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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
Question no.19. Sub question 3
Kg will change when being shifted from derrick to lower hold 2m above kg so GM will also change
Gm= 0.58 and list will be 1.60degree to starboard
Q.7
Final listing moment is 700(p), not starboard
For case 2; since, both the tanks are slack, therefore, Total FSC = 0.3456m x 2 = 0.6912m.
Good luck
Ex -11 List Ques No. 18, Part 2 have a mistake in total Vertical movements…..it should be 87000 not 87200 which gives us a final answer as follows
List = 3* 51′ or 3.85 degrees
Q.7 listing moment is 700 port not stbd