OOPS, Is 6000 lbs to much for two 29' x 23"dia toons

Discussion in 'Boat Design' started by luckyjr, Oct 20, 2012.

  1. luckyjr
    Joined: Aug 2011
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    luckyjr Junior Member

    Weighed Project today , Very surprised with weight. Looks as if TRI TOON needed?
     

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  2. murdomack
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    murdomack New Member

    Assuming that a Toon is a Tubular Pontoon, 2 will displace,

    2 X Pi X 23 X 23 / 144 / 4 X 29 X 62.427 pounds

    = 10,446.8 pounds, so they will be 57.43% submerged at the weighed weight.
     
  3. kerosene
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    kerosene Senior Member

    2*Pi * r*r =area

    Didn't you use diameter instead of radius in your calc?
     
    Last edited: Oct 20, 2012
  4. Mr Efficiency
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    Mr Efficiency Senior Member

    5500lbs approx per side
     
  5. murdomack
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    murdomack New Member

    r^2 = d^2 /4

    We used r in school mathematics, but d in engineering. Whatever floats your boat, as they say.
     
  6. kerosene
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    kerosene Senior Member

    Ah i see now.
     
  7. murdomack
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    murdomack New Member

    If you are not adding any more weight and you get three or four people aboard grossing at 625 lbs then you will displace another 10 cu ft of water.
    If the unlikely event that they all stand on one side it will dip down between 2-1/2" and 3".
     
  8. Red Dwarf
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    Red Dwarf Senior Member

    Don't do it, it can easily flip.:eek: How high is the CG? Where is the cg longitudinally located?

    Once you pass the midway point on a pontoon the additional buoyancy per inch of depth quickly drops to zero. You are already past 50% empty. Once you load people and stuff it will get much worse.

    Now imagine a perfect storm situation. You have a couple extra people on the boat because ____, Someone catches a big fish on one side and everyone goes to that side to see it, the wake of a passing boat hits the other side, FLIP.
     
  9. luckyjr
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    luckyjr Junior Member

    I am adding a 3rd toon

    A 24' x 25" 3rd toon. Does that solve my problem?:confused:
     
  10. murdomack
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    murdomack New Member

    You do not say what your loaded weight will be, so nobody can answer you.

    Could you change the existing two pontoons to square or rectangular shapes as that would increase your bouyancy. I'm not an expert on these things, but I think adding any required bouyancy at the sides would be better.
     
  11. Submarine Tom

    Submarine Tom Previous Member

    Lucky-J,

    Your luck is about to run out.

    You're pontoons are dangerously over loaded.

    Never mind your guests moving to one side, when you get into your first rough sea, the rolling momentum combined with loading will capsize the boat.

    Your liability has now skyrocketed because this thread is testament to your awareness.
     

  12. luckyjr
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    luckyjr Junior Member

    I am adding a 25" x 24' center pontoon plus in the back there are one 24" dia x 36" pontoons on each side turned the 36" way which can be jacked down to be fully submerged for stability. The cog is very low because roof and sides are very light. The sides are sloping in to move the cog more to the insides the pontoons. I owned and ran 2 ASME certified manufacturing plants in my working life. I am adding 6500 lbs lift to useful load. My max load will be 1800 lbs. The 2 small pontoons can be increased ? if need and now can be expanded to 15' wide outriggers. Thanks for your concern and any suggestions to increase safety would be appreciated.

    The roof and structural weighs 320 lbs spread over a 19' length = 17lbs per Lft + AC. 11ft has no structure but fencing. The floor and side structural are a different design and more ridged than plywood or aluminum.
     
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