Selecting a suitable anchor point
A union selected to be used as an anchor point must be solid , and sound enough to support the possible shock load applied if the climber were to fall . Conduct a thorough tree inspection prior to leaving the ground - consider every element detailed in Chapter 2.3 : Evaluating tree anchors .
Good anchor point selection - knowing how the tree will behave under the loads applied during climbing - is a key skill for good climbing . Always apply a safety margin - do not select anchor points that will ‘ only just ’ support your weight - it is easy to apply more load than you expect .
A common guide is to select anchor points that are ‘ at a minimum ’ the thickness of your forearm for a single load . Remember , anchor points are an integral part of the climber ’ s lifesupport and rigging systems and as such selecting a suitable anchor point for the intended activity is a key skill for safe , efficient and productive climbing and work .
Do not use any of the following anchor points without testing or additional bracing or support :
Small branches .
Do not use any single branch smaller than the climber ’ s forearm – ensure the rope is installed around the stem rather than just over the branch .
Small branches attached directly to the parent trunk may be epicormic shoots , and may fail under very little load .
Along the branch length or toward the end .
Leverage will hugely increase the force on the union , particularly on horizontal branches or branches that tend toward the horizontal . Even larger branches that are still fairly thick at the point where the rope passes over the branch may break unexpectedly under surprisingly low loads if climbers attach to the branch end .
Dead or decayed wood .
Recently dead wood , particularly where the whole tree is dead , may be almost as strong as green timber , but any long-dead branches that have lost the finer twigs should be avoided .
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