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Drawings of junk rig conversion for Freedom 33

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  • 09 Mar 2011 07:21
    Quote
    Reply # 541974 on 531461
    Anonymous member
    Hi Barry,

    Your boom could stay at the height you like. Boom up or yard down are only two of the ways.

    Sheeting geometry also benefits from the leech of the sail moving forward or the sheeting point moving aft. 

    The possibility exists for you to reduce the fore-&-aft dimension of both sails, and to keep your CE where it is, maybe adding a little balance to your mizzen. 

    And a  boomkin wouldn't have to be backstay-worthy to sheet a junk mizzen. It could even be retractable. (I can't remember now whether you have a self-steering vane back there.)

    Also, I know you want to work from one template per sail for the regular cambered panels, but I'll labour again my point about small P increasing upwards, because I think the anti-twist and equal-power sheet spans help considerably.

    Between modestly generous SA/Ds of 18 or 19, and your design with 23, I guess I'm suggesting that some sail area is worth giving up, for the sake of everything in the rig fitting and working great to start with.

    Those are all my troublesome thoughts for today...

    Regards,
    Kurt
    Last modified: 09 Mar 2011 07:21 | Anonymous member
  • 08 Mar 2011 22:13
    Quote
    Reply # 541676 on 540455
    Deleted user
    Kurt Jon Ulmer wrote: Hi Flutterby,

    After touring through this fascinating discussion yet again, my opinion now is simply this. (I swallow) 

    If you could reduce your planned sail area by 10 or 15%, many of the variables that have been straining for attention, would suddenly (aah) relax. 

    That would give you breathing space for things like sheets in all their attitudes, halyard drift at the masthead, clearance between sails, deck space, simplicity in general and etcetera. 

    Unless, that is, you race, or will be extending the length of your waterline, or you sail without an engine.

    Sincerely,
    Kurt

    Yes, it would ease a few things.  Actually I just "found" an extra foot of mast I'm not using. My measurements in my spreadsheet for drawing the masts were in error.  I did have enough "sanity" to not immediately re-design the sails to spread this extra foot between all my panels....although it was tempting!

    And this does indeed give me a tiny bit more slack in the design in many directions.

    I can see how it would get even easier were I to reduce sail a little bit more.

    But in answer to your last question--no, I don't race, and don't plan to extend the waterline, although I might be able to put a small notched sugar scoop (around the rudder) on the transom, extending back a foot or two.  It would make the transom a much more reasonable place to board Flutterby, so it is tempting.  But not until I've got a haulout scheduled with an extra two weeks for the job, as it is very optional.

    And while I do have an engine, and it is pretty reliable--I do very much want the good option of sailing instead of firing it up, should the wind drop down a little bit.  And for ocean crossings, I only have 25 gallons of diesel tankage (plus one jerry jug), which won't last long if I motor whenever the wind drops.  And I dislike sailing so slowly I'm not sure if I've got steerage or not.

    For me, the biggest downside to reducing sail further is that to help my sheeting problems, I need to move the boom up, rather than move the yard down.  And that will impact my ability to sail upright, even reefed--any designed in boom height stays up all the time. Even if I moved the yard down and the boom up, the fully reefed CE is still raised.

    Barry
  • 07 Mar 2011 08:12
    Quote
    Reply # 540455 on 531461
    Anonymous member
    Hi Flutterby,

    After touring through this fascinating discussion yet again, my opinion now is simply this. (I swallow) 

    If you could reduce your planned sail area by 10 or 15%, many of the variables that have been straining for attention, would suddenly (aah) relax. 

    That would give you breathing space for things like sheets in all their attitudes, halyard drift at the masthead, clearance between sails, deck space, simplicity in general and etcetera. 

    Unless, that is, you race, or will be extending the length of your waterline, or you sail without an engine.

    Sincerely,
    Kurt
    Last modified: 07 Mar 2011 08:12 | Anonymous member
  • 01 Mar 2011 21:28
    Quote
    Reply # 535659 on 531461
    Anonymous member
    I used to think that there are those that do and those that doodle but doodlers who do too do my head in.  Good on you guys - it must be great to have your sort of mind!
  • 01 Mar 2011 21:19
    Quote
    Reply # 535653 on 531461
    Anonymous member
    I'm right with you in wanting to try a split rig jib/mainsail and un-split mizzen on a ketch. If only I didn't already have a serviceable suit of sails, I would be doing something similar to what you are planning. I would like to see whether the performance could match that of my wingsails, with less complexity. Someone has to be the pioneer, and if you can demonstrate a good ocean-going rig, we'll have moved forward.

    Having said that, I need to take the sails off this winter for a 50,000 mile service, I need to replace some battens that got bent, and there's a friendly sailmaker nearby who is keenly interested in these developments. Just maybe...

    I've put a sketch, "split rig ketch", in "David's Doodles", in Box.
  • 01 Mar 2011 21:04
    Quote
    Reply # 535640 on 531461
    Anonymous member
    Barry,
    I love the spirit of that last paragraph.
    Good on you.
    Kurt
  • 01 Mar 2011 17:23
    Quote
    Reply # 535440 on 531461
    Deleted user
    David,

    I should clarify that when I say simple, I mean simple in operation--I am willing to put plenty of effort into design and construction, especially if it will pay off in good (and simple) sailing later.  Slieve was recounting how happy he is with the simplicity of his rig in operation, so that does fit pretty well.

    You are quite right that the split rig is experimental, and still getting a few things worked out.  Slieve has been very generous in giving me assistance even though he still wants to do another iteration on the details before he does a writeup encouraging others to follow his example.  To my knowledge, mine will be the second one ever built.  I am hoping for great sailing performance, and hoping that along the way we will help Slieve better understand how this rig works.

    I'm trying to work a fine line here--If I don't try anything new, I'm could miss out on some amazing opportunities.  But if I go too far ahead of what anybody knows I'm likely to have to build three or four sets of sails before I have one that I'm happy with.  And a split rig ketch looks like a really promising opportunity, so I'm going to try it out.

    Barry
  • 01 Mar 2011 17:18
    Quote
    Reply # 535437 on 533613
    Deleted user
    Kurt Jon Ulmer wrote:
    Flutterby,

    One more thorn in the flesh, from mehitabel's compromise...

    Changing from cat schooner to junk schooner, I cut 11' off the head of our mainmast and 9' off the fore. I made the conservative choice to settle for a modest but real increase in sail area, in favour of stability and stiffness. The masts feel much better to me now. And... sometimes I have wished for more sail.

    Kurt

    Thanks.  I'm still considering reducing my sails a tiny bit.  My masts on the other hand are tall but light, and shortening them would not be a job taken lightly.  (Thank you to Freedom & TPI for the carbon fiber!)

    If I had heavy wooden masts, I could easily see choosing to shorten them for stability as you chose on mehitabel.

    Barry
  • 28 Feb 2011 07:02
    Quote
    Reply # 534378 on 532756
    Anonymous member
    Barry & Meps / Stellrecht & Schulte wrote: David & Kurt, thank you for your comments.  I appreciate the help and the challenges to my assumptions.  My goal here to build a simple, reliable, and good performing rig capable of crossing oceans.  I'm not trying to develop something new--just trying to get the best ideas previously tested to fit well on my boat.
    Well, that doesn't gel too well with using a split rig. Remember that Slieve's rig has proven to be pretty effective at showing bermudan boats the way around a race-course, but that's not the same as being proven to be capable of crossing oceans. He has had trouble because, unlike other junk-based rigs, the "jibs" can flog, and self-destruct, if not full of wind. I would want to put in dinghy mainsail style battens into each "jib" section. 
    But I really think that with your absolutely vast sail area, to add jibs is to make life unnecessarily complicated. Just plain cambered panels in the main would satisfy the "simple, reliable" goal better, and would also take care of the "good performing" goal. 
    Having said that, I never want to discourage anyone from trying something new. If you don't try, you'll never know whether it would have worked or not.
  • 26 Feb 2011 19:00
    Quote
    Reply # 533617 on 533400
    Deleted user
    Kurt Jon Ulmer wrote:
    Head panel area and 'control in winds over 30 knots' - When I look at my sails reefed to only the head panel, I don't wish for more area or more battens up there. I decided PJR Fig 2.24 would give a good top to a sail, and it's worked well for us.

    Panels same size - Why? But having said that, our panels are close and gradually go from the 90 sq.ft head to the 60 sq.ft bottom panel on the main.
    Those two I can answer right now.  This is based on experiences that Arne related either in some of his articles or on the Yahoo group.  One of his early rigs had two very big head panels, with more area than the lower sheeted panels and he found it hard to control twist in the head area of that sail.

    Johanna and other sail plans he designed all try to keep the panel area the same.  For low AR sails like Johanna, he uses the transitional panel to accomplish this.  With my higher AR sails, I am making my top panels look more "transitional" than triangular.

    So I guess I mean I'm trying to keep the two head panels from getting too big (or too small).  That PJR Fig 2.24 shape looks fine, but for me doesn't justify different batten lengths.  I'm with you in not wanting a third batten up there--At least not with my high aspect ratio sails.

    As for making all the lower panels the same size, that is mostly lazyness--only one template to loft for them that way.  (I still haven't worked through the varied-P sheet arrangements you talked about.)  But having each reef be the same size seems like it will behave the way I expect it to when I'm reefing.
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