Minimum Industry Standard series

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1: Preparing for tree removal

• Introduction to tree rigging and dismantling

Arriving on site

• Scope of works

Preparing to remove trees – site setup

Tree removal strategies

Tree inspection for dismantling

• Hazard control measures for tree dismantling

Basic rigging concepts

• Parts of an aerial rigging system

Selecting and inspecting rigging equipment

• Rigging equipment: general concepts and terminology
• Rigging equipment inspection checklist

Aerial rigging systems

• Common components of a rigging system
• Selecting anchor points in trees – tree strength and structural integrity
• Fixed rope anchor points – attaching a rope
• Running bowline
• Round turn with 2 half-hitches
• Main attachment knot plus half-hitch
• Clove hitch with two half-hitches
• Cow’s hitch with better half
• Timber hitch
• Karabiner
• Karabiner and sling
• Shackle or similar connector
• Other fixed-rope attachments
• Moving rope anchor points
• Natural crotch
• Block, rigging block, impact block
• Pulleys
• Rigging rings
• Moving rope anchor point attachment components
• Sling, tape sling, tube tape sling
• Loopie sling
• Whoopie sling
• Dead-eye sling
• Other anchor points and attachment options
• Rope brakes
• Trunk wraps
• Wraps in tree
• PortaWrap or similar floating friction brake
• Bollard, drum or similar

Rigging equipment configuration and proper use

• Example of misconfigured rigging equipment

Designing a rigging system 

• Rigging system design considerations
• Estimating weight of sections
• Tree species density table

Introduction to forces in rigging

• Different loads on components in rigging system

2: Dismantling trees 

• Performing works

Communication during tree work

• Call-and-response protocol
• Hand and whistle signals for use on tree sites

Using a chainsaw in trees 

Cut sequences and techniques – branches

Straight back cut 

• Step cut – undercut made first – top cut inside
• Step cut – undercut made first – top cut outside
• Step cut – top cut made first
• Step cut – lateral cuts
• Scarf and back cut – downward
• Scarf and back cut – upward
• Box cut

Cut sequences and techniques – tree heads and timber

• Falling the head out of a tree
• Falling sections of timber
• Falling sections of timber – landing sections flat
• Cutting techniques where trunk diameter is greater than bar length
• Blocking down: step cuts on timber

Falling techniques for tree dismantling – use of wedges and taglines 

Rigging operations 

Rigging attachment point: cut and behaviour 

• Rigging upright sections
• Rigging lateral sections or branches

Rope control during rigging operations 

Rope control: rope brakes and friction management 

• Installing rope brakes 
• Using rope brakes: adding tension 
• Rope control during rigging operations – general principles 
• Tips for using rope brakes 

Returning rigging components 

Specific rigging techniques 

Natural crotch rigging 

Applying friction at the point of cut 

• Techniques for applying friction at the point of cut 
• Branch removal – wraps method 1 
• Branch removal – wraps method 2 
• Artificial rope brake at point of cut 
• Snatching – wraps at point of cut 

Snatching 

Minimising peak force in negative rigging 

• Estimating peak loads in negative rigging 
• Mass damping 

Bracing a rigging point 

Floating anchors: highlines and multiple point floating anchors

Speed line or zip line 

Running anchor rigging 

• Running anchor rigging example 

Lifting systems 

Guying a tree 

3: Completing tree removal 

• Biosecurity and transmission of pathogens 

Completion of works 

Appendix A: Rigging system diagrams 

Positive rigging systems 

• Simple anchor | friction at base of tree 
• Butt tying 
• Tip tying 
• Use of a tagline 76
• Use of multiple anchor points 
• Cradle rigging 
• Lifting 
• Friction applied at anchor point/s in tree 
• Use of multiple rigging ropes – shared load or load transfer 11
• Floating anchor 1: single floating anchor 12
• Running anchor 1 183
• Running anchor 2: speed line 184
• Floating anchor 2: high line 185

Negative rigging systems 

• Snatching 
• Snatching – friction at point of cut 
• Negative rigging – redirects
• Friction at the point of cut 1: negative branch rigging 
• Friction at the point of cut 2: transferring loads 
• Running anchor 3: negative rigging 
• Vertical speed line 

Appendix B: Working the angles 

Introduction to forces 

• Working in newtons 
• Force, lever arm and bending moment 
• Lever arm 
• Force vectors at anchor points 
• Deflection forces