Thank you.
The boat is 1979 Bristol 29.9 = ~30' sloop. Forestay wire is 316 1/4" 1x19. This clevis pin should be 3/8". Last time the stem fitting and flange were professionally inspected was 2 years in the SF bay area. They had corrosion then, and there is more now.
Do you think there is something that can be done as a preventive measure?
Sorry, I didn't understand the part about the weak shackle connection. The forestay slid down either when mounting the mast or in waves - there is about 1/4" of free pin on the opposite side before the pinhead. I was thinking that the shackle body would hold the toggle in place even if the forestay toggle jaw moved up or down the pin. Basically, the shackle pin would be in the same place as the clevis pin now, and the D part of the shackle would hang in the air, like so:
This way I could also quickly attach a jib halyard and/or spinnaker halyard to the shackle in case the forestay breaks...
For example, Ronstan 3/8" wide or regular D shackle should have at least the same strength rating as the wire:
http://www.amazon.com/Ronstan-Wide-D.../dp/B005O2QTVS
What do you think?
Many thanks!
Gleb