Flat, hinged or cambered?

  • 16 Aug 2018 09:18
    Reply # 6576504 on 6576377
    David wrote: As the longest piece of batten is only 2.5 metres, it wouldn't be impossible for me to get 38mm high quality GRP tubes from the supplier that I use, make up the battens and hinges, and send them downto NZ.
    'Strewth, what an offer.  I need to think about this.  The darling wee boat has to go very respectably to windward, otherwise everyone will think I've trashed your design.  And I might not get to the islands ...  On the other hand, as you appear to think that Weaverbird sails adequately, then I assume you feel the concept will work on Siblim.

    The fibreglass battens I bought here were bloody useless and I loathe alloy ones, to be honest, but yours from the UK, complete with hinges, sound like an investment worth making. Will you be able to take the time out from making your new wing sail, though?

    (BTW, I did mention that Badger's sails were HAR.)

  • 16 Aug 2018 08:07
    Reply # 6576466 on 6575572
    Anonymous member (Administrator)
    David Tyler wrote:
    Arne wrote:

    Webmaster,
    Are you sure this belongs in the General Forum and not in the Technical Forum?

    Arne

    I agree, this is very much a technical topic.

    David and Arne,

    I agree that it could fit into the Technical Forum, within the description of:

    discuss matters to do with improving the junk and related rigs

    But, referring back to the original questions on both topics, I chose to put it in the general forum with reference to:

    request advice on choosing and using a junk rig

    To my (admittedly pedantic) eye, the use of 'a' instead of 'the' suggested this as the best place for what is essentially a discussion of which variety of junk rig to use.

    However, either Forum will work, and if you both still feel it should be in the Technical Forum, I can easily move it across.  As two of our most prolific posters, you have a good 'feel' for what fits where.

    Mark

  • 16 Aug 2018 06:34
    Reply # 6576377 on 6575734
    Annie wrote:
    David wrote:On my mini lathe, I just have enough capacity to turn hinges for 38mm tube.


    Having managed to bend 38mm T6 battens on Fantail, I'm think if I were going for alloy, I'd have to go larger on SibLim.  So that puts the kibosh on that idea.  Back to shelf foot!
    As the longest piece of batten is only 2.5 metres, it wouldn't be impossible for me to get 38mm high quality GRP tubes from the supplier that I use, make up the battens and hinges, and send them downto NZ.
    Last modified: 16 Aug 2018 06:34 | Anonymous member
  • 16 Aug 2018 06:28
    Reply # 6576373 on 461931

    Annie, one factor that you may have overlooked is that being a schooner, Badger's sails were of highish AR. That makes a big difference to the line loadings.

    Are you thinking of the size of Tystie's current mainsail, and forgetting that I cut quite a lot off the luff when I got to NZ and converted her into a ketch again? Under the single sail, she was fully powered under both fantail sail and the later, Mustang one.

    Anyway, the takeaway from both of our ocean voyaging experiences is that the flatter the sail, the easier it is to live with - provided that you have the patience of a saint if you sail engine-free. But I would just mention Kehaar, flat sailed and engineless, failing to get through the ITCZ and retreating to Hawai'i. And let's not forget The Rime of the Ancient Mariner. Engineless, and had a little difficulty in calm weather, as I recall.

    I still want to pursue the idea of hinges + minimal sewn in camber for SibLim, as therein lies one of the keys to stress free sailing with good windward ability, I'm finding. I don't claim that you'd beat Arne in a race around Stavanger Fjord, but I do think that you'd enjoy a passage up the Islands more.

  • 15 Aug 2018 22:45
    Reply # 6575734 on 6574492
    David wrote:On my mini lathe, I just have enough capacity to turn hinges for 38mm tube.


    Having managed to bend 38mm T6 battens on Fantail, I'm think if I were going for alloy, I'd have to go larger on SibLim.  So that puts the kibosh on that idea.  Back to shelf foot!
  • 15 Aug 2018 22:35
    Reply # 6575728 on 6574458
    David wrote: A small efficient diesel plus a large tank of fuel is a key component of a stress-free cruising boat.

    No, David, I have to disagree.  it's the attitude of the sailor that is the k
    ey component of a stress-free cruising boat.  To me, using an engine in the calms, defeats the object of the exercise, which is to travel across the ocean under sail, using the wind and accepting the calms, while treading lightly.  I would get no satisfaction from a fast passage facilitated by use of an engine.  Each to his own, of course, I know I'm in a minority, but people have sailed engineless, in all parts of the world, with flat sails.  

    This was due largely to the cyclical diagonal loadings that occur in the throat area of a high peaked sail - not an issue in a lightly used coastal cruising boat, but needs to be taken seriously and guarded against in an ocean cruiser, with plenty of reinforcing patches.

    I assume that here you mean with cambered sails?  We never used much reinforcement on Badger's sails and got 80,000 miles out of one suit.  This is why I am still ambivalent about camber.  My idea of stress free sailing includes a rig that isn't stressed.

    The second voyage also contains plenty of windward work, but is more of a mixed bag. Some camber is certainly desirable, though. The physical work was very much less demanding, with the low peaked yard. This matters a lot, with an ageing singlehanded crew. I made the voyage quite fast, because I was able to keep up with sail changes without exhausting myself. I had been challenged to get to NZ in time for Annie's 60th birthday party, and only missed by a week, due to strong winds and washing machine seas off Tonga that made me need a rest, not through lack of windward ability.

    But the sail was a lot smaller, too!

    Would I put Weaverbird's rig on an ocean cruising boat? Yes, absolutely. In two seasons, of four full-time months each and a total of 3300 miles, it's proved sound and reliable in all kinds of conditions. Just as much, and perhaps even more to the point for cruising is that it's as effortless and thought free a manner of sailing as is possible. Arne's postings on his rigs are often about how you need to do "thus" and "thus" to the YHP and THP and LHP and HKP to get them to set well. My YHP is redundant under full sail, and only lightly taken in when deeply reefed. My LHP (no THP necessary) can be easily taken in with one hand whilst steering with the other. The sail sets well, with little tweaking and conscious thought on my part. Why? Mostly because of the yard angle and its shorter length, and the particular shape of the upper panels, and not because of depth of camber, or the way in which camber is added. This is what truly matters when ocean cruising. On a dark moonless squally night, being able to reefing and unreef, and knowing that your sail is well set even though you can't actually see it, is worth more than that last ounce of windward ability.


    Let us not forget, that the high-peaked, HAR, classic H/McL sails on Badger were simplicity itself to handle, offshore or for coastal sailing.  There was only any noticeable load on the YHP when the sail was well reefed and no LHP was necessary. We got where we wanted to go, but she was definitely resolute rather than lively to windward.  It seems to me that camber changes all this: if altering the sail plan can restore the peace and simplicity of Badger's rig - something where I could reef both sails, in the dark, from the control station without a problem -  and allow the boat to go well to windward, then I should be happy.  But I am sure that I'm not alone in that I don't want my boat to be a motor sailer or resort to using fossil fuels because I'm bored and frustrated.

    We need more reports, more experimentation and more people clocking up the miles.  I'm hoping that Asmat will write for the magazine.  And am prepared to try something new (to me) on Siblim.


  • 15 Aug 2018 21:07
    Reply # 6575572 on 6575565
    Anonymous wrote:

    Webmaster,
    Are you sure this belongs in the General Forum and not in the Technical Forum?

    Arne

    I agree, this is very much a technical topic.
  • 15 Aug 2018 21:03
    Reply # 6575565 on 461931
    Anonymous member (Administrator)

    Webmaster,
    Are you sure this belongs in the General Forum and not in the Technical Forum?

    Arne

  • 15 Aug 2018 20:52
    Reply # 6575556 on 461931
    Anonymous member (Administrator)

    The two forum topics relating to flat, hinged or cambered sails have been merged - I hope this does not cause any great confusion!  I have opted to keep the new topic in the general forum as part of a broader general discussion about the junk rig, although accept that it could also have gone to the technical one.

    Webmaster

  • 15 Aug 2018 20:15
    Reply # 6575499 on 461931
    Deleted user

    one thing I think  makes Paul's aero junk appealing is the potential to change camber on the fly. The multitude of moving parts Annie mentioned is the main concern I see with it.

    I find the sheer simplicity of Arnes rigs every bit as amazing as the ingenuity David has built into his. 

    I suspect that if Junkies weren't rugged individualists by nature they'd be motoring in a bermuda rig instead.

    Bill

    Merged topic from TECHNICAL FORUM: 15 Aug 2018 20:49
       " ...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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