Bosch GKE Professional 40 BCE Original Instructions Manual page 37

OBJ_BUCH-716-001.book Page 37 Tuesday, January 13, 2009 3:26 PM
Position and set short logs safely before sawing.
Saw only wood or wooden objects. When saw-
ing, always take care to avoid hitting stones,
nails, etc., as these could be thrown up, could
cause damage to the chain, or could result in se-
rious injury to the operator or bystanders.
Keep a running chain saw clear of wire fencing
or the ground.
Use of the saw to thin out branches or bushes is
not approved.
Length cuts must be carried out with particular
care, as leverage with the gripping teeth 12 is
not possible. Guide the chain saw at a flat angle
to avoid kickback.
When working on a slope, operate above or to
the side of the trunk or laying tree.
Be careful not to trip over tree stumps, branch-
es, roots, etc.
Cutting Wood under Tension (see figure H)
Be extremely careful when sawing wood,
branches or trees under tension. Leave saw
jobs like these to trained professionals.
There is a high risk of accidents.
When sawing logs supported on both ends, start
the cut from above (Y) about one third of the di-
ameter into the log and then finish the cut at the
same spot from below (Z), in order to avoid
splitting of the log or jamming of the saw. Avoid
contact of the saw chain with the ground.
When sawing logs supported on only one end,
start the cut from below (Y) about one third of
the diameter into the log and then finish the cut
at the same spot from above (Z), in order to
avoid splitting of the log or jamming of the saw.
Felling Trees (see figure I)
Always wear hard hat to protect head
against falling branches.
The chain saw may only be used to fell trees
smaller in diameter than the length of the
chain bar.
Secure the work area. Ensure no persons or
animals are in the vicinity of the falling tree
( ).
Bosch Power Tools
Never attempt to free a jammed chain saw
with the motor running. Use wooden wedg-
es to free a jammed chain saw.
When bucking and felling operations are being
performed by two or more persons at the same
time, the felling operations should be separated
from the bucking operations by a distance of at
least twice the height of the tree being felled.
Trees should not be felled in a manner that
would endanger any person, strike any utility
line or cause any property damage. If the tree
does make contact with a utility line, the compa-
ny should be notified immediately.
The chain saw operator should keep on the up-
hill side of the terrain as the tree is likely to roll
or slide downhill after it is felled.
An escape path ( ) should be planned and
cleared as necessary before cuts are started.
The escape path should extend back and diago-
nally to the rear of the expected line of fall.
Before felling is started, consider the natural
lean of the tree, the location of larger branches
and the wind direction to judge which way the
tree will fall.
Remove dirt, stones, loose bark, nails, staples,
and wire from the tree.
Notching undercut: Make the notch (X – W) 1/3
the diameter of the tree, perpendicular to the di-
rection of fall. Make the lower horizontal notch-
ing cut first. This will help to avoid pinching ei-
ther the saw chain or the guide bar when the
second notch is being made.
Felling back-cut: Make the felling back-cut (Y)
at least 50 mm higher than the horizontal notch-
ing cut. Carry out the felling back-cut parallel to
the horizontal notching cut. Make the felling
back-cut so that enough wood is left to act as a
hinge. The hinge-wood keeps the tree from
twisting and falling in the wrong direction. Do
not cut through the hinge.
As the felling gets close to the hinge, the tree
should begin to fall. If there is any chance that
the tree may not fall in the desired direction or
may rock back and bind the saw chain, stop cut-
ting before the felling back-cut is complete and
use wedges of wood, plastic or aluminium to
open the cut and drop the tree along the desired
line of fall.
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