Longitudidual center of gravity 계산법
1) Sum up the weight of cargo, fuel oil, lubricating oil, fresh water, ballast water in each tank and
deadweight constant, then the sum of these weight is deadweight of the ship, and
then add the lightweight to the deadweight, total value indicates the displacement (Disp)
2) Multiply each weight by their LCG, then the product is the moment of each weight about A.P.
3) Sum up these moment of each tank and add the moment of deadweight constant,
then the sum is the moment of deadweight and then add the moment of lightweight to that of deadweight.
4) Divide the total moment of 3) by the displacement, then the value is the LCG of current loaded condition.
5) Read off the following items corresponding to displacement from 'Hydrostatic Table'.
deq = Draft corresponding to displacement (Disp) (m)
LCB = Center of buoyancy from A.P at deq (m)
LCF = Center of floatation from A.P at deq (m)
MTC = Moment to change trim 1 Cm at deq(ton-m)
6) Calculation trim by the following formula:
T = (Disp. x BG)/(MTC x 100)
Where, BG = LCB - LCG
7) Calculate the drafts of 'FP'(dF) and 'AP'(dA) given by distributing the trim
between 'FP' and 'AP' according to the position of LCF as belows.
dF = deq - t x (LBP - LCF)/LBP
dA = deq + t x LCF /LBP
dm = (dF + dA )/2
When small amounts of the cargo, ballast water, fuel oil, lubricating oil and fresh
water are loaded or unloaded from any conditions and it is necessary to calculate the
trim and draft of new condition, it is convenient to use the 'Trimming Table'.