WORKING
TECHNIQUES
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.
(82)
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. (83)
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. (84)
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 Technical
data section to
find out which lengths of bar are recommended
for your
saw.
There are methods for felling trees with a diameter
larger
than the bar length. However these methods involve a
much greater risk that the kickback zone of the bar will
come into contact with the tree. (4)
Freeing a tree that has fallen badly
Freeing
a "trapped
tree"
It is very dangerous
to remove a trapped tree and there is
high accident
risk.
Never try to fell the tree that is trapped.
Never work in the risk zone of the hanging trapped tree.
(85)
The safest method is to use a winch.
Tractor-mounted
Portable
Cutting
trees and branches
that are in tension
Preparations:
Work out which side is in tension and where
the point of maximum tension is (i.e. where it would break
if it was bent even more). (86)
Decide which is the safest way to release the tension and
whether you are able to do it safely. In complicated
situations the only safe method is to put aside your chain
saw and use a winch.
General
advice:
Position yourself so that you will be clear of the tree or
branch when the tension is released. (87)
Make one or more cuts at or near the point of maximum
tension. Make as many cuts of sufficient depth as
necessary
to reduce the tension and make the tree or
branch break at the point of maximum tension. (88)
Never cut straight
through
a tree or branch
that is in
tension!
If you must cut across tree/limb,
make two to three cuts,
one inch apart, one to two inches deep. (89)
Continue to cut deeper until tree/limb bends and tension
is released. (90)
Cut tree/limb from outside the bend, after tension has
been released.
How to avoid
kickback
A
WARNING!
Kickback
can happen very
sudden y and violently; kicking the chain
saw
bar and chain back at the user. If
this happens
when the chain is racy ng it
can cause very serious, even fatal
injuries. It is vital you understand
what
causes kickback
and that you can avoid
it by taking care and using the right
working
technique.
What is kickback?
The word kickback is used to describe
the sudden
reaction that causes the chain saw and bar to jump off an
object when the upper quadrant
of the tip of the bar,
known as the kickback zone, touches an object. (61)
Kickback always occurs in the cutting plane of the bar.
Normally
the chain saw and bar are thrown backwards
and upwards towards the user. However, the chain saw
may move in a different direction depending
on the way it
was being used when the kickback zone of the bar
touched the object. (7)
Kickback only occurs if the kickback zone of the bar
touches an object. (4)
Limbing
A
WARNING!
A majority
of kickback
accidents
occur during
limbing.
Do not
use the kickback
zone of the guide
bar.
Be extremely cautious
and avoid
contacting
the log, other limbs or objects
with the nose of the guide
bar. Be
extremely
cautious
of limbs under
tension.They
can spring back toward
you and cause loss of control resulting
in injury,
Make sure that you can stand and move about safely.
Work on the left side of the trunk. Work as close as
possible to the chain saw for maximum control. If possible,
let the weight of the chain saw rest on the trunk.
Keep the trunk between you and the chain saw as you
move along the trunk.
Cutting
the trunk
into logs
Bee instructions
under the heading Basic cutting
technique.
1153135-49
Rev.6 2013-12-09
English - 25