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the end is hanging unsupported over the end, tension is created on
the upper surface due to the weight of the overhanging log stretching
the fibers. Likewise, the underside of the log is compressed, and the
fibers are being pushed together. If a cut is made in this area, the
kerf will have the tendency to close up during the cut. This cut would
pinch the blade.
Felling a tree
See Fig. 1 - 8.
When bucking and felling operations are being performed by two
or more persons at the same time, the felling operations should
be separated from the bucking operation 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 person, strike any utility line, or
cause any property damage. If the tree does make contact with any
utility line, the company should be notified immediately.
The chainsaw 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 should be planned and cleared as necessary before
cuts are started. The escape path should extend back and diagonally
to the rear of the expected line of fall.
Before felling starts, 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.
Do not attempt to fell trees that are rotten or have been damaged by
wind, fire, lightning, etc. This is extremely dangerous and should only
be completed by professional tree surgeons.
1.
Notching undercut
See Fig. 1 - 6.
Make the notch 1/3 the diameter of the tree, perpendicular to the
direction of the fall. Make the lower horizontal notching cut first.
Cutting the horizontal notching cut first helps to avoid pinching
either the saw chain or the guide bar when the second notch is
being made.
2. Felling-back cut
See Fig. 1 - 6.
Make the felling-back cut at least 50 mm/2 in. higher than the
horizontal notching cut. Keep 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 falling 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 desired
direction or it may rock back and bind the saw chain, stop cutting
before the felling-back cut is complete and use wedges of wood,
plastic, or aluminium to open the cut and drop the tree along the
desired line of fall.
When the tree begins to fall, remove the chainsaw from the cut,
stop the motor, put the chainsaw down, and use the retreat
path planned. Be alert for falling overhead limbs and watch your
footing.
Removing buttress roots
See Fig. 7 - 8.
A buttress root is a large root extending from the trunk of the tree
above the ground. Remove large buttress roots before felling. Make
the horizontal cut into the buttress first, followed by the vertical
cut. Remove the resulting loose section from the work area. Follow
the correct tree felling procedure after you have removed the large
buttress roots.
30
Bucking a log
See Fig. 9 - 11.
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 supported 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 underbucking the
lower 2/3 to meet the first cut.
When bucking on a slope, always stand on the uphill side of the log. To
maintain control when "cutting through", release the cutting pressure
near the end of the cut without relaxing your grip on the chainsaw
handles. Don't let the chain contact the ground. After completing the
cut, wait for the saw chain to stop before you move the chainsaw.
Always stop the motor before moving from tree to tree.
Limbing a tree
See Fig. 12 - 13.
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. Branches under tension should be cut from the
bottom up to avoid binding the chainsaw.
Springpoles
See Fig.14.
A springpole is any log, branch, rooted stump, or sapling that is bent
under tension by other wood so that it springs back if the wood
holding it is cut or removed.
On a fallen tree, a rooted stump has a high potential of springing back
to the upright position during the bucking cut to separate the log
from the stump. Watch out for springpoles—they are dangerous. Do
not attempt to cut bent branches or stumps that are under tension
unless you are professionally trained and competent to do so.
WARNING! Springpoles are dangerous and could strike the
operator, causing the operator to lose control of the chainsaw.
This could result in a severe or fatal injury to the operator.
Cutting springpoles should be done by trained users.
RESIDUAL RISKS
Even when the product is used as prescribed, it is still impossible
to completely eliminate certain residual risk factors. The following
hazards may arise during use and the operator should pay special
attention to avoid the following:
● injury caused by vibration
– Always use the right tool for the job. Use designated handles.
Restrict working time and exposure.
● injury caused by to exposure to noise
– Wear hearing protection and limit exposure.
● injury caused by contact with exposed saw teeth of the chain
● injury caused by thrown-out pieces of the workpiece (wood
chips, splinters)
● injury caused by dust and particles
● injury to the skin caused by contact with lubricants
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