Which stability occurs when a negative righting arm leads to capsizing?

Which stability occurs when a negative righting arm leads to capsizing?

• A. Positive stability
• B. Neutral stability
• C. Negative stability (Correct)
• D. None

Answer: (C)

Stability is about whether a heel creates a restoring or overturning moment. The righting arm, GZ, is the horizontal distance between the lines of action of the buoyant force and gravity when the vessel heels. If GZ is positive, the buoyancy and weight produce a turning moment that tends to bring the vessel back upright, which is positive stability. If GZ is zero, the moment is zero and the vessel is neutrally stable at that angle. If GZ is negative, the forces create a turning moment that pushes the vessel further over, leading to capsizing—that is negative stability. So when a negative righting arm leads to capsizing, that describes negative stability. Positive and neutral stability don’t cause further capsizing, and saying none applies would be incorrect.

Stability is about whether a heel creates a restoring or overturning moment. The righting arm, GZ, is the horizontal distance between the lines of action of the buoyant force and gravity when the vessel heels. If GZ is positive, the buoyancy and weight produce a turning moment that tends to bring the vessel back upright, which is positive stability. If GZ is zero, the moment is zero and the vessel is neutrally stable at that angle. If GZ is negative, the forces create a turning moment that pushes the vessel further over, leading to capsizing—that is negative stability. So when a negative righting arm leads to capsizing, that describes negative stability. Positive and neutral stability don’t cause further capsizing, and saying none applies would be incorrect.