A ship of 12500 tonnes displacement, KM 7m and KG 6.4m, has a 3 degree list to starboard and has yet to load 500 tonnes of cargo. There is space available in the tween decks, centres of gravity 6m each side of the centre line. Find how much cargo to load on each side if the ship is to complete loading upright.

A ship of 12500 tonnes displacement, KM 7m and KG 6.4m, has a 3 degree list to starboard and has yet to load 500 tonnes of cargo. There is space available in the tween decks, centres of gravity 6m each side of the centre line. Find how much cargo to load on each side if the ship is to complete loading upright.

Reference: Ship Stability for Masters & Mates (6^th edition), Exercise – 14.8

 

Solution:

GM = KM – KG = 7 – 6.4 = 0.6 m

Tan θ = GG₁ / GM

=> GG₁ = tan θ * GM

=> GG₁ = tan3⁰ * 0.6

Let, W tons of cargo is loaded in the port and 500-w tons in the starboard side

Weight (ton)	TCG (m)	Moment (ton-m)
12500	0.031 (s)	393.058
W	6 (p)	6w
500-w	6 (p)	3000-6w

 

Moment in port = Moment in starboard

=> 6w = 393.058 + 3000 – 6w

=> w = 282.75 tons in port

In starboard = 500 – 282.75 = 217.25 tons