
possible or dangerous to try to make it fall
in the direction you first intended.
IMPORTANT! It takes a lot of experience to
fell a tree. Inexperienced users of chain saws
should not fell trees. Do not attempt any task
beyond your experience level!
WARNING:
Unless you have
special training we advise you not
to fell trees with a diameter larger
than the bar length of your saw!
IMPORTANT! During critical felling opera-
tions, hearing protectors should be lifted
immediately when sawing is completed so
that sounds and warning signals can be
heard.
