WORKING TECHNIQUES
of climbing lines and support its weight centrally down the operator’s spine.
When moving the saw from any attachment point to another, operators should ensure it is secured in the new position before releasing it from the previous attachment point.
Using the chainsaw in the tree
An analysis of accidents with these saws during tree service operations shows the primary cause as being inappropriate
•not having a firm grip on the saw if it kicks back.
•a lack of control of the saw such that it is more liable to contact climbing lines and operators body (particularly the left hand and arm)
•loosing control from insecure work position resulting in contact with the saw (unexpected movement during operation of the saw)
Securing the work position for two-handed use
To allow the operator to hold the saw with both hands, they should as general rule, aim for secure work position where they are operating the saw at:
•hip level when cutting horizontal sections.
•solar plexus level when cutting vertical sections.
Where the operator is working close into vertical stems with a low lateral forces on their work position, then a good footing may be all that is needed to maintain a secure work position. However as operators move away from the stem, they will need to take steps to remove or counteract the increasing lateral forces by, for example, a
Gaining a good footing at the working position can be assisted by use of a temporary foot stirrup created from an endless sling.
Starting the saw in the tree
When starting the saw in the tree, the operator should:
a)apply the chain brake before starting.
b)hold saw on either the left or right of the body when starting:
1on the left side hold the saw with the left hand on the front handle and thrust the saw away from the body while holding the pull starter cord in the other hand.
2on the right side, hold the saw with the right hand on either handle and thrust the saw away from the body while holding the pull starter cord in the left hand.
The chain brake should always be engaged before lowering a running saw onto its strop. Operators should always check the saw has sufficient fuel before undertaking critical cuts.
One-hand use of the chainsaw
Operators should never use a chain saw onehanded.
Operators should never:
•cut with the kickback zone at the tip of the chainsaw guide bar
•‘hold and cut’ sections.
•attempt to catch falling sections.
•Cut in the tree when he/she is only secured with one rope, always use 2 secured lines.
•check condition of harness, belt and ropes at regular frequent intervals.
Freeing a trapped saw
If the saw should become trapped during cutting, operators should:
•switch off the saw and attach it securely to the tree inboard (i.e. towards the truck side) of the cut or to a separate tool line.
•pull the saw from the kerf whilst lifting the branch as necessary.
•if necessary, use a handsaw or second chain saw to release the trapped saw by cutting a minimum of 30 cm away from the trapped saw.
Whether a handsaw or a chainsaw is used to free a stuck saw, the release cuts should always be outboard (toward the tips of the branch), in order to prevent the saw being taken with the section and further complicating the situation.
Basic cutting technique
General
•Always use full throttle when cutting!
•Reduce the speed to idle after every cut (running the engine for too long at full throttle without any load, i.e. without any resistance from the chain during cutting, can lead to serious engine damage).
•Cutting from above = Cutting with a pulling chain.
•Cutting from below = Cutting with pushing chain.
Cutting with a pushing chain increases the risk of kickback. See instructions under the heading How to avoid kickback.
Terms
Cutting = General term for cutting through wood.
Limbing = Cutting branches off a felled tree.
Splitting = When the object you are cutting breaks off before the cut is complete.
English – 27
