Page 130 - statbility for masters and mates

118 Ship Stability for Masters and Mates
tan y GG1 GM
0:035 0:0259 1:35
; y 1 290 Ans. Final list 1 290 to starboard
Example 3
A ship of 8000 tonnes displacement has a GM 0.5 m. A quantity of grain in the hold, estimated at 80 tonnes, shifts and, as a result, the centre of gravity of this grain moves 6.1 m horizontally and 1.5 m vertically. Find the resultant list.
Fig. 13.5
Referring to Figure 13.5, let the centre of gravity of the grain shift from g to g2. This will cause the ship's centre of gravity to shift from G to G2 in a direction parallel to gg2. The horizontal components of these shifts are g to g1 and G to G1 respectively, whilst the vertical components are g1g2 and G1G2.
GG1 w d G1G2 w d WW
80 6:1 8000
GG1 0:061 m
In Figure 13.5 GX G1G2
GX 0:015m GM 0:500m XM 0:485m
Ans. List 7 120
80 1:5 8000
G1G2 0:015 m tany XG2
XG2 GG1 XG2 0:061m
MX
tany 0:061 0:126
0:485 tany 0:126