how to turn

Discussion in 'Boat Design' started by prathab, Oct 27, 2014.

  1. prathab
    Joined: Mar 2014
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    Location: india

    prathab Junior Member

    i am building sport fishing boat 7.2 meter , planking will be completes by next week . now i need easiest method to turn the hull , ( weight is around 300 kg )
     
  2. PAR
    Joined: Nov 2003
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    Location: Eustis, FL

    PAR Yacht Designer/Builder

    There's no best way to roll a hull over and there are several ways you can do it. The weight you're working with isn't much to worry about, though the bulk often causes the most difficulty. The most common back yard method, is to build a temporary gantry and hoist the boat from one side, tipping it up to it's balance point. At this stage the hull is blocked up and the gantry moved, so you can reset the gantry hoist gear and continue lowering her down inverted.

    I've rolled many hulls and projects over the years and I've found the safest and fastest way is with heavy equipment, such as a back hoe, bucket loader, fork lift or small crane. These machine make the weight a non-issue, so it's just a matter of hoisting gear setup and having enough space to perform the roll. Some folks have made huge circular forms and physically roll the hull on these forms, though this takes more room, it's fairly easy, assuming the rolling forms are stout enough (I've seen them break in mid roll).

    A handy tree limb can be all you need, with a chain fall or come-along used for the hoist. This is slow, but effective. Again, there's lots of ways to do it, just put your head to it and you'll figure out something. How much space on reach side of the hull do you have? Can you roll it over completely or will you have to only have enough room to flip in place? Are you limited by roof rafters or other overhead issues? In other words, can you provide more information about your work environment and conditions, that may favor some methods over others? Besides, this will give us a chance to see you project . . . :)
     
  3. philSweet
    Joined: May 2008
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    Location: Beaufort, SC and H'ville, NC

    philSweet Senior Member

    You might find a couple of these handy -

    http://www.walmart.com/ip/98-Big-Jo...fault&beacon_version=1.0.0&findingMethod=p13n

    and one of these -

    https://www.aceindustries.com/p-153-34-ton-little-mule-manual-cable-hoist.aspx

    But I agree with PAR, a bucket loader with fork or boom attachments is way more secure. Is the hull skinned in heavy glass, or is it raw cedar? The hardness of the hull and its ability to withstand point loading has a lot to do with what you can get away with. I've rolled one with a rope to my truck on two rolls of scrap carpet, but I wasn't too concerned about minor blemishes on that one.
     
  4. rwatson
    Joined: Aug 2007
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    Location: Tasmania,Australia

    rwatson Senior Member

  5. TANSL
    Joined: Sep 2011
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    Location: Spain

    TANSL Senior Member

    No advice has the slightest sense unless we know what the hull material and thickness, what state is advancing, strengthening that has already been built, etc.
    So, show us an image or give us more details so that we can say something meaningful and, above all, something helpful to you.
    What I've done in my boat could even be bad for your boat. One must be cautious with the advice.
     
  6. rwatson
    Joined: Aug 2007
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    Location: Tasmania,Australia

    rwatson Senior Member

    For goodness sake, how much more do you need to know ?

    "sport fishing boat 7.2 meter , planking will be completes by next week . now i need easiest method to turn the hull , ( weight is around 300 kg )"

    three strong men could do it, all the suggestions here are waaaay more conservative than that
     
  7. TANSL
    Joined: Sep 2011
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    Location: Spain

    TANSL Senior Member

    Don´t you get angry rwatson but when something that seems so simple need a consultation of experts in a club such as this forum makes me think that there is something that may need clarification.
    For goodness sake, is not simple to think that you can do with three strong men?. Let's be serious, my friend.
    It costs nothing to study better things and give answers as concretely as possible.
    For goodness sake, should I apologize for asking prudence?.
     
  8. rxcomposite
    Joined: Jan 2005
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    Location: Philippines

    rxcomposite Senior Member

    300 kilos, 3 men. That would keeping in control of 100 kilos each till its way over their heads.
     

  9. WestVanHan
    Joined: Aug 2009
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    Location: Vancouver

    WestVanHan Not a Senior Member

    I saw the results of someone turning over a smaller boat without much thought or care-it took him another month to fix the damage they'd done.
     
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