A quantity of grain, estimated at 100 tonnes, shifts 10m horizontally and 1.5m vertically in a ship of 9000 tonnes displacement. If the ship’s original GM was 0.5m, find the resulting list.

A quantity of grain, estimated at 100 tonnes, shifts 10m horizontally and 1.5m vertically in a ship of 9000 tonnes displacement. If the ship’s original GM was 0.5m, find the resulting list.

Reference: Ship Stability for Masters & Mates (6^th edition), Exercise – 14.6

 

Solution:

G₁G₂ = w*d/∆

           = 100*1.5/9000

           = 1/60 m

GG₁ = w*h/∆

         = 100*10/9000

         = 1/9 m

Tanθ = GG₁/GM-G₁G₂

=> θ = tan^-1 ((1/9) / 0.5 - (1/60))

=> θ = 12⁰ 57`