A ship of 10 000 tonne displacement has its centre of gravity 3 m above the keel. Masses of 2000, 300 and 50 tonne are removed from positions 1.5, 4.5 and 6 m above the keel. Find the new displacement and position of the centre of gravity.

A ship of 10 000 tonne displacement has its centre of gravity 3 m above the keel. Masses of 2000, 300 and 50 tonne are removed from positions 1.5, 4.5 and 6 m above the keel. Find the new displacement and position of the centre of gravity.

Reference: REED'S NAVAL ARCHITECTURE FOR MARINE ENGINEERS (4^th edition), Exercise – 4.6

 

Solution:

Mass (ton)	KG (m)	Moment (keel)
10000	3	30000
-2000	1.5	-3000
-300	4.5	-1350
-50	6	-300
∑ = 7650		∑ = 25350

 

New KG = moment/mass

               = 25350/7650

               = 3.314 m above the keel