Question for J. Dillon and/or Mike Fields

[Dennis Marshall]

From reading previous posts, I understand that you folks fly about a 100sq ft spritsail. Would you care to share those dimensions with me? I'd appreciate it very much.

Regards,

Dennis

[J. Dillon]

Dennis,

I had to dig for my old drawings but they are :
Luff 11'1"
Foot 10'
Head 7'
leech 15'1"
reef up from foot 3'

Diagonal from throat to clew 13'5"

Last year Todd B. cut a jib that was approximately 30 sq ft. set flying

This gave greater speed to the "Carrianne" and I think she points a little higher.
I was concerned that I might up set the balance of the boat with the addition of a jib but no significant difference in weather helm could be determined. Apparently she a forgiving boat.

You'll have to wait for more exact dimensions directly from the sail will have to wait. She is still in the water and actively sailed.

http://www.imagestation.com/picture/sraid36/pd39ef576cb186404c94c54db0e7fb4db/fd239269.jpg

The snotter needs tightening in this image.

JD

[Todd Bradshaw]

Make that 41.7 sq. ft. on the jib (Luff 14' 4", Foot 7'2", Leech 11' 10". L.P. 6.677').

Here are a few more 100 sq. ft. Spritsails to play with. They're just different ways to spread out the sail area and all have somewhat differing shapes.

#1 - Luff 10.25', Foot 9.37', Leech 15.03', Head 8.2', Diag. throat to clew 11'.

#2 - Luff 11.5', Foot 9.75', Leech 14.73', Head 6.4', Diag. throat to clew 13.98', Diag. peak to tack 16.22'.

#3 - Luff 11.77', Foot 10.09', Leech 14.3', Head 5.88', Diag. throat to clew 14.38', Diag. peak to tack 15.64'.

#4 (high peak) - Luff 10.46', Foot 10.46', Leech 17.26', Head 7', Diag. throat to clew 13.75', Diag. peak to tack 17.08'.

These are the reference lines for laying out the basic shapes. Most Spritsails in this size range will also have around 1"-1.5" of luff round added with the maximum about 45% of the way up the luff, 1.5"-2.5" or so, of hollow cut into the leech to prevent flapping and 3-4" of foot-round added about 45% of the foot length aft of the tack corner. The panel seams that strike the foot are then broadseamed near the foot edge to give the foot a bit of a cupped shape and prevent the added foot-round portion from just hanging there like a flap. The head is cut without round or hollow (straight) and will sag slightly in use, putting draft into the top section of the sail.

[Dennis Marshall]

JD and Todd, thanks for the replies, they are much appreciated.

Todd, I have a question that perhaps you can answer. Let's say I have a boat that is gunter sloop rigged with a main of 76 sq ft and jib of 30ft. How difficult would it be to convert the main to spritsail -- same area, and keep the jib but set it flying as JD does on his boat. Would a lot of fiddling and moving of maststeps/partners be required do ya think? Also, it is rather odd to see a Spritsail with Jib, is the jib worth the added complexity?

Dennis

[J. Dillon]

Dennis,

Just had to post a decent image of the main sail.
http://www.imagestation.com/picture/sraid10/p9f8889e9ed3fef496f9d6ebd54111f39/fe029891.jpg By the way, no complexity to the jib, just a halyard
proper leads & cleats and a fair lead for the tack leading aft to the convenience of crew or skipper. It's worth it.

JD

[Dennis Marshall]

Thanks, JD, showing pics like that just before bed time means some sweet dreaming smile.gif !

Dennis

[Todd Bradshaw]

Of course it all depends upon the proportions of your particular gunter main and the spritsail that you intend to replace it with, but the effect on helm balance and the location of the partners, step, etc. may not change all that much. I grabbed a couple fairly typical sailplans from my files, scaled them both to 76 sq. ft. and stacked them as shown here. The gunter looks larger, but it seems to be a combination of optical illusion and the fact that it has some roach, which isn't usually counted as measured sail area.

http://www.imagestation.com/picture/sraid36/p0fedb18de6cd062cdf3aa2843c7493f4/fd231499.jpg

So, it can probably be done and you might not even feel much difference in balance. What you probably will notice is that when you turn off on a deep reach or run, you no longer have a boom to hold the clew out.

[Dennis Marshall]

Todd, thanks so much for posting the superimposed images of gunter and spritsail. If I went with such a rig, I would use a boom or spritboom on the spristail. My experiences of a loose footed boomless spritsail and block on the tack have been very limitied, but less than serendipitous. :(

Dennis

[Meerkat]

JD; What kind of boat is that you have? I like the way the bow "noses up" smile.gif About 16' LOA?

[J. Dillon]

Meerkat,

"Carrianne" is a sprit sail skiff of my own design. 18'2" bow to transom. Of course the rudder extends a little past the transom.

http://www.imagestation.com/picture/sraid10/p420885e6a7a4ee378956de92c8c348b9/fe029b7d.jpg
In the image she is reefed with the jib up. If you look close you can see the stem, which extends up enough to secure dock lines. V shaped chocks aft of the stem enable security of the lines and take the wear and tear.

JD