Side View
1
Compression
2
Tension
Chain Saw Basics
(cont’d)
Site Preparation Tips
•
Prepare the cutting area by clearing away brush,
branches, vines, etc.
•
Remove any unnecessary tools and coil up excess
hydraulic hose.
•
Survey the limb, branch or tree to predict the direction or
path of fall. Be sure that no personnel are in that area.
Some factors that will influence the direction or path of
fall of the tree include, but are not limited to:
–
weight distribution of the limbs and branches.
The weight distribution can be changed by
pruning.
–
the lean of the tree. A tree that leans will tend to fall in
the direction it leans.
–
wind direction. Do not fell a tree in strong winds.
•
If working in a municipal area, plan the direction of fall so
that a limb or tree doesn’t fall into a roadway, strike a
nearby building, contact nearby power lines, etc.
•
If the tree is on an incline, work uphill from the fall
path. A tree or branch might tend to bounce or roll
downhill.
•
Plan and clear two emergency exit routes, in case the tree
falls in an unexpected direction.
COMPRESSION AND TENSION
Any branch or log will have two forces acting on it
— compression and tension. As the branch or log is cut,
compression tends to push the two halves toward each other.
Tension tends to pull the two halves apart.
Refer to the illustrations. A log or limb supported at both ends
has the compression on the top. A log or limb supported at one
end has the compression on the bottom.
Make the first cut on the compression side. Cut through
approximately 1/3 of the log’s diameter. Make the second cut
on the tension side. This will decrease the likelihood that the
saw will become pinched in the cut.
Figure 8 – Compression on Top
Figure 9 – Compression on Bottom
Side View
Tension
2
1
Compression
10
