SibLim 10 metre

  • 06 Nov 2021 19:11
    Reply # 12105622 on 12102914
    David wrote:

    Yes, the rig does look quite far aft, doesn't it? On the other hand, Annie says that Fanshi has too much lee helm in light conditions, and I think that's because the twin skegs are more effective than a single skeg would be, at holding the stern up to weather. So I'm proposing to use less lead than is usual, maybe no more than 5%.



    I wouldn't bet on that, David.  I think it is the sail.  It 'wants' to set too far forward because the halliard hauls the centre of the yard forward from where it 'should' be according to the sail plan.  I am adjusting it (yet again) today and have rigged up a running yard parrel that drags  the yard back more to where it should be at full sail.  (I had a standing one, but it made pulling the sail up shockingly hard work.)  I'm also removing the cones from the battens (sorry about that) - the sail just doesn't look right with them so far aft.

    As soon as I reef, the sling point can move aft more easily and the lee helm vanishes.  The skegs make no difference to how the boat moves at anchor.  I would have expectedd them to do so if they make so much difference to how she sails.  I am no expert and not a designer, but my feeling is that it's the sail that is wrong and not the mast placement.  (I have also confirmed my hunch that you designed a sail for a 2 degree rake, instead of the 4 degrees that we have.)

  • 05 Nov 2021 19:52
    Reply # 12103088 on 10668989

    Right, that is a very good reason. I may have read that and then forgot about it. First hand experience is the best design input.

  • 05 Nov 2021 18:32
    Reply # 12102914 on 10668989

    Yes, the rig does look quite far aft, doesn't it? On the other hand, Annie says that Fanshi has too much lee helm in light conditions, and I think that's because the twin skegs are more effective than a single skeg would be, at holding the stern up to weather. So I'm proposing to use less lead than is usual, maybe no more than 5%.

  • 05 Nov 2021 17:56
    Reply # 12102843 on 12101654
    Anonymous wrote:

    A quick peek at SibLim 10m with Poppy's SJR. The mast is a hybrid base on a 10 inch diameter tube.

    At first glance I would want the mast a bit more forward. Maybe one mast diameter.
  • 05 Nov 2021 10:27
    Reply # 12101785 on 10668989
    Anonymous member (Administrator)

    My Johanna came with a dead diesel, so I fitted a 9.9hp Yamaha with a hi-thrust leg (2000). I had it until I sold the boat in 2014. It didn’t live a very hard life. I mainly used it for getting out of the harbour, and in no wind, when cruising (which I did quite a bit in those days).

    Putting an outboard on that 3 ton sailboat was quite unusual at the time, but I congratulated myself for the choice. The unit was plenty powerful enough for safe harbour manoeuvring, with the benefit of vectored thrust. Max speed was 6.3kts, the same as the hull speed, and at 5.5kts the noise was low and the fuel consumption was less than 0.5 litre/NM.
    I once towed another 3-ton sailboat behind us, and we hardly noticed it. An extra bonus of that high-thrust leg was how powerful it was in reverse. This let us do precise harbour manoeuvres in strong winds: We kept the stern into the wind, and let the bow take care of itself (..held downwind by the windage of the mast...).

    I definitely recommend that engine. It was easy to start and to swing up or down, and the gear lever sitting close to the throttle made it easy to reach, even without a remote control.

    Arne


  • 05 Nov 2021 09:18
    Reply # 12101654 on 10668989

    A quick peek at SibLim 10m with Poppy's SJR. The mast is a hybrid base on a 10 inch diameter tube.

    1 file
  • 05 Nov 2021 08:25
    Reply # 12101602 on 10668989
    Anonymous member (Administrator)

    They come with long shaft (L) or extended shaft (X), I don't think I have seen one with a standard shaft.


    The one I had sure was a sweet-running motor.

    I also had a 15hp Honda at the time, and was able to compare them on a 19' displacement hull. I thought the Yamaha was quieter and smoother. The Honda gave slightly more speed (in a straight line) but ventilated badly when trying to turn at full throttle, so in practice the Yamaha Hi Thrust with its bigger, slower turning propeller was the superior motor.

    The only other "barge model" I have seen in New Zealand, in that size category, was a Mercury "big foot" 15hp 4 stroke. About the same size and weight as the Yamaha and Honda referred to above. I don't know how they compare.


    Last modified: 05 Nov 2021 08:35 | Anonymous member (Administrator)
  • 05 Nov 2021 07:53
    Reply # 12101561 on 10668989

    OK, I think we're coming down in favour of the Yamaha 9.9 High Thrust, or whatever seems to be the best choice of outboard at the time of purchase.

    In other news, it seems that the best choice of rig is simply to use Poppy's size and shape of SJR - the right size, a convenient length of batten, convenient mast placement just aft of the double berth, and gets away from cluttering up the foredeck and saloon with the masts of a schooner rig. And using twin rudders and skegs with an outboard permits me to adjust the position of the CLR as required.

    I've also had a look at whether I could squeeze the LOA down to 9.5m, reducing the beam in proportion, and still fulfilling the design brief, but it all seems a bit too tight. 10m seems to give the "elbow room" desired. So the major aspects of the design seem to be settling down. 

  • 03 Nov 2021 21:30
    Reply # 12097355 on 10668989
    Anonymous member (Administrator)

    Green-ness: consume less and sail more.

    Related to our boating life, I think these two factors are most important:

    • 1.      Choose a boat (new or old) of solid construction, which will last ‘forever’. Many of the grp-boats from the sixties and seventies still appear to stay sound. Their systems are quite simple and can be repaired when needed.
    • 2.      Choose a sailboat, and then one which is easy to sail and which goes well to windward, so one actually elects to sail instead of motoring.

    I think that upwind performance has been given too little value. I am not talking about break-neck racing speeds, with the crew perched on the rail, only good and predictable progress in light winds (in particular) as well as in winds up to (and included) F6. I find that tacking against F6 is no fun, but motoring is no better in those conditions. At least my Ingeborg does it, but of course with cold spray flying everywhere.

    Think about it: The engine of a motor boat may well burn fuel equivalent to several times the displacement of the vessel during its lifespan. In comparison, my outboard may have burnt as much as two litres this summer. That was enough to move us 150-200NM during our 15 day-sails.
    As I bet most of you do, I frequently spot sailboats motoring around during perfect sailing conditions. This just turns me sad.

    I have never felt a missionary call to promote the JR  -  maybe until now:
    Fitting a good JR could bring new life to an elderly but structurally sound sailboat with a tired rig. This would be both quite satisfying and also a lot greener than scrapping it and buying a new boat. The JR would even encourage one to sail most of the time.

    Sooo good luck with the 10m SibLim, Donald  -  and give her as generous sail area as your intended sailing lets you have!

    Cheers, Arne


    Last modified: 04 Nov 2021 09:15 | Anonymous member (Administrator)
  • 03 Nov 2021 17:33
    Reply # 12096643 on 12095656
    Anonymous wrote:In all the reporting about COP26 I haven't heard anyone saying we all just need to use less! LIM!  They're expecting further industrialization to sort the climate out. 
    LIM is a wonderful idea but there is a whole world of people who have no internet, cellphone, or electric anything, who are cooking their daily meal over an open fire... inside their dwelling. Suggesting to these people to use less when having electric anything would for sure reduce their impact on the earth is maybe less than reasonable. On the plus side, perhaps these people will be in a better position to not ramp up their power use than richer nations do now. But in any case, the world's power consumption is going to continue to rise even assuming rich country people (1rst world?) use less. There is no simple solution I think.... maybe mandating 20 year warranty on Cars and appliances (and outboard motors of any type) would be a bigger start.


    enough rant, in the end a used outboard is going to be the least expensive option. There are lots to choose from and they can be swapped out easily (as I am finding) and the old one can be sold... for parts if nothing else. When electric outboards get to that "easy access to used" point, they will have their  time in the sun too. There are already places where 2 strokes (including Detroit diesels) are banned and those same places are already drafting laws to phase out fuel driven motors in the future. So learn to sail in tight spaces ;)

    I am waiting for light enough and flexible enough and strong enough solar panels I can use them for sail cloth.

    Last modified: 03 Nov 2021 17:35 | Anonymous member
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