Ship Stability Notes

KN cross curves of stability - KN is the righting lever measured from the keel. To obtain the righting levers for a particular displacement & KG the values of KN are first obtained from the curves by inspection at the displacement concerned.

EXAMPLE SHOWING USE OF CROSS CURVES (KN) ^

GZ calculations must be submitted for all sea going conditions. It is recommended that the following format be submitted for each condition included in the booklet:

Righting Lever GZ = KN - KG Sin Æ

where KN = Cross Curve ordinate
KG = Centre of Gravity above base (corrected for free surface effects)
and Æ = Angle of Inclination

Condition No.
Corresponding Displacement = tonnes

KN	Æ °	Sin Æ	KG Sin Æ	GZ = (KN-KG Sin Æ )
	5	.0872
	10	.1736
	20	.3420
	30	.5000
	40	.6428
	60	.8660
	80	.9848

The Statical Stability curve may be drawn for each condition by using the GZ values calculated in the last column.

APPENDIX‘B’ ^

RECOMMENDED DATUM LINES FOR HYDROSTATIC
PROPERTIES AND CENTRES OF GRAVITY