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    Re: A credible AIS track for the Costa Concordia
    From: Jaap vd Heide
    Date: 2012 Jan 25, 14:10 -0800

    It is all a matter of keeping the centre of gravity (well) below the metacentric height.
    When for a given situation it isn't, or the distance is to small, you take in ballast.

    See also http://en.wikipedia.org/wiki/Metacentric_height

    Risky: partly filled ballast tanks or compartments: when the so called "free surface area" becomes to big and the boat heels for some reason, the water that has been taken in intentionally or unintentionally will flow to the lowest point, thus only adding to the heeling force. Which in most cases will mean adding to the problem.

    Jaap

    Lu Abel wrote:
    "I nonetheless have to wonder how any amount of water ballast 20 or 30 feet below the water can right stem-to-stern steel superstructures 100 feet above the waterline from all but the most trivial heel."


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