Could adding a Yankee power up my F31 upwind?

Corsair F31s have a fractional, minimally overlapping jib, and the boats struggle a big upwind in light air (2-8 knots TWS). I would like to explore adding a masthead "yankee" to remedy this weakness.

Many sailors have tried to remedy this weakness by using a "screecher", which is a relatively low aspect ratio sail. On the stock sail plan, the head of the screecher is below the spin halyard exit. It is hard to make these sails really point.

My thought is that a high aspect ratio yankee, set at the masthead, could be set with the jib still flying-- that on the f31 sail plan, this would give pretty good separation from the jib-- and that using top tier sail cloth, a lock and a structured luff, you could get a reasonably straight luff and a flat sail-- and that with all that maybe you could really point in light air

The yankee would have the following characteristics:

- Much smaller in area than atypical screecher. The stock jib is about 20s square meters. The yankee might be between 20 and 30 square meters, as opposed to the stock screecher area of 40 sq meters.

- no battens.

- Set on a lock at the masthead, tensioned with a 3:1 tackle at the tack. The tack would be at the screecher location on the sprit, which is supported by the bobstay.

- supported by supplemental shrouds led to the intersection of the aft beams and the floats (where there is a substantial eye for the spinnaker turning blocks).

- Sail cloth to be as light as is compatible with retaining shape in the 2-8 wind range. maybe 3di raw

- Structured luff, with integrated light weight and relatively flexible PBO sling cable-- ie. not a giant torque rope.

I have uploaded a sketch.

Do you think that such such a configuration could be made to really point? Or would the interference between the jib and the yankee make it ineffectual?

 

The roller seems like an extra complication and cost. Since it is only for light winds, it would make sense to set it flying. Othewise, more sail area, even if not in an optimal configuration will help.

 

Good luck getting a sailmaker to actually build you one. During our recent refit, I had pretty much your specs, and was presented with a code zero with a higher clew than normal. I’ve heard that Yankees are all the rage down in California, maybe a sailmaker down there?

My theory about the Yankee as far as pointing is that the other sails will shove the wind over to it, and it won’t have to be pulled in as tight, as well as being up higher and benefit from gradient.

Add to that better twist control off the wind, and smaller size & weight for easier handling, esp if you need a quick take down while short handling.

My current sail is powerful enough so it brings the apparent wind way forward in really light airs, but IMHO, loses some advantage as far as not having a high aspect ratio, which is especially better in light airs. I was hoping one of the new stronger but light nylon fabrics would work, since I would be using it in only really light airs (real & apparent), but got talked out of that. The top down roller is nice though, and the grey looks cool…

we have 2 sets of running backs, one to the top of the mast, and one to the jib hounds @ 3/4. The code zero goes to topmast.

But except for Doug Christie (vale & fair winds ), I usually leave a loft believing I know nothing…..

 

hi paul- your thinking is mine exactly. Looking for a sail maker to really analyze the idea without preconceptions.

here is a PNW boat with a sail sort of like what i am thinking of. Owner reports good success going upwind.

 

Russel is around here- why not PM him? He might have a guy at North?

 

We are in touch.

 

Thinking about why I went for the Yankee array & what Russel’s G 32 sail’s leaches ending at the mast) reminded me of (besides Bethwaite and clippers of course):

-this link did not work- google A M O Smith ‘high lift devices’

I’ve never had any luck getting a sailmaker (besides Doug) to seriously engage in any conversation about the concept. (Edit;Maybe WB?)

Edit: Anybody done this & noticed any changes in helm balance?

 

Link ^ doesn’t work- Google A M O Smith ‘high lift devices’