Stability – I : Chapter 6

4. 500 tonnes of cargo of discharge from the lower the lower hold (KG 3m ) of a vessel whose displacement and KG before discharging were 11500 tonnes and 6.3m . Find the final KG.

Solution:

Given:-

Weight = 11500t
Initial KG = 6.3m
Cargo discharged = 500t, KG =3m

Ship’s weight	KG	VM
11500t	4m	39,600tm
(+)100 t  load	15m	( +)1500tm

Final W =11000t                                          Final VM =70950tm

We know that:

Final KG         =        (Final VM / Final Weight)
Final KG         =    (70,950/11000)
=6.45m

5. 500 tonnes of cargo was shifted 15 meters vertically downwards in a vessel of 10000 tonnes displacement. Find the effect it has on the KG of the vessel and whether KG increases or decreases.

Solution:

Given:-

Weight =10000t,
Cargo shifted downward =500t,

We know that:-

GG1()  = (w x d)/( total weight)
= (500 x 15)/ 10000
=0.75m

Since, The weight is shifted vertically   downward,  the KG of ship will also go down parallel to the KG of the weight

Hence, KG of the ship decrease by 0.75m