Stability – I : Chapter 11

18. A ship displacing 12000t has KM 9.0m KG 7.25m. A 200t heavy lift is to be loaded by ship’s jumbo whose head is 24m above the Keel . Find

• The list as soon as the derrick picks up the weight from the wharf on the stbd side with an outrech of 15m.
• The list when the weight is placed on the upper deck KG 10m , 7m stbd of the centre line.

Solution:

Ship’s wt	KG	VM	LM
12000	7.25	87000	0
(+)200 t	24	4800	(15 x200)s

Final W = 12200                                 Final VM = 91800 tm      FLM = 3000

We know that :
Final KG = (Final VM/Final W)
Final KG = (91800/12200)
= 7.524m

Again , we can calculate
GM = (KM – KG)
= (9.0 – 7.524)
= 1.476m

We know that :
tanθ     =  Final LM / (W x GM)
= 3000/(12200 x 1.4476)
=  9 degree 45min