Originally Posted by belizesailor
Great! Actual data. Thanks for posting
Can you post a link on making a side-spliced Y?
I'm puzzled why a prusick (sp?) hitch would lose so much strength if used to connect bridle
to chain. For example, I'm thinking of prusick hitch to the mid section of 3/4 three strand nylon, tail of line for prusick hitch them somehow attached to chain. I don't like the idea of directly connecting it due to chafe, but several examples of that posted here. I would prefer splicing in a thimble and attaching via a shackle or similar....or at least a section of heavy cover for chafe protection inside a soft shackle loop.
Under this configuaration, I would expect the 3 strand to retain 100% strength because it has no knots or splices. The prusick hitch would adjust to diameter loss in the 3 strand due to stretch (could cycling at attachment point of prusicks hitch damage the 3 strand?). The line used for prusicks hitch would lose some strength due to hitch, but if its dyneema
then even a 20-30% loss would still result in a WLL way above what's needed.
A y-splice is the same as an eye splice without the eye. Just splice a second leg into the main leg. This is how the Mantus
bridles are made.
The weakness of the prusik is that it will slide at about 50% of the prusik cordage strength (polyester). Since the prusik must be ~ 30% smaller than the main line, that means it slips at about 25-30% when wet. That is good for a climber, as it absorbs fall energy before breaking, but not so good here. But in practice they work fine because we seldom see that sort of force, perhaps scope
increases just a little, and you probably dragged first. They will not slip on chain. I've never heard of one failing. I use one sometimes, simply connecting a spectra loop to the bridle
with a carabiner.
The reality is, with 2-leg bridles, they are always over built and they all work. Failures are either chafe on deck
or contact with the bottom causing something to cut or unhook(this is the leading cause of non-locking hooks coming off--keep the bridle apex off the bottom).