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    Re: Rolling Cruise Ship
    From: Dave Walden
    Date: 2006 Jul 20, 23:54 -0500

    Typically, in large ships, the initial hard over starboard rudder
    generates not just a starboard yaw angle, but a starboard down roll
    angle. (I imagine looking forward from aft of the ship, the side force
    generated by the lift of the rudder is obviously aft of the cg, so it
    generates the desired yaw moment, but it's also below the cg so it
    generates an undesired roll moment.)  The yaw moment slowly induces a
    yaw angle, this angle generates the forces which result in the turning
    of the ship.  As the ship goes into the turn, eventually, the roll
    moment induced by the cg being above the lateral center of effort
    overcomes the turning moment, and the ship recovers from the inital
    "inboard" heel, and heels "outboard" (now like you as the passenger in
    a car in high speed turn, or the car itself).  (As the ship begins to
    turn, the effective angle of attack of the flow into the rudder is also
    decreasing, aiding the 'recovery'.)


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