Page 144 - statbility for masters and mates

132 Ship Stability for Masters and Mates
BR the horizontal component of the shift of the centre of buoyancy. BT BG sin y
also
; Moment of statical stability W
V
1 BG sin y
BR v hh1 V
v hh
Exercise 14
1 A ship of 10 000 tonnes displacement has GM 0.5 m. Calculate the moment of statical stability when the ship is heeled 734 degrees.
2 When a ship of 12000 tonnes displacement is heeled 514 degrees the moment of statical stability is 300 tonnes m KG 7.5 m. Find the height of the metacentre above the keel.
3 Find the moment of statical stability when a ship of 10450 tonnes displacement is heeled 6 degrees if the GM is 0.5 m.
4 When a ship of 10000 tonnes displacement is heeled 15 degrees, the righting lever is 0.2 m, KM 6.8 m. Find the KG and the moment of statical stability.
5 A box-shaped vessel 55m 7.5m 6m has KG 2.7m, and ¯oats in salt water on an even keel at 4m draft F and A. Calculate the moments of statical stability at (a) 6 degrees heel and (b) 24 degrees heel.
6 A ship of 10 000 tonnes displacement has KG 5.5 m, KB 2.8 m, and BM 3 m. Calculate the moments of statical stability at (a) 5 degrees heel and (b) 25 degrees heel.
7 A box-shaped vessel of 3200 tonnes displacement has GM 0.5 m, and beam 15 m, and is ¯oating at 4 m draft. Find the moments of statical stability at 5 degrees and 25 degrees heel.
8 A ship of 11 000 tonnes displacement has a moment of statical stability of 500 tonnes m when heeled 5 degrees. Find the initial metacentric height.
9 (a) Write a brief description on the characteristics associated with an `Angle of Loll'.
(b) For a box-shaped barge, the breadth is 6.4 m and the draft is 2.44 m even keel, with a KG of 2.67 m.
Using the given wall-sided formula, calculate the GZ ordinates up to an angle of heel of 20 , in 4 increments. From the results construct a Statical Stability curve up to 20 angle of heel. Label the important points on this constructed curve.
GZ siny GM 12 BMtan2y