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Rigging and sling angles.

  1. Oct 13, 2013 #1


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    Was reading a book on rigging and it had this note that intrigued me:

    Ensure that the sling angle is always greater than 45° and preferably greater than 60°. When the
    horizontal distance between the attachment points on the load is less than the length of the
    shortest sling leg, then the angle is greater than 60° and generally safe

    What happens if not? Why this admonition? What's the danger in a "flatter" sling?
  2. jcsd
  3. Oct 13, 2013 #2
    First of all, note that there are two ways of measuring sling angle. The method commonly used in the US is to measure the angle from the horizontal; I guess you are in the US. In the UK the usual system is to measure the angle included at the apex of the sling. So the equivalent advice in the UK would be "ensure that the sling angle is always less than 90° and preferably less than 60°".

    With a "flatter" sling (larger angle in the UK, smaller in the US) the tension in the slings is much greater which can lead to failure of the sling or attachment points. The first diagram on http://www.haroldpotter.co.uk/chain-sling-information-z-14.html#.UlrxHxA8HF8 [Broken] gives a useful illustration.
    Last edited by a moderator: May 6, 2017
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