ASWP16 Use of a Mobile Crane to Remove Trees
5.4.2 Crane Rigging – Single Sling Configuration
Step Action
Place choker around tree and
secure to headache ball
Ensure choker is secured properly
Ensure sling bend ratios are not exceeded
Ensure the Safe Work Load (SWL) of the sling is not
exceeded
Place choker so that when lifted the section of tree will
move in a direction away from hazards or unintended
targets
To prevent sling slippage it may be necessary to cut
notches for securing slings
Communicate to crane operator
to pretension line
Communication between crane operator and arborist shall
be clear and concise
Crane operator places tension on tree
Pretension on tree should normally equal the estimated
weight of the load of the piece to be cut
5.5 Cut Section
Step Action
Visually inspect rigging system to
ensure it is secured to tree stem
prior to lifting
Check that the headache ball and crane lifting line are
in a vertical line with the centre of gravity
Check that the choker(s) is secured
Check that there is no twisting of the lift line or
choker(s)
Check that there is a direct path from choker(s) to hook
and there are no limbs in the way
Worker aloft descends to cut
location
Cut location should be at shoulder level to allow for cut
sections to swing away from the chain saw
Establish an escape route
Escape route / method should allow the worker to move
out of the way if a section or limb swings in a different
direction than anticipated
Secure to tree using work
positioning equipment – if
ascending by climbing tree
Ensure lift will not tangle climber's fall protection
equipment
Determine style of chain saw cut to
be made
Angle Cut or Straight cut
Sawing should finish at the pinch point of the load
working around the circumference of the section
Note: A Snap Cut should be avoided. The Snap Cut
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