6 Minutes For Safety: Hazard Tree Felling - Tips #1

 Felling a hazard tree requires accurate risk assessment and complexity
analysis, and demands the sawyer’s full situational awareness.

In all cases, remember to establish and maintain a secure felling area.

Do not bypass hazard trees without taking some action such as felling or
establishing a No-Work-Zone.

Degree of hazard varies with tree size, species, and type/location of defect:

• Stem defects resulting in tree failure, i.e., collapse;
• Weakened sapwood resulting in loss of control when falling trees & limits solid wood for wedging;
• Overhead hazards, i.e., dead or hanging limbs falling on the faller. 

Indicators of potential felling hazards:

• Dead Limbs: limbs of all sizes and species with decay evident cracking, or loose hung-up limbs. Avoid working under overhead hazards.
• Witches Broom: caused by mistletoe infection, limbs can grow very large and heavy (200+ lbs).
• Split Trunk: cracked trunk from frost, lightning or wind. Visible evidence of advanced decay indicates serious weakness where the tree could fail.
• Stem Damage: caused by windfall scarring, fire, machine, and animal damage, as well as heart rot diseases.
• Thick Sloughing Bark or Sloughing Sapwood: usually found on dead trees. Loose bark on Douglas fir or loose sapwood on wind snapped cedars can dislodge during falling.
• Butt and Stem Cankers: usually found on deciduous trees but can occur on Douglas fir and pine. The infected areas weaken the stem.
• Fungal Fruiting Bodies or Conks: found on stems may indicate massive interior rot 1 – 2 yards above and below conk. Excessive resinosis (resin flow) also indicates heart or root diseases.
• Heavy Tree Lean: may be caused by damaged roots or lifting root mats, shallow or wet soils. In some cases, the tree may have corrected itself which can be determined by looking for corrected top growth.
• Root Condition: look for any ground cracks around the base of the tree, signs of decay or fungal conks on the roots.
• Cat Face: look for enough solid wood to construct an effective undercut and back cut.

References: Hazard Tree Safety Web Page - Link
.6 Minutes For Safety Task Group • 3833 S. Development Ave • Boise, ID
83705

CFN - California Fire News 2012 

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