12
16
To avoid pushback
1. Be alert to forces or situations that may cause
material to pinch the top of the chain.
2. Do not cut more than one log at a time.
3. Do not twist the saw when withdrawing the bar
from a plunge cut or under buck cut (gures 25 to
27 and 33, pages 13 and 15), because the chain
can pinch.
Pull-in:
Pull-in occurs when the chain on the bottom of the bar
is suddenly stopped. The chain on the bottom of the
bar stops when it is pinched, caught or encounters a
foreign object in the wood (see g. 15). The reaction of
the chain pulls the saw forward, causing the operator
to lose control.
Pull-in frequently occurs when the spike bar of the
saw is not held securely against the tree or limb and
when the chain is not rotating at full speed before it
contacts the wood.
WARNING!
Use extreme caution when cutting small size brush
and saplings which may easily catch the chain and
pull you off balance.
To avoid pull-in
1. Always start a cut with the chain rotating at full speed
and the spike bar in contact with the wood.
2. Pull-in may also be prevented by using plastic
wedges to open the kerf or cut.
Cutting techniques
Felling
Felling is cutting down a tree.
Before felling a tree, consider carefully all conditions
which may affect the direction of fall, including:
The intended direction of the fall.
The neutral lean of the tree.
Any unusually heavy limb structure.
Surrounding trees and obstacles.
The wind direction and speed.
WARNING!
Always observe the general condition of the tree.
Look for decay and rot in the trunk. If it is rotted
inside, it could snap and fall toward the operator
while being cut.
Also look for broken or dead branches which could
vibrate loose and fall on the operator. When fell-
ing on a slope, the operator should stand on the
up-hill side.
Pushback:
Pushback occurs when the chain on the top of the
bar is suddenly stopped when it is pinched, caught
or encounters a foreign object in the wood. The reac-
tion of the chain drives the saw straight back toward
the operator causing loss of saw control. Pushback
fre-quently occurs when the top of the bar is used for
cutting (g. 14).
14
15
When felling in the vicinity of roads, railways and
power lines, etc., take extra precautions (see g.
16). Inform the police, utility company or railway
authority before beginning to cut.