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Mike Kajan Yacht Designs

Discussion in 'Yacht Renderings & Plans' started by Kajan, Nov 28, 2009.

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  1. Yacht News

    Yacht News YF News Editor

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    Neither am I but with the 'cutout' you gave at the base of the semi-vertical bow it seems to leave little space for the bulb you created. How is the bulb going to effectively work? Most or all of the bulbs I have seen on yachts and ships tend to project forward of the bow.
  2. Henning

    Henning Senior Member

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    It projects forward of the waterline interface.
  3. Kajan

    Kajan Senior Member

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    I would imagine it doesn't matter to some degree what the bow look like above the waterline. Check the link 'Surfer' had attached in a previous post above.

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  4. Kajan

    Kajan Senior Member

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    200m deck plan

    Layout to come.

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  5. Kajan

    Kajan Senior Member

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    53m Axe bow

    I hope you guys don't mind me posting some smaller designs while the 200m is taking shape layout wise.

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  6. Henning

    Henning Senior Member

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    Nah, but the satellite reception is really going to suck with the radar blasting into the dish....
  7. K1W1

    K1W1 Senior Member

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    Kajan- Why don't you have a look at using Pump Jets instead of Transverse Thrusters?

    They are much quieter and also give you an alternate emergency propulsion system.
  8. Kajan

    Kajan Senior Member

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    Henning, it sounds obvious when you think of it. I'm surprised there are so many designs out there with this problem.

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  9. Kajan

    Kajan Senior Member

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    K1W1, this is fairly new to me so I did a quick search on the Internet and found many interesting facts, thanks for the tip!

    Cheers!
  10. 84far

    84far Senior Member

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    Kajan, love the 53m. yet again the hull looks great when its a different colour to the cabin.

    far
  11. Kajan

    Kajan Senior Member

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    Thanks, Far! Yes, I agree. The 640 resolution makes the small lines and details less visible when in white and I think the contrast works out nicely.
  12. Henning

    Henning Senior Member

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    That and masts causing blind spots, surprises me every day. My buddy is working on a Heesen where they just had to make a new mast because of this, and the mast on the Kingship I'm on had to be changed as well. No offense directed, but the primary issue is designers with no sea time. Lot's of problems become very obvious with a few years at sea.
  13. Kajan

    Kajan Senior Member

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    25m Axe bow

    It's snowing here right now so I thought some colour could brighten things up a bit.

    A Happy New Year to you all!


    /Mike

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  14. Kajan

    Kajan Senior Member

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    73m "Golden Nugget"

    Too close to a wedding cake? Please, feel free to comment!

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  15. Yacht News

    Yacht News YF News Editor

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    I actually love the aesthethics of the "golden nugget" minus the hull windows, that is the only thing I do not like about her. "Too close to a wedding cake?" Come on Karjan! She looks nothing like "Wedge Too" so she looks nothing like one!

    The 25-meter axe-bow: wouldn't that be a pretty wet ride with an axe-bow for such a 'small boat'? I think Axe-bows work pretty well with considerably larger yachts. That's just my take on it.
  16. Kajan

    Kajan Senior Member

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    Thanks, YachtNews! I wanted the hull windows to add to the elongated feel of the design, hence the stretched design of the windows, I felt that had the windows been taller, the overall appearance would have been a taller yacht.

    I also wanted to design windows not too often seen that would also work with the hull design in general.

    And yes, you’re probably right regarding the axe bow concept on a 25m boat.
    I thought it would be interesting if perhaps a fellow YF member could shed some light on the matter.

    I’m aware of the discussion held some two years ago regarding the axe bow, in the “Axe Bow / Enlarged Ship Study” thread, and I must say, it’s fantastic to see the knowledge and experience fellow members possess.

    It would have been interesting if the minimum requirements regarding length, width and height of the hull, if there are any, could have been included in this discussion or is it simply a question of how wet you want to get?

    Makes you wonder if there is a way of putting together a formula or chart of some kind with all the aspects such as desired speed, fuel ratio, wave height, pitch, risk of nose-diving, deflecting spray… you enter the inputs and out comes a curve or a chart with recommendations. Neat!

    I mean, when is it best to go with a conventional, axe, wave piercing, bulbous or even Lars’ integrated bulbous bow, or is this just common knowledge among N/A’s, from a pure hydrodynamic point of view, all fancy above the waterline design aside?

    I guess both Lars/AMG and Palmer Johnson with the latest PJ170 are on to something. ;)

    Cheers!
    /Mike
  17. Kajan

    Kajan Senior Member

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    25m ver2

    If you manage to keep the deck less wet with a less extreme bow, I guess there are other ways to get it wet.
    You would probably have to keep it dry when under way but that way the jacuzzi bottom could double as a sky light.

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  18. Henning

    Henning Senior Member

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    Even without water in it, a jacuzzi is a lot of weight to put up on the bow. Also, there is no advantage to using that bow form on a planing hull boat.
  19. Kajan

    Kajan Senior Member

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    A typical 4 person Jacuzzi has a dry weight of about 200Kg including pumps and nozzles.
    If built in carbon fiber you could probably knock some 50Kg off that weight plus the fact that you’re removing some material from the superstructure.

    The net weight increase would probably be less then 100Kg = average weight of a healthy Swede. :)
    I’m not totally convinced that it would have any serious negative effect on a 25m boat.

    Regarding the lesser advantage of this particular bow, well I assume there are YF members more suited then me to take you up on that.
    I wonder where builders like Mulder, Wally, Pinasse to mention a few, gets the idea that it has an advantage? Or is it simply a design trend?
  20. Yacht News

    Yacht News YF News Editor

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    Also, no water would stay in the Jacuzzi, not on a 25-meter boat unless the boat ploughed into a wave;) Having it located on the bow you probably could never use the jac while underway only if your sitting at anchor or alongside or something.
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