10. Initial Stability Flashcards
Term
Definition
Initial Stability
The stability of a vessel in the condition when the center of gravity is at its lowest point at the beginning of a voyage.
Metacentric Height (GM)
The vertical distance between the center of gravity and the metacenter. It is a key indicator of initial stability.
Metacenter (M)
The point about which a ship rolls and pitches; higher metacenter indicates greater initial stability.
Center of Gravity (G)
The point through which the weight of the vessel acts vertically downwards.
Righting Arm (GZ)
The horizontal distance between the center of gravity and the center of buoyancy when a vessel is inclined. It is a measure of the vessel’s ability to right itself.
Center of Buoyancy (B)
The center of the volume of water displaced by the ship’s hull.
Free Surface Effect
The effect on stability caused by the movement of liquids in partially filled tanks within the vessel, reducing the ship’s overall stability.
Rolling Period
The time it takes for a ship to roll from side to side, which indicates the ship’s initial stability.
Angle of Loll
The angle to which a ship with negative initial stability will lean without external force.
Angle of Inclination
The angle at which a ship is tilted due to external forces or cargo shift.
Dynamic Stability
The ability of a ship to resist overturning in rough seas, influenced by the initial stability.
Heeling Moment
The external force applied to a ship causing it to tilt or heel.
Static Stability
The initial stability of a ship in calm waters, usually evaluated by its righting arm curve against heeling angles.
Tender Ship
A ship with a high center of gravity and small metacentric height, having sensitive and quick responses to external forces.