🔍 Key Concepts

• Longitudinal center of gravity (LCG) moves toward where weight is added and away from where weight is removed • Effect on total displacement and total longitudinal moments (W × LCG) when a tank is emptied • Using the formula for a new LCG after a weight change: sum of moments divided by new total displacement

💭 Think About

• From the Sample Load Form #4, identify the original ship’s displacement and original LCG, then identify the weight and LCG of the liquid mud being dumped • Think through what happens to total weight and total longitudinal moment when that liquid mud is removed—do both decrease by the same proportion, or differently? • After you recalculate the total longitudinal moment and total displacement, where will the new LCG be relative to the original—slightly forward, slightly aft, or nearly the same?

✅ Before You Answer

• Be sure you use the correct weight and LCG position for the liquid mud tank(s) shown on the Deep Driller form, not a generic value • After subtracting the mud’s weight from the total displacement, also subtract its moment (weight × its LCG) from the total moment before solving for new LCG • Double‑check that your final LCG value is reasonable compared with the original LCG (it should not move an unrealistically large distance for the size of the weight removed)