If the tree trunk is supported at both ends as
shown, first cut through a third of the trunk diam-
eter from the top side, then cut through the
remaining
2/3 from the bottom side level with the top cut.
Delimbing trees
This is the process of cutting branches from a
felled tree. In the case of large, downward-growing
branches that support the tree, cut up the tree
trunk before delimbing. Cut off smaller branches
with a single cut as shown in the illustration.
Branches that are under tension should be cut
from below to avoid jamming the saw.
Felling a tree
If two or more persons are cutting and felling trees
at the same time, the clearance between the felling
and cutting persons should be equal to at least
twice the height of the tree to be felled. When
felling trees, it must be ensured that no other
persons are exposed to danger, no supply lines
are damaged and no property damage is caused.
Should a tree come in contact with a supply line,
the utility company must be informed immediately.
When performing sawing jobs on a slope, the
chainsaw operator should remain above the tree to
be felled, since the tree will probably roll or slip
downhill after being felled.
Before felling, an escape route should be planned
and, if necessary, cleared. The escape route
should lead diagonally backwards away from the
direction in which the tree is expected to fall (see
figure).
Emergency
escape
route
Danger zone
Danger zone
Danger zone
Emergency
escape route
2.) 2/3
1.) 1/3
1.) 1/3
2.) 2/3
FELLING
DIRECTION
Before felling, the natural inclination of the tree, the
position of large branches and the wind direction
must be taken into account when assessing the
direction in which the tree is expected to fall.
Dirt, stones, loose bark, nails, clamps and wire
must be removed from the tree.
Starting a notch:
Saw a notch (A) with a depth of 1/3 of the tree's
diameter at a right angle to the falling direction, as
shown in the figure.
C
A
B
First cut the bottom, horizontal notch. Jamming of
the chainsaw or guide bar when cutting the notch
can thus be avoided.
Starting a felling cut:
Start the felling cut (B) at least 50 mm above the
horizontal notch (see figure). Execute the felling cut
parallel to the horizontal notch cut. Make the felling
cut deep enough so that a breaking bar (C)
remains in position and can act as a hinge. The bar
prevents the tree from turning and falling in the
wrong direction. Do not saw through the bar.
Width of the bar (C): 50 mm.
When the felling cut approaches the bar, the tree
should start to fall. If it becomes apparent that the
tree will possibly not fall in the desired direction, or
inclines back and the sawing chain jams, interrupt
the felling cut and use wedges made of wood,
plastic or aluminium to open the cut and return the
tree back to the desired felling line.
When the tree starts falling, remove the chainsaw
from the cut, switch it off, set it down and leave the
danger zone via the planned escape route. Watch
out for falling branches and take care not to
stumble.
Retensioning the sawing chain
When working with the chainsaw, the sawing chain
expands as a result of heat. It then starts to sag
and can jump out of the cutter groove.
Check the chain tension (as specified in chapter
7.1) and retighten the chain if necessary.
If the sawing chain is retensioned when it is hot, at
the end or work it must be slackened because
otherwise cooling could result in high contraction
tension.
Insufficient chain lubrication
If the oil reservoir is still almost full after chainsaw
operation of around 20 minutes, it may be that the
oil channel (12) of the machine, or the oil inlet bore
(14) of the cutter, is obstructed and has to be
cleaned.
ENGLISH
ENG
1/3
19