Why are barges not hydrodynamic?

Discussion in 'Boat Design' started by joceline, Feb 3, 2011.

  1. joceline
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    joceline Junior Member

    Why are barges for goods like coal or corn stumpy square boxes, instead of nicely shaped vessels? Does anyone know the exact reason?

    Is it merely design and construction costs which prevent a barge from taking an efficient shape?
     
  2. daiquiri
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    daiquiri Engineering and Design

    Cargo volume, shallow draft and low speeds are the reason.
    The need to maximize the volume, to minimize the draft and the fact that the speed is low (in the friction-dominated range) give the shapes you see around.
     
  3. Eric Sponberg
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    Eric Sponberg Senior Member

    It is simply because a rectangular barge packs in the most capacity. Barges are intended to move slowly so that moving them consumes the least amount of fuel, while at the same time packing in the most capacity. Therefore, the cost per ton per mile is the lowest. Rectangular is also the easiest and cheapest to build.

    Eric
     
  4. tom28571
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    tom28571 Senior Member

    You guys missed the most important reason that barges are rectangular. Volume and carrying capacity are important but its mainly so they can be easily grouped together very stable in large tows of a dozen or more barges.
     
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  5. mark775

    mark775 Guest

    A vast majority of barges only see each other in passing, despite what you see in protected waters.
     
  6. Submarine Tom

    Submarine Tom Previous Member

    I guess a circular barge would then be the most efficient use of space?

    "Does anyone know the exact reason?"

    There is no exact reason, there are however several contributing reasons, most of which have been covered above.

    -Tom
     
  7. jehardiman
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    jehardiman Senior Member

    And to be honest, in a barge with good rakes, the fuel costs per ton-knot is fairly good. So air freight for strawberries, barges for gravel.
     
  8. gonzo
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    gonzo Senior Member

    Barges in the Mississippi can be seven wide and ten long. They are massive.
     

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  9. BATAAN
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    BATAAN Senior Member

    On the Mississippi, large rafts of up to 20 barges are the usual setup. In Alaska it's one barge, one tug, and the barge can have a whole village's supplies for a year on it (and usually does).
    Mark, what's the craziest, most unusual, weirdest thing you ever saw on a barge?
     
  10. Landlubber
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    Landlubber Senior Member

    ....sometime when you are in China, watch the canal barges at work, thousands every day travel with all sorts of goods, but the gravel barges are really something else, loaded beyond the upper decks, they "float" underwater...really, with the deck coamings only above the water level, the funniest thing you will ever see......amazing that they do not loose many.
     
  11. ancient kayaker
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    ancient kayaker aka Terry Haines

    The sections of the booster rockets used on the US Space Shuttle used to travel by barge from Utah. I can't find an image though.
     
  12. daiquiri
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    daiquiri Engineering and Design

    If one didn't have to care about the loaded and unloaded stability and about draft, the answer would be - yes. ;)
     
  13. bntii
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    bntii Senior Member

  14. daiquiri
    Joined: May 2004
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    daiquiri Engineering and Design

    This story reminded me of traditional boats used for fishing and cargo transport along the coast of northern Adriatic sea, called "trabaccoli" (plural of "trabaccolo"). So I've done a quick search in my library and have scanned this photo of a trabaccolo at work. No, it's not flooded, it's just carying a load of sand. :) And that's not the most extreme loading it could take. Sometimes they would sail with water gently streaming over the deck, just like those chinese boats you have described...
    That's a motorized version of the boat, the photo was taken in 1960, when most of trabaccoli, traditionally gaff or lugsail rigged sailboats, have been transformed to motorsailers or pure motorboats.

    Just to make a comparison of freeboards, you can see an unloaded trabaccolo here: http://picasaweb.google.com/lh/photo/D_ZrsO6YQfL2xfA15K8Nkg or here: http://www.sullacrestadellonda.it/musei/images/cesenatico_pascoli.jpg

    Cheers
     

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  15. cthippo
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    cthippo Senior Member

    That's the external fuel tank for the shuttle, which comes from Texas (I think) by barge.

    The solid rocket booster segments are made in Utah by Thiokil and are shipped by rail to Florida. Attached is a picture of the cars used to move them.

    Somewhere I have pictures of nuclear reactor vessels being barged upriver to Hanford for disposal, but I can't lay my hands on them at the moment.
     

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