Kolin Powick’s (of Black Diamond) conclusions are below:
As always, I must state a disclaimer that these findings are somewhat unofficial—just some information to think about. I’m not a climbing guide and don’t even play one on TV. These experiments are NOT all inclusive or totally encompassing by any means—much more testing would be required in order to come to any firm conclusions. It is important that all climbers use their best judgment out in the hills.
First off, our results were very comparable to Chris Harmston’s findings, and I agree with his recommendations—before you join two slings together think about the following:
- Is it possible to use a longer sling altogether?
- If you need to join to slings, using a carabiner is stronger
And in addition:
- If you must join two slings, use the same materials and width
- Symmetrical knots (like the Strop Bend and Climber’s Hitch) appear to perform better than a standard Girth Hitch when joining two slings together.”