manski:
jakethesnake:
stevieboy308:
Putting a twist in a strap does weaken it.Try pulling a sheet of at apart from the middle, you won’t do it, pull it apart from the edge and you will. A 2m strap with a twist is 2m at the middle, both outer edges are slightly more due to the half a circle it’s covered too, do you end up with high tension on the outsides and a lower 1 in the middle, that not how they’re designed to work, DCPC dude is right
Thanks for the confirmation stevie, of course it does.
This from page 116 of the Spanset Load Control Guide :-
– Use only lashing equipment that is not
twisted when tensioning
It does not specifically explain why but then they are one of the biggest load control / safety harness people around.
spanset.com/uploads/au/Span … hapter.pdf
BUT…
Another manufacturer say this :-
Applying twists to your lashings
Another benefactor influencing the strength of the lashing is the number of twists in a lashing. In this particular case there were 5 twists per lashing over a length of 60cm (2ft). These twists resulted in a loss of over 500daN.
Often people like to apply one twist in the woven lashing to prevent flapping/rattling during transport. One twist in a longer length lashing does not have negative consequences on the strength.
cargorestraintsystems.com.au/wh … g-webbing/
They are both ozzie firms so might have got it all upside down 
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It would still be a question what exactly is meant by “a longer length lashing” and “the strength”.
I assume the point at which twisting becomes a problem is when it alters the relation of the weave beyond what it is designed to accommodate within the rated strength.
A twirl in a flat strap leads to the outer edges taking a longer path between two points than the middle area of the strap, and the more twirls (and the tighter the twirl) the larger the discrepancy becomes.
It’s like how banisters on a spiral staircase have an outer bannister far longer in length than the inner bannister, to cover the same vertical distance. If the bannisters were made of rope of equal lengths and a load applied at their ends at the foot of the staircase, the inner rope would be totally flaccid while the outer rope would be taut (and carrying all the load).