Stationary Rope Technique ( SRT ) work positioning systems
A stationary rope technique system is where the rope itself is fixed ( secured ) to an anchor , and the climber moves up and down along the rope .
Arborists adopted SRT devices such as cammed ascenders to assist with long ascents . In recent years , an increasing number of climbers have chosen to use SRT systems for work positioning within the crown of the tree . A wide range of arboristspecific devices for SRT work positioning are available , but devices from the industrial access , climbing and rescue worlds are also used .
The climber on the left has attached their rope directly to the structure of the tree at the top anchor . This method is described as a canopy anchor . The setup is not lowerable in any way ; an injured climber must be rescued .
In addition , the climber on the left has attached themselves to the branch where they are working with their lanyard . The lanyard can be used to ‘ offset ’ the climber ’ s weight by tensioning the lanyard and climbing line and lifting the branch up toward the climber .
If the climber must be rescued , the lanyard must be removed from the branch before the climber is lifted or lowered . Neglecting to remove the lanyard before lowering the climber will transfer the climber ’ s full weight onto the branch and may snap the branch .
The climber on the right is ascending their rope . The rope is not tied off at the top anchor ; rather it passes over a suspension point and is tied off back at the ground .
The rope is tied off at a basal anchor . This is a common setup during ascent but should be swapped for a canopy anchor whilst the arborist is working , to avoid accidents due to damage occurring to the basal anchor or to the anchor side of the rope .
If the casualty is set on a basal anchor and is not attached with their lanyard , it may be possible to perform a ground-based rescue by attaching a belay system to the anchor side of the rope and disconnecting the basal anchor to lower the casualty from the ground .
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