Discussion in 'Stability' started by hbomb8, Mar 15, 2011.

  1. hbomb8
    Joined: Mar 2011
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    Location: Newcastle Upon Tyne, UK

    hbomb8 New Member

    hi there, i am struggling with a university assignment at the moment. how do i calculate the change in LCF (it was assumed to be at amidships originally) after one of the aft, starboard compartments has been flooded? any help would be much appreciated.
  2. jehardiman
    Joined: Aug 2004
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    Location: Port Orchard, Washington, USA

    jehardiman Senior Member

    The same way it was calculated before the compartment was flooded.

    The LCF is the line about which the ship trims when a weight is moved on the vessel. It is found using the first longitudinal moment of area (i.e. the intergral over the area of {x dx dy}) so that the displacement stays the same for small angles of trim.

    For the damaged case like you have, you must first sink and trim the ship before you can calculate the new LCF. Are they looking for an exact answer or is this a mythical "rectangular barge"?

    Edit; Just to note, the area is the effective waterplane, so the damaged compartment is excluded.
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