Magnitude of intended load |
Very high
( tensioned highline or floating anchor )
|
High
( ground-based lift and lower system )
|
Normal
( Single person or pick-off )
|
Angle of load |
Over 60 ° to stem |
Less than 60 ° to stem |
Less than 30 ° to stem |
Branch health |
Dead branch
Long dead , no twigs remaining
|
Dead branch
Newly dead , branch retains fine dead twigs
|
Living branch |
Tree structure |
Recent severe damage or multiple severe defects |
Normal tree with some defects that have been present for many years |
Healthy tree with no identifiable defects |
Anchor damaged or tied in to load |
Anchor failure associated with accident
Loaded rope attached to anchor
|
Anchor has been impacted by accident or works |
Anchor entirely separate from accident |
Tree species |
Known weak species ( e . g . Ailanthus altissima , Salix sp .). |
Familiar local species |
Identified species , known to be of normal strength or better |
Unfamiliar species |