Working With Tree Service Chain-Saws From A Rope And Harness - Husqvarna T425 Manual De Instrucciones

7 Take great care when you cut with the top edge of the
bar, i.e. when cutting from the underside of the object.
This is known as cutting on the push stroke. The chain
tries to push the chain saw back towards the user. If
the saw chain is jamming, the saw may be pushed
back at you.
8 Unless the user resists this pushing force there is a
risk that the chain saw will move so far backwards that
only the kickback zone of the bar is in contact with the
tree, which will lead to a kickback.
Cutting with the bottom edge of the bar, i.e. from the
top of the object downwards, is known as cutting on
the pull stroke. In this case the chain saw pulls itself
towards the tree and the front edge of the chain saw
body rests naturally on the trunk when cutting. Cutting
on the pull stroke gives the operator better control
over the chain saw and the position of the kickback
zone.
9 Follow the instructions on sharpening and maintaining
your bar and chain. When you replace the bar and
chain use only combinations that are recommended
by us. See instructions under the headings Cutting
equipment and Technical data.
Working with tree service chain-saws
from a rope and harness
This chapter sets out working practices to reduce the risk
of injury from tree service chainsaws when working at
height from a rope and harness. While it may form the
basis of guidance and training literature, it should not be
regarded as a substitute for formal training.
General requirements working at height
Operators of tree service chainsaws working at height
from a rope and harness should never work alone. A
competent ground worker trained in appropriate
emergency procedures should assist them.
Operators of tree service chainsaws for this work should
be trained in general safe climbing and work positioning
techniques and shall properly equipped with harnesses,
WORKING TECHNIQUES
ropes, strops, karabiners and other equipment for
maintaining secure and safe working positions for both
themselves and the saw.
Preparing to use the saw in the tree
The chain saw should be checked, fuelled, started and
warmed up by the ground worker and the chain brake
should be engaged before it is sent up to the operator in
the tree. The chainsaw should be fitted with a suitable
strop for attaching to the operator's harness:
a) choke the strop around the attachment point on the
rear of the saw (A).
b) provide suitable karabiners to allow indirect (i.e. via the
strop) and direct attachment (i.e. at the attachment point
on the saw) of saw to the operators harness.
c) ensure the saw is securely attached when it is being sent up to the operator.
d) ensure the saw is secured to the harness before it is
disconnected from the means of ascent.
The saw should only be attached to the recommended
attachment points on the harness. These may be at mid-
point (front or rear) or at the sides. Where possible
attaching the saw to centre rear mid-point will keep it clear
of climbing lines and support its weight centrally down the
operator's spine.
When moving the saw from any attachment point to
another, operators should ensure it is secured in the new
position before releasing it from the previous attachment
point.
Using the chainsaw in the tree
An analysis of accidents with these saws during tree
service operations shows the primary cause as being
inappropriate one-handed use of the saw. In the vast
majority of accidents, operators fail to adopt a secure
work position witch allows them to hold both handles of
the saw. This results in an increased risk of injury due to:
• not having a firm grip on the saw if it kicks back.
• a lack of control of the saw such that it is more liable
to contact climbing lines and operators body
(particularly the left hand and arm)
• loosing control from insecure work position resulting
in contact with the saw (unexpected movement during
operation of the saw)
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