Exam Question

A ship of 10000 tonne displacement floats in sea water of density 1025 kg/m3 at a draught of 6m. A rectangular tank 1Om long and 8 m wide is partially full of oil fuel of density 900 kg/m3. In this condition, the KG of the ship is 6.25m.

Other hydrostatic data for the above condition are:

Centre of buoyancy above the keel (KB) = 3.325m

Transverse metacentre above the centre of buovancy (BM) = 4.865m

Tonnes per centimeter immersion (TPC) = 20.5

Calculate the change in effective metacentric height when a rectangular tank 12m long. 10m wide and 6m deep, with its base 1m above the keel, is filled to a depth of 5m with, sea water ballast.

Note: Assume the ship to be wall-sided over the affected range of draught.