/ belay set up
I personally wouldn't use 6mm for a belay as there are stronger alternatives like your ropes and sewn slings.
I use 6mil..
I have carried a coil of 4metre length of 6mm static cord for belays on multi pitch routes
Bombproof (so long as the gear holds!)
so 6mm do and 6mm dont?? Im assuming 6mm cord is a dynamic stretch
It's safe enough of course but there are better, stronger alternatives.
I don't use cord for belays personally, I think it's quite rare for cord to be the best option and therefore don't carry it.
6mm is strong enough, 7mm is a lot stronger but obviously bulkier...
so what about the use of nylon tape?
what is 6mm rated to?
surely a 240cm dyneema sling is 5 times lighter than cord? and double the strength?
I find open tapes and cords just complicates building belays. 120cm slings (240 in some instances) are my go-to product for most belays but I use my ropes too for all other times.
6mm cord is going to have a breaking strain of around 750kg, roughly equivalent to 7.5 KN. There may be some advantage over a sling because it may be more dynamic, but also loss of strength because it has to be knotted.
A factor 2 leader fall could generate 9KN at the belay.
Assuming you have 2 or 3 pieces of gear placed, in appropriate positions and well equalised with loops of the cord this is obviously safe (especially since small pieces of gear may be rated less than the 7.5KN cord anyway, and some nuts and hexes may be tied using 6mm cord).
The main problem comes if it's not perfectly equalised and one strand of cord comes into play before the others. It's highly unlikely, but that could be 9KN on a 7.5KN strand of cord (rather than on a 22KN sling or better still a length of the climbing rope itself).
There is also the risk of knot failure / slippage, which you should be able to avoid by tying correctly but which is largely avoided using sewn slings or the climbing rope.
Thanks Ron, that does it then, cord only for emergencies or abseiling otherwise slings.
What about tape, nylon non dyneema
As highclimber said, you'd just be adding complexity and faff in order to achieve what, exactly?
Just use the rope(s), a long dyneema sling or two, or if you really want to look American, a cordelette made of 7mm nylon or 5.5 mm kevlar cord.
I use 7mm cord as a snake cord/sling, it is handy. And use long slings as cordelettes also, the rope is always the strongest thing to use to set up a belay.
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