prv
Well-Known Member
For what it's worth, I had that size of shackle in the forestay of a 24-footer without any worries. Although, 1) it was a gaff rig, so generally lower loads, 2) there were also the jib and staysail luffs, independent of the stay, which would have held the mast up had the stay failed. I specifically had a bow shackle on the end of the wire because the next part of the connection was a lashing, and the bow gave lots of room for plenty of turns of rope. Bit of a different situation to yours.
Pete
Pete