Anti Capsize / Damage and Sails

Discussion in 'Multihulls' started by Fanie, Dec 8, 2007.

  1. Fanie
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    Fanie Fanie

    I was discussing a sail design with someone yesterday and it seems there are two basic thing that can cause capsizing or damage on (most) multi-hulls.

    If the wind is strong enough the multi-hull can capsize due to sail pressure
    If the multi-hull's righting moment is enough the mast can break or damage

    A search did not come up with a preventative solution for this.

    Why isn't there an adjustable clutch that works like a cleat that would let some line out if the line tention exceeds the set drag on the line ? It may be uncomfortable to trim the line back in but it would be better than to capsize or get damage on a mast.
     
  2. yipster
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    yipster designer

    a mono heels but can go flat or fail just as well etcetera
    but yes, i also was wondering about a power control unit
     
  3. masalai
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    masalai masalai

    Fanie, on your small boat just hold the sheet in one hand and the tiller in the other. Fly a hull, 'tis fun and still exhilarating for oldies like me. The biggest I have done that is a "Hobie 16", but do not wrap the sheet around your hand!, use gloves (golfing grips worked for me) else you won't be able to let go! when you need to.

    On smaller cats (14 ft) sailed solo fit a 6ft length of old but good sheet outside each hull about midships, when you capsize climb up the centerboard or hull keel line, grab the rope & lean out, and up she will come with you under then easy to get underway again. Need 2 up for the Hobie as I am a bit on the light side then. Try recovery when yours is in the shallows to get the idea.

    Some of the hire fleets attach a styrofoam flying saucer shape on the top of the mast to prevent complete inversion. only goes to about 100 degrees.
     
    Last edited: Dec 8, 2007
  4. Fanie
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    Fanie Fanie

    I was actually thinking about larger boats. Holding onto one of those big sails could have interesting results with you disappearing off the bridge in a fraction of a second, with the sail then at the far end I suspect will shake everything hangin from ye off ;)

    Such a drag should not be too difficult to make... a disk with the cleat V's all round and a guide in and guide out should do it. The tentioner could have a shaft through the V-ed disk and clutch disks similar to those on a fishing reel.

    A simple electronic circuit could warn when some line was dragged through the disk triggered by the rotation so you could adjust the sail again. The winch could sit on the back of the guide.
     
  5. masalai
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    masalai masalai

    In that case why not a quick release cleat (camcleat)?
     
  6. Fanie
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    Fanie Fanie

    Well, you may not always sit right with it when things go wrong. It may also mean that it is one less thing that may require urgent attention at that moment.

    Since I fish I don't want to worry about the sails... they should take care of themselves.
     
  7. Alan M.
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    Alan M. Senior Member

    You hold on to the mainsheet or headsail sheet, or both (which may be thru a camcleat on a bigger boat) when you are sailing the boat hard, i.e. racing. We would take the sheets out of the self tailers and put them into camcleats so they could be released quickly.

    If you are fishing, or cruising, or unable to pay attention for whatever reason, then you shouldn't be pushing that hard - if the wind is getting up, reef down.
     
  8. Fanie
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    Fanie Fanie

    Game fish require some speed to fish for.

    What happens when that sudden unexpected wind hits the sails ?
     
  9. masalai
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    masalai masalai

    Arrr Fanie, are you getting bored on the days off this weekend?

    Trolling about 6knots should suit most targeted species, even the odd Philamon could appreciate a tow. I hear two legged pig tastes somewhat like fish/chicken? I knew a cannibal from PNG who had actually eaten same and preferred it.

    Oops not the drivel thread - - Oh well it is now! advise Frosty please.
     
  10. Richard Atkin
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    Richard Atkin atn_atkin@hotmail.com

    I have every intention of putting auto-release cleats on my future cruising catamaran. I think it would be very easy to do....basic physics....low cost. A system like that would also be great for beaching at full speed without sudden shock to the rig.
    Fanie, I think the biggest cause for capsize on cruising cats is tripping. Just too much speed for the conditions.
    - Richard
     
  11. catsketcher
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    catsketcher Senior Member

    read the old books

    Hello all

    Sheet release systems have been used before. They were quite common in magazines of the late 60's early 70s. Look up the AYRS site and scan their catalogue on early multihulls.

    Without meaning to sound stuffy - get stuck into the old books to learn from the experience of others. There are good reasons why the sheet release system has been discarded - they are prompted by wave action, hard to adjust properly and nowadays most cats are much more capsize resistant that their early sisters. Multihulls magazine and Multihull World Australia are a good source of ideas.

    cheers

    Phil Thompson
     
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  12. rob denney
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    rob denney Senior Member

    G'day,

    Phil's advice is excellent, although there are apparently devices on the ORMA tris which work well.

    A much safer solution is a rig which automatically spills the wind in a gust. ie an unstayed mast. This has the added benefits of being able to hoist and lower the sail at any angle to the wind, being able to depower instantly by letting the sheet go on any point of sail, has little or nothing to maintain, and if the boat is designed for it, will be cheaper to buy.

    regards,

    Rob
     
  13. Pericles
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    Pericles Senior Member

    Anyone thought of using rubber sheets? Wait, that did not say what I meant. :D

    Some kind of spring system to ease the main sheet temporarily in a squall? How about oil filled torque wrench dampers set into the hull structure or even a large version of a friction release game fishing reel? Actually, the Omer Soft WIng Sail would windcock immediately the mainsheet was released and depower the vessel. http://www.omerwingsail.com/

    Pericles
     
  14. yipster
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    yipster designer

    aye, someone brought it up to a rib exhibitor at the last mets, yipster
     

  15. Richard Atkin
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    Richard Atkin atn_atkin@hotmail.com

    Do unstayed masts last very long? I like the idea uf using a boomless mainsail with an unstayed mast.....just let the thing go like a flag, when beaching etc. hmmm...I wonder how bad a boomless mainsail would be on a reach.
     
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