Page 386 - statbility for masters and mates

374 Ship Stability for Masters and Mates
Example 1
Maximum kg Deadweight Moment Deadweight
10 260 2000
5:13 m
Using the Simpli®ed Stability Data shown in Diagram 3 (Figure 44.1), estimate the amount of cargo (kg 3 m) which can be loaded so that after completion of loading the ship does not have de®cient stability. Prior to loading the cargo the following weights were already on board:
250 t fuel oil
50 t fresh water
2000 t cargo
The light displacement is 1000 t, and the loaded Summer displacement is 3500 t
kg 0.5 m Free Surface Moment 1400 t m kg 5.0 m Free Surface Moment 500 t m
kg 4.0 m
Item
Light disp. Fuel oil Free surface Fresh water Free surface Cargo
Present cond.
Maximum balance Summer displ.
Weight Kg
1000t ± 250 t 0.5 m
±± 50t 5.0m ±±
Deadweight Moment
± 125tm 1400tm 250tm 500tm 8000tm
10275tm Point 2 (Satisfactory)
600tm
10875tm Point 3 (Satisfactory)
2000 t 3300 t
200 t 3500
4.0 m 3.0 m
Since 10 875 tonnes metres is less than the maximum permissible deadweight moment at a displacement of 3500 tonnes, the ship will not have de®cient stability and may load 200 tonnes of cargo.
Ans. Load 200 tonnes.
Example 2
Using the Maximum Permissible Deadweight Moment diagram 3 (Figure 44.1) and the information given below, ®nd the quantity of timber deck cargo (Kg 8.0 m) which can be loaded, allowing 15 per cent for water absorption during the voyage.