Bosch GKE 35 BCE Professional User Manual

Page 28

28 | English

1 609 929 V11 | (23.8.11)

Bosch Power Tools

Cutting Wood under Tension (see figure H)
f

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 diameter 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 or-

der to avoid splitting of the log or jamming of the saw.
Felling Trees (see figure I)
f

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 (n).

Never attempt to free a jammed chain saw with the mo-

tor running. Use wooden wedges to free a jammed

chain saw.

When cutting and felling operations are being performed by

two or more persons at the same time, the felling operations

should be separated from the cutting 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 per-

son, strike any utility line or cause any property damage. If the

tree does make contact with a utility line, the company should

be notified immediately.
The chain saw operator should keep on the uphill side of the

terrain as the tree is likely to roll or slide downhill after it is

felled.
An escape path (o) should be planned and cleared as neces-

sary before cuts are started. The escape path should extend

back and diagonally 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 diame-

ter of the tree, perpendicular to the direction of fall. Make the

lower horizontal notching cut first. This will help to avoid

pinching either the saw chain or the guide bar when the sec-

ond notch is being made.
Felling back-cut: Make the felling back-cut (Y) at least

50 mm higher than the horizontal notching 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 fall-

ing 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 de-

sired direction or may rock back and bind the saw chain,

stop cutting and switch the chain saw off. Use wedges (Z)

of wood, plastic or aluminium to open the cut and drop the

tree along the desired line of fall.

– When the tree does not begin to fall when the felling gets

close to the hinge, remove the chain saw from the cut,

switch off and make the tree fall by driving a wedge (Z) into

the horizontal cut.

When the tree begins to fall, remove the chain saw from the

cut (if not already taken place), stop the motor, and put the

chain saw down. Leave the danger area via the retreat path

planned. Be alert for overhead limbs falling and watch your

footing.
Limbing a Tree (see figure K)
Limbing is removing the branches from a fallen tree. When

limbing, leave larger lower limbs to support the log off the

ground. Remove the small limbs in one cut as illustrated in the

figure. Branches under tension should be cut from the bottom

up to avoid binding the chain saw.
Bucking a Log (see figures L – O)
Bucking is cutting a log into lengths. It is important to make

sure your footing is firm and your weight is evenly distributed

on both feet. When possible, the log should be raised and sup-

ported by the use of limbs, logs or chocks. Follow the simple

directions for easy cutting.
When the log is supported along its entire length, it is cut from

the top (overbuck).
When the log is supported on one end, cut 1/3 the diameter

from the underside (underbuck). Then make the finished cut

by overbucking to meet the first cut.
When the log is supported on both ends, cut 1/3 the diameter

from the top overbuck. Then make the finished cut by under-

bucking the lower 2/3 to meet the first cut.
When bucking on a slope, always stand on the uphill side of

the log. When “cutting through”, release the cutting pressure

near the end of the cut without relaxing your grip on the chain

saw handles in order to maintain complete control. Don’t let

the chain contact the ground. After completing the cut, wait

for the saw chain to stop before you move the chain saw. Al-

ways stop the chain saw motor before moving from tree to

tree.

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