Acceptable deflections in masts

[airturb]

HI ALL AGAIN

Once again, another design question...what would be the allowable deflection of a mast to consider it "successful"? I'm not concerned with the stresses involved for a particular deflection, but rather the interaction that this deflection will have with the sail.

Cheers.

But it's a question without an answer, isn't it??

It depends on the mainsail. A rigid main will need less mast bend, a dacron main will need more. Then there's the effect of the way that the class or rule measures SA, and whether the luff curve is measured area or not. Plus there must be many other details; the amount of mast bend depends on whether it is a masthead rig, a runnerless rig, or a runner rig. If you have too much mast bend in a runnerless rig on a sizable yacht, the forestay tension drops away too much so the jib shape is impaired.