CarpeDiem 430 Posted July 23, 2016 Share Posted July 23, 2016 Hi all, I am wanting to replace our mainsheet with a 6:1 with a cascaded 4:1. It's currently a very difficult to manage 3:1 that goes back to the mast, down to the shroud and then comes along the deck to the cockpit. I have tried to use the Harken Calculator http://www.harken.com/MainsheetLoading/ to calculate the load, but the technical notes say that it shouldn't be used for sails with large roaches and we have a square top. I tried contacting Harken NZ for support, but it's been a week now and I have had no response. Which is kind of disappointing because I was intent on using Harken blocks at the time, since then I have found a few other neat solutions by Ronstan and Lewmar. But I am still stuck with calculating the load. My Sail maker says that the sail is 48m2 The measurements are: Luff: 13.5 Foot: 5m Distance from aft of boom 1.8m Max wind speed: 20knots - once over 20 knots we should of reefed 2 knots ago so this has a bit of fat in it Is anyone able to assist me with calculating the mainsheet load? Thanks Quote Link to post Share on other sites
ScottiE 174 Posted July 23, 2016 Share Posted July 23, 2016 Yeh contact Chris Mitchell at AES http://www.aes.net.nz Quote Link to post Share on other sites
eruptn 95 Posted July 25, 2016 Share Posted July 25, 2016 Google mainsheet load an you will get 4 or 5 calculators. Run each one an compare, if they give similar results you will be in the right ball park ? Quote Link to post Share on other sites
jay 3 Posted July 25, 2016 Share Posted July 25, 2016 Harken's calculator tells how to adjust for a square top. I believe this gives load under sail, as opposed to shock load? For example when doing an uncontrolled gybe, where loads would be much greater. Not sure how one would calculate the potential shock load, which would be more important for sizing gear? Also, can you use a winch for the main when it is under greater load? Quote Link to post Share on other sites
smithy09 50 Posted July 27, 2016 Share Posted July 27, 2016 I've got a loadcell you could borrow if that would help. Up to 5000kg in tension... Find out the REAL load! Quote Link to post Share on other sites
Black Panther 1,584 Posted July 27, 2016 Share Posted July 27, 2016 Funny you should say that KM _ I was just looking at this: Quote Link to post Share on other sites
Black Panther 1,584 Posted July 27, 2016 Share Posted July 27, 2016 And wondering about NZ women?????? Quote Link to post Share on other sites
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