An oil tanker of 17 000 tonne displacement has its centre of gravity 1 m aft of midships and has 250 tonne of oil fuel in its forward deep tank 75 m from midships. This fuel is transferred to the after oil fuel bunker whose centre is 50 m from midships. 200 tonne of fuel from the after bunker is now burned. Calculate the new position of the centre of gravity: (a) after the oil has been transferred (b) after the oil has been used.
An oil tanker of 17 000 tonne displacement has its centre of gravity 1 m aft of midships and has 250 tonne of oil fuel in its forward deep tank 75 m from midships. This fuel is transferred to the after oil fuel bunker whose centre is 50 m from midships. 200 tonne of fuel from the after bunker is now burned. Calculate the new position of the centre of gravity:
(a) after the oil has been transferred
(b) after the oil has been used.
Reference: REED'S
NAVAL ARCHITECTURE FOR MARINE ENGINEERS (4th edition), Exercise – 4.4
Solution:
a)
Shift in LCG = mass moved*distance moved/displacement
=
250*(75+50)/17000
= 1.838 m AFT
New LCG = 1 + 1.838 = 2.838 m AFT
b)
|
Mass (ton) |
LCG (m) |
Moment(midship) |
|
17000 |
+2.838 |
+48246 |
|
-200 |
+50 |
-10000 |
|
∑ =
16800 |
|
∑ =
38246 |
New LCG = moment/mass
= 38246/16800
= 2.27 m AFT
Comments
Post a Comment