Stability – I : Chapter 11

Ship’s wt	KG	VM
10000 t	7.45m	74500 tm
(-)100 t	2.45m	(-) 245 tm

Final W = 9900 t                                                     Final VM = 74255 tm

We know that:
Final KG = (Final VM)/ (Final W)
Final KG = (74255 / 9900)
= 7.5m

Final GM = (KM –KG)
= (8.25 – 7.50) m
= 0.75m

Tanθ =  LM /( W x GM)
= 600/(9900 x 0.75)
= 4.62 degree.

7. A ship of 10000 t displacement, KG 8.3m carries out the following cargo operation:

Qty. (t)	LOaded or discharge	KG (m)	Distance off centre line
200	D	10.0	5m port
800	D	2.3	4m stbd
500	D	5.2	3m port
250	L	8.0	Nil
250	L	12.0	Nil

If the final KM is 9.6m, find the list.

Solution:

Ship’s wt	KG	VM	CL	LM
10000 t	8.3	83000
(-) 200(Dish)	10.0	(-) 2000	5P	1000 P
(- ) 800(Dish)	2.3	(-)  1840	4S	3200 S
(-) 500(Dish)	5.2	(-) 2600	3P	1500 P
(+) 250(load)	8.0	(+) 2000	NIL
(+) 250(load)	12.0	(+) 3000	NIL

Final W = 9000 t                                Final VM =81560 tm                  Final LM = 700(S)

Final KG = (Final VM)/ (Final W)
Final KG = (81560 / 9000)
= 9.062 m

We know that:
GM = (KM – KG)
= (9.6 – 9.062)
= 0.538m

Tanθ   =   (Final LM)/(final W x GM)
= (700)/(9000 x 0.538)
=  8.2 degree