Halyard Calculations

[Jmolan]

I have a 34' Searunner Trimaran. 35' mast twin spreader cutter rigged. What I am looking for is how do you determine the loads that the halyards carry? I am sure there is a place to find this, but I am stumped.
I suspect I may be loading more than a mono hull because in a puff the boat will be more stable and not heel and spill wind. If that is true than I may ned to up the load calculation some.
What I think I see is most halyards are spec'd for ease of use on the hands.
Where I am going is I have used 3/16 Dynex. It has a breaking strength of 1 ton

http://www.hampidjan.is/media/pdf/Dy...april_2006.pdf

It has been great to use locally around here, but as I consider going for days offshore I want to know what kind of a margin I have (if any) on this line.

Since it was too small to be able to handle. I took a former halyard of 7/16's or 1/2" and took out the core for 10 or 15 feet. Then I ran the Dynex inside and black taped the ends. (ugly but so far has worked.) So it is like a wire to rope halyard with Dynex replacing the wire.

In a years use of a lot of sails I see no wear and no problems that are serious. I need to be careful when winching it up as it is so small it can ove ride if I am not paying attention. And the stuff really sings when going to weather......like a guitar string!

But all said I want to continue down this path, I do not have a pile of expensive unused stuff after i hoist the sail, it is easy on the hands, super-light, and not much $. What am I missing?

How can one determine the loads being involved?