Mizzen forestay

Does anyone know of any good methods to calculate the forestay load? I have seen Germanischer Lloyds rules for righting moment share but it seems to only take in to consideration the force when all sails are up. With a yawl, quite often the mizzen is used in unison with a smaller jib in heavier winds therefore the condition set with Germanischer is not really valid. Any views? I have doubled this assumed righting moment to design the mast, would it seem appropriate to use the nordic boat standart with this righting moment and mast height above the water line?

 

I have always thought the Mizzen Forestay load (assuming there is no upwind sail hanked to it) is a function of the mizzen sheet load.

 

an idea..

I tried searching for something on the internet like you did, however I did not find anything concrete. If I were in your position I would contact a reputable sail maker like Mack Sails or Doyle Sails and see what they do to their calculations.