🔍 Key Concepts

• Use Sheet 2 – Hydrostatic Data for SS AMERICAN MARINER to get the vessel’s displacement, TPI (tons per inch immersion), and MCT 1" at the initial mean draft based on the given forward and aft drafts. • Compute the net weight change (total load minus total discharge) and use TPI to find the change in mean draft before you deal with trim. • Use the trimming moment method: trimming moment = Σ(w × distance from LCF), then trim (in inches) = trimming moment ÷ MCT 1". Split that trim between forward and aft drafts using the lever arms to the perpendiculars.

💭 Think About

• First, what is the vessel’s initial mean draft, and which line on Sheet 2 corresponds to that draft so you can read off displacement, TPI, and MCT 1"? • After you compute the net change in displacement from the loading/discharging table, how does that change the mean draft, and in which direction (deeper or lighter)? • When you form w × d moments, are you measuring each weight’s distance from LCF or from amidships, and how do you convert from one to the other using the data on Sheet 2?

✅ Before You Answer

• Be sure you have all drafts and distances in consistent units (convert feet and inches to decimal feet or inches before doing moments). • Confirm the sign of each moment: loads forward of LCF cause trim by the bow; loads aft of LCF cause trim by the stern (and discharges have the opposite effect). • After applying both the mean-draft change and the trim corrections, re-check that the difference between final forward and aft drafts matches the total trim you calculated and that one of the choices matches both numbers.