cunningham

[Renoir]

I plan to add a cunningham for the main. There would be a S/S U-bolt on the port side of the boom to dead-end a line to which passes up and through the cunningham cringle thence down to just below the boom attaching to the becket of block and tackle. The tackle attaches to a fitting on the deck or lower part of mast.

For a 350 sq ft main what should be the SWL of the fitting on the boom and the fitting on the deck? What SWL rating should the line and tackle have? Should I use 8:1? Is there a better plan?

Thanks,
Rick

[AaronS]

My favorite way to rig a cunningham is with a 4:1 purchase and a cascade through the cringle giving you "effectively" an 8:1 purchase. A pennant of dyneema, or other high modulus line for the cascade, and some 40mm fiddle blocks with a cam might work nicely for you...

Aaron