Jonsered CS 2139T - Manual (Page 24)

24 – English
WORKING TECHNIQUES
Once you have decided which way you want the top of the tree
to fall you must assess which way the top of the tree would fall
naturally.
Several factors affect this:
• Lean of the tree
• Bend
• Wind direction
• Arrangement of branches
• Weight of snow
You may find you are forced to let the tree fall in its natural
direction because it is impossible or dangerous to try to make
it fall in the direction you first intended.
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.
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
finish 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.
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.
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.
Make the felling cut about 3-5 cm (1.5-2 inches) above the
bottom directional cut.
Set the spike bumper (if one is fitted) just behind the felling
hinge. Use full throttle and advance the chain/bar slowly into
the tree. Make sure the tree does not start to move in the
opposite direction to your intended felling direction. Drive a
wedge or breaking bar into the cut as soon as it is deep
enough.
!
WARNING! During critical felling operations,
hearing protectors should be lifted
immediately when sawing is completed so
that sounds and warning signals can be
heard.