A 7 metre variant of SibLim

  • 10 Dec 2018 11:19
    Reply # 6953160 on 6951860
    Anonymous wrote: All the talk about southern ocean rollovers got me thinking about how, or whether, this boat could be made ocean-ready. I think it could, with a Mingming-style hinged companionway hatch that could be dogged shut and watertight.

    Met this French couple who had an interesting take on this. At the bottom of the companionway steps beneath the dogged hatch were a pair or race car seats with 5 point harnesses - one on each side. Bolted to the bulkhead. 

    In any event the majority of really bad weather seems to be at the edges of of the oceans rather than the middles (notwithstanding rotating storms).




  • 10 Dec 2018 07:05
    Reply # 6953026 on 6951860
    David wrote: Yes, in the hands of a Prudent Mariner. There's plenty of previous form on this- Trekka, for example. All the talk about southern ocean rollovers got me thinking about how, or whether, this boat could be made ocean-ready. I think it could, with a Mingming-style hinged companionway hatch that could be dogged shut and watertight.The deck is in the right kind of shape, approaching a whaleback form so that water is shed quickly and inverted stability is minimised. That central part of the deck could  even be higher, to further improve that feature, along the lines of the RNLI lifeboats that have high superstructures to make them self-right rapidly. For resistance to knockdown, I think you either go for a deep keel for maximum righting moment, or shoal draught so that you skid down the breaking waves, as catamarans should do, without tripping up, and this design goes the latter way. Carrying capacity is enough for a singlehander to make the long hauls from Canaries to the Windies and from Panama to the Tuamotus.
    Well, I'm not sure how prudent I am - my form over the past couple of decades would appear to indicate the opposite if anything - but if the 7m variation can sail around the world, then taking my 8m to Fiji (as I have tentative plans to do) seems less than foolhardy.

    Actually, the more I work with this boat, the more confidence I have in her sturdiness and potential seaworthiness.  And I shall certainly have a strong and waterproof companionway/pram hood area.  I have a friend rebuilding a Trekka, who says he's planning to sail with me: it would be interesting to compare our experiences at the end of the passage.

    Hey, you might as well dream while you build.

  • 10 Dec 2018 00:46
    Reply # 6952502 on 6951800
    Anonymous wrote:



    Daivd 

    Although I have a boat waiting for me in NZ, the idea of a kit to build and get me to NZ is very enticing.   I actually have a set of Wharram plans sat on my coffee table but SibLim 7m......

    Peter

    Hmmm,

    a 23 foot boat from UK to NZ

    You sure about that ?

    Maybe I am just getting old (well OK I am) but I am thinking that might be marginal.

    Perhaps not, I dunno.


    Gary

    I'm currently living and working in Japan...  It would be Japan to NZ

    Peter

  • 09 Dec 2018 16:26
    Reply # 6951990 on 6951209
    David wrote:

    Bilgeboard cases, end posts glued in place. In the model, these are 25.5 x 8mm, at full size 109 x 34mm.

    In hindsight, these end posts should have been glued to the bulkheads first, while they were still horizontal on the floor, as we did on Annie's SibLim. This would have helped to keep the case sides flat. The exposed faces of both the end posts and the case sides would be glassed, filled and faired and resin coated while still horizontal, in the full size boat.
  • 09 Dec 2018 14:50
    Reply # 6951860 on 6951800
    Gary wrote: Hmmm,

    a 23 foot boat from UK to NZ

    You sure about that ?

    Maybe I am just getting old (well OK I am) but I am thinking that might be marginal.

    Perhaps not, I dunno.

    Yes, in the hands of a Prudent Mariner. There's plenty of previous form on this- Trekka, for example. All the talk about southern ocean rollovers got me thinking about how, or whether, this boat could be made ocean-ready. I think it could, with a Mingming-style hinged companionway hatch that could be dogged shut and watertight.The deck is in the right kind of shape, approaching a whaleback form so that water is shed quickly and inverted stability is minimised. That central part of the deck could  even be higher, to further improve that feature, along the lines of the RNLI lifeboats that have high superstructures to make them self-right rapidly. For resistance to knockdown, I think you either go for a deep keel for maximum righting moment, or shoal draught so that you skid down the breaking waves, as catamarans should do, without tripping up, and this design goes the latter way. Carrying capacity is enough for a singlehander to make the long hauls from Canaries to the Windies and from Panama to the Tuamotus.
  • 09 Dec 2018 12:33
    Reply # 6951804 on 6951800
    Gary Pearce wrote: 
    Hmmm,

    a 23 foot boat from UK to NZ

    You sure about that ?

    well, things like that have been done…

    there was a german family who made the trip around the globe with an 'etap 21'. young andreas (3 years old at departure) enjoyed standing headroom for the first part of the voyage…

    ueli

    Last modified: 09 Dec 2018 12:34 | Anonymous member
  • 09 Dec 2018 11:18
    Reply # 6951800 on 6950605



    Daivd 

    Although I have a boat waiting for me in NZ, the idea of a kit to build and get me to NZ is very enticing.   I actually have a set of Wharram plans sat on my coffee table but SibLim 7m......

    Peter

    Hmmm,

    a 23 foot boat from UK to NZ

    You sure about that ?

    Maybe I am just getting old (well OK I am) but I am thinking that might be marginal.

    Perhaps not, I dunno.


  • 08 Dec 2018 17:09
    Reply # 6951209 on 6010674

    Bilgeboard cases, end posts glued in place. In the model, these are 25.5 x 8mm, at full size 109 x 34mm.

  • 08 Dec 2018 14:06
    Reply # 6951075 on 6010674

    Bearers to support berth locker lids.

    Floor at stn 4.

    Floor at stn 6.

    These two floors are to support the bottom hull panel.

    Forehatch framing completed and forecabin headlining added.

    At full size, thick sheets of MDF would now be put on top of both headlinings, so that they can be walked on.
    Last modified: 08 Dec 2018 14:16 | Anonymous member
  • 08 Dec 2018 04:13
    Reply # 6950605 on 6949499
    Anonymous wrote:
    David wrote:

    This is looking great David. Your photos are starting to pique my interest for the next boat. I am actually enjoying building my catamaran, it is good to have a project and something to make me spend spare time creatively, so I think there will be a 'next' boat when this one is finished. I like the idea of all plywood construction. Following with interest!

    Wow, you're going to be a serial boatbuilder? Well, by the time you've finished the Eco 6, the drawings and design of the SibLim 7 should be proven, and ready for you to come back into the monohull camp :-)

    As indeed they will be ready for all JRA members who are looking for a creative project.

    I see that I've spent 16 days on the setup so far (about a couple of hours for each session).  At full size, I think it would be reasonable to expect to get to the same stage within about a month of full days of work, considering that it would be sensible to epoxy coat the pieces before assembly.

    Who else is following with interest?


    Daivd 

    Although I have a boat waiting for me in NZ, the idea of a kit to build and get me to NZ is very enticing.   I actually have a set of Wharram plans sat on my coffee table but SibLim 7m......

    Peter

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