[quote=bruiser][quote=dmgbear55]Getting ready to order a new set of sails for my 5.2 and I like the idea of going to the square top sail. This adds about 11 sq. ft. to the main moving the center of effort aft somewhat. Since I'm also planning to change the standing rigging now would be the time to tweek the dimensions so that moving the mast forward to get the center of effort back to where it belongs would be easy to do.
Has anyone sorted this out, or is there enough adjustment in the standard rig dimensions to accommodate this change?
dg[/quote]
I have a question regarding this train of thought "moving the center of effort aft" . Where did this information come from? Is this what sail makers are saying about adding a square top sail?
I will explain the reason form my question and then the experts can set me straight. Sail design has been evolving towards higher aspect designs which is a faster sail. What this high aspect means is that the sail is taller, but also narrower front to back. It is said that the aft part of the sail (back half) of the main is a good deal of drag as well as a lot of surface that contributes to pressure to turn the boat over (simply blowing it sideways). The high aspect design result in more forward speed by eliminating a lot of the aft of the main sail sail area as well as adding sail area to the forward part of sail resulting in more force on the boat in the forward direction rather than just pushing it sideways, the go fast equation (the lifting wing part). I would think this would move the center of effort forward rather than back if properly designed. No?
In regard to a square top sail versus the pin head, the assumption I had, was you are taking sail away from the back half of the sail and moving sail area up to the top to get a more uniform wing from top to bottom with the result being a higher aspect shape than what you get from a pin head main. This result is more pressure forward rather than sideway for a faster sail.
The other benefit of the higher aspect sail is that twisting off the square top is very easy thereby reducing sail area very fast in puffy conditions. This makes controlling the sail much easier than conventional pin heads.
In summary my impression of a square top was not just piling on sail at the top of the mast. Am I just making this stuff up?
Thanks in advance<!-- editby --><em>Edited by bruiser on Aug 22, 2016 - 06:11 PM.</em><!-- end editby --> [/quote]
No HTML tags allowed (except inside [code][/code] tags)
