Stiga PR 500 Li 48, Operator'S Manual, Page: 35 / 47

EN - 13
go during cutting and the risk of the tree
being unstable after the branch has been cut.
When limbing, it is necessary to
leave the lower, larger branches to
support the trunk on the ground.
Remove the small branches with
a single cut (Fig. 28.A).
It is recommended to cut the tensioned branches
working from the bottom upwards to prevent
the chainsaw from bending (Fig. 28.B).
6.6.4 Bucking the trunk
Bucking means sawing a tree trunk into logs.
It is essential to make sure your feet are
positioned firmly on the ground, and your weight
is distributed equally on both feet. If possible,
it is recommended to raise and support the
trunk using branches, logs or blocks of wood.
It is easier to saw a log using the
spiked bumper (Fig. 1.I):
1. plant the spiked bumper into the log and use
it as a pivot. Cut with an arched motion to
make the bar penetrate the wood (Fig. 29);
2. repeat several times if necessary, changing
the point where you plant the spiked bumper.
• Trunk lying on the ground
When the entire trunk is lying on the
ground, it is bucked from the top
down (overbucking) (Fig. 30.A).
– Cut up to half the diameter, roll the log
over and finish sawing on the other side.
• Trunk resting on one end only
When the trunk is resting on one end only:
– saw through 1/3 of the diameter from the
bottom up (underbucking) (Fig. 31.A);
– then perform the final cut, overbucking
to reach the first cut (Fig. 31.B).
• Trunk resting on both ends
When the trunk is resting on both ends:
– saw through 1/3 of the diameter from the
top down (overbucking) (Fig. 32.A);
– then perform the final cut, underbucking the
lower 2/3 to reach the first cut (Fig.. 32.B).
• Sloping trunk
Always stand uphill when bucking
a sloping trunk (Fig. 33).
During the operation, to maintain control when
the cut is almost complete, reduce the bucking
pressure without removing removing your
hands from the machine hand grips. Take all
necessary precautions to prevent the machine
from coming into contact with the ground.
6.7 FOR PRUNING HIGH UP USING A
ROPE AND A BELT HARNESS
IMPORTANT This chapter describes the
work procedures implemented to reduce
the risk of injuries when using chainsaws
for trimming and performing height work
aided by a rope and belt harness.
This is not intended to replace formal
training on the subject. The guidelines
provided in this appendix are only examples
of best practice. National laws and
regulations must always be observed.
6.7.1 Using the chainsaw with two hands
Using the chainsaw with two hands allows you to:
– maintain a firmer grip on the chainsaw
in the event of a kickback;
– maintain a level of control over the
chainsaw that decreases the probability
of it coming into contact with the
ropes and the operator's body;
– adopt a safe work position to avoid any
loss of control that could lead to contact
with the chainsaw (unintentional movement
while the chainsaw is running).
In order to be able to grip the chainsaw
with both hands, as a general rule, the
operator must always try to maintain a
safe position when using the chainsaw:
– at a hip level when cutting horizontally or
– at a solar plexus level when cutting vertically.
• When the operator is working close to
vertical trunks, with reduced lateral force
on the working position, stable support is
sufficient to maintain a safe working position.
• When the operator moves away from the
trunk, the lateral forces increase and it
is necessary to eliminate or offset them
using one of the following methods:
– add an additional fastening point
for the main rope to stabilise it;
– use a flat strap with end slots adjustable
from the harness fastened to an
additional fastening point (Fig. 34);
• Use of a temporary foot stirrup, created by
a ring belt, can make it easier to achieve
a stable working position. (Fig. 35).
6.7.2 Using the chainsaw with one hand
Do not work with one hand if you
are in an unstable working position or
when using a chainsaw instead of a
handsaw to cut small sized branches.