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The "Sib-Lim" Challenge

  • 30 Dec 2014 20:08
    Quote
    Reply # 3178434 on 3169990
    Deleted user
    David Tyler wrote:

    Annie,

    The more I think about it, the more I'd like to see you sailing and living aboard a scaled-down version of Tystie. The hull form lends itself well to drying out safely, lying down gracefully to one side or the other for you to scrub.

    • A strong central keel and skeg that take the ground first and absorb any punishment due to wave action, if you ground in less than ideal circumstances.
    • A single chine, giving the form stability that a shoal draft boat needs.
    • A curved 'V' hull form underwater, for seakindliness and an easy rolling action as the tide leaves her. Double diagonal construction.
    • Flat topsides of sheets of plywood, for speed of construction and ease of fendering against pontoons and walls.
    • Vertically lifting bilgeboards, in cases that are set right out against the topsides, that can be used as legs when it's safe to do so. Good sailing performance, and no chance of jamming the slot with pebbles, unlike a centreboard.
    • Raised topsides, unlike Tystie, for maximum internal volume.
    • A draft of 2ft should be possible, but I'd want to use some external ballast which would also protect the keel - a piece of old railway track?
    • A higher bow than Tystie, with a small Chinese bow transom, to give more working area for anchoring.
    • Accommodation layout and rig very similar to Fantail's.

    [ edit - yes, I know I said all that right at the beginning of this topic, but I want to keep it alive and at the forefront of your minds :-)  ]
    David Tyler wrote:

    I've found a little time to make a sketch of the five panel hull that I talked of. You'll find it in the illustrations photogallery...


    David,

    Did you find Tystie's open transom as useful as hoped when ocean cruising? Would you recommend an open transom for your Sim-Lim design?
  • 30 Dec 2014 05:23
    Quote
    Reply # 3178120 on 3144241
    Deleted user

    Hi Annie,

    Dipping in late, with some designs from Tad Roberts that might interest or inspire you. All have junk sail options!

    HARRY, a 26ft sailing barge... a little heavy at 10Klbs, holds down the 'houseboat' end of the range.

    (http://www.tadroberts.ca/services/small-boats/sail/harry126)at 10Klbs displacement

    HARRY II, 27ft sailing scow... more what I think you're picturing, at 7Klbs. Junk styling and much more sleek than HARRY.

    http://www.tadroberts.ca/services/small-boats/sail/harry226

    NU-WA, a 20ft ply junk... approach can be enlarged to meet your wish list.

    (http://www.tadroberts.ca/services/small-boats/sail/nu-wa20)

    And LITTLE TILIKUM, 25ft ... a Thames Bargelet(!) at 7Klbs. Not plywood, nor entirely simple, but could be strip-planked or quick-molded. Once built, might meet your needs very well.

    http://www.tadroberts.ca/services/small-boats/sail/littletillicum25


    Hope some of these are at least eye-candy!  8)

    Dave Z
  • 28 Dec 2014 00:20
    Quote
    Reply # 3177320 on 3144241
    Anonymous member

    I've found a little time to make a sketch of the five panel hull that I talked of. You'll find it in the illustrations photogallery. 

    It looks OK as a sketch, but I haven’t the software to work it up properly. 

    LOA 26ft, Beam 9ft 9in, draught 2ft, approximate displacement 3 tons, as requested. Total height 6ft, which after subtracting the structure will give about 5ft 4in headroom. I think that with this width of bottom, 2ft, she can be hauled down, but will not fall down.

    I’ve made it as simple to build as I can, but inevitably there will be some torturing of the sloping panels to do, around the forefoot. There would be a curved stem and bow transom to laminate, otherwise the bulkheads and frames would be straight-sided. The deck is tightly radiussed amidships, but flat towards the sheerline, to give the required headroom without making the side-decks too steeply angled.
  • 15 Dec 2014 22:21
    Quote
    Reply # 3170759 on 3144241
    Anonymous member
    Peter: Thanks for your offer.  I’ll wait until the Ultimate Design comes up before putting you to all that trouble, however.  Yes, I know of Red Fox, but the trouble is that generally speaking, you can't just add 30% all round and hope to end up with something as good as the original.  Oh that it were so easy!

    David.  Yes, I can see your point about twist.  I’m sure you can see mine about skill limitations.  Five panel would be a very interesting compromise and I could even consider using my idea of a hefty lump of steel, on the bottom panel to act as ballast and protect the hull from oysters.  (The Pacific Oyster farming industry has led to a proliferation of these animals and their shells are like razors and not always visible.)  I’d prefer to carry my water in jerricans rather than in a tank. As well as the usual argument, ie that it stops all the water being lost or contaminated, I very rarely go alongside and ferry my water by jerrican, which presently means having things on board that are normally not in use.
  • 15 Dec 2014 18:05
    Quote
    Reply # 3170585 on 3170214
    Anonymous member
    Annie Hill wrote:Could you bear to change your curved V to flat V?  I feel double diagonal would be more of a challenge to me than simple chine, but could possibly be persuaded otherwise. 
    Single chine plywood hulls can be difficult to build, due to the large amount of twist in the bottom panels, near the bow. Double diagonal allows you to build up this twisted shape a piece at a time.
    There is another hull form I rather like - a five panel hull, with vertical topsides down to the waterline, then sloping panels, then a horizontal central panel which is wide enough to ground on without falling over, wide enough to accommodate ballast and tankage in a low, central location, wide enough for an aperture for an outboard leg, but narrow enough for careening, with a masthead line taken down to a strong fixed point. Maybe about 400mm - 500mm wide, for Sib-Lim. Better, I think, than the three panels of dories and sampans.
  • 15 Dec 2014 10:13
    Quote
    Reply # 3170305 on 3170214
    Deleted user
    Annie Hill wrote:Well, David, I could certainly be tempted: you seem to be ticking most of the boxes.  And one of the things that worries me would be having an unproven hull design.  Going to windward is not my favourite but is occasionally necessary.  Could you bear to change your curved V to flat V?  I feel double diagonal would be more of a challenge to me than simple chine, but could possibly be persuaded otherwise.  A sketch plan would be very welcome.   :-)

    Annie, if you decide to go with David's idea I have lots of photos of Mallie's hull build which you may find useful. I could load them onto a cd and post them to you.

    Have you considered the Red Fox 200 designed by the late David Thomas. It has a virtually flat hull, min draft  0.2 m and max 0.89 m with bilge boards like Tystie and Mallie plus a lifting rudder. Of course at only 20 ' it is probably too small and there are probably none in NZ but I was thinking more of the design if it could be re-designed as say a 26' version. Just a thought.
  • 15 Dec 2014 04:15
    Quote
    Reply # 3170214 on 3144241
    Anonymous member
    Well, David, I could certainly be tempted: you seem to be ticking most of the boxes.  And one of the things that worries me would be having an unproven hull design.  Going to windward is not my favourite but is occasionally necessary.  Could you bear to change your curved V to flat V?  I feel double diagonal would be more of a challenge to me than simple chine, but could possibly be persuaded otherwise.  A sketch plan would be very welcome.   :-)
  • 14 Dec 2014 16:34
    Quote
    Reply # 3169990 on 3144241
    Anonymous member

    Annie,

    The more I think about it, the more I'd like to see you sailing and living aboard a scaled-down version of Tystie. The hull form lends itself well to drying out safely, lying down gracefully to one side or the other for you to scrub.

    • A strong central keel and skeg that take the ground first and absorb any punishment due to wave action, if you ground in less than ideal circumstances.
    • A single chine, giving the form stability that a shoal draft boat needs.
    • A curved 'V' hull form underwater, for seakindliness and an easy rolling action as the tide leaves her. Double diagonal construction.
    • Flat topsides of sheets of plywood, for speed of construction and ease of fendering against pontoons and walls.
    • Vertically lifting bilgeboards, in cases that are set right out against the topsides, that can be used as legs when it's safe to do so. Good sailing performance, and no chance of jamming the slot with pebbles, unlike a centreboard.
    • Raised topsides, unlike Tystie, for maximum internal volume.
    • A draft of 2ft should be possible, but I'd want to use some external ballast which would also protect the keel - a piece of old railway track?
    • A higher bow than Tystie, with a small Chinese bow transom, to give more working area for anchoring.
    • Accommodation layout and rig very similar to Fantail's.

    [ edit - yes, I know I said all that right at the beginning of this topic, but I want to keep it alive and at the forefront of your minds :-)  ]

    Last modified: 14 Dec 2014 17:09 | Anonymous member
  • 01 Dec 2014 13:41
    Quote
    Reply # 3160304 on 3144241
    Anonymous member

    Beauty - of course, in the eye of the beholder.  I guess based on a standard KD860, it would look a bit more dumpy. 

    As you say Oryx is a fair size for one.  The standard KD860, is 8.6m, so still a little large.  I am with you on size. Though also weight comes into it.  Cats win here, though loose on windage - hence the 'ugly' reverse sheer to present a better aerodynamic profile.

    BUILD TIME

    It would interesting for views on how long a Sib-Lim would be to build,  mono or cat.  Pete says Oryx about 2 years mainly singlehanded,  the complicated biplane rig must have taken a fair time.  KD860 listed at 1200hrs, though I guess that is for the basic sail-away hull.  What is it that takes the significant time in a build.  I suspect it is much to do with finishing off,  nice cupboards, exposed timber, wood stoves, electrics and water services etc.


    Last modified: 01 Dec 2014 13:45 | Anonymous member
  • 30 Nov 2014 22:10
    Quote
    Reply # 3160033 on 3158990
    Anonymous member
    Mark Thomasson wrote:

    JUNK CATAMARAN

    Just for fun I sketched over Petes Oryx to look more like a Badger and with a single fanned junk rig.  Better looking?

    Of course the Gary Lepac Dragon Wings had a very Chinese look, if that is what is desired.

    Posted in Technical Forum / Illustrations


    I have to confess to finding Oryx far from attractive and couldn't live with her myself, although she is beautifully built and fitted out, as I would expect from Pete.  Your sketch is infinitely more attractive to my eyes and the single mast makes heaps more sense.  I However, she is a big boat and even Pete took several years to build her - I have no intention of spending that amount of time building.  Couldn't afford it, apart from anything else, because I will need to rent a space to build.  But I could see myself sailing around something like your sketch if she were only 7 or 8 m long.


    Dragon Wings is way too big and has the disadvantage of all 'double canoes' that you either have to cross from one hull to the other in wind and rain, or end up carrying around a spare hull that is rarely used.
       " ...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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