Questions of floating crane whose boom can rotate?

Discussion in 'Boatbuilding' started by xichyu, Apr 13, 2016.

  1. xichyu
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    xichyu Junior Member

    Floating crane is important for ocean engineering. The boom of floating crane can rotate(360 degree, I do not know the name of the floating crane) when it lift a thing.
    I think the longitudinal strength and compartment arrangements of ballast tank of floating crane is varying during working.
    How does compartments arrangement of ballast tank of a comman floating crane whose boom can rotate?
    What is the jointing of hull and crane like? Because I can not find the resourse of crane.
    And where can I download a CAD of floating crane whose boom can rotate?

    (Many floating crane adjust load base on the experience of captain. I want to optimize the process of adjusting load during lifting a thing)
     
  2. TANSL
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    TANSL Senior Member

    I think you should study well how they work these floating cranes. Once the load lifted, boom hanging, it does not seem very sensible to move it 360 degrees. In addition, change ballast, once it lifted the load, can be dangerous and, of course, can not be varied if the crane is moving.
    Once known the way of working of these devices, to create a "loading instrument" (computer program) would not be very complicated but also should take into account the structural strength of the whole, not just its flotation, for each position of cargo and ballast.
    Many boats have, is mandatory, a "loading instrument" similar to the one you're thinking.
     
  3. xichyu
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    xichyu Junior Member

    Thanks for your answer
    Floating crane may lift a thing from a place to another place,so the boom rotate
    Many small ship do not have a "loading instrument" in developing countries.
     
  4. TANSL
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    TANSL Senior Member

    You're right, it is only mandatory for some types of ships, but some apply it voluntarily. What I wanted to say is that this software is very normal, its use is regulated for years.
    I also wanted to point out that, although the crane, of course, can rotate, should be avoided to make two movements at once.
     
  5. gonzo
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    gonzo Senior Member

    Floating cranes are called derricks
     
  6. TANSL
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    TANSL Senior Member

    No, that's not accurate. You see Wikipedia, for example, to check.
     
  7. gonzo
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    gonzo Senior Member

    Wikipedia:p
     
  8. PAR
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    PAR Yacht Designer/Builder

    There may be a translation issue at play here, but both terms work, though floating crane is usually as the name suggests. I thing what the OP is referring to is a fully rotating shipboard crane, which may be 360 degrees, though more often than not has a more limited amount of rotation. More accurately, a floating crane is a dedicated ship, that's a heavy lift crane, while a derrick is usually a function of a single element of the a vessel. In both cases the crane may be fixed, partly or fully movable/rotating.

    Also, it's quite common to hoist or lower the load, while also rotating the boom. On many loads or off loads, it's required, just to clear obstructions. Additionally, I've never seen a shipboard crane that didn't have full instrumentation, in regard to what the crane was doing, so I don't understand the last statement about crane instrumentation on smaller vessels, nor what a developing country has to do with it. Maybe he's referring to scales, which again suggests a translation issue at play.
     
  9. gonzo
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    gonzo Senior Member

    I believe he refers to a load cell. Often times the calculated load is based on crane extension, boom angle and hydraulic pressure. Some old cranes have a table on the dash to calculate the load.
     
  10. xichyu
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    xichyu Junior Member

    “I also wanted to point out that, although the crane, of course, can rotate, should be avoided to make two movements at once.”“No, that's not accurate. You see Wikipedia, for example, to check.”
    Thanks,I indeed lack actual practice about it
     
  11. xichyu
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    xichyu Junior Member

    Thanks!
    load cell?
    OK,I will Google it
    “Some old cranes have a table on the dash to calculate the load.”
    I think so!
     
  12. xichyu
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    xichyu Junior Member

    “fully rotating shipboard crane” may express my idea very well,Thanks!
    But,I confusing about derrick and floating crane now
    OK,I will Google it
    And,small ship is relatively
    Not every place have a serious safety rule
    Old ships also do not have a "loading instrument" in developing countries.
     
  13. PAR
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    PAR Yacht Designer/Builder

    Typically a derrick is a piece of equipment aboard a vessel, while a floating crane is a boat, with the sole purpose of being used to hoist stuff.

    Even the smallest cranes can tell you how much their current lift is, either by some simple math and an instrument panel mounted chart (as Gonzo mentioned) or by a physical gauge, that accurately (relatively) shows the weight on the hook.

    Xichyu, which school are you attending and what level are you at (freshman, senior, etc.)? It seems you're looking to get assignments performed through online discussion, rather than tackling your textbooks and developing an understanding through them.
     

  14. xichyu
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    xichyu Junior Member

    A freshman of Dalian Maritime University
    I asked many questions here. Some is from studying,some is my interesting
    I want to be an engineer who has rich experience in practice.
     
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