What is a GZ curve in ship stability?
The curve of statical stability, or GZ curve as it is most commonly referred to, is a graphical representation of the ship’s transverse statical stability.
What is GZ in maritime?
Righting lever (GZ) is defined as the horizontal distance, measured in metres, between the centre of gravity (G) and the vertical line of action of the buoyancy force (Bf) acting through the centre of buoyancy (B1) when the ship is heeled.
What is G in ship stability?
The measure of a ship’s initial stability, when upright or nearly upright, is indicated by the height of the metacenter (M) above (G), which is referred to as the metacenter height, GM, while the horizontal distance, GZ, more accurately indicates the measure of stability at angles of heel (OB:FO: “Theta”) in excess of …
What is GZ format?
GZIP is the file format, and GZ is the file extension used for GZIP compressed files.
How do you calculate GZ of a ship?
GZ=GM sin φ and is called the righting lever. GM is known as the metacentric height. For a given position of G, as M can be taken as fixed for small inclinations, GM will be constant for any particular waterline.
What is the purpose of a GZ curve?
The point where the GZ curve meets the horizontal axis (shown as ‘C’ in the figure), is called the point of vanishing stability, since righting lever becomes zero at this point. So, any heel beyond this angle would result in a condition of negative stability.
What is KB in ship stability?
The vertical distance (along the ship’s centerline) between the keel and the centre of buoyancy is expressed as ‘KB’, as shown in Figure 3.
What is the value of GZ at angle of vanishing stability?
The angle at which GZ becomes zero is known as the point of vanishing stability and defines the range of stability.
How stable is a ship with a high GZ curve?
Thus, it should not be assumed that a ship is stable enough only if the value of the maximum GZ is high. A GZ curve with a very high maximum value might not have the sufficient area, and as a result, the ship will capsize easily because it wouldn’t be able to absorb enough energy before capsizing.
How to draw the curve of statical stability using GZ?
> To draw the curve of statical stability (discussed above), we need GZ values for various angles of heel. For this we use the GZ cross curves of stability. > The graph where the righting lever (GZ) is plotted against the displacement. > These curves are plotted for an assumed KG, tabulating GZ values for various displacements and angles of list.
What are cross curves of stability of a ship?
Cross Curves of Stability / KN Curves: It is due to this reason, KN curves are also provided in the Stability Booklet of a ship, so that, in case the ship is operating in a loading condition it hadn’t operated in before, the GZ curve can still be obtained easily to determine the stability of the ship.
What is a GZ curve?
Calculating the value of GZ, at specified angles of heel for a ship’s particular condition of loading, will allow a curve of statical stability, or GZ curve, to be produced. The greater the values of GZ, the greater will be the area under the curve.