MCA CoC Ship Stability

Question 1

What is the metacentric height (GM) and why is it important for ship stability?

Accepted Answer

The vertical distance between the centre of gravity (G) and the metacentre (M) — it measures initial stability

Answer

The distance from the waterline to the deck — it determines freeboard

Answer

The distance between the keel and the centre of buoyancy — it determines draught

Answer

The horizontal distance between the centre of gravity and the centre of buoyancy — it determines trim

Question 2

A vessel has a displacement of 8,000 tonnes. A weight of 200 tonnes is loaded 10 metres above the keel. The original KG was 6.0 metres. What is the new KG?

Accepted Answer

6.10 metres

Answer

6.20 metres

Answer

6.00 metres

Answer

5.90 metres

Question 3

What is the 'free surface effect' and how does it affect a vessel's stability?

Accepted Answer

It is the reduction in effective GM caused by liquid in partially filled tanks moving as the vessel heels

Answer

It is the effect of waves on the vessel's hull, increasing resistance

Answer

It is the increase in stability when ballast tanks are completely full

Answer

It is the effect of wind pressure on the vessel's superstructure

Question 4

What does a negative GM indicate about a vessel's condition?

Accepted Answer

The vessel is in unstable equilibrium and will loll to one side

Answer

The vessel is in stable equilibrium and will return upright

Answer

The vessel has excessive stability and will roll sharply

Answer

The vessel has insufficient freeboard for the cargo loaded

Question 5

What is the purpose of the inclining experiment carried out on a vessel?

Accepted Answer

To determine the vessel's lightship displacement and position of the centre of gravity (KG)

Answer

To test the watertight integrity of the hull

Answer

To measure the vessel's speed and engine power

Answer

To calculate the vessel's maximum cargo capacity

Question 6

A vessel lists 5° to port after loading cargo. The Master suspects asymmetric loading. What is the most appropriate first corrective action?

Accepted Answer

Transfer ballast from port to starboard tanks

Answer

Ballast the starboard double-bottom tanks to maximum capacity

Answer

Discharge cargo from the port side

Answer

Increase speed to reduce the list through dynamic effects