Adding a second story to a displacement cruiser trawler

Discussion in 'Boat Design' started by Mobcat, May 21, 2020.

  1. Mobcat
    Joined: May 2020
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    Location: Australia

    Mobcat Junior Member

    LOL we have always called her our ugly duckling, she has nice lines to the sheer but looses it when you design space into Sqm of living area relative to length, we are happy with the outcome what we loose in aesthetics we make up with liveability thus far, as I said she sleeps 10 comfortably not to shabby for a 42fter I think we would all agree.
    Happy days
    Mobcat
     
  2. Mobcat
    Joined: May 2020
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    Location: Australia

    Mobcat Junior Member

    This will give you all an idea of the lay out so far
    4DA349E1-AFBF-44E5-81CB-F5981A8E149B.jpeg 6AA01A5E-014E-4570-AF07-F0E6140CBC61.jpeg 9D7BE105-29FC-4C38-AF2E-EE6D309C8662.jpeg 14EC4B18-5A6D-40D8-9251-E781195B89A2.jpeg DD3EC66F-F1DE-4C6F-9104-55B54177DD35.jpeg 8152C866-B74F-4835-928A-62F6B4480077.jpeg AF4252B5-9E4E-4AF5-9D9A-D991821BD5C9.jpeg 573B312C-6823-4291-B2AE-D9C61D946597.jpeg 9A0D7438-6232-4D45-B62B-1B9A448389F2.jpeg 9016E836-9A3F-4846-AB17-E370238096FD.jpeg 93F1C889-72C1-4694-8686-CC865A75E2A4.jpeg 4DA349E1-AFBF-44E5-81CB-F5981A8E149B.jpeg 9A3F181F-51ED-4CD3-99DA-E882D7EDF6B8.jpeg B59FB525-F190-4109-9D64-144E14DED47F.jpeg 8AA5EAF0-36EF-4A4E-9689-5040FC1E3457.jpeg E3C12E30-D43C-410C-BFEC-855F7EC85452.jpeg This will give you all an idea of the layout so far E3C12E30-D43C-410C-BFEC-855F7EC85452.jpeg 8AA5EAF0-36EF-4A4E-9689-5040FC1E3457.jpeg B59FB525-F190-4109-9D64-144E14DED47F.jpeg 9A3F181F-51ED-4CD3-99DA-E882D7EDF6B8.jpeg 4DA349E1-AFBF-44E5-81CB-F5981A8E149B.jpeg 6AA01A5E-014E-4570-AF07-F0E6140CBC61.jpeg 9D7BE105-29FC-4C38-AF2E-EE6D309C8662.jpeg 14EC4B18-5A6D-40D8-9251-E781195B89A2.jpeg DD3EC66F-F1DE-4C6F-9104-55B54177DD35.jpeg 8152C866-B74F-4835-928A-62F6B4480077.jpeg AF4252B5-9E4E-4AF5-9D9A-D991821BD5C9.jpeg 573B312C-6823-4291-B2AE-D9C61D946597.jpeg 9A0D7438-6232-4D45-B62B-1B9A448389F2.jpeg 9016E836-9A3F-4846-AB17-E370238096FD.jpeg 93F1C889-72C1-4694-8686-CC865A75E2A4.jpeg
     
  3. JSL
    Joined: Nov 2012
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    Location: Delta BC

    JSL Senior Member

    another 'feature' about your 'second story'.
    If it goes to the hull width (ie: extended to the side) you may not be able to (or should not) tie alongside a similar boat or pier, etc. If you do and there is wave (wake, etc) from a passing boat the boat will roll and the topside will impact.
    I saw a good example of this several years ago. Two similar boats (40' trawlers) 'rafted' up in a bay when a wash from a passing boat hit them on a beam and the boats started rolling.... in opposite directions. One owner knew what was going to happen and climbed between the boats to hold them apart. Only his very quick thinking prevented him from getting crushed. The boats 'hit' and the damage was fairly extensive.
     
  4. Mobcat
    Joined: May 2020
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    Location: Australia

    Mobcat Junior Member

    You're right JSL, I am only going to build it to the width of the original wheel house, we built a full beam salon when we built the boat but the second story will be around 500mm narrower, it will also leave a nice walkway around the boats second story to access the rear deck lines etc.
    I am starting to build the fly bridge next week first which will be open with a hard top and after that’s built I will look at the rest of the project relative to the naval architect report on the second story , I do think it will be easier to draw some nice lines for the second story and rear deck tender davit with the fly bridge built first.
    Happy days
    Mobcat
     
  5. Annode

    Annode Previous Member

    I say go for it. sounds like not much more than adding a mast. do you know where the CofG is?
    Dont presume that the experts who designed the thing in the first place did the level of analysis that is available today. Its probably based on a design from the 50s or 60s. This is not rocket science!
    This boat has a helicopter on the roof and 2lbs of cr** in a 1lb bag and it floats just fine.
    also keep in mind, the $10m boat in the vid complied with all the regs and was professionally engineered by a marine engineer. you dont need them and 10in of regs to get the CofG approx right.
     
  6. JSL
    Joined: Nov 2012
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    Location: Delta BC

    JSL Senior Member

    Another matter to allow for is unpredictable weight(s) topsides which can affect stability. This can range from the dinghy filling with water during a heavy rain, snow loads, ice accretion, etc. Probably not a worry in Australia but can be in higher latitudes in winter. Then, there is wind load which if you have enough 'sail' area may cause a permanent heel of a few degrees when operating in beam winds... a nuisance .
     
  7. Milehog
    Joined: Aug 2006
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    Location: NW

    Milehog Clever Quip

    Just sayin'.
    [​IMG]
     
  8. bajansailor
    Joined: Oct 2007
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    Location: Barbados

    bajansailor Marine Surveyor

    I presume that this is going to be a trimaran, and he has not yet built the stabilizing outriggers? :)
     
  9. Milehog
    Joined: Aug 2006
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    Location: NW

    Milehog Clever Quip

    I doubt the inspiration of that yacht includes amas.
    Not that it will need them, it will capsize on the street long before it makes it to a launch ramp.
     

  10. JSL
    Joined: Nov 2012
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    Location: Delta BC

    JSL Senior Member

    Try this. Not as attractive as earlier ideas but quick & easy'.
    An optional safety feature: Mount athwartships & leave wheels on so at about 15 deg. heel the trailer rolls off, you regain original stability, and prevents total capsize. redneck_yacht.jpg
     
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