Lets have a discussion on sealable walkway hatchs

Discussion in 'Boat Design' started by goldhunter_2, Apr 1, 2012.

  1. MikeJohns
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    MikeJohns Senior Member

    The head of water is specified by class or Flag requirements and will usually be the center of the door to the free deck. Whether a design is adequate or not depends on the size of the door and the design pressure. You simply add stiffeners as the design pressure goes up.

    It's easy enough to engineer WT doors for specific applications. They don't have to be round on the ends either, a half hexagon is more easily fabricated by a yard (If you don't want square doors).
     
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  2. goldhunter_2
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    goldhunter_2 Junior Member

    ok thanks mike

    round combings for the hatch and bulkhead are simple enough to fabricate
     
  3. ronieyuan
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    ronieyuan New Member

    its interesting to study more
    and make it more cheap
     
  4. MikeJohns
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    MikeJohns Senior Member

    There are also small design features that can result in a much lighter door, for example extending a hinge mount to partially stiffen the door panel. enough to prevent buckling.
     
  5. Submarine Tom

    Submarine Tom Previous Member

    Trouble is, if one's open, they're probably all open.

    Complacency sinks a lot of boats unfortunately.
     
  6. michael pierzga
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    michael pierzga Senior Member

    If you have forward, aft and engine room waterproof bulkheads, then You are trying to solve a problem that does not exist. Properly designed, built and maintainted boats dont sink.....they burn.

    The yacht Im sailing has no structural bulkheads...only bulkheads to organize the interior and to contain fire.

    Concentrate on fire resistance , fire doors and speak to a naval architect before proceeding.
     
  7. Submarine Tom

    Submarine Tom Previous Member

    Good point Michael.
     
  8. TeddyDiver
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    TeddyDiver Gollywobbler

    Interesting point of view.. thou I :rolleyes:
    Sensible.. but that's a part of proper design process..
     
  9. goldhunter_2
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    goldhunter_2 Junior Member

    I did say these are EXTRA non-required bulkheads hat I personally wanted on the yacht. These bulkheads propose would be to help contain flooding and reduce the spread of fire


    didn't they say something like that about the titanic also:D the way i see it is any vessel can sink if mine takes damage just that one in a million time in the ice waters I want the best chance to keep myself out of the water for better survivability of course with out bulkheads if I was put in that water the human body can survival what maybe 15-30 minutes after that I would be dead anyway so not putting bulkheads n the yacht wouldn't matter to me anymore. I guess it all depends on your point of view



    My main propose for the added bulkheads is flooding but they have great side effects such as sound damping, insulation , reducing spreads of fire, origination of the interior.
    over the years I have built or repaired boats in pretty much all the different types of common materials, my choice for using aluminum on this build had many reasons such as easy for me to build, the easy for me to repair at pretty much any beach where I can ground the hull, resale value for when I kids sell it, add fire resistance.
    Aluminum like any metal will melt at a certain temp and the thinner it is the quicker it heats up to that point BUT it does not burn as easily as wood or even fiberglass hulls. So by using aluminum watertight flood bulkheads to organize the interior of the hull it also reduces the area the fire can spread before I would have a chance to attempt to get it out , it also keeps the fire in a smaller area and a smaller fire produces somewhat less heat then a larger fire.

    .
     
  10. goldhunter_2
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    goldhunter_2 Junior Member


    Now seeing the basic drawings of the doors I agree, stepping down material thickness , heavy duty framing , beads etc etc . I would think that the bulkhead would give way before the door (except when water is pushing the door in the open direction) as the bulkheads have greater spans between longitudinal bracing.

    I have read one now that "claims" the doors will hold against flooding form either side personally I still have trouble believing that in less it was a slow flooding any thoughts on this issue?
     
  11. MikeJohns
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    MikeJohns Senior Member

    The doors should be able to take the pressure head from either side, that's the main reason for the flange around the door, it also happens to be a convenient sealing edge to bite into the rubber seal.

    We always load the door from both sides in an analysis. The elasticity of door and of the seal have to be considered from the pushing open side. There are also a host of expensive self sealing seal products made for doors that need to stand a higher pressure. But on a yacht you would be well served with a much simpler arrangement.
     
  12. FAST FRED
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    FAST FRED Senior Member

    "Trouble is, if one's open, they're probably all open.

    Complacency sinks a lot of boats unfortunately."

    The floodings I have read about seen more from daytime open hatches and a big gust of wind.

    FF
     
  13. Submarine Tom

    Submarine Tom Previous Member

    So, they were open.
     
  14. goldhunter_2
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    goldhunter_2 Junior Member

    ya'll are talking more about deck hatch's being open in that situation aren't you
     

  15. Submarine Tom

    Submarine Tom Previous Member

    I don't know what he/she's talking about GH2 other than open hatches.

    But I do know what you're talking about.
     
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