Ingeborg, Arne's Marieholm IF

  • 30 Jan 2015 17:07
    Reply # 3214216 on 3032430

    Dennis,

    May I jump in and answer, as an offshore sailor? I sail with rather less than SA/D = 15, and find my performance to be good enough. Offshore, in a cap-full of wind, I'd rather have a smaller sail, not so heavily reefed, than a large sail, so heavily reefed that it is difficult to control the twist. Downwind, I never feel short of performance, as any junk rig, of any size, is more efficient than the same size of bermudan rig (Poor unfortunate people, they use a spinnaker because they must). Upwind, it's better to have a smaller, more efficient sail than a larger, not so efficient sail; that's why I favour wing sails, and why I am tending towards higher aspect ratios. 

    I would say that SA/D = 15 is enough for offshore use, and the further offshore, the less camber is necessary. Of course, there are times when you would like all the drive you can get, but on average, over a long passage, a flatter, smaller sail is easier to live with than a fuller, larger sail.

  • 30 Jan 2015 15:07
    Reply # 3214119 on 3032430
    Deleted user

    Arne,

    I have been doing my homework (reading PJR and "The Cambered Panel Junk Rig") and return more knowledgeable.  But not without questions.

    1.  You suggest a SA/Disp of 20+ to compensate for the lack of a spinnaker which makes sense for coastal cruising.  What about offshore sailing single handed where a spinnaker would be a luxury rather than an expected tool?

    In the range of small offshore capable sloops (Frances 26, Contessa 26, Marieholm 26 and  IF) would you still be so generous?  They all run around 15  SA/Disp in a BR.

    Do you know what sort of SA/Disp predominates among the offshore sailing JR community?

    2.  Why do you not cut the paper patterns to gross measurements  (including hem etc)?  I am sure there is a good reason, it just escapes me. 

    Dennis


  • 28 Dec 2014 19:54
    Reply # 3177487 on 3177187
    Deleted user
    dennis gibbons wrote:

    Ash,

    Having looked at the drawings and notes, I have a concern about the viability/efficiency of using a line to create the floating pivot. I would think a stronger and more stable mechanism could be designed. 

    Regarding the Upside down vane, have you checked out Mr. V?  Were I to design a vane, it might due to incorporate their upper half.

    Dennis

    Hi Dennis,

    Yep i know what you mean, but string can be strong, cheap, easily replaced if showing chafe and has been used by lots of Servo Pendulums to operate tillers and wheels, i like it as it can be disconnected in a trice by freeing it from a jamming cleat, and it is a servo pendulum - without lines across the cockpit. Mr V is excellent i think, and is a manufactured version of Jan's idea.

    Ash

  • 27 Dec 2014 22:47
    Reply # 3177304 on 3177214
    Anonymous member (Administrator)
    dennis gibbons wrote:Arne,

    Thank you for the lead (the internal search function).  It will save me a lot of time catching up to where the group has weighed in already.

    It will also limit my extraneous posts on this thread.

     

    Dennis


    Dennis,
    I may carry several hats, but not that of the "Editor JRA", so I guess you should rather  address your thanks to David Ty.

    Arne

     

    Last modified: 27 Dec 2014 22:47 | Anonymous member (Administrator)
  • 27 Dec 2014 17:31
    Reply # 3177214 on 3032430
    Deleted user
    Arne,

    Thank you for the lead (the internal search function).  It will save me a lot of time catching up to where the group has weighed in already.

    It will also limit my extraneous posts on this thread.


    Dennis

  • 27 Dec 2014 17:17
    Reply # 3177210 on 3176939
    dennis gibbons wrote:

    Arne,

    I was wondering if you were going to implement a wind vane steering system on your IF.

    If so, will you be considering Jan Alkema's Rudder Head Mount idea?  The IF would seem to an appropriate hull for that very interesting design.

    If this has already been discussed to death, please just point me to the thread.


    Dennis

    Yes, it has. Here, among other places:

    http://www.junkrigassociation.org/technical_forum/673518

    How did I find that, quickly and easily? I entered "upside down vane" in our search box at the top of the Members' Area page.

  • 27 Dec 2014 15:47
    Reply # 3177187 on 3032430
    Deleted user

    Ash,

    Having looked at the drawings and notes, I have a concern about the viability/efficiency of using a line to create the floating pivot. I would think a stronger and more stable mechanism could be designed. 

    Regarding the Upside down vane, have you checked out Mr. V?  Were I to design a vane, it might due to incorporate their upper half.

    Dennis

  • 27 Dec 2014 15:24
    Reply # 3177184 on 3032430
    Anonymous member (Administrator)

    Dennis, Ash

    I already have Otto, my homemade wind vane of Bill Belcher’s OGT MkII design lying around. This worked well on an earlier boat, but will be a number too small on the unbalanced rudder of the IF. My preferred adaption of that wind vane would be via a separate (retractable) auxiliary rudder.

    However, as I have no serious deep-water sailing in mind, a wind vane is not high on my to-do list. I must be happy enough when the new rig is operational. Next step then is to do small additions to the interior (galley, table, w.c. and maybe a heater, some day).

    But one thing at the time  -  many projects have run aground because of too many plans..

    Cheers, Arne

     

  • 27 Dec 2014 13:28
    Reply # 3177169 on 3176939
    Deleted user
    dennis gibbons wrote:

    will you be considering Jan Alkema's Rudder Head Mount idea?  



    Dennis

    Hi Dennis,

    Not seeking to steal Arne's reply - just commenting as an aside, The RHM by Jan is i think a great design - perfect for a transom/rudder/tiller arrangement. I have purchased the drawing from Jan and can provide his details if anyone requires(and the AYRS article)I am also persuaded by the Upside down vane (USD) so will give that a go when i reach that stage.

    Ash

  • 26 Dec 2014 17:49
    Reply # 3176939 on 3032430
    Deleted user

    Arne,

    I was wondering if you were going to implement a wind vane steering system on your IF.

    If so, will you be considering Jan Alkema's Rudder Head Mount idea?  The IF would seem to an appropriate hull for that very interesting design.

    If this has already been discussed to death, please just point me to the thread.


    Dennis

       " ...there is nothing - absolutely nothing - half so much worth doing as simply messing about in junk-rigged boats" 
                                                               - the Chinese Water Rat

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