Rope angle
Good work positioning is often about maintaining a good rope angle . Climbers with a more vertical rope angle will be better able to use the rope for support whilst moving around . They will put less force on branches and branch unions , need to spend less effort to maintain balance , and will be well protected from possible pendulum swings .
Rope angle can be described in degrees , with 0 ° occurring where the climber is directly under their anchor point ( the climbing ropes are vertical ) and 90 ° being where the climber is level with their anchor point ( the climbing ropes are horizontal ).
The image on the right shows a climber with a 26 ° rope angle progressing along a branch .
It is not possible to designate a specific point where rope angle becomes dangerous , as rope angles of even 90 ° may be safe if the climber is protected by redirects or is within a meter or two of their anchor points . Conversely , even a rope angle of 30 ° may be dangerous if a pendulum swing would result in the climber striking the trunk or another part of the tree ’ s structure .
A rule of thumb for rescuers is to install additional points of attachment to prevent a pendulum swing whenever the main rope angles exceed 45 °.
Additional points of attachment to prevent a swing might be the use of a lanyard to attach directly to the branch or stem being accessed , or the installation of an additional climbing system or redirect above the climber .
Please see lanyard use ( pg . 108 ) and redirects ( pg . 109 ) later in this chapter for further details .
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