Page 94 - statbility for masters and mates

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Ship Stability for Masters and Mates
;Areaof12 WP h=3 a 4b 2c 4d 2e 4f 112 g 2h 12j or 13 h S1
Example 1
The length of a ship's water-plane is 100 metres. The lengths of the half- ordinates commencing from forward are as follows:
0, 3.6, 6.0, 7.3, 7.7, 7.6, 4.8, 2.8 and 0.6 metres respectively: Midway between the last two half-ordinates is one whose length is 2.8 metres.
Find the area of the waterplane.
12 ord: SM Area function 010
3.6 6.0 7.3 7.7 7.6 4.8 2.8 0.6
4 14.4 2 12.0 4 29.2 2 15.4 4 30.4
112 7.2 2 5.6 12 0.3
114.5 S1
Area 23 CI S1
CI 100=7 14:29 m
Area of WP 23 14:29 114:5 Ans. Area of WP 1;090:5sqm
Note how the CI used was the Largest CI in the ship's water-plane.
In some cases an even more accurate result may be obtained by dividing the water-plane into three separate areas as shown in Figure 10.12 and introducing
intermediate semi-ordinates at the bow and the stern.
Area 1 h=2 13 a 4b c h=3 12 a 2b 12 c
Area 2 h=3 c 4d 2e 4f g Area 3 h=2 13 g 4h j
h=3 12 g 2h 12 j