Page 101 - statbility for masters and mates

Simpson's Rules for areas and centroids 89
It will be noted that this procedure is similar to that for ®nding the position of the Centre of Flotation, which is the two-dimensional centre of gravity of each water-plane.
Example 1
A ship is ¯oating upright on an even keel at 6.0 m draft F and A. The areas of the water-planes are as follows:
Draft(m) 0 1 2 3 4 5 6
Area (sq. m) 5000 5600 6020 6025 Find the ship's KB at this draft.
6025
6025 6025
Water-plane Area SM
A 6025 1
B 6025 4
C 6025 2
D 6025 4
E 6020 2
F 5600 4
G 50001
Fig. 10.18
Volume function
6025 24100 12050 24100 12040 22400 5000
Levers
6 5 4 3 2 1 0
Moment function
36 150 120500 48200 72300 24080 22400 0
323630 S2
105715 S1
KB Moment about keel
volume of displacement ; KB S2 CI
S1
323 630 1:0
105 715
Ans. KB 3.06 metres
0:51 d approximately.