what we think can be a possible 'window' for a new jib design would be like this:
leech: 5.20 m
luff: 5.30 m
base: 1.30 m
I would like to compare our proposal with what are the sizes of the selftacking jib you might be using on a taipan 4.9 in F16 set up?
Naturally I have a Taipan platform that was converted to full F16 mode. This means that more fore triangle (mast, fore stay, spi pole) is still the same as on your standard Taipans. My jib luff does however move passed the bridle plate and along the strut down to the spi pole.
The measurements of my jib are :
Op voorlijk (lijkt langst)
Luff length jib = 5480 mm
Leech length jib = 5300 mm
Foot = 1220 mm (measured from farthest point forward on luff to the virtual intersection point of foot and leech)
Distance sheet corner to luff measured along a line perpendicular to the luff : 1180 mm
My leech in concave and the max deviation of the straight line through the top and the clew is 60 mm. (The leech is curving towards the mast)
I have 3 full battens in the jib.
The surface area is = 0.5 * 5,48 * 1,18 + 2/3 * 5.30 * 0.06 = 6.4664 / 2 + 0,212 = 3.2332 + 0,212 = 3.4452 v.m. = 3.45 v.m.
In summary : 3.45 sq. mtrs.
The jib fits very well inside the fore triangle and it alles ample room for the selftacking rail, car and block system.
I would not make the leech bend more towards the mast as the leech is just touching the spreader arms when sailing upwind.
It does look however that the fore triangle will allow a little more luff length and even more leech length than that.
Right now I'm pulling my jib all the way down to the pole so that my 390 mm spreader arms are not poking in my jib, But the standard taipans all have 350 mm spreaders arms. I used to sail with my jib higher on the forestay in the beginning, even 50 or more higher. That is how I know than longer luff/leech lengths are possible. I would not move the leech further back on the penalty to the spreader arms pushing against the leech and disturbing the curvature of the jib there. I would go into details but the pushing action is NOT dependent on spreader arm length.
My advice would be to let the jib move passed the strut all the way down to the spi pole. Have an 5500 mm luff, a 5350 mtr leech and a 1220 mm foot and a concave leech with 0.06 deviation at max ;if you are going to fit a selftacking rail. If not that a longer foot will be necessary to reach the blocks on the mainbeam.
I hope this helps,
Wouter
