Ingeborg and Jester - comparisions between sail area and cambered or flat panels.

  • 01 Apr 2022 01:27
    Reply # 12689499 on 4175442

    Well that solves it then!  I was afraid of “a over-canvassing”, but I wanted lots of area, figuring I could reef.  I guess I was being too conservative & will up it to the 350sf you suggest.

    Doghouse idea started with Ming-Ming’s & Wave Rover, but I thought a Ferrari like the Contessa needed curves, and I wanted to retain the signature arch.

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  • 31 Mar 2022 22:36
    Reply # 12689315 on 4175442
    Anonymous member (Administrator)

    Jester’s mast is set quite far aft. The purpose of my exercise was to find how broad a sail I could fit to that mast and still get away with 22% mast balance, and without moving the CE of the sail, compared to the original. It turned out that a batten length of B=4.0m worked fine. I knew I could then make a full-length yard at 60° fit, after adjusting the mast to upright (from 1.9° aft rake). Then it was just a question of sketching in that yard and boom in such a way that there were good enough clearance above deck and between the halyard’s slingpoint and the mast top (0.18B). This turned out to produce a sail with AR = 2.32.

    Now I had actually a master sail in my ‘library’, with AR= 2.30. This was given a new top section with a yard angle 60° and with the two top panels the same area as the lower panels. No need for a special panel 3. This was then scaled to B= 4.00m and tried on Jester. The sail suited fine and came out with a sail area of 29.6sqm. Only now did I get to see that sail area.

    Pango’s sail of 330sqft is 30.65sqm in real numbers.  That is only marginally bigger than the sail of my Ingeborg  -  with one reef  -  at 30.15sqm. I surely am glad for those extra five square metres in Ingeborg’s sail. With her mast reaching only 9.6m above the waterline, this is still a quite seaworthy rig, in my view.


  • 31 Mar 2022 19:21
    Reply # 12689053 on 12688185
    Anonymous wrote:

    Interesting!  Here's the working sailplan for a H-M junk rig on my Contessa 26

    Only 311 sq.ft Mark?  Contessa can handle more than that under JR.
    330 sq.ft on mine, and I reckon she could do with at least another 20 and she is a low aspect rig too, so you should be able to cram more on there even on a conservative JR rig for the Contessa.

    Btw, like the new dog house, looks familiar! :-)

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  • 31 Mar 2022 09:00
    Reply # 12688335 on 4175442

    I've always thought that Jester (1960) was woefully under-canvassed, and wondered why none of her owners or guardians ever got around to making her a new sail along the lines of what we now know as the H-M planform, that had been developed fully by  the time that Galway Blazer II was rigged (1968). I think you've got the area and AR about right, Arne, for the kind of Atlantic crossings that she was designed to make.

  • 31 Mar 2022 02:47
    Reply # 12688185 on 4175442

    Interesting!  Here's the working sailplan for a H-M junk rig on my Contessa 26

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  • 30 Mar 2022 21:39
    Reply # 12687836 on 4175442
    Anonymous member (Administrator)

    Stavanger, after another sunny but chilly day.

    Still a bit early to go sailing here, or even for scrubbing the deck and cockpit. The sun shines invitingly every day, but when there is frost in the morning, it is wiser to wait a little. Then the TV and web is full of that terrible war. To stay half sane, I have amused myself tonight with drawing a new JR for Jester.

    The idea was to see what can be done to improve Jester with a new sail, set on the original mast, and with the CE in the same fore-aft position. Even without positioning the boom very low, or making the drift for the halyard span short, the resulting H-M style sail with 60° yard ended up at 29.6sqm. Its mast balance is around 22%, after the mast has been adjusted to stay fully upright.

    See for yourself.

    I also let you compare Ingeborg and Jester sitting side by side (same scale). I don’t dare to bet which would be fastest when close-hauled. Downwind, my guess is that Ingeborg would take the lead in light winds, while jester would take the lead when Ingeborg needs a reef.

    What do you think?


    (se Arne's sketches section 7)

    Last modified: 07 Feb 2024 20:46 | Anonymous member (Administrator)
  • 23 Aug 2016 14:03
    Reply # 4205687 on 4175442


    Not sure - Blondie used to stand in the hatchway with the coachroof deck at waist level to operate lines. There's 4 ft of clearance from coachroof deck to boom on Blondie's original drawings. Maybe it could drop a foot or so. This picture seems to indicate that's already been done on her replacement. There's perhaps another foot of slack at the mast head. Still need to find another 3-4 feet, I reckon. 34-35 ft LAP?


    Last modified: 23 Aug 2016 14:05 | Anonymous
  • 23 Aug 2016 13:25
    Reply # 4205600 on 4175442
    Deleted user

    This is my dream!  The split junk rig on a modified Folkboat--I simply need to work up the cash . . . and the nerve.

  • 23 Aug 2016 12:31
    Reply # 4205448 on 4175442

    The thing is, Chris, that the foot of Jester's sail is much higher than it needs to be, or should be. The extra hoist for a 30 sq m sail can easily be found there. 

  • 23 Aug 2016 10:36
    Reply # 4205309 on 4205114
    Deleted user
    David Tyler wrote:Same planform, cambered and split - OK. But please, scaled up to at least 30 sq m!

    Well, yes, but I think that might require a change of planform. Jester's rig is already pretty tall for a 25 foot boat (LAP c. 30 ft. ?). Keeping the same planform and increasing sail area to 30 sq m would raise this to around 35-36 feet (although Jester possibly has a mast taller than it need be for that sail). 


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