π Key Concepts
β’ Use the white pages for the SS AMERICAN MARINER liquid tanks to find the vertical center of gravity (KG) for each specific tank listed (DB and DT tanks).
β’ Remember the combined KG of several weights is found from the total moments divided by total weight: \( KG_{total} = \frac{\sum (w_i \times KG_i)}{\sum w_i} \).
β’ Be sure you are using the correct column in the tank tables (KG/VCG above baseline) for the fill condition that matches the listed quantities.
π Think About
β’ For each tank in the table (DB 1 CL, DB 1A CL, DB 2 P, etc.), what two pieces of information do you need from the Stability Data Reference Book to compute its moment about the keel?
β’ Once you have the individual tank moments, how do you combine them to get one overall KG for the entire liquid load?
β’ Are any tanks paired port and starboard, and if so, does that affect KG or only transverse moments? How does that simplify your work for this question?
β
Before You Answer
β’ Confirm that the numbers in the questionβs table (e.g., 48.2, 81.9, 71.2, etc.) are weights in tons for each tank, not KG values themselves.
β’ For each tank, verify you are using the correct KG/VCG value for that exact tank and loading condition from the white pages (do not mix up DB and DT tank tables).
β’ After summing all tank weights and moments, double-check your final computation of \( KG_{total} = \frac{\text{Total Moment}}{\text{Total Weight}} \) and see which answer choice is closest to that result.