Rack & Pinion Jacking arrangment

Discussion in 'Class Societies' started by conceptia, May 25, 2010.

  1. conceptia
    Joined: Nov 2009
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    conceptia Naval Architect

    Hello guys, do any of you have any idea of rack and pinion jacking arrangement of Jackup rigs. Is there any particular rule criterion for the design of the same? If so, please share. There hadn't been a new topic for a while so thought of discussing something new I heard about.
    I also attach a diagram of the same.:D
     

    Attached Files:

    conceptia, May 25, 2010
    #1
  2. alan white
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    alan white Senior Member

    Jacks work in a lot of different ways. I am going to build a set of jacks to raise a boat on/off a trailer or stands. Simplicity of design is important because jacks often sit outdoors in the weather and they must perform safely when needed.
    That drawing looks a little complicated, but then I don't understand its particular usage, so maybe you can explain.
     
    alan white, May 25, 2010
    #2
  3. Stumble
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    Stumble Senior Member

    Stumble, May 25, 2010
    #3
  4. HReeve
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    HReeve Junior Member

    The Class Society Rules for jacking systems are more goal-based rather than prescribing a specific design. Class just wants to verify that the system has the stated holding capacity.

    There are only a few manufacturers, each with their own design, and they are very tight with the details. Even as a NA working on the design of legs for a liftboat, they are hesitant to give us the performance information that we need to properly model the jacking system stiffness in FEA.
     
    HReeve, May 25, 2010
    #4
  5. alan white
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    alan white Senior Member

    alan white, May 25, 2010
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  6. conceptia
    Joined: Nov 2009
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    conceptia Naval Architect

    Reeve, in case of a dumb barge functioning for drilling support do we have to do the FE analysis? Also, if the legs are cylindrical(not trussed legs) how will the gearing system be looking like?
     
    conceptia, May 26, 2010
    #6

  8. Anoop_ODL
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    Anoop_ODL Anoop

    Conceptia, FE analysis to be done to confirm structural adequacy - dumb barge or not.
    There are mainly two types of cyl legs; one with racks welded to two sides, the other with hydraulic jacking system.
     
    Anoop_ODL, Jun 20, 2010
    #7
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