Old as Dirt!
Join Date: Nov 2008
Location: Tampa Bay Area
Thanked 139 Times in 132 Posts
Rep Power: 8
Re: Using Jib and Genoa at the same time to create spinnaker
I've seen a light air 'drifter' that was a 2 ply sail on a common luff... tie the clews together to use it as a light air 'genny', split them on separate sheets and open it up butterfly style for running.. might make more sense than fighting two separate sails on hanks. - plus equal areas as you suggest.
That rig was, for awhile, known as a "Twizzle Rig" and was quite a novelty although, as TDW noted in his post preceding yours, it did induce terrible harmonic rolling. The twin headsail rig was somewhat perfected later by Eric and Susan Hiscock (of Wanderer fame) who found/proved that twin head sails, flown "free flying" and tacked mid-way between the stem head and the forward lowers on either forequarter with poles angled forward 10º to 15º (to induce dihedral angle) with the main hard sheeted amidships and the helm free allowed a yacht to run off quite comfortably with minimum roll. Today, however, with reliable self steering and/or an auto pilot taking charge, running "down wind" at a gybe angle of 160º to 165º allows for comfortable sailing with maximized VMG under main and polled out Genoa or asymmetrical. One sails about 7% further but one's VMG is so much better that the added distance is more than off-set and one is much more comfortable as one's tea isn't constantly pitched off the galley bench, eh?
"It is not so much for its beauty that the sea makes a claim upon men's hearts, as for that subtle something, that quality of air, that emanation from the waves, that so wonderfully renews a weary spirit."