CALCULATION PROCEDURE

A shift of inclining weight or in other words an inclining moment due to such a shift may be related to a ships stabilizing moment as follows.

w x d = Δ x GM Tan θ (1)

Of all the quantities in the above equation, only GM is the unknown.

Thus,

GM = w x d /( Δ x Tan θ) (2)

This is the governing equation for an inclining experiment. Thus we relate the inclining moment w x d to GM and isolate GM from the exercise. Once GM is known, we may easily deduce KG (VCG) by relating the height of metacenter KM to GM as

KM = KG + GM (3)

KM can be obtained from the hydrostatic tables. GM is deduced as explained earlier. The KG can be determined as

KG = KM – GM (4)

This KG is the effective KG inclusive of the weights to go off board. This KG is corrected for,

i. Weights to go off board

ii. Weights to go onboard

iii. Weights to be re located

This will yield the actual lightship particulars of the ship. The weights to go off board shall consist of people onboard, any equipment to be offloaded, partially or fully filled tanks and the inclining weights (if a tank is partially filled its weight & FSM shall be deducted). The weights to go onboard shall contain those things that are part of the ship but currently off board.