🔍 Key Concepts

• Use the mean draft to enter Sheet 2 of the Stability Data Reference Book and obtain displacement, TPI (tons per inch immersion), MT1 (moment to change trim 1 inch), and LCF (longitudinal center of flotation). • Treat each load/discharge as a trimming moment about amidships: Moment = weight × distance (fwd = +, aft = −), then relate total trimming moment to change of trim using MT1. • Separate the effects: (1) sinkage/rise due to net weight using TPI (same at both ends), and (2) change of trim distributed between FWD and AFT drafts based on the position of the LCF and the length between perpendiculars.

💭 Think About

• What is the vessel’s initial mean draft, and what displacement, TPI, MT1, and LCF values correspond to that condition (or the closest one) on Sheet 2? • After you sum all loads and discharges, what is the net weight change and direction (load vs discharge), and how many inches of even‑keel draft change does that create using TPI? • When you sum all trimming moments about amidships, what is the total trimming moment, what is the resulting change of trim in inches (using MT1), and how do you split that change between the FWD and AFT drafts based on the LCF location?

✅ Before You Answer

• Be sure the signs are correct: loads forward of amidships create a bow‑down (positive) trimming moment; loads aft create stern‑down (negative) (or vice‑versa, depending on your sign convention—just stay consistent). • Verify that the final mean draft implied by your answer choices matches the mean draft you calculate from displacement and TPI; eliminate options whose mean draft change does not match the net weight change. • Confirm that the difference between final FWD and AFT drafts (trim) equals your computed change of trim (within rounding), and that the bow moves in the correct direction based on where the majority of weight was added.